The Speed of Light (and Gravity?)

Within Relativity Theory, if there is anything unintuitive it is the fact that in the entire Universe, it is the speed of light (and gravity?) alone that is absolute or fixed, not something like space being absolute or time being absolute. It’s unintuitive in that all the other not-light bits and pieces that are in motion can be added or subtracted. The lone exception to that universal rule that velocities can be mathematically combined is the speed of light (and gravity?).

Repeat for emphasis: the anomaly here is that in any other scenario, anything that is not-light and in motion, velocities can be added and subtracted. Repeat again: with that one speed of light exception, velocities may be added or subtracted. If you are on a treadmill that’s moving left at 5 MPH, and you’re on it walking to the right at 5 MPH, to an external observer you are waking yet standing still. You’re much more likely to hit a home run if the wind is blowing towards the outfield fences; planes fly faster with a tailwind than with a headwind; you swim in the river faster going with the flow than against the current. If you are in a train that is moving at say 100 km/hour and you throw a ball at 10 km/hour in the direction at which the train is moving, to an observer outside the train, your ball is traveling at 110 km/hour. If you throw the ball towards the rear of the train, an outside observer will measure the ball as moving at 90 km/hour. If on the other hand, you shine a flashlight in the train, an outside observer will see the velocity of the resulting light beam moving at the speed of light – not the speed of light PLUS the velocity of the train, or the speed of light MINUS the velocity of the train, but at the speed of light! That’s nuts, but it’s scientifically nuts and been proven again and again in any experiment you care to devise. I have no issue with experimentally verified results. That doesn’t mean I don’t have issues with the anomaly.

The velocity of light is a constant to an external observer no matter what. Why that should be no one knows, but it is so. However, my take on this can of worms, which as a consequence requires somewhat counter-intuitively that both time and length have to be flexible, is one should always be a bit suspect when it comes to the lone ranger, the lone ranger being the exception to the rule*. I don’t tend to like exceptions to the rule. There’s something weird afoot here. Mother Nature is trying to tell us something we haven’t figured out yet.

All that said, the speed of light isn’t really a constant if you take into consideration the differing mediums that light can travel through. However, the speed of light is probably also a constant within whatever other medium it happens to be in. The speed of light in air at STP (standard temperature and pressure) is less than the speed of light in the relative vacuum of outer space; even less traveling through pure water and less again traveling through clear glass. One would presume that just as the speed of light in space is constant for observers regardless if they are traveling in a high velocity spaceship or as an astronaut ‘stationary’ on the International Space Station, the speed of light in water sould be a constant for the crew in a submarine that’s underway thus in motion or a diver standing on the seabed.  

That makes me sort of wonder, theoretically, if you could get an underwater submarine to go faster than the speed of light in water (or an aircraft to outpace the speed of light in air), though in either case that would be less than the speed of light in a vacuum, could you then claim, albeit with qualifiers (in water; in air), that you actually traveled faster than the speed of light, if only for the bragging rights? 

Apart from light (photons), presumably gravity, or gravity-waves, also propagate at the speed of light and thus a gravity-wave would have a constant speed regardless of any frame of reference for any observer. But I also presume that necessitates finding the hypothetical graviton particle (to mirror the photon) and that, for the moment, resides in the unknown basket.

That brings up yet another puzzlement. Is gravity just geometry as per General Relativity or is gravity a force transmitted by a force particle, the theoretical graviton, and thus more akin to electromagnetism’s photons (infinite extension; obeys the inverse square relationship) apart from lacking EM’s negative counterpoint – in the case of gravity, that’s antigravity.

Speaking of gravity (gravitons) and light (photons), if gravity can have an effect on light (i.e. – the gravitational lens), then it should be a two-way street and light should be able to have an observable affect on gravity, but I can’t recall ever reading about that aspect of the relationship. 

As per the speed of light being medium dependent; one speed in a vacuum, another in water, well that makes for an interesting question when considering gravity. If a gravity-wave is approaching Earth, will it have one constant velocity in the vacuum of space for all observers, then a differing velocity as it passes through our atmosphere, then another value as it passes through the ocean and yet others as it hits the various density layers inside the planet?    

As is often the case, there tends to be more questions than answers!

*Not that the differing rules for the speed of light vis-à-vis other not-light velocities is the only exception to the rule in modern physics. Quantum tunneling is one of those exceptions to the rule of causality. With respect to the standard model of cosmology and the Big Bang, first there was nothing; then there was something. That means the Big Bang event created both matter and energy out of less than thin air. That’s also a free lunch and one of those exceptions to the rule of physical law usually expressed as the conservation of matter and energy. All these exceptions to the norm suggest that some of the final chapters in modern physics haven’t yet been written.



Natural Philosophy: Some Random Thoughts

There’s nothing too controversial about the idea that other universes in a Multiverse could have differing laws, relationships and principles of physics than our own. It’s one way of explaining why our Universe is a Goldilocks Universe. If you have billions and billions of universes each with a unique or differing set of laws, relationships and principles of physics, well probability suggests that one universe should just right for life – a Goldilocks Universe. Since we can only exist inside a Goldilocks Universe, well that explains that. But what if the laws, relationships and principles of physics in our Universe changed over time, or over space, or both! Then it’s probably time to turn out the lights, shut and lock the lab door and go home. It’s time to find a new career. But amazingly, there is (controversial) evidence that that is just that. Physical constants aren’t. 

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If whatever powers-that-be are simulating our universe, then they could be simulating others as well – a simulated Multiverse! And each and every simulated universe of that Multiverse could have simulated parallel universes. That’s a simulated Megaverse!

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One of the 64,000 $64,000 questions: Can you pour stuff down a Black Hole indefinitely, or does the Black Hole have a finite capacity and ultimately or eventually will have to spew stuff out the ‘other side’ (i.e. – producing a White Hole) as you keep pouring in more and more and more? I’d wager the conservation relationships and principles of physics and chemistry hold sway here. What goes in ultimately comes out. That doesn’t mean there’s not a temporary holding vessel. Or, in more human terms, you fill what’s empty; you empty what’s full, but in-between those two there’s storage in the stomach and the intestines; the lungs and the bladder.

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You are all no doubt well aware of the General Theory of Relativity which holds that light (in a pure vacuum) always travels at constant velocity (300,000 km/sec), no matter what frame of reference you are viewing that light in – totally contrary to experience and expectations, but true nevertheless. That translates into length and mass and rate-of-change (time) all being variables, variations depending on what frame of reference you are in. Light of course is one manifestation of the electromagnetic force. That suggests to me that magnetism must also propagate at 300,000 km/sec. Two north magnetic poles or one north and one south magnetic pole, suddenly brought into existence, 300,000 km apart, won’t feel any mutual repulsion or attraction respectfully until one-half of one second after-the-fact, when the two forces meet in the middle and start doing their thing.

But that constant speed of a force, must equally apply to gravity. If the Sun were to suddenly in a split of a split of a split second vanish, it would be eight minutes before Planet Earth would be rudderless, or rather orbitless. No matter what your frame of reference, you’d ‘see’ gravity propagate outwards at 300,000 km/sec. The same must apply to ‘dark energy’, that anti-gravity force. I imagine the same would apply to the propagation of the strong and the week nuclear force as well.

Of course one cannot turn on and turn off gravity (or the strong and weak nuclear forces) like you can a light (or radio, UV, IR, etc.) beam or magnetic field, which is a bit of a bummer in testing the relativistic properties of a gravity beam.

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Quantum physicist Erwin Schrodinger had a lot of trouble accepting some of the weirder philosophical concepts inherent in quantum physics. Specifically, that something, a fundamental particle like an electron, could both be, and not be, at the same time – in a state of superposition – that was only resolved when an observation or measurement was made. Schrodinger decided to replace the electron with a cat-in-a-box that was in a superposition of states being both dead and alive at the same time, the resolution of either/or decided when an observer actually observed the cat-in-the-box.

Now my idea is to replace the cat-in-the-box with you-in-a-sealed-room in a 50/50 dead/alive state of superposition. To someone not in the room, you are both dead and alive at the same time – until they take a peek in your room and at you. The question is, you know perfectly well you are not both dead and alive at the same time; you are your own observer. Presumably the cat is its own observer, and by extension an electron is its own observer. But how can an electron be self-aware? 

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Gravity; it’s what holds you firmly to Terra Firma. If I ask you what holds you firmly to Terra Firma you’d answer “gravity”. But if then asked to explain exactly what it is and how it works you’d be stumped. Giving the Newtonian equations makes predictions but doesn’t give explanations.

However, there are two explanations for gravity if I read the textbooks correctly.

Gravity Is Just Another Force: Firstly, there are in this worldview four fundamental forces: the electromagnetic force, the strong and weak nuclear forces, and gravity. Forces have accompanying elementary particles witch convey the force. In the case of the electromagnetic force, the particle is the photon. The particle associated with gravity has been dubbed the graviton. Unfortunately, it has never (to date) been detected. Now the central issue here is try as they might, physicists cannot unify the four forces into one whole, called a Theory of Everything or TOE*. Since everything should be related to everything else, gravity should be, if not a brother or sister to the other three force-related siblings, at least a kissing cousin. Alas, it’s an unrelated hermit that wants no ancestry with the other three.

Gravity Is Just the Geometry of Space-Time: The second is that mass ‘tells’ space-time how to warp, and warped space-time ‘tells’ mass how to move – seemingly experimentally verified more than several times over. The movement of mass in warped space-time is what we interpret as the ‘force of gravity’, but gravity is actually the actions of mass moving in space-time geometry. If gravity is just geometry and mass deviates from the straight and narrow path because lots of other mass has warped space-time from the flatland Great Plains to the peaks and valleys of the space-time Rockies, then there’s no apparent need or reason that I can see to unify gravity with the other forces and their particles. There is no graviton. If there is no causality link with the other three (quantum level) forces, there’s no need for a TOE. There’s no need to reconcile the 98 pound of weakling gravity with the Atlas physiques of electromagnetism, etc. 

Gravity is highly anomalous. Apart from the fact that gravity is the 98 pound weakling of all the forces (you can pull a paperclip up into the air with just a tiny magnet even though the entire Planet Earth’s gravity is tugging back); and that the graviton hasn’t been spotted anywhere, anytime, anyhow; and that TOE is a no-go; but lastly there are those cosmic twin anomalies, Dark Matter and Dark Energy.

We can’t see, or even detect directly, 96% of the Universe! We have no idea what 96% of the Universe is composed of. If that’s not anomalous, I don’t know what is. Both however have revealed themselves indirectly via their gravity (in the case of Dark Matter) or their antigravity (in the case of Dark Energy). Some of that ‘missing’ part of the Universe is matter of unknown composition, but like all good matter, has gravity. It’s the gravitational effect on matter we can see that gives the game away. Some more (way more) of that ‘missing’ part of the cosmos is Dark Energy which is that unknown stuff which is accelerating the expansion rate of the Universe and if that’s not anomalous, I don’t know what is since by rights the expansion rate of the Universe should be decelerating under the force of gravity. The fact that it’s accelerating suggests that Dark Energy is a form of antigravity, a repulsive force driving things apart at ever faster and faster rates. Though antigravity is really outside the accepted realm of physics (though not sci-fi), there is a symmetrical parallel with the electromagnetic force, which is both attractive like gravity (north pole to south pole) and repulsive (north pole to north pole, or south pole to south pole).

So, gravitational anomalies abound.

*The exception is that the highly theoretical (read purely mathematical) String Theory, Superstring Theory or M-Theory can produce a TOE. The downside is that it takes a whole potful of highly theoretical (read purely mathematical) extra dimensions of which we have no awareness of and can’t (yet) detect. That’s just a bit too ad hoc for me, though many a theoretical physicist goes to sleep by counting their strings instead of their sheep.

UFOs and Our WW2 Atomic Bombs

A rarely seen, ‘long lost’ Walt Disney UFO documentary titled “Alien Encounters from New Tomorrowland” hosted by Robert Urich, is a program that’s pro-UFO as in UFOs being the product of extraterrestrial intelligences. Unfortunately, though while I have relatively little bone to pick with the general content, it did repeat what IMHO is a fundamental error which is the relationship between our use of nuclear weapons in WW2 and the arrival of the aliens (if aliens there be) in 1947. 

One common mythology surrounding the rational for UFOs arriving at Planet Earth in 1947 has to do with human civilization advertising itself to the cosmos as the nuclear new boy on the block in 1945. Planet Earth becoming a nuclear power would obviously be upsetting to extraterrestrials, so the mythology goes, akin to how countries like the United States, Great Britain, Australia, etc. get nervous about North Korea or Iran going nuclear. However, unless aliens were already in spitting distance of Earth*, that scenario (the link between 1945 atomic blasts and the 1947 arrival of extraterrestrial UFOs) is blatant nonsense for several reasons - distance and glare.

Now I like the UFO ETH (ExtraTerrestrial Hypothesis) as much as the next person, but our WW2 atomic bomb explosions are not why they’re here, initially or otherwise.

Let’s start with distance. I assume any extraterrestrial intelligences will be housed on a planet around a star. The nearest stellar system to Earth is the Centauri System, Alpha Centauri, etc. Unfortunately, the Centauri System is over four light years away, and that’s your best case distance scenario. Light, including the flash from an atomic bomb, travels at one light year per year. So, a 1945 atomic blast wouldn’t register at the Centauri System until latter 1949, or several years after the initial 1947 origin to the modern UFO phenomena.

But that’s not the end of the distance issue. Even if our hypothetical Centauri aliens saw those WW2 atomic blasts from a planet around Alpha Centauri in 1949 our time (those four years it took that atomic light to reach the Centauri system starting out in our 1945), they, the aliens, still have to travel from their Centauri system to our solar system and Planet Earth. They can’t do that in less than four years. We couldn’t do it (Earth to Centauri) with our current rocket technology in under 10,000 years! So, even assuming our alien friends could rocket at the speed of light, and that’s a hell of a big assumption, they ain’t gonna get here until 1953 minimum in response to our 1945 atomic bomb explosions, even if they leave their Centauri system post haste upon viewing our use of nuclear technology. That’s hardly the 1947 when the modern UFO era started.

Secondly, there’s glare. Viewed from even the nearest Centauri System, the separation of Planet Earth from the Sun is so small that Earth would be 100% lost in the glare of the Sun, just like you probably couldn’t see a BB just immediately off fractionally to the side of a powerful spotlight. Now the light from an atomic bomb is miniscule relative to the faint sunlight reflected off by Planet Earth itself, our planet itself lost in the far, far, far brighter light emitted by the Sun itself. Translated, there is just no way to see the flash of a WW2 atomic explosion from over four light years away, and that’s assuming the alien home planet is even that close. So, something’s screwy somewhere and that something is the assumed relationship twixt the arrival of the ‘flying saucers’ in 1947 and the start of our nuclear era in 1945.

Distance and glare collectively rule out aliens arriving on Earth in 1947 due to having witnessed a 1945 atomic bomb explosion, unless of course they were already within spitting distance.

So there is however that pesky Star Trek scenario (see below) that aliens just happened by sheer coincidence to be nearby when we advertised our destructive atomic bomb technologies big time. However, IMHO, the odds that aliens would just happen to be in the neighbourhood when our first atomic bombs went off is as likely as you being at ground zero when something extraordinary dramatic event happened. It might happen once in your lifetime – say you were in the bank when the bank robbers rushed it. But if your lifespan is paralleled with the duration Planet Earth has been around to date, what odds that the bank robbery (the parallel to the WW2 atomic blasts) and your presence in the bank (the parallel to aliens being in the neighbourhood) would coincide? Aliens passing by could be at any old time in Earth’s general history, just like your banking visits could be any old time in your general history. But the atomic blasts, and the bank robbery, were at one very specific time. Yes, the two timelines, the general and the specific, might intersect just so, but you’d probably be safer betting your money on the lottery than betting on that likelihood.

You might argue that perhaps aliens a long time ago set up nearby automatic on-station monitors to monitor for that very event – Earth’s transition to a nuclear planet. However, it would still take four years for that automated message to reach the hypothetical aliens around the Centauri system, and of course the time needed for the trip from Centauri back to Earth.

Myth busted.

*Akin to how the Vulcans happened to be passing by in near Earth space just as humanity set off its first warp drive signature attracting their attention as related in the film “Star Trek [TNG]: First Contact”.

The Physics and Philosophy of Time: Part One

“What is time?” That is a question that has been pondered and debated for probably thousands of years by some of the finest philosophical and scientific minds ever produced, without any definitive resolution. So, I’m NOT going to pretend that this is THE ANSWER – the be all and end all to the question. It’s some of my thoughts, which hopefully are as valid as anyone else’s!

What Is Time? It has been said that time is just Nature’s way of preventing everything from happening at once! But the word ‘happening’ is significant because if something happens, something changes. To my way of thinking, time is synonymous with change; time is a measurement of change; change gives the concept of time tangible meaning. If nothing ever changed, if nothing ever happened, it would be meaningless to talk about time. Time is just our informal perception or more formal measurement of rate-of-change. Rates-of-change vary depending on how fast you travel relative to some other frame of reference (the General Theory of Relativity) so the time intervals that measure that rate-of-change vary accordingly. I also can’t help but wonder whether, speaking of things relative, whether one could insist on a constant rate-of-change that’s made constant because your rate-of-time varies, or the more common view from day-to-day experience that rate-of-time is constant but rate-of-change varies.

It’s not difficult to understand why you are not aware of time passing when you sleep. It’s because you’re not aware or cognoscente of anything changing while you’re asleep. In fact, sleep is a way of achieving time travel. You go to sleep at 11 pm. Next thing you know its 7 am and you’ve traveled eight hours into the future seemingly instantly!

Thusly, I conclude that time doesn’t have a separate reality. I mean you can’t weigh time, it has no mass, it has no charge or energy, it isn’t a force and has no particle associated with it, you can’t put time to any physical use, nor can you manipulate time. You certainly can’t bottle and sell it! It’s about as intangible a something as the Universe allows.

Did time exist before there was anyone around to put a label to it? I mean in a pre-life era, change certainly took place – rocks eroded, the tides ebbed and flowed. But was there time? I suggest the answer is ‘no’ in that it takes a certain level of intellect to recognize change or rate-of-change. A rock doesn’t perceive time, nor does the beach upon which the tides act. The changes are physically real enough, but it takes something as complex as a living organism (not of necessity just a human organism) to perceive and understand change, and rate-of-change, which – human beings – for lack of a better word, we call it all happening (i.e. rate-of-change) as a concept called ‘time’.

By analogy, there is the oft quoted puzzle of there being this tree in a forest which falls. Does the falling/fallen tree produce any sound if no one (meaning humans) is around to hear it? (Of course there would be animals like bears, deer, possums, birds, etc. that would hear the sound, but let’s suppose that the forest contains just plants which I assume we can agree on, can’t hear. Now regardless of whether any animals are around or not, the falling tree will produce vibrations in the air (usually air, but vibrations can be equally transmitted in a liquid or solid medium). But vibrating air isn’t by itself sound. Sound is the perception (and possible interpretation) of those vibrations, and that takes a detection device and software (ears and a brain). So, there is no sound without ears and a brain, although the vibrating air is quite real regardless.

Time too, by way of my analogy, is akin to sound; change or rate-of-change is akin to the vibrating air. The former two (time and sound) are perceptions of physical events; the latter two (change and vibrating air) are the real physical events.

You’d think that therefore time wouldn’t exist in a vacuum or at a temperature of absolute zero, as how could anything change in a vacuum which contains nothing or at absolute zero when all motion ceases? Ah, enter the weird and wonderful world of quantum physics and discover that quantum activity, happenings, change, motion, etc. exists even in an apparent perfect vacuum and even at as close to absolute zero as makes no odds. In quantum physics, there’s no possibility of a perfect vacuum; absolute zero is only abstract and can’t ever be actually achieved. Therefore, time always exists as well. There seems to be no way to ever shut down quantum activity and achieving a perfect vacuum and/or absolute zero, so we’re in no danger of ever having our perception of time cease.

The shortest (quantum) unit of time possible is just that interval below which no possible change can happen. In other words, even the quickest ever possible change one can imagine takes an absolute minimum amount of time.

Change also implies there must be causality – there must be a cause that produces an effect, or in other words, something is affected by something else that occurred previously. Going from cause to effect implies a change and a time interval must have taken place into which that change fits. This introduces the commonly used phrase ‘arrow of time’. If time is our perception of change, then what is the ‘arrow of time’? Methinks it’s the reality that on the macro scale at least change happens only in one direction – cause precedes effect; effect follows cause, and that’s change. Examples of such one way cause and effect change include dropping the china cup and it breaks. A broken cup does assemble itself and then leap off the floor into your hand. Humans tend to be conceived, get born, grow up and age. Hair turns gray (or falls out), you get wrinkles and liver spots, and you die. You don’t rise from the grave, re-animate, and age backwards towards childhood and pop back into the womb! A hot cup of coffee cools off to room temperature. A cold cup of coffee doesn’t heat up by itself; even if there’s potential energy enough in the environment (air molecules flying around) to theoretically heat it up.  In other words, you can’t unscramble (or un-boil) an egg. 

Present Time: The Concept of ‘Now’: Does the present actually exist? We speak of it was if it does. But does it? Now I’m sure there’s no debating that there is a past, and that there will be a future. I’m sure there’s no debating that what we’d call five years ago exists in the past; five years on from when you read this is clearly the future. What about five months ago, or ahead?  What about five days or five hours or five seconds? Is half a second ago the past? Is half a second hence the future? Of course it is. In fact, I suggest you can split units of time ever shorter and shorter, but still admit that ‘ago’ means past; hence means future, even if 0.000005 of a second ago really is past, and 0.000005 of a second hence is the future. So where comes the ‘now’ or the present?

While there is a past, and will be a future, there really does exist a present. There apparently is such a thing as the shortest interval of time and nothing shorter can exist in reality. That shortest interval of time is known as Planck-Wheeler time, below which time as we know it ceases to exist. It’s about 10 to the minus 43^rd of a second. That’s how long your present lasts for! One Planck-Wheeler time unit behind you is now forever locked in as part of your unalterable past. One Planck-Wheeler time unit ahead, is still part of your malleable (free will?) future.

Even without resorting to quite such a tiny present, physics logic suggests that you really are an isolated individual that cannot share the present with the rest of the world. Lets imagine this couple, say we call them Clive and Jane, sitting down for their evening meal. Clive says to Jane, “pass the salt please darling”. Now Clive utters that phrase in his present and Jane hears it in her present. But both presents aren’t simultaneous. When Jane hears it in her present, it’s simultaneously Clive’s past because it takes time for sound to travel from voice to ear (and light from mouth to eye). Actually, when Jane hears the word “salt”, “pass the” is already in her past while “please darling” is still in her future. In other words, Clive and Jane can’t ever share the same present even though both pass through identical simultaneously now’s.

Here’s a form of time travel. When Jane looks in a mirror, the image she sees in her present is actually of herself from her past – an ever so slightly younger version of herself because it takes an interval of time for the light to be reflected off Jane, onto the mirror, reflected off that, and back to Jane’s eyes.

In summary, nothing you see or hear has the exact same reality that you perceive in your present because there has been a time lag and things change over time – even incredibly short intervals of time. A common example is looking at a distant star. The star you see in you’re here and now isn’t the same star that exists in that same here and now. You’re looking at a star, which, for all you know, just may no longer exist!

Of course you do live your entire life in the actual ‘now’ – you certainly don’t literally live in any part of your past, nor your future. Your life, your lifetime of ‘now’, is a string of Planck-Wheeler time units.

More Anomalies: Another Top Baker’s Dozen: Part One

From the cosmic to the quantum; from the macro to the micro; from the natural world to the human world, enigmas are everywhere. Here’s another baker’s dozen worth.

You may not be happy with the world as it is, but at least it’s orderly and makes logical sense. Walk, don’t walk, green yellow red; money trickles in, money flows out; friends and politicians come and go, enemies and stuff accumulate; the sun rises and sets, the moon waxes and wanes; people are born, people die; the days, weeks, months, seasons. and years come and go with regularity. But dig a bit deeper beneath the surface and the world and the cosmos it inhabits, is one anomalous place.

THE BIG BANG EVENT: This is no doubt a concept that nearly everyone has heard about, and swallowed hook, line and cosmological sinker because scientists present this creation of the Universe scenario as fact. It’s not fact; just the most viable theory of many theories and it has serious flaws. The accepted theoretical account of the creation or event that kick-started our Universe off not only has that event a something that created all of matter and energy, but all of time and space as well, and this creation event, to boot, all took place in a volume less than that of a pinhead (something in the realm of the quantum) and for no apparent reason at all. First there was nothing; then there was something. Wow!

At best observations that support this are indirect being made some 13.7 billion years after-the-fact. Those indirect observations that provide evidence for the Big Bang event are the fact that the Universe is expanding; the Universe has a temperature – the remnants from the hot Big Bang called the cosmic microwave background radiation (CMBR) and the amounts and ratio of hydrogen to helium. In reality there are no direct observations as nobody was present at Ground Zero all those billions of years ago.

There are really a couple of anomalies present in the standard Big Bang account. 1) You have a violation of causality – something (space, time, matter and energy) created from nothing which is a violation of several conservation laws or relationships. 2) You have a violation of pure common sense that tells you that you can not stuff the contents of the entire Universe into the realm of the quantum, something actually way less in volume in fact than a pinhead. If that’s not anomalous, I don’t know what is!

SPEED OF LIGHT: The anomaly here is that in any other scenario, velocities can be added and subtracted, except the velocity that’s known as the speed of light. Within Relativity Theory, if there is anything unintuitive it is the fact that in the entire Universe, it is the speed of light alone that is absolute or fixed, not something like space or time. It’s unintuitive in that all other bits and pieces that are in motion can be added or subtracted. So, if you are in a train that is moving at say 100 km/hour and you throw a ball at 10 km/hour in the direction at which the train is moving, to an observer outside the train, your ball is travelling at 110 km/hour. If you throw the ball towards the rear of the train, an outside observer will measure the ball as moving at 90 km/hour. If on the other hand, you shine a flashlight in the train, an outside observer will see the velocity of the resulting light beam moving at the speed of light – not the speed of light PLUS the velocity of the train, or the speed of light MINUS the velocity of the train, but at the speed of light! That’s nuts, but it’s scientifically nuts and been proven again and again in any experiment you care to devise.

QUANTUM GRAVITY AND THE THEORY OF EVERYTHING: We have the Theory of General Relativity (gravity) and Quantum Physics. Both are bedrocks of modern physics. Both are accurate to a high degree of experimental precision. Both aren’t compatible - with each other. Apparently, one (or both) of these theories must be wrong, or at best incomplete. That’s why the unification of the two (a theory of quantum gravity) is physics’ Holy Grail. However, that Holy Grail is proving as difficult to find as the Biblical Grail itself! But for the moment, it’s like the universe has two independent sets of laws – one governing the very large (gravity); one the very small (the quantum). This makes no natural or scientific sense.

We have observations of four physical forces yet no theory which unites the three quantum forces (electromagnetism, the strong nuclear force and the weak nuclear force) with the one classical force – gravity. Theory needs to be satisfied. All of the four fundamental forces should be interconnected; some sort of unification principle must be in operation that relates all four, one to the other. However, these four fundamental forces that govern the Universe show no signs of any obvious unification – well actually the three quantum ones do (known as the GUT – Grand Unified Theory), but that’s where the unification ends. Gravity remains the wallflower. If the Big Bang theory is to be proven correct as stated, scientists must of necessity come up with a viable theory of quantum gravity that is an acceptable unification of the trio of quantum forces with gravity. There is, to date, no viable theory of quantum gravity despite thousands of physicists searching for one over many generations now. Mother Nature is an anomalous bitch!

QUASARS: Quasars are ‘quasi-stellar objects’. They are ‘stellar’ because they aren’t all that large (like a galaxy). They are ‘quasi’ because they give off energy way, way, way more times greater than any star known in any astronomical catalogue. They seem to be primordial objects – they formed long ago and are now far away.  Quasars, like stars or galaxies, are their own entities and if two or more show a very close and special causality relationships then they should show identical recessional velocities (since the Universe is expanding and they are part of the Universe and that expansion). Recessional velocities are measured by an object’s red-shift. Theory identifies red-shift with velocity. However, you apparently have some observations of causality connected quasar pairs with vastly differing red-shifts (measurements of their recessional velocities). The anomaly, in an analogy, is that you can not have a runner running at 15 miles per hour holding hands with another runner running at 3 miles per hour!

MASS: There are three fundamental properties of particles (like the electron, neutrinos, the numerous quarks, etc.) and their anti-particles (like the positron). They are charge, spin and mass. As the song goes, two out of three ain’t bad, but that still leaves one out of three out of joint. In this case, it’s mass. Nobody can predict from first principles what the masses of the fundamental particles should be. That’s fairly disturbing for something as fundamental as mass. Despite the relatively large number of particles (including their equal and opposite anti-particles), there are only a few allowed values for charge and spin, values pretty much confined to the physics infield. But, for some reason, the mass (usually expressed in equivalent energy units – Einstein’s famous equation) of the various particles are not only scattered throughout the physics ballpark but are all over the city map and beyond. They take on values (albeit one value per type of particle) over many orders of magnitude without any apparent pattern or regularity or relationship between them – and nobody has the foggiest idea why, not a validly theoretical idea, or even a ‘far out’ idea. Why should mass differ so greatly from the other fundamental properties part and parcel of those elementary particles? It’s like someone just drew a few dozens of numbers out of a hat containing multi hundreds of thousands of values and assigned them to the few dozens of particles willy-nilly. Something is screwy somewhere because something so fundamental shouldn’t be so anomalous.

PHYSICAL CONSTANTS: There are constant reports of physical constants that aren’t – constant that is. Physical constants are just that – a constant. They have just one value, everywhere, every-when, and no exceptions. But apparently some ‘constants’ have more than one value depending of where and/or when. Theory and observations (if correct) are yet again not in harmony and that’s totally nuts!

TIME TRAVEL: Time travel to the past is a staple of science fiction, but surprisingly has actual viability in modern general relativity physics. In general relativity physics, time travel to the past is theoretically possible – though damned difficult in practice. However, that means that those time travel paradoxes are possible, even likely.

The anomaly are those lovable paradoxes like going back in time, say ten years, and killing yourself (which is a novel way of committing suicide), which means you couldn’t have existed to go back in time in the first place in order to kill yourself, which means you’re not dead so you can go back in time and murder yourself, etc. What kind of physics is that?

The second anomaly however is that no time travellers have been observed from our future. You would think various significant historical events would be swarming with historians and tourists from the future where time travel is possible. Nobody from our present or past has time traveled back in time and left a proof-positive calling card that we’ve ever found in the fossil record or recorded in the history books.

If something is possible, especially something as interesting as time travel, we would expect to see either people from our future in the here and now, or evidence that we’ve travelled to the past, like finding a human skeleton buried inside a T-Rex skeleton, as in inside the area where the T-Rex’s abdominal cavity would be! We don’t.

To be continued…

Time Travel via Parallel Universes: Part One

Parallel universes, or alternative universes or mirror universes have had a long run of popularity in science fiction and science fantasy, in both print and visual formats. One need only look at an “Alice in Wonderland” or look no further than the “Star Trek” universe (our Universe in less than obvious disguise) to view the near endless plot variations that such parallel / alternative / mirror universes provide our heroes and heroines. While there are some serious reasons to suspect that parallel universes do exist, there’s another, albeit more theoretical proof of the parallel universe concept. Time travel is the name of the game!

Why go back in time at all? Just to observe? That’s okay, as long as you look and don’t touch. Just to get rich? Probably! Just to do good deeds? I’d have to advise against that. Travelling to the past from the future, armed with the knowledge of what that future holds, brings a ‘wealth’ of opportunities – accent on the wealth. I mean go back in time and there’s this new company called IBM or Microsoft just starting to sell shares. You’d make a killing! You know in advance about the Global Financial Crisis. Put that to your advantage! Knowledge is power. Maybe all our billionaires are time travellers from the future who came back to make a killing! Sorry for taking such a cynical view. Actually the danger is the ‘butterfly effect’. Go back in time, be a goodie-goodie two shoes and correct something – kill Hitler in 1935 say – and the ripple effect could have so changed the future from which you came from that you might never have existed. Say that soldier in WWII, killed by the Nazis, lived instead because you assassinated Hitler in 1935 and he married your Mum instead of your Dad. You were then never born. Or say you assassinated Hitler in 1935, and someone else took over the leadership, but that someone started up Germany’s nuclear program almost immediately. Thus, Germany had the A-bomb when she started WWII – Germany won! Of course maybe somebody else goes back in time and assassinates you just before you bump off Hitler! Lesson: You do not muck around by changing the past since you can’t predict the rippling effects on down the line. Ray Bradbury’s excellent short story (also filmed) that illustrates this point nicely is “The Sound of Thunder”.

Be that as it may, I can immediately think of four actual, possible or theoretical ways of doing the time warp – again!

The first is your tried and true traditional time travel into the future, and one which you have no control over – we all travel into the future at the speed of one second per second.

Secondly, there’s a possible albeit highly theoretical equivalent for an antimatter you. You’d have a tried and true traditional time travel into the past, again one which you have no control over, and again (presumably) at a rate of one second per second. That’s because of the idea that antimatter is just normal matter, but normal matter going backwards in time at the rate of one second per second. I don’t rate that too highly on the reality scale. 

Thirdly, when you view any object, you’re time travelling back into the past. That’s because it takes a finite amount of time for light to reach you from whatever it is you’re looking at. What you actually see is how it looked that finite amount of time ago. Since you always view what happened in the past, I guess that’s a form of time travel! By the way, even if you directly touch or taste something, it still takes a finite time to travel on up the nerves to the brain and a finite time to register and be processed.

Fourthly, there’s the concept that if you travel and accelerate outwards at a significant percentage of the speed of light, stop, reverse, accelerate and come home again, when you land, you will have aged less than those stay-at-homes, or translated, you’ve travelled into the future a lot quicker than otherwise would have been the case. You and your stay-at-home twin are now both at the same point in time again; it’s just that you have biologically aged far less. That’s the ‘twin paradox’ of relativity physics, but it’s no paradox – it actually happens.

Interestingly, at the micro, hence macro levels, the laws of physics do not forbid other ways and means of time travel, for example using rotating Black Holes, wormholes, etc. While these are theoretically possible, in practice it would be difficult in the extreme, very energy intensive, and certainly way, way beyond our current, or even projected, level of technology, and may indeed remain forever out of our practical experiences and thus remain a parlour game for physics professors. But maybe, just maybe…

However, for starters, there’s a catch – there’s always a catch! Travelling backwards in time is restricted. You can’t travel back in time beyond the point where the time travel device was first constructed. If we should construct such a device in say the year 2050, nobody will be able to visit 2949 or any earlier date. Thus, since no such terrestrial device yet exists, we’re not overrun by tourists from our future. Our descendents can’t reach us. We cannot have time travelling visitors from the future who can tell us our future because they are not from our future, but from the future of an elsewhere – you guessed it, from the future of a parallel universe where a time travelling devise exists.

The reason, as I understand it, that you can’t time travel in your time travelling device before the device itself existed, is that your device isn’t a machine or a device you sit in – it’s a medium. It’s likely to a natural object, even if manipulated – rotating Black Holes or wormholes. A tunnel allows you to go from one side of the mountain to another, but in doing so you don’t take the tunnel with you. A ship travels through the water – it doesn’t take the water along with it. A tennis ball gets hit by the tennis racket; it doesn’t take the racket along with it. Instead, it relies on finding another racket in its new ‘universe’ or ‘time frame’ or court, able to return it home! You probably get the drift. That’s why you can’t go back in time further than the medium itself you used. If your mountain tunnel was built in 2009, you can’t go through and exit it in 2008! But you could go through and exit it in 2010, so you’re not of necessity stuck in the past if you get the analogy. The tunnel allows travel both ways, but just not before it was constructed. Anyway, forget your time travel movies with machines – no machines allowed. Probably the best movie to illustrate the point that the device is a medium and not a machine is “The Final Countdown”.

That of course says nothing about extraterrestrial intelligence(s) time travellers who may have had a working time travel devices eons ago, so we certainly can’t rule out, or preclude such a possibility – there’s those pesky UFOs again!

To be continued…

Infinities, Like Diamonds, Are Forever

I get rather irritated by the rather loose use of ‘infinity’ by physicists and science writers. At least I assume its ‘loose’ as I can see very few cases where an actual infinity can exist, other than in cases of mathematical abstractions, puzzles and paradoxes. I really assume they mean in most cases ultra tiny or extremely large, and not literally infinity as in infinitely large or small. Let’s examine the case for infinity applying to time, temperature, space or volume, density, velocity, matter and energy, and gravity.

“Ben Casey” was one of the better known and more profound of dramatic TV shows.  The introduction to each episode went as follows: “Man – Woman – Birth – Death – Infinity”. Well, of course the use of the word ‘infinity’ applies only as long as man and woman get their act together, which, in all probability, won’t really be forever and ever, amen. But what you can forgive in a TV show isn’t in the same league when infinity is misused by those who should know better.

Infinity, at one end of the scale, is akin to forever and ever, amen. There is no end; there is no limit. On the other end of the scale is something more familiar to us – zero. Zero is infinitely small. So, what of the various concepts that surround us in our life, our Universe, and in our everything – can they be infinite?

Time: Time apparently comes in quantum sized bits. That is, you can’t have an interval of zero time. The smallest allowable time span, while incredibly short, isn’t zero, and is known as a Planck-Wheeler time unit. Can time be infinitely long? As long as there is change, there is time (which is rate of change), and as long as there is quantum activity in the vacuum energy there is change. That just means that if you had the ability to magnify the microscopic by many orders of magnitude, right down to the quantum level, you’d witness constant activity as virtual particles get created out of the vacuum energy and ultimately annihilate and return their borrowed energy required for their creation back to the vacuum energy.

If our Universe had a beginning, which apparently it did (the Big Bang event) and should our Universe finally stop expanding and reverse direction and ultimately all come together in the mother of all Black Holes and go ‘poof’, then clearly time, as far as our Universe is concerned, is finite, time sandwiched between the Alpha and the Omega. But, if our Universe has always been and always will be (as it would be in the ‘Steady State’ model of our Universe), or if our Universe continues to expand, ever expand, and expand some more without end, or if our Universe is one of an endless number, a cyclic or oscillating Universe that goes boom, expands, stops, contracts, goes ‘poof’, but the ‘poof’ creates another bang, etc. then time is infinitely long, even if our Universe exists for a finite segment within that infinity.

Temperature: Despite reading a comment in one of the books by the renowned astrophysicist Stephen Hawking that at the time of the Big Bang event, the temperature of the embryo Universe was infinite, you can not have an infinitely hot temperature. Temperature is the measurement of the average motion of matter’s particles. The faster they move or vibrate, the hotter things are. So, infinitely hot would imply that matter, or rather the fundamental particles that make up matter, were moving infinitely fast. But infinitely fast would mean faster than the speed of light, which is a no-no. If the Universe started off with an infinitely high temperature, then no matter how much the Universe expanded, it would remain at an infinitely high temperature, because any infinity that’s diluted, divided by a finite number, is still infinity. Since our Universe isn’t currently infinitely hot, it couldn’t have been infinitely hot at anytime in the past. 

An infinitely small temperature would have to be absolute zero of course. However, absolute zero is unobtainable again because of quantum fluctuations in the vacuum energy. In physics, the lowest possible energy state isn’t ever zero because that would violate the Heisenberg Uncertainty Principle which states that it is fundamentally impossible to know both the exact location and the precise velocity simultaneously. At absolute zero, the particle wouldn’t have any motion; thus its location and its velocity would be precisely known. That’s not allowed. Since the Universe has an overall finite temperature, as it expands, it continues to cool. But, no matter how much the Universe expands, it can’t cool down to absolutely nothing.

Space or Volume: If there was a Big Bang event, a location in space and time where our Universe is defined as having a beginning, then clearly the Universe had then, has now, and will always have a finite size, albeit expanding, ever expanding. Of course, if it keeps expanding for an infinite amount of time, then after an infinite amount of time our Universe would have an infinite volume. It’s also possible that our Universe, itself finite in volume, could exist in a larger infinite sea of space. In contrast to the Big Bang scenario, a rival theory, the ‘Steady State’ type of universe where new matter is constantly being created, could be infinite in volume. As new matter is constantly being created, assuming the ‘Steady State’ universe has always been and always will be, it would need infinite space to accommodate it all. Alas, the ‘Steady State’ theory hasn’t been viable, except to a few never-say-die true believers, for decades. However, there could be a Multiverse that could, in theory, be comprised of an infinite number of individual universes, of which our Universe is but one, in which case the Multiverse space or volume would have to be infinite. A finite Multiverse (a finite number of universes) wouldn’t need an infinite amount of space, but that doesn’t preclude a finite Multiverse existing within an infinite amount of space.

Density: Density can not be infinitely small – zero – because of quantum fluctuations in the vacuum energy. Virtual particles are always popping into and out of existence in the vacuum energy. As long as you have ‘stuff’ you must have density. The concept of absolutely nothing would have zero density, but it’s not possible to achieve a state of absolutely nothing.

Density on the other end of the scale can not be infinitely large, as is frequently claimed for Black Hole singularities or the state of the Universe at the time of the Big Bang event. You’d need infinite mass to achieve infinite density and clearly neither a Black Hole, nor our Universe has infinite mass. It would also seemingly have an infinite amount of energy to expand a Universe from a singularity point of presumed infinite density, and since there isn’t an infinite amount of mass in our Universe, there can’t be an infinite amount of energy, as matter and energy are two sides of the same coin as per Einstein’s most famous equation. It’s often stated in more colourful language that mass is just frozen energy. 

Either the Big Bang event singularity (and Black Hole singularities by analogy) was infinitely dense and had zero volume, or it was not. If they (Big Bang and Black Hole singularities) do not have infinite densities and zero volumes (and the alternative are really quite ridiculous), then singularities have a finite density and a finite volume and can grow in size as more stuff is added on. The upshot is that singularities can reach a size where quantum effects are negligible. Or, in other words, singularities aren’t of necessity quantum objects. To explain the importance here is that in the realm of the singularity as is currently accepted, one needs both the classical physics of gravity, and the quantum physics of the microscopic, to adequately describe the properties of any singularity. Unfortunately, there’s as of yet, no accepted theory of quantum gravity. Despite the lack of a theory of quantum gravity, you will usually read that the Big Bang event started off as an infinitely dense object of zero dimensions – a singularity. The origin of our Universe was a quantum event since the size of the singularity was within the realm of the quantum. I maintain that while as one extrapolates backwards in time towards the Big Bang event, the Universe gets smaller and smaller, it does not even reach the stage where the Universe becomes so tiny that for all practical purposes it has infinite density (that’s where the gravity comes in) and zero volume (where quantum physics rule).   

Velocity: Velocity can of course appear to be infinitely small – zero – but only relative to some other object. You may be standing still relative to the Earth’s surface, but the Earth is rotating on its axis and revolving around the sun, which in turn is moving relative to other stars, etc. However, at the quantum level, those quantum fluctuations, the quantum jitters, that never ending seething activity in the vacuum energy, means that even a rock stilling apparently still on the ground is actually vibrating. In addition, the rock is expanding and contracting as the daily temperature waxes and wanes. So, appearances are deceiving here. You can’t in fact have zero velocity, and in fact having an absolute zero velocity again violates the Heisenberg Uncertainty Principle. The closest you could achieve is a thought experiment where the Universe consists of one, and only one elementary particle. There’s nothing else to measure its velocity relative to, well, something else – there is no something else.   

Velocity can’t be infinitely fast as you’d have to break the light speed barrier. On the other hand, you can travel faster than the speed of light (superluminal) if that was your natural state to begin with, but hypothetical faster-than-light particles (tachyons) haven’t ever been detected, and there is no reason to believe they would travel infinitely fast even if they did exist. Anything that travelled infinitely fast in a finite Universe would be everywhere in every Planck-Wheeler unit of time. Translated, the entire Universe could consist of just one particle!

Matter and Energy: Since matter equals energy, and energy equals matter, by considering one, we consider both. Temperature is a form of energy, and we’ve already seen that temperature can neither be infinitely large nor small (zero). Further, one can’t have an infinite amount of matter without an infinite amount of space to put it in. Since we take stock in the Big Bang model of our Universe, and since that model dictates a finite volume, albeit an expanding one, it’s still finite and so the matter contained within must be finite, and therefore so is the energy content of the Universe.

And you can’t have zero matter and/or energy for reasons which should be pretty apparent by now.

Gravity: Although gravity is the weakest of the four known physical forces, it most certainly acts over long distances. Even though the pull of gravity weakens with increasing distance, it never reaches the infinitely minimum – zero. As long as there is so much as two fundamental bits of matter in the Universe, gravity will never equal zero. It’s probably nonsense to talk of gravity if there was only one elementary particle in the cosmos, since gravity is an attractive force between two or more bits of matter.

Further, because it is the amount of matter in our Universe which determines the overall gravitational quota of the Universe, and because that amount of matter is finite, that quota of gravity must be finite, even if all that matter were lumped together at one time and in one place.

Further reading in infinities:

Barrow, John D.; The Infinite Book: A Short Guide to the Boundless, Timeless and Endless; Vintage, London; 2005:

Clegg, Brian; Infinity: The Quest to Think the Unthinkable; Carroll & Graf, N.Y.; 2003:

Are Black Holes Really So Weird? Part Two

Black Holes have a certain aura about them. They are associated, in the minds of the general populace, with a certain mystique or ultra-mystery about them – terrifying objects that gobble up everything within range – the ultimate devourer, doomsday machine, berserker and weapon of mass destruction (if you could figure out how to manipulate one of course) all rolled into one. But Black Holes have other aspects about them that are equally fascinating, and not really all that weird, though some bits are weirder than others. But you don’t have to be a geek to come to terms with these concepts. 

Continued from yesterday’s blog…

Now the common perception about Black Holes is that nothing gets out past the event horizon once it finds itself beneath it. That’s not quite the case. In theory, as discovered by cosmologist/physicist Stephen Hawking, radiation can escape – sort of – and this radiation is now called Hawking radiation. Macro objects, objects we associate with classical physics, can not get from inside an event horizon to outside an event horizon without travelling faster than the speed of light, which unfortunately, should you find yourself below and event horizon, is the ultimate cosmic speed limit. There’s no ‘get out of jail’ card. Travelling faster than light speed is not allowed.

But, any elementary particles, in the micro size realm and subject to quantum phenomena, can escape – again in theory; this hasn’t be verified by direct observation (which is currently in the too hard basket). It you are a fundamental particle, just below the event horizon, you might, just might, due to quantum fluctuations or jitters / the vacuum energy / the Heisenberg Uncertainty Principle, quantum tunnel your way, the tiniest fraction of a distance imaginable, past the mathematical event horizon boundary, to outside and potential freedom. Of course most particles might get sucked right back in again, but a tiny fraction gets away, carrying with it energy (thus the Black Hole has a temperature) and therefore mass, so the Black Hole loses a bit of mass and shrinks a bit. This quantum tunnelling, crossing an energy barrier without having in theory sufficient energy to do so, is sort of like how a radioactive atom goes ‘poof’ and decays to a more stable state. Something in the nucleus, not having enough energy to break out, nevertheless quantum tunnels its way out – ‘poof’.   

Very much like a human being, from the very moment a Black Hole is born, say out of the gravitational collapse of a super-massive star that’s run out of nuclear fuel and stellar puff, it will start to die, to evaporate via Hawking radiation. However, in a Universe still very much dominated by matter and energy (including the all pervasive cosmic microwave background radiation), way more stuff finds its way into a Black Hole than gets out – by many orders of magnitude. For every bit (particle) that escapes, millions of bits (particles) get trapped inside. But (and here I assume an ever expanding Universe that never results in a Big Crunch), what happens when all the available matter and energy (all those particle bits) has been consumed and Black Holes can’t grow anymore (and here I assume that individual Black Holes are so far apart and expanding away from each other that they don’t consume each other). Then, evaporation – Hawking radiation output – exceeds input, and slowly, ever so slowly, and I do mean extremely slowly (as in measured over trillions of years), Black Holes get smaller and smaller until there’s nothing left. But our now ever more vastly expanded and immensely larger than it currently is Universe is filled (albeit to a much rarified extent) with just particles – particles adrift in the eternal cold of near absolute zero temperature (zero degrees Kelvin, the absolute theoretical minimum temperature possible).

However, the ultimate death of Black Holes has posed a significant problem to some physicists, causing quite a bit of controversy in the process.

What happens to the information content that a Black Hole can gobble up? Say you toss a book, or a CD, or a fully loaded human brain into a Black Hole. Is the information contained in that book (or whatever) lost to the Universe forever? [Perhaps given the state of information overload we suffer from that might be a blessing!]

You can not have macro stuff spew out of a Black Hole without violating basic physics. Macro stuff, say in the form of a book or a CD or a human, stuff full of information, falls in – that identical macro stuff, stuff full of information, does not, can not, come back out again. It is not only an improbable event, but an impossible one and a violation of the law of physics. But we have seen that in theory at least, Hawking radiation can get back out, because radiation isn’t macro, its micro, or in the realm of the quantum.

Note that it wasn’t Hawking radiation that was tossed into the Black Hole in the first place, but a book or CD or a human being or a whatever macro object, so escaping Hawking radiation isn’t that book or that CD or that whatever, but a bit of this and a bit of that and there’s no way of distinguishing the this from the that. Though there is apparently no way to reassemble the bits into all its separate meaningful messages; one-on-one, all the bits are nevertheless there.

If you were somehow able to reassemble bits of Hawking radiation emitted from all the bits and pieces which the Black Hole swallowed – which can escape – into a meaningful message(s), how would you know that message was something part and parcel of some information that went down the Black Hole gurgler in the first place? You’re more likely to have assembled one letter from one book, another letter from another book, yet a third letter from a third book, etc. The information (say sentence) you have assembled never entered the Black Hole in that form at all!

Still, a Black Hole, in theory, eventually spews out all the information it absorbed over its existence, ultimately via Hawking radiation. Some scientists insist there is, there must be, a way to reassemble the bits into all its separate meaningful messages; one-on-one.

So therein lies the controversy – macro stuff does go in; macro stuff does come out. Macro stuff ultimately escapes as micro stuff – Hawking radiation. Some scientists will say you can’t in theory reassemble and separate out the signal from the noise; others say you can, in fact it must be possible.

As indicated above, some physicists make a big deal over the loss of information via a Black Hole relative to any other way – probably because of the non-reversibility factor already described. Methinks personally it’s a non-event. Why? The fundamental question this all boils down to be that information – in any form – is a composite of elementary particles. A book, or a CD, or Morse code ink drops, or a human brain is a composite of particles. An electron, all on its own, isn’t telling you very much (for that matter, either is any individual letter in a book – by itself). Loss of information seems to be another example of dust-to-dust, ashes-to-ashes; only it’s a more fundamental case of elementary particles to elementary particles. It’s how the Universe began and its how the Universe will end up if the current observational astronomical trends continue into the indefinite future.

There’s one other solution to the ‘is information lost forever or is it not’ paradox. It’s considered a possibility that a Black Hole, because is so distorts time and space – in the extreme - ultimately buds off from our Universe and starts or enters another universe, or a baby universe (part of a Multiverse). In such a case, any information is budded off with it and lost to our Universe forever. Of course our loss is the other universe’s gain; maybe a Black Hole(s) in some other universe has dumped its information load (or overload) onto our Universe! 

There’s one further spin-off from the Black Holes make baby universes idea. In a Multiverse, different universes may have different laws of physics. There’s no reason why the laws of physics in our Universe need be identical in another universe. Thus, there might be some universes where the local physics favor the formation of Black Holes, and some universes where local physics can’t make Black Holes. Those universes that can easily make Black Holes will ‘breed’ and produce baby universes. Those universes that can’t readily make Black Holes will ‘breed’ less. Those universes that can’t produce Black Holes will be sterile. Do you see the connection with Darwinian ideas? Some universes are more ‘fit’ to reproduce than others!

Now that’s weird!  There’s one other bit of weirdness I like about Black Holes, and that is that what’s inside them may well be a new form of matter. Ordinary matter goes into a Black Hole, but the conditions inside them are so extreme that there’s some sort of phase transition (like when ice goes to water goes to steam or vice-versa) and while it’s still matter, it’s matter but not as we know it. The theoretical evidence for that idea is that if you have a matter star, and an antimatter star, and you introduce them to each other, what you get is one almighty Ka-Boom! But, if your matter star compresses into a Black Hole, and your antimatter star compresses into a Black Hole, and you combine the two, what you get is just a larger Black Hole!

Some more weirdness: It’s suggested that information going into a Black Hole is actually ‘stored’ in the event horizon, that two dimensional ‘surface’ marking the point of no return that surrounds the Black Hole’s singularity – whatever that actually is. The event horizon concept isn’t difficult to envision – Earth’s crust and oceans are a two dimensional surface surrounding the spherical three dimensional planet.

Now as more and more stuff enters a Black Hole, the event horizon expands accordingly – obviously - just like our crust (area) would get bigger if Earth’s volume increased. The event horizon is also the area where Hawking radiation is emitted from.

Now say you are inside a Black Hole’s event horizon – that’s the wrong side to be on, but this is just a thought experiment and I’ll assume you haven’t been crushed into a tiny pinprick of stuff, stuff that could equally be rusted automobiles or stuff formally made from gold, silver and diamonds. There’s lots of trapped radiation (photons) in there with you because light can enter a Black Hole. Those photons can struggle up, losing energy with each unit of distance gained, to reach the event horizon, but no farther. Their energy has exhausted itself. I gather they can just barely touch and ‘reflect’ off the underside of the event horizon and come back down again (in a direction towards the singularity), picking up the energy again that they expended in their futile gesture of escape. So, you, being also beneath the event horizon can see the event horizon from the inside via these trapped photons. You can also see beyond the event horizon via new photons entering the Black Hole from outside the event horizon – photons that will join their trapped or prisoner kin. It’s like a half-way mirror. If you are inside a Black Hole, you can see out, because light can pass through the Black Hole’s event horizon to you, but people on the good side or outside of the event horizon can’t see you because light reflecting off you can’t make it past that event horizon barrier.

One further question, could we actually be living within a Black Hole, or translated, is our Universe actually a Black Hole? Now one could (and people have) suggested that one could consider the entire Universe as being the inside of a Black Hole – after all, nothing can escape from the Universe. Well, if you can’t escape from inside a Black Hole, and assuming there’s no escape from our Universe (you are trapped in this Universe, like it or lump it), then a rose by any other name…

However, our Universe doesn’t exactly mirror a real Black Hole unless there is an outside to our Universe – a beyond the boundary or horizon that allows stuff to get into our Universe, our Universe ultimately trapping it.

So, Black Holes residing inside a Black Hole Universe, which maybe residing inside…

Russian dolls within Russian dolls within Russian dolls within Russian dolls.

Saving the best for last, could you become a Black Hole? Well, the short answer is presumably, ‘yes’. The reasoning goes as follows. If you travel at ever increasing velocities, under special relativity, your mass gets correspondingly greater and greater, and your length gets shorter and shorter. Translated, your density gets greater and greater; your own gravity gets higher and higher. At light speed (impossible to achieve), your mass would be infinite; your volume zero; your density and gravity infinite. Well, that’s not on. But, before even approaching that limit, your mass would be theoretically great enough; your volume low enough, your density and gravity great enough, that you’d warp space-time sufficiently enough to turn into a Black Hole! As noted above, what actually comprises a Black Hole is irrelevant. Any stuff will do – gold, silver and diamonds; rusted automobiles; or flesh-and-blood (i.e. – you).

Here are a few further recommended readings:

Begelman, Mitchell & Rees, Martin; Gravity’s Fatal Attraction: Black Holes in the Universe;  [2^nd Edition]; Cambridge University Press, Cambridge; 2010:

Susskind, Leonard; The Black Hole War: My Battle With Stephen Hawking to Make the World Safe for Quantum Mechanics; Back Bay Books, New York; 2008:

Thorne, Kip S.; Black Holes & Time Warps: Einstein’s Outrageous Legacy; W.W. Norton & Company, New York; 1994:

Are Black Holes Really So Weird? Part One

Black Holes have a certain aura about them. They are associated, in the minds of the general populace, with a certain mystique or ultra-mystery about them – terrifying objects that gobble up everything within range – the ultimate devourer, doomsday machine, berserker and weapon of mass destruction (if you could figure out how to manipulate one of course) all rolled into one. But Black Holes have other aspects about them that are equally fascinating, and not really all that weird, though some bits are weirder than others. But you don’t have to be a geek to come to terms with these concepts. 

The aura of the Black Hole, even if not quite as dramatic as a doomsday device, is hardly less within the astronomical community, to quantum physicists, or relativists (scientists who special in general and/or special relativity).  Though there’s little doubt today of their actual existence, a logical consequence of Einstein’s theories of relativity, Einstein himself refused to give credence to them. The well-ordered universe just wouldn’t actually create such monstrosities he believed. He wasn’t alone in that point of view, and as their theoretical certainty became ever stronger, scientists tried to find ever more unique ways to prevent them from forming – to no avail.

But are Black Holes really as strange and mysterious and deserving of their aura and status as unique astronomical objects?

Black Holes may have no hair, which is to say they lack the individuality of whatever formed them so if you’ve ‘seen’ one Black Hole you’ve ‘seen’ them all. Translated, a Black Hole made out of rusted automobiles will ‘look’ the same as one made out of star-stuff, as one made out of pure gold, silver and diamonds. But Black Holes do have (or could have) certain properties. All Black Holes most certainly have mass and therefore gravity; they certainly have size (a volume, an area, a circumference, etc.); they certainly have a shape (spherical). Black Holes (against all intuitive prediction) have a temperature (Hawking radiation). They can have spin (rotation), and they may have an overall electric charge. So what’s unique about that?

The property we most associate with Black Holes is gravity, a function of mass - the more mass, the more gravity. Associated with that concept is escape velocity – how fast do you need to go to escape an object’s gravity well never to return. 

Now our moon has gravity and an associated escape velocity. Planet Earth has greater gravity and therefore a higher escape velocity (about seven miles per second). Planet Jupiter has an even greater gravitational field and thus you need even more oomph to escape. Our sun is another notch higher up, and so it goes. Keeping in mind that gravity is related not to something’s size, but to its mass, a White Dwarf star, while smaller than our sun, has greater gravity and therefore escape velocity. Then comes Neutron Stars (pulsars) and you really need some rocket power to get away from those babies!

However, there is a limit to velocity, escape or otherwise.  That limit is the speed of light, or about 186,000 miles per second (roughly 300,000 kilometres/second). So what happens when there is so much mass, or so much gravity, that the escape velocity exceeds that of 186,000 miles per second? The quick answer is nothing – you can’t escape; nothing can escape – not even light. That’s pretty straight forward and you don’t even need a course in relativity to figure it out! The absence of light is darkness, so any object that has an escape velocity greater than that of light will be dark – in other words, a Black Hole. The only difference twixt a Black Hole and any other macro object is that a Black Hole’s escape velocity exceeds that of light. That’s it; end of differences.

If you can’t see a Black Hole, how could you know they actually (as opposed to theoretically) exist? Simple – Black Holes have gravity, and the gravity of Black Holes can influence matter we can see. So, if you see a star going too and fro in orbit around something you can’t see, then that something is probably a Black Hole. Matter (interstellar dust and gas) spiralling into, but just prior to entering a Black Hole can also give off a tell-tale electromagnetic signature.

Because of such intense gravity, individuality is squeezed out. Planet Earth has highs (mountain peaks) and lows (ocean troughs) and a slight equatorial bulge, but if it’s size were reduced (while retaining mass) to the extent that her gravity created a greater-than-light escape velocity, then Planet Earth would become a perfect sphere of super dense crushed matter. No peaks, no troughs, no bulge – no personality, or no hair! 

Now objects tend to have a surface – an inside and an outside. In the case of Planet Earth, let’s call beneath the crust Earth’s inside; above the crust Earth’s exterior. The same goes for Black Holes. The inside centre of a Black Hole is called a singularity. The ‘surface’ of a Black Hole is called the event horizon – it’s the purely mathematical line where the escape velocity goes from faster than light speed (event horizon and below) to a permitted escape velocity (event horizon and above). Earth’s usually quoted escape velocity is given to be at Earth’s solid surface or sea level. But even sat 100 miles above, there’s still as escape velocity, it’s just less than 100 miles further down. In like style, a Black Hole’s escape velocity decreases from the singularity outwards, but doesn’t become permissible (less than light speed) until the altitude of the event horizon is reached. Thus one can not see anything, any events that are below this mathematical event horizon because anything below can’t get out, including light. Finally, the distance between the singularity and the event horizon varies depending on the mass of the Black Hole.

It’s what’s below the event horizon that’s really of interest given that it can’t be seen; no information escapes to inform us or give us any real clues of the conditions beneath. One has to rely on physics’ theoretical equations to predict conditions – conditions that really can’t be verified by any direct observation.

Unfortunately, these equations, the equations of general relativity, break down when one approaches the singularity. That’s because in order to come to terms with what a singularity is like, one has to merge general relativity (gravity) with quantum physics (because the singularity is thought to be of a size within the realm of quantum phenomena), or produce a theory of quantum gravity. Alas, that has yet to be accomplished. So, understanding the physics inside a Black Hole is one of Mother Nature’s final frontiers!

For example, taken to their logical conclusions, physics’ equations (general relativity) dictate that a singularity must have zero volume and infinite density. Physicists are well aware that whenever ‘infinities’ pop up in their musings, something’s wrong and they need to go back to the drawing board (blackboard?) and refine things to a greater or lesser extent. Hopefully, a theory of quantum gravity will do that, but for the here and now, you’ll find texts which state that a singularity has zero volume and infinite density. That’s clearly a nonsense, for if one had infinity density, one must have infinite gravity as the greater the density an object has, the greater its gravitational attraction. Now even though gravity dilutes as it spreads throughout space and away from the object of its affection, any dilution of infinity is still infinity. Since Black Holes and associated singularities are thought to be common in the observable universe, there should be at least one that’s had time since the Big Bang to project its gravitational influence onto us – say the massive Black Hole singularity at the centre of our Milky Way Galaxy, less than 50,000 light years away. Quite obviously we’re not being subjected to an infinite gravitational attraction towards our galactic centre, which tends to put the kibosh on, and confirms the breakdown as to what the equations predict for a Black Hole’s singularity.

So, if a Black Hole’s singularity doesn’t have zero volume and therefore infinite density, then it must clearly have a finite volume and a finite density which has implications for the origin of our Universe since conventional wisdom associates the Big Bang event with a singularity (and if there were to ever be a Big Crunch event, that would have to end up as a singularity).

The logic goes something like this. A singularity must have a finite density because having an infinite density is ridiculous. A singularity must have a finite volume because any object that has mass can’t be dimensionless – that too would be ridiculous – and Black Holes certainly have mass since they have gravity. If the Black Hole continues to grow, then the singularity continues to add mass to it, and its density increases. But, eventually the density reaches some sort of maximum possible – it’s finite after all and can’t become infinite. So as matter continues to be added to the singularity, the volume or size of the singularity must grow – and grow – and grow – and grow. Eventually, the volume of the singularity must be such that it falls outside of the realm of quantum physics. Translated, in other words, not only is a singularity of greater than zero volume, it may not even be tiny. It could be massive – stellar sized; even galactic sized! That then does away with the absurdity that our entire universe started out as something less than atomic sized something akin to a tiny pinprick!

Now the other interesting thing is that gravity probably isn’t really a force like electromagnetism or the strong and weak nuclear forces and shouldn’t be lumped in with them (which physics texts do). Rather, gravity, according to general relativity, is rather a manifestation of space-time geometry. As the saying goes, ‘matter (gravity) tells space-time how to bend; bent space-time tells matter how to move’. That movement we interpret as gravity.

So, space-time near, around or in a Black Hole is about as bent, or warped, as you can get, or conversely, the local geometry is so extreme or curved that not even light can get beyond the Black Hole’s event horizon. The geometry creates a sort of well, so deep and so steep, that the velocity needed to escape is greater than special relativity allows. [Special relativity covers the speed of light; general relativity deals with gravity and space-time.]

What does the extreme warping of space-time mean – apart from making the Black Hole, black? Well, presumably if you distort space-time sufficiently, then you, in theory, can make shortcuts through space and/or time.

Let’s have an analogy. Say you take a balloon and mark out a North and South Pole on the surface. The distance between the two is either half the circumference of the balloon (if you go via the surface or normal space), or the diameter (if you tunnel through, call that hyperspace). Now squeeze the balloon such that the North and South Poles are forced close together; maybe even touching. While this doesn’t help reduce the travelling distance if you stay on the surface (normal space), the tunnelling (hyperspace) distance in the now warped balloon is vastly reduced. If it took you a year say to tunnel from North to South in the standard balloon, then post warping it might take you only a week (or less). In fact, if the Poles were squeezed into direct contact, then you could travel via normal space from one to the other instantaneously – no need for hyperspace. Of course if you actually wished to travel from some other point on the balloon’s surface to some other point, the squeezing might not do you much good. In fact, the East – West distance has increased! So, the odds that the warping will be just right for your travel needs could be highly problematical. A local Black Hole warping that favours you travelling to Sirius quick smart is of little consequence if you wish to actually go to Alpha Centauri.  But then as some old wise sage said, ‘life wasn’t meant to be easy’!

Now since space and time are intractably connected, points in time, like points in space, can be squeezed closer together. So the North and South Pole bits could easily have been a past and a future. Actually, because it’s really space-time, you probably have a combination of both. You don’t travel from 2000 AD Adelaide to 2000 AD Sydney in the wink of an eye; nor from 2000 AD Adelaide to 3000 AD Adelaide in that same wink, rather from (say) 2000 AD Adelaide to 3000 AD Sydney in an eye blink.

I’ve seen speculation that a Black Hole could warp space-time so greatly that it could ‘pinch’ itself off from our Universe and disappear entirely. Of course if it did so it could no longer have any influence within our cosmos. However, if something as massive as the Black Hole at the centre of our Milky Way Galaxy isn’t enough to pinch space-time sufficiently to disappear, then perhaps it just doesn’t happen – or maybe it takes the mass of an entire universe to do it. Say one universe’s Big Crunch’s mother of all Black Holes plus singularity warps space-time so much that it becomes another universe’s Big Bang!

To be continued…