A Perfect Vacuum, Not

I recall the movie “Alien” had a tagline along the lines of ‘In space, no one can hear you scream’. Why? Because space is a vacuum, and sound (as in screaming) cannot travel from point A to point B if there’s a vacuum in-between. But the question really is, is space a perfect vacuum? Can one achieve a perfect vacuum? If not, why not?

One of the big scientific oops often depicted in Hollywood (and other country’s equivalents) sci-fi space operas is an external view of spaceships, etc. in deep space chug-chug-chugging along with all appropriate sound effects, and/or blasting away with laser cannons or photon torpedos, ditto with appropriate sound effects. Of course, if you really were an external viewer, what would you actually hear? - Absolutely nothing. It would be, or should be, like viewing a silent film from the pre-talkies era. But, for the sake of dramatics, Hollywood (etc.) ignores the physics of it all. ‘Artistic licence’ is what it’s called I believe. 

However, in the physics classroom, where artistic licence isn’t allowed, I’m sure we can all recall from our student days a demonstration of the ringing alarm clock inside the bell jar. As the air was pumped out from the bell jar, the ringing got softer and softer and softer until you heard nothing at all, even though the alarm clock was still jangling away. Of course the science teacher or physics professor told you there was now a total vacuum inside the bell jar and thus no sound could travel from point A – the alarm clock inside the vacuum inside the bell jar, to point B – your ears which were outside the bell jar.

Of course it should be obvious to blind Freddy that there was no such thing as a total or perfect vacuum inside the bell jar. Firstly, no pump is good enough or efficient enough or strong enough to remove each and every last molecule of air from the bell jar. [Of course there is no such thing as a molecule of air, rather atoms and molecules of the various substances that together make up what we call air, but for the sake of simplicity let’s make believe there are molecules of air.] Even discounting those rarefied air molecules left within the bell jar, molecules few and far enough in-between as to prevent the sound of the alarm clock from reaching your ears, the inside of the bell jar still wasn’t a total vacuum.

Why? Well assuming the bell jar was made of glass; light was pouring through the bell jar, and light is a something. The inside of the bell jar was full of visible light. Okay, let’s make the bell jar out of solid lead. That blocks out the light – right? Wrong. Visible light is but a small part of the entire electromagnetic spectrum. Radio waves (a form of non-visible ‘light’) will probably pass through the leaden bell jar, or gamma rays. Even if you succeed in blocking out all of the wavelengths and frequencies of the electromagnetic spectrum, there are still cosmic rays. If you make the leaden bell jar thick enough you might block out all of the cosmic rays, but that still leaves neutrinos, and in order to block all of those, you’d need a bell jar that had a lead thickness of hundreds of light years. Neutrinos can pass through leaden walls as easily as Casper the Friendly Ghost – even easier!

Okay, so you’ve got a perfect pump to remove all the air molecules and sufficient shielding to prevent even neutrinos from entering and passing through. That’s that; now you have your perfect vacuum – right? Wrong again.

You still have gravity not only surrounding but inside the otherwise perfectly shielded bell jar. Even if there were no other matter in the entire Universe, the bell jar itself is made of matter and has its own gravity which resides inside the jar as well as extending to infinity outside of it. Since nothing we know of can block the force of gravity, well that alone puts the kibosh on the perfect vacuum. Gravity is really a real thing, and if you doubt it, I invite you to try to leap tall buildings at a single bound!

Now a perfect vacuum would have to have a temperature of absolute zero, given the total absence of any material substance within. Temperature of course is just a measurement of the average molecular or atomic motion of molecules, atoms, even their fundamental particles. No stuff means a temperature of absolute zero. However the Universe isn’t lacking in stuff which moves around from place to place

For quite another reason however, absolute zero, zero degrees on the Kelvin scale, (or minus 273.15 degrees Celsius or minus 459.67 degrees Fahrenheit) is only theoretical and can never be obtained. That’s because the concept of absolute zero violates the Heisenberg Uncertainty Principle which states that it is impossible, no matter how good your measuring instruments are, to simultaneously know the position and momentum of anything, because the very act of measuring something must alter both parameters. That’s because something must bounce off what you are trying to measure and hence interact with your measuring device, but that bounce alters the position and momentum of that in which you are interested. At a theoretical absolute zero, nothing moves and thus you would know both the position and momentum of that or any object, even say an electron, with absolution precision. The momentum is zero and thus your object is in, and stays in, a fixed location – and besides, there’s nothing to bounce off it anyway, because that something (usually a photon) must also have zero energy and is thus at rest.

And thus we have the concept of the vacuum energy, or quantum fluctuations or the quantum jitters. That is to say, at the extreme micro level, there is always activity and thus motion and thus temperature above the theoretical minimum of absolute zero - thus, no perfect vacuum is possible. Even the best vacuum will have the quantum jitters. Oh, and by the way, the quantum jitters or the vacuum energy has been experimentally verified.

So, if you were somehow expecting that there was such a thing as a perfect vacuum, you’re out of luck, not that that I’m sure will cause anyone any loss of shuteye. However, that doesn’t alter the fact that in space, no one can hear you scream! You don’t need a perfect vacuum for that to be true.

Reality: Really Real, Pseudo-Real, or Unreal? Part Two

Reality – it could vary from your mind alone as the entirety of all existence to you being the figment of someone else’s imagination. Without your five senses and brain thingy, you wouldn’t experience any reality at all. There are as many versions of reality as there are living things, up through and including ‘living’ machines – artificial intelligence (AI). But is there any reality at all in the absence of living things, including AI?

Continued from yesterday’s blog…

The Reality of Both Nothing and Something:

There has to be some nothing as well as some something. If everything were something, then nothing could move as all the Universe would be chockablock – like the fad of a VW, or a phone booth being stuffed full to overflowing with college kids. You couldn’t push anything out of the way as there would be no nothing to push it into!

The Reality of Something: Matter & Energy:

We live in the world of the macro and in the realm of classical physics – the physics you were taught in high school. Your homes, cars and offices are probably filled with electronic gadgets that operate in the realm of the micro – quantum physics (which you probably weren’t taught in high school). You’d think that there should be a smooth and continuous transition from the macro/classical to the micro/quantum, and vice versa, as you go up or down the scale of size. However, I’m hard pressed to think of an example in reality where both quantum and classical physical concepts or laws have to be integrated in order to explain or predict something. Again, it’s like there are two different sets of software running the cosmos!

That said, the reality of matter and energy in our macro day-to-day existence, while obvious, depends on the reality of the bits and pieces that make up the realm of the micro. So, molecules had better be real, and atoms and the particles that make them up – things like quarks and electrons and neutrinos. Thus, it’s disturbing to read in various books on particle and quantum physics that these are treated as point (dimensionless) particles. Presumably this is to make the mathematics easier or simpler (and just pick up an academic text in these subjects, open to a random page, and see what I mean). Clearly a dimensionless particle can not have reality as particles have mass. That implies of necessity that the particles must have size – a volume. If you gather up an infinite number of dimensionless particles, you could fit them into zero volume. Since macro bits and pieces have volume – you have a volume – you can not be ultimately comprised of dimensionless micro bits!

Further, we have all these high energy ‘atom smashers’ (particle accelerators) where the objective is to smash one particle into another at higher and higher energies and see what happens. If the particles, usually electrons or protons, had zero volume, they couldn’t collide! Despite phrases like ‘point particles’, particles really have three dimensions (volume), and thus objects around you, including you, have volume. Particles have reality, and so do you. And because mass and energy are interchangeable, energy has reality. If you doubt that, put your hand on a hot stove!

In addition, the very fact that we experience variety in matter tells us that there must be more than one kind of matter. If there were only one kind of stuff – say electrons and only electrons – then everything we experience would be just that stuff; only that stuff; that stuff alone. No variety – it’s all things electron! That’s clearly not the case, so there’s more to matter than just, say, electrons!

The Reality of Nothing: Time & Space: 

Go into a dark, quiet room with no sensory distractions. You know that time is passing all around you, yet you can’t detect this time with any of your five senses. You can’t see time; hear time; smell time; taste time; or touch time. To detect time, you need some intermediary mechanism – look at your watch; listen to the ticking of a clock; feel your pulse. Translated, to detect time (and by the way ditto space), you need matter/energy which time as some effect on. Put another way, if matter/energy did not exist, the concept of time would be meaningless. (Ditto space – in the absence of matter/energy you couldn’t detect space with your five senses. There’d be nothing to see, hear, taste, touch or smell.)

Space has no meaning unless there is something inside it, and/or outside it, to give it some boundary and hence reality. If there’s no matter/energy, there’s no need of any space for it to reside in. So, time and space aren’t real without matter and energy. Only matter and energy have reality.

Since time and space are meaningless concepts without matter and energy, its nonsense to talk about creating time and space. You’d automatically create time and space if you could create matter/energy. Alas, the conservation laws of physics state that matter and energy can neither be created nor destroyed only changed in form. Presumably nothing can create matter/energy – certainly no human being has ever done it – and since I reject the concept of a supernatural creator being (God), I’m forced to conclude that matter and energy, therefore space and time, have always existed and will always exist. [Eliminating a creator God from consideration simplifies things no end.]

Your Pet’s Reality:

I’ll assume that as your pet (assuming you have one or more), or some other animal you have had a relationship with or observed closely, can’t speak for itself or themselves, and as you’re totally familiar with your pet’s personality, that you’re a good spokesperson for them – as good as it’s going to get anyway.  So, if you were your pet (bird, fish, cat, whatever) how would your perception or knowledge of reality shift – if it does.

Firstly there’s a near universal reality for all higher life forms – including humans. That universality is expressed in the phrase “empty what’s full; fill what’s empty; scratch where it itches”!

Humour aside let’s start with the initial gateways – the senses.  We’re all aware that our sensory apparatus can and has been exceeded by some animals – including common household pets. Not only is vision more acute in some animals, but extends further into the ultraviolet and/or infrared than ours. Hearing is keener; sense of smell is sharper; pressure gradients more noticeable, etc. Be all that as it may, I can’t see that altering basic perceptions of reality in any significant way.

Ditto for physical abilities - birds gotta fly; fish gotta swim; horses gotta run. Again, there’s nothing significantly different in principle here. The fact that a horse can run faster than you doesn’t give the horse a whole different perspective or outlook on the world. 

Yet, on our home world, there is a life form, with a most alien of realities, at least relative to us or from our perspective. The most alien of realities, from our point of view, must be experienced by that of a fish, even a pet goldfish. Consider, we live for all practical purposes in a two dimensional world – the surface of our planet. Fish live in a three dimensional world. They, for all practical purposes, experience no weather or climate. There’s not much temperature variation. They, depending on species and depth, may never experience a day-night cycle, rather live all the time in absolute darkness. They don’t experience gravity per say as the water and swim bladders produce neutral buoyancy.  From our point of view, I guess, their reality is not only quite different, but certainly more boring – although boring is a rather emotive term. The fish may not have any comprehension of what boring is.  So, having a conversation with a fish (a thought experiment obviously) might be about the closest one could come to terms with a substantial alternative reality. Except the absolutes, the basics are still there – survival, food, sex, etc.

Reality is ultimately perceived and processed by our brains, and our companion animals have brains, just as we do. Animals have a “The You” component to them. Pets clearly can think, make (to them anyway) intelligent decisions; they can and do dream. They have emotions. They can learn; they have memories. They have a world view.

Yet, I’m sure that 99.9% of the time your pets and mine have absolutely no comprehension of what you are doing or why. They may like warmth, but have no idea of what thermodynamics is. They like sex but the purpose and genetics of it all is beyond them. They like food but have no comprehension of agriculture and manufacturing and transport and distribution and money and shopping and all those bits and pieces that put doggie food in the doggie bowl. Yet your activities, warmth, sex, food is of course part of their reality, although not part of their understanding.

Now our companion animals are fairly closely related species to us. Felines, of which I have two, have a worldview. However, their worldview, concerns, philosophy, science, etc. revolves around whether there’s food in their food bowl; do they have a clean litter box to access; am I around when required to open doors for them and where are the mice hiding! I often envy their relatively uncomplicated lives. No pondering the great issues like looking at a star and wondering if an alien cat is looking back in this direction; no comprehension of taxes or money so-called compulsory voting or politics.

Four billions of years of evolution (assuming an origin of life within 500 million years of Earth’s origin) made no demands or requirements for living things to comprehend abstract things like philosophy or science (like cosmology or quantum mechanics) or mathematics, not to mention politics and economics. The sum total of our (meaning life, not just humans) concerns, over those four billion years, our worldview, or our reality, centered on food, shelter, sex and just plain survival. That’s also true for the hundreds of thousands of years, all through human evolution, into what we’ve become now. And that’s true today. I’m sure 99.9% of good folks (meaning humans) today pay near zero attention to these abstract non-essentials in their day-to-day existence. It’s bad enough that our lives have been enhanced by the abstractions of government and taxes and bills and nine-to-five jobs (or lack thereof).

So herein lays my fundamental question. If our companion animals can’t come to terms with the Big Picture, ultimate reality, relative to us, but we ourselves are only just that little bit further along in evolutionary (brain-related) advancement (call that advanced IQ or whatever) relative to them, then, what makes you think that the entire vista of reality is comprehensible to you? I sometimes wonder if we’re yet fully biologically or mentally equipped to ponder the great abstracts – comprehend the fullness of reality, not just the few bits and pieces that we have come to terms with and think as being the near be all and end all of what’s real. Perhaps our worldview of these things are not only limited, but of necessity will be limited. Translated, perhaps further eons yet worth of brain development might be necessary to fully comprehend our reality; what we comprehend currently might be, relatively speaking, just a tiny bit in advance of what our animal friends comprehend! There’s a long, long, road to hoe. 

To be continued…