[Harri (OP)]

I read that most of an atom is 'empty space'. Is it true to say that this same empty space is the space that pervades throughout outer space and the universe?

[alancalverd]

Yes. Nothing is nothing, anywhere and everywhere. There is a higher probability of finding a nucleus or an electron close to the center of an atom than outside it, but what isn't there, isn't there. At least that is the "orbiting particle" model of an atom.

The alternative and more useful model is to consider the orbital probability function of an electron rather than the particle itself as being "real", so at any point within the classical radius of an atom you will find the "smell" of an electron, with no truly empty space.
 

[Harri (OP)]

Is this nothing, nothing with potential to produce something? Big bang? things popping in, things popping out of existence? Is there something behind this nothing?

[alancalverd]

There's no evidence, just the appearance of the remnant of what might once have been a big bang, but no reason to suspect it came from nothing.

[Halc]

Is it true to say that this same empty space is the space that pervades throughout outer space and the universe?

The same thing, yes.
'Space' as it is being used here is just a set of locations, each of which can be specified as a set of coordinates and separated by meters or whatever unit pleases you.

What constitutes that space being 'empty' or not is perhaps what you are getting at with your question. Is a meter of 'outer space' really empty?  Probably not since any sensor put out there would immediately detect all sorts of radiation and such in all directions, which means the space is chock full of interesting things.  Same with the atom I think, where even at the quantum level, it becomes 'what are the probability of measuring something at location x,y,z', which isn't a very different question than the one we asked in outer space.

On a different note, it seems that no fundamental particle has ever been described with a volume of space that it occupies, and thus it gets kind of meaningless to ponder what percentage of an atom is 'empty' or not.

[alancalverd]

space is chock full of interesting things

Not quite chock full, surely? If time is "what prevents everything happening at once", then space is "what prevents everything being in one lump".

[charles1948]

Yes. Nothing is nothing, anywhere and everywhere. There is a higher probability of finding a nucleus or an electron close to the center of an atom than outside it, but what isn't there, isn't there. At least that is the "orbiting particle" model of an atom.

The alternative and more useful model is to consider the orbital probability function of an electron rather than the particle itself as being "real", so at any point within the classical radius of an atom you will find the "smell" of an electron, with no truly empty space.

You refer to the "smell" of an electron.  That sounds evocative, and poetic. But does it work in the real world.

I mean, the computers that we're using to communicate with each other, don't use vague "smelly"  smeared out blobs of electric charge.

They use precise electrons.  And these clear-cut particles of electric-charge, are the entire basis of our modern digital technology.. Would digital technology even work, if electrons were smeared-out blobs.

So ,do you need to reconsider your position?

[Kryptid]

Would digital technology even work, if electrons were smeared-out blobs.

Yeah, it would work just fine. The imprecision in their location and momentum is not so large as to render those technologies inoperative.

[Halc]

Would digital technology even work, if electrons were smeared-out blobs.

Yeah, it would work just fine. The imprecision in their location and momentum is not so large as to render those technologies inoperative.

Digital technology and brain cells both actually rely on the imprecision in their location, hence both technologies would be rendered inoperative if electrons had classic location and momentum. Both (transistors and cells) utilize quantum tunneling to send signals across barriers otherwise insurmountable by the voltages employed.

[charles1948]

Would digital technology even work, if electrons were smeared-out blobs.

Yeah, it would work just fine. The imprecision in their location and momentum is not so large as to render those technologies inoperative.

Digital technology and brain cells both actually rely on the imprecision in their location, hence both technologies would be rendered inoperative if electrons had classic location and momentum. Both (transistors and cells) utilize quantum tunneling to send signals across barriers otherwise insurmountable by the voltages employed.

Thanks Halc, I've often thought that the enormous processing power of the human brain,  can't possibly be explained in terms of the crude on/off transistor switches that we employ in  our digital computers. 

You rightly point out that even these switches, depend to some extent on quantum effects, such as tunnelling,

But these effects are constrained by the vey simple nature of the transistors. Which are basically made of silicon, and not much else.

Whereas our brains are built of organic molecules which far exceed transistors in atomic, and chemical complexity.

This complexity may generate quantum operations on a very large scale.  And explain why our brains operate so astonishingly well..

[Bored chemist]

Thanks Halc, I've often thought that the enormous processing power of the human brain,  can't possibly be explained in terms of the crude on/off transistor switches that we employ in  our digital computers. 

You rightly point out that even these switches, depend to some extent on quantum effects, such as tunnelling,

But these effects are constrained by the vey simple nature of the transistors. Which are basically made of silicon, and not much else.

Whereas our brains are built of organic molecules which far exceed transistors in atomic, and chemical complexity.

This complexity may generate quantum operations on a very large scale.  And explain why our brains operate so astonishingly well..

Could that be summed up as you don't understand the brain and you don't understand QM, so you assume that one explains the other?

[Halc]

Thanks Halc, I've often thought that the enormous processing power of the human brain,  can't possibly be explained in terms of the crude on/off transistor switches that we employ in  our digital computers.

Neurons are effectively on/off switches of a biochemical sort. They fire or they don't.
A brain has 100 billion cells running at about 20 watts, and the largest CPU might have a sixth that many transistors running at a similar wattage, so brains are still more energy efficient.  The area of the chip is about 1/300th that of the brain, so the chip wins in terms of density.  It would probably take hundreds of transistors to simulate what a brain cell does, and hundreds of brain cells to simulate what a transistor does, so that just shows that a direct comparison isn't particularly meaningful.

But these effects are constrained by the vey simple nature of the transistors. Which are basically made of silicon, and not much else.

Nerve cells are more complex mostly because they have an additional task of staying alive. They're biochemical transistors of a sort which get their energy from combustion of chemicals instead of from the electrical currents.

Whereas our brains are built of organic molecules which far exceed transistors in atomic, and chemical complexity.

That's not a good thing. A simple thing doing a task is more desirable than a complex method of achieving the task.

This complexity may generate quantum operations on a very large scale.

The quantum effects enable the complex behavior, not the other way around.  A super-simple creature or transistor device (say jellyfish or transistor radio) still utilize quantum effects for their operation, but are in no way particularly complex. Complexity comes from scaling up the simple effects that quantum behavior enables.

[Petrochemicals]

Is it true to say that this same empty space is the space that pervades throughout outer space and the universe?

The same thing, yes.
'Space' as it is being used here is just a set of locations, each of which can be specified as a set of coordinates and separated by meters or whatever unit pleases you.

Is it space as in space time, limited by c, or is it the stuff of black holes and subspace?  I have read that a nuclear fission reaction is faster than C but is excused the limitation due to it being outside the normal bounds of space.

[Kryptid]

I have read that a nuclear fission reaction is faster than C but is excused the limitation due to it being outside the normal bounds of space.

That's only somewhat true. The Cherenkov radiation produced by the reactor (the blue glow) is caused by charged particles travelling through the surrounding water faster than the local speed of light. The speed of light in water is slower than it is in a vacuum. Those particles are still moving slower than light in a vacuum.