If we first assume the universe started with a Big Bang, then there should have been a shock-wave extending out from the center. Science tells us that the shock-wave could not move faster than the speed of light. Did it? — Don Wade

I think the shock wave you are talking about is space. As for travelling faster than the speed of light - the universe is about 14 billion years old while the diameter of the universe is about 90 billion light years. It is generally explained that movement associated with expansion of space doesn't count in the light speed calculation. I've never gotten that, but who am I to argue with Einstein?

Based on Earth physics? We assume everything works on Earth the way it does elsewhere. It makes sense that it would. But so did lots of things that never came to fruition.

there should have been a shock-wave extending out from the center. — Don Wade

Shock waves require a medium - pretty much any and every wave requires a medium.

I think the shock wave you are talking about is space. — T Clark

Voila!

I think the shock wave you are talking about is space. — T Clark

If it was space before the big bang, and space after the big bang - then what changed? Plus, light still only travels at a defined velocity in space. Then did light travel faster before the big bang?

Shock waves require a medium - pretty much any and every wave requires a medium. — tim wood

Not electromagnetic radiation.

If it was space before the big bang, and space after the big bang - then what changed? Plus, light still only travels at a defined velocity in space. Then did light travel faster before the big bang? — Don Wade

There was no space before the big bang. As for the speed of light, I already explained as much as I know. And there was no light before the big bang.

I could live with that. It reminds me of a hypothesis I have:

When I go out on a moonless night and look up into a star-studded blackness, I intuitively know there is a metric shit-ton of light headed my way that I cannot yet see. It’s not that this light has yet to be generated. No, it was generated all right. It just hasn’t got here yet, unlike all the light that I do see, itself having left its star-point of origin so many lightyears ago.

It’s also not that it is the light to arrive shortly, from the same source as, but trailing behind the light arriving now, from a star or whatever. No, the unseen light was already generated from another source (Big Bang?) than what I can see, and its on its way but not yet visible. All the visible light (stars, etc.) are just out front, like us.

Now bear with me here. Scientists have told me that energy and matter can change, one into the other. But these scientists always leave time laying over here to the side, as if it could not likewise convert into energy or matter. But I thought, what if it could?

In that case, I think this light that I cannot see, but which I feel is headed my way, is actually the future (time) in the form of Dark Energy.

I also intuitively know there is a metric shit-ton of matter flying away from me so fast that I can’t see it. It does not and cannot reflect light back to me. I think this matter is the past (time). I think it is Dark Matter.

I also think that maybe this Dark Energy (the future), is not necessarily so far away that I can’t see it yet, but that maybe Dark Energy is, at least in part, blocked from my view from the fleeing past. Maybe Dark matter gets in the way.

But where I am in the here-and-now is the conversion point, where the future arrives and converts into the past, going from Dark Energy to Dark Matter.

To the extent physicists have calculated the amount of Dark Matter in the universe, as a percentage of the whole, maybe Dark Energy, or the future, accounts for the balance of the whole. Maybe we can thus determine the amount of time, or future we have left.

Sometimes it helps my thinking to consider particles. I like the idea of particles. While they don’t, in and of themselves, preclude the possibility of strings or waves, they work well as a tool in this idea of mine.

Where matter and energy can convert, one into the other, so too time and space can be tossed in the mix and likewise convert. The future can become energy, and matter, and now, and the past. Likewise, the past can become energy, and matter, and now, and the past.

So, a star that casts off its own light, say a photon, is looking at the backside of its own photon. It can't see it go, but go it does. If that star could some how run around and get in front of its cast-off photon and look back and see it coming, it would be seeing its own past. But if it got so far in front of its own cast-off photon that the photon was not yet visible, it would be, like us, not seeing the future before it got here.

Now, lets say that photon from that star were headed toward a near miss with the Earth, and I stepped out behind it to watch it whip by, I would see coming but not going. The back side of a photon is invisible. It’s the past that might be remembered but cannot be seen. The front side of that photon is only visible when it gets here, but until then it is invisible. It is the future.

I was a Recon Team Leader in the Marine Corps and sometimes we'd blow shit up. I'd take a brick of C-4 and roll and warm it in my hands until it was a ball. I'd stick a blasting cap in it, attach a fuse and set it off. It made a big bang. I'd imagine (and sometimes I could see) a shock wave. I'd figure there was some aspects of that C-4 on the outside of the ball that would precede the aspects from the center to follow. I knew that the outside stuff would not exceed the speed of the blast, and it would indeed start to slow in advance of the inside stuff. But it was nevertheless out front and the inside stuff had to catch up.

I'm thinking if you had a singularity on it's way to Heat Death, then maybe parts of it are waiting for the other parts to catch up. And when it does! Talk about light! In sum, I think we are all in a singularity, in Heat Death, and everywhere in between, all at the same time, past, present and future. But All is perceiving all aspects of itself. However, those aspects (like us) are regulated to providing our own perspective. So, while we are all together in a singularity, there must be space for all us aspects to perceive in. So we perceive we have space to perceive in. And we do. But from the perspective of All, it's All one; i.e. a singularity. Dark Energy and Dark Matter (the future and the past) hide the singularity from us, creating the perception of space to perceive in.

The idea that the speed of light is some final arbiter of this or that seems rather limiting to me.

Not electromagnetic radiation. — T Clark

Yes. It occurred to me that maybe wave/particle duality covers that. A particle where there is not a medium, a wave in media.

Yeah, so the OP posits a shock wave and asked a question about it, but does not tell us what the shock wave might be.

The thread then proceeds by choosing various instances of shock waves and discussing how the question might be answered for each.

Then we have the problem that arrises from pop physics books that are for the most part written without the mathematical structure that underpins physics. Some readers think that is all there is to physics, that it's just conjecture, and so they throw in stuff such as that time might be converted to mass without any background theorising.

In both scenarios we have bits that work and bits that are junk. Such threads serve as bad examples of philosophical thinking, and worse examples of physics.

But the thread will run for a page or two as folk compare their misinterpretations.

I'll stop throwing ideas on the wall when "your people" quit talking about all the walls they are running into. Discuss among yourselves.

Hello, James.

The trouble with physics and philosophy is that they are quite difficult. It looks easy, but one keeps finding out that one has gone astray. It looks lie folk are just making shit up - and indeed, some are; but the critique... there's the thing. If one comes here, one will be criticised.

Bringing this back to your post, Einstein didn't just guess that energy could be turned into mass, and vice versa; it wasn't quite just shit he made up. He derived it with the calculations he found after positing that the laws of physics should be the same for all frames of reference.

It followed, mathematically, from that assumption.

Can you provide something similar for you conjecture that mass can turn into time? How do we measure mass in seconds? Weeks in kilograms?

If this bursts your bubble, then welcome to philosophy.

I'm not complaining, so it certainly wasn't my bubble that was burst. In fact, your failure to address the sophomoric shit on the wall with a dumbed-down response on the merits that simple folks can understand leads me to believe you said too much. It must be frustrating for you to be in this arena with the likes of me. I'm surprised you're not back in a lab somewhere doing real work.

I'm new to this board, but I've been fooling around with philosophy for 45 + years. I don't get paid for it but I don't find that relevant (see my definition of philosophy in the recent thread on that point). I also find that philosophy has it's own wall(s). See the recent thread on self-evidence. I begged for help from the smart people, but crickets.

Then I hear physicists struggling with their own walls (dark matter, dark energy, spooky action at a distance, etc.). In fact, one of those walls seems to run counter to the fundamental, underlying principles of logic (a branch of philosophy?). How can this be here and there at the same time? Hmmm. I guess I better break out the calculator that doesn't seem to be working.

I hear about these physics walls in public, and not "pop physics books." I make up my own shit.

Finally, I don't derive anything, because I am not Einstein, a physicist, a mathematician, or anything close. Thus, I cannot provide you with something similar for my conjecture. I can, however, provide you with conjecture. If you can't make anything out of it, or explain it to a lay person, I'm sorry. Welcome to philosophy.

I replied to your other thread.

But I have to ask, what were you expecting in response to a post on a philosophy forum? Of course it was going to meet criticism.

It's what we do.

Same is in the other thread, I was expecting something to do with the merits of why my idea is wrong.

That's what you got. Perhaps you didn't recognise it.

Probably not. You really have to dumb things down for me.

OK. Try this:

You're dreaming. A reverie such as this is not physics. Same goes for .

You're not very good at this. You should probably stick with the smart people and leave us monkeys to throw shit on the wall. (P.S. What was Einstein's position on dreams and reverie? Just curious.)

You're not very good at this. — James Riley

Thank you, I've been doing it longer than you, so perhaps you will be able to achieve better results in a few years.

ad verecundiam? Or something similar having to do with time?

Are you admitting that time converts to matter? HAHAHAHA. Sorry.

No, what I meant was, your ability to dumb things down for us simple people is wanting. Either you don't know what "the merits" means, or you are just avoiding the schooling of me on Dark Matter, Dark Energy, or, in harkening back to the other thread, self-evidence.

Nothing can move through space faster than light, but new space being created does not count as things moving through space. During the inflationary epoch, new space was added between all the things in the universe at a rate that made them much farther away from each other in much less time than it would take light to travel that same distance. But nothing actually moved through that space faster than light.

If eternal inflation is true, then that inflationary epoch is the normal state of the universe, which is consequently MUCH much bigger and older than the part of it we’re familiar with. The universe as we know it is just a temporary little blip in that enormously larger universe, a tiny part that very briefly slowed down at random, dumping some of that enormous inflationary energy into all the other fields that the universe as we know it is made of. And over time, this part of the greater universe is gradually speeding back up and dissolving back into the rest of it, which has still been expanding at breakneck speed this whole while.

During the inflationary epoch, new space was added between all the things in the universe at a rate that made them much farther away from each other in much less time than it would take light to travel that same distance. — Pfhorrest

If two things are moving at whatever speed, or not moving at all, but space is added between them at a speed faster than light, are not those two things being separated from each other at a speed faster than light? If the "space speed" is not part of "thing speed" simply because space is adding, and the things aren't contributing, is there a distinction with a relevant difference? Aren't those two things moving apart faster than the speed of light, if only by the addition of space? Thanks.

is there a distinction with a relevant difference? — James Riley

Yep. For instance, if space is expanding at a steady rate (say doubling in size every unit of time), the two objects will get farther and farther away from each other at an "accelerating" rate, but neither will experience any acceleration: both will feel like they're coasting in an inertial reference frame, and actually if you tied them together such that they had to stay the same distance apart despite the expansion of space, then they would experience an acceleration (it would feel like there was antigravity pushing away from their common center, because they're basically being accelerated toward each other, but despite that are remaining the same distance apart).

Aren't those two things moving apart faster than the speed of light, if only by the addition of space? — James Riley

Yes, but that doesn't violate the laws of relativity, because those laws are only about things moving through space, not about space expanding.

We can see this in practice just looking out into space: farther away things are receding away from us faster than closer things, because space is still accelerating and a multiple of a long distance is much bigger than the same multiple of a small distance, and far-enough-away things are therefore receding so fast that light from them will never reach us (because it's not fast enough to cover more space than is being created in the time it takes to cover that), and that threshold is the edge of the observable universe.

I get that conceptually, but it seems in all those examples we are concerning ourselves with how the situation is perceived, or experienced, by the objects (or someone residing on the objects) as opposed to being an outside observer. As you say, it would not violate the laws of relativity, but if the experience was observed as we are doing in this discussion, conceptually, then that relative position would see two objects moving away from each other faster than the speed of light?

Another question: If everything is flying away from everything else (or, if space is growing between), isn't the relative experience of any one of those things that of stasis? What direction could one be going from anything without going toward something? To have space grow between, wouldn't it have to be still? and everything was flying away (as in space was growing between). Now this is going to probably sound stupid, but if, in your example of looking into space, aren't we seeing the same thing if we run around to the other side of the planet and look in that different direction into space? Or from any point on Earth into space? I guess what I getting at here is this: can we or are with between two different things with space growing between us and them in opposite directions? If there are no directions, wouldn't that make us the center of the universe?

I'm going to hit the rack now, and I'll check in tomorrow, but I appreciate your taking the time to address the merits.

Such threads serve as bad examples of philosophical thinking, and worse examples of physics.

But the thread will run for a page or two as folk compare their misinterpretations. — Banno

Unfortunately true. :sweat:

:up:

Nothing can move through space faster than light, but new space being created does not count as things moving through space. During the inflationary epoch, new space was added between all the things in the universe at a rate that made them much farther away from each other in much less time than it would take light to travel that same distance. But nothing actually moved through that space faster than light.

If eternal inflation is true, then that inflationary epoch is the normal state of the universe, which is consequently MUCH much bigger and older than the part of it we’re familiar with. The universe as we know it is just a temporary little blip in that enormously larger universe, a tiny part that very briefly slowed down at random, dumping some of that enormous inflationary energy into all the other fields that the universe as we know it is made of. And over time, this part of the greater universe is gradually speeding back up and dissolving back into the rest of it, which has still been expanding at breakneck speed this whole while. — Pfhorrest

:100: :clap:

was observed as we are doing in this discussion, conceptually, then that relative position would see two objects moving away from each other faster than the speed of light? — James Riley

In a sense, yes.

Another question: If everything is flying away from everything else (or, if space is growing between), isn't the relative experience of any one of those things that of stasis? What direction could one be going from anything without going toward something? To have space grow between, wouldn't it have to be still? and everything was flying away (as in space was growing between). Now this is going to probably sound stupid, but if, in your example of looking into space, aren't we seeing the same thing if we run around to the other side of the planet and look in that different direction into space? Or from any point on Earth into space? I guess what I getting at here is this: can we or are with between two different things with space growing between us and them in opposite directions? If there are no directions, wouldn't that make us the center of the universe? — James Riley

Everything in space would observe itself as seeming to be at rest and at the center of the expanding universe; so yes, we do too, but not because of anything special about us.

space is added between them — James Riley

Space isn't added between galaxies. All of space is expanding so the fabric of space between galaxies is stretching. The analogy generally used is to an inflating balloon. Two marks put on the balloon with a marker will move apart just because of the expansion of the balloon. Of course, space is a three dimensional compared to the two dimensional surface of the balloon. Or is it four dimensional?

The confusion which so often results when one means to examine the expansion of the metric of space is because we conflate this, or otherwise treat it as equivalent with objects moving within its boundary at an ever broadening distance from each other, notwithstanding that such an effect is coincident as well, rather than something more intrinsic to the space itself. Which is to say, that while there exists most clearly, and as has been well-established by the available evidence, a fundamental limit to the relative pace with which any object can move, so far as it possesses a definite mass, and indeed, even for those objects which are regarded as massless, and with the required energy-expenditure needed to maintain its movement at such a pace increasing to infinity asymptotically as it begins to reach this limit; when one considers instead the shift in the so-called metric of space, with this latter concept allowing us to define ideas of physical distance at all, then from an observer sitting idle at a fixed point relative to some other point occupied so far off as to make the scales at which this expansion occurs, apply, it will seem as though a superluminal velocity is attained. Such structures however, are said to thus fall outside the observer's light-cone, because the photonic-information which is encompassing of that part of space subject to expansion cannot reach the observer by virtue of its inability to overtake how far the associated point-source has receded from the observer's own line of view, in that its image is forever confined to the immediate wake of expansion. This is the reason for why, at least for those with a formal interest in the study of stellar dynamics, we speak only of those regions of the universe which are "observable", as even under the assumption that a telescope of infinite size and complexity could be constructed, because the very notion of distance on these scales is expanded upon so continuously, what may be sighted are only remnants of that which took place in the past, and even then, the photonic-signatures, or imagery, corresponding to a particular such event may require a greater period than the universe will ever exist for, to have even a chance of reaching our position so as to thereby preclude their reaching us outright. That these effects aren't dominant on a more local scale is in consequence of the force of gravitational attraction, which keeps those masses that are in fair proximity to each other tightly bound enough to minimize their respective recession; that empty-space is in contrast, much more prevalent on the supra-galactic scale is why expansion becomes so prominent, herein, and as compared to those scales which are locally based.

Space isn't added between galaxies. All of space is expanding so the fabric of space between galaxies is stretching. — T Clark

He didn't say specifically between galaxies. New space is being added everywhere. That's what it is for the fabric of spaced to get stretched: a length of space gets transformed into a greater length of space. There is now more space, so space was added.

You could quibble that it's really more like it's multiplied, but when you multiply positives the result is always the same as adding something would be. In any case, the amount of space -- everywhere, and so also between any two things -- is increased.

As I noted in my earlier argument, the effect of its expansion dominates at the scale of so-called cosmic filaments, which are some of the largest known structures in the universe and generally fall within the range of several dozen, to perhaps even a hundred megaparsecs in length. These structures consist of many unique superclusters, which themselves consist of tens to as many as thousands depending upon how one characterizes them, of unique galaxies in close proximity to each other, and as being gravitationally bound. This indicates, that the scale at which expansion of the metric of space dominates is nearly three orders of magnitude greater than what has thence been suggested.