Meaning in any case that you know of examples where matter moves faster than c. What is such an example?

According to you to, relativity doesn't work? — tim wood

Within the universe there is a wide range of existents, from very large to very small. Relativity works in the middle area.

I understand - or I grant the claim - that relativity likely breaks down at the quantum level. But at what large-scale does it break down?

So far this discussion, for the topic of which I claim no special knowledge, appears to be people telling everyone they have discovered that bumblebees cannot fly.

But at what large-scale does it break down? — tim wood

The scale of galaxies, where what is called spatial expansion has an impact, with the requirement for dark energy, dark matter, etc..

"Einstein Was Right! Scientists Confirm General Relativity Works With Distant Galaxy"
https://www.space.com/40958-einstein-general-relativity-test-distant-galaxy.html

I'm not arguing relativity itself. Instead I am arguing that some people are fools. They have an opportunity to demonstrate they are not fools - that they are right! So far they prefer to be just fools.

Right, so long as we posit the real existence of those unobservables, dark energy and dark matter, to account for the discrepancies between what is observed and what relativity theory predicts, relativity works just fine.

The OP is about the speed of light, c. The theory says that matter can't go faster. Folks on this thread are dismissive of theory, but are coy about the how and why. If c is no longer the upper bound of velocities, it must be because some bit of matter goes or is going faster. What matter? Where, when, and how measured? Asking for the substance behind claims is fair practice. Refusal of substantive reply is the track of the intellectual infant - worse, actually, because it is not mere error.

I think Gary explained it to you quite well. If I understood correctly, what he said was that for the (material) parts of the universe to get to where they are right now, from the big bang, they must have traveled faster than the speed of light. I did not check his math, but I think this is what he was saying anyway. Does it not make sense to you?

1 - the size of the universe, which on current estimates is more than 98bn light years across - and therefore more than 4 times the widest spread that could be achieved by an exploding singularity at the speed of light. — Gary Enfield

they must have traveled faster than the speed of light. — Metaphysician Undercover

Must have? Is that what you think too?

Try this video (3rd time referenced):

www.youtube.com/watch?v=vIJTwYOZrGU — tim wood

Keep in mind he has dismissed without any consideration all of the science involved. They must be wrong and he must be correct. On what authority? He says so! That's not science, instead it's colossal stupidity. He has not discovered anything or developed anything or demonstrated anything. He has stumbled across what has been well-known for a long time, does not understand it, and commits that greatest of fallacies, "Because I do not know, therefore I know!"

edit: and this one:
https://www.youtube.com/watch?v=dr6nNvw55C4

and this one:
https://www.youtube.com/watch?v=u23vZsJbrjE

Ah.

I see.

I really don't see why faster than light possibilities are such a feared thing to consider. — Gary Enfield

Well, apart from the laws of physics becoming inconsistent... yeah, what are folk worried about.

Sorry tim, but your references don't seem to address the issue, and I see no basis for your accusation of "colossal stupidity". But It's not my argument, so I'll leave it at that.

And when I look out my window, the earth seems flat. So it must be flat, yes?

Sorry, I don't see the relevance, but you can make that conclusion if you want, I will not.

As I've understood it, the idea that because the "universe" is about 14 billion year old and is about 90+ billion light years across, it must be that a lot of things are and have been moving faster than the speed of light. And this offered as a conclusion with no other evidence or development. A review of the videos will persuade anyone that the whole matter is just plain not that simple. For example, what exactly is the speed of light? What does it mean? How and by whom measured, under what circumstances and contexts. And what does "the size of the universe" mean? The answers to these matter, and without considering them, comments have no intrinsic sense or meaning, whether they sound good or not. Just like my claiming the world is obviously flat and everyone who says otherwise is wrong, because of what I see out my window. .

A review of the videos will persuade anyone that the whole matter is just plain not that simple. For example, what exactly is the speed of light? What does it mean? How and by whom measured, under what circumstances and contexts. — tim wood

I think that's exactly the point of the op, designating "the speed of light" as a constant has been proven to be a mistake.

And what do you suppose the mistake is, exactly. For example, the "speed of light" is no constant at all, as expressed it's akin to saying the "speed of the car." In itself, without meaning. And light travels at different speeds through different media. But what we all mean by c as the speed of light is its maximum speed. Now, is that what you hold to be in error? That light has a maximum speed?

As I said, it's not my argument, so those questions I'll ignore. I was just pointing out some issues I had with what you were saying. Those questions you propose are irrelevant to the points I made.

Lol! Issues indeed! I see I have under-appreciated your gift for understatement!

Well, apart from the laws of physics becoming inconsistent... yeah, what are folk worried about. — Banno

Hi Banno

I don't think there are inconsistencies..
The Laws concerning movement won't be affected by the possibility that travel faster than light is possible.

In practical terms, the only things that would be affected in our Earth-bound circumstances are the potential amounts of energy being released in a nuclear explosion - because it is only when you get to those levels that we get to anything near the factors that the speed of light would affect.

Given that the energy from even detonated nuclear explosions, (which we have tried to measure as verification of estimates), can themselves only be estimated by their effects, the potential reality exposed by the size and age of the universe will have no practical impact on the application of our current descriptive laws.

I think Gary explained it to you quite well. If I understood correctly, what he said was that for the (material) parts of the universe to get to where they are right now, from the big bang, they must have traveled faster than the speed of light. I did not check his math, but I think this is what he was saying anyway. Does it not make sense to you? — Metaphysician Undercover

Thanks for that "MU".
The maths is quite simple....

The age of the universe is now agreed at approx 13.7 billion years.
An explosion at the speed of light would travel outwards 13.7 billion light years in that time.
However that is only a radius, so that distance has to be doubled for the diameter.
So 27.4 billion light years should therefore be the maximum diameter but scientists/cosmologists agree that the universe is at least 96billion light years across.

Hope that helps.

Maybe. Seems far more likely that you haven't quite grasped relativistic physics.

The assumption is that he laws of physics are the same for every observer - that they are consistent. But the speed of light can be derived from Maxwell's equations. Hence the speed of light must be the same for every observer.

The equations of relativity explain how this can be accounted for in a consistent fashion. Those equations also show that no mass can travel faster than the speed of light.

Hence if something were to travel faster than light, the laws of physics could not be the same for every observer.

They would be inconsistent.

Hi Banno

An interesting reply - thank you.

As I understand it, Maxwell's equations only demonstrate how we consistently perceive light.
The size of the universe is a measurement within our perception.

Those equations also show that no mass can travel faster than the speed of light. — Banno

They only do this I believe because they assume a fixed c. That is not proof - it simply says that there might not be anything that could push faster.

However, what is to say that the special circumstances of the Big Bang wouldn't create a faster push?

Maxwell's equations only demonstrate how we consistently perceive light. — Gary Enfield

They are correct for any observer.

They only do this I believe because they assume a fixed c. — Gary Enfield

The laws of physics dictate the speed of light. Hence, if the laws of physics are the same for all observers, then the speed of light must be the same for all observers.

Seems far more likely that you haven't quite grasped relativistic physics. — Banno

What is the case is that separation caused by spatial expansion, is not considered to be properly called spatial "motion". Very large objects like galaxies get further apart without actually moving at all, because spatial expansion does not qualify as "motion". Since this activity of separating from each other, due to spatial expansion, is not a form of "motion", material things can separate at rates which are much faster than the speed of light, without violating principles of relativity, because within the confines of that theoretical structure, this does not qualify as "motion".

You ought to be able to see, that in the effort to maintain general relativity as the applicable theory for motions in the universe, we have now developed a whole new category of motion which does not qualify as "motion", because "motion" is defined by that theory. In other words, if we want all the types of motion which we have observational evidence for in the universe, to be measurable within one consistent theory of motion, we need a different theory. General relativity does not allow that this type of motion which is the result of spatial expansion is "motion".

The age of the universe is now agreed at approx 13.7 billion years.
An explosion at the speed of light would travel outwards 13.7 billion light years in that time.
However that is only a radius, so that distance has to be doubled for the diameter.
So 27.4 billion light years should therefore be the maximum diameter but scientists/cosmologists agree that the universe is at least 96billion light years across. — Gary Enfield

1) Static universe. The light we see from the oldest object we see is about 13.7 Bn years old . How far away was it when the light we see now was emitted? Ans., 13.7 Bn LYs. How far away is it now? 13.7 Bn LYs.

2) Expanding universe. Ditto. How far away was it then? A lot closer. How far away is it now? Wa-ay more than 13.7 Bn LYs.

How far? The visible universe now reckoned to be around 96 Bn LYs across. How big is the universe itself? The people who have done that reckoning reckon that the universe itself is even at the least much larger.

How to understand? Crude example. You're sitting in a parked car: how fast are you going? Ans.: zero. The car is going 80 mph. How fast? With respect to the car, zero! And that's it. Movement through space, speed-of-light. Expansion of space itself? Apparently and manifestly not so limited, the difference between movement through a medium and movement of the medium itself, "movement" in the latter case different,and not so easily defined or understood,

And your "argument" above, isn't. It's just an observation borrowed and used without sense, understanding, or modesty enough to realize it's incomplete, thereby your conclusions without adequate ground and thus meritless. And a clue to that is your international fame, prizes, and the newsmen at your door.

You've misunderstood. But that's what you do. General Relativity is about curved space-time, but you treat that as if it were an ad hoc hypothesis added after the fact.

I'm regretting answering any of your posts, Meta. You inhabit a weird meta-world were explanations don't serve any purpose. Enjoy.

General Relativity is about curved space-time... — Banno

Right, and special relativity is about curved space-time too ... not. Yet they're still both "relativity". I think you're missing something there Banno. General relativity is how the principles of special relativity are adapted to account for gravity.

You are inhabited by some strange mind which thinks it knows what it obviously does not. So you haven't the foggiest clue how to explain anything.

You are inhabited by some strange mind which thinks it knows what it obviously does not. So you haven't the foggiest clue how to explain anything. — Metaphysician Undercover

:rofl:

When reading Meta's views on physics, one should keep in mind that he rejects the notion of instantaneous velocity.

The speed of light can be derived directly from Maxwells' equations. That is, it is as much a part of physical law as F=ma and v=u+at.