Treading the light fantastic: Einstein challenged

[Celebration]

http://www.smh.com.au/news/science/was-einstein-wrong/2006/01/18/1137553651249.html

According to Albert Einstein's theory of relativity, enunciated a century ago, the speed of light - the "c" in his famous equation e=mc 2 - has been a constant 299,792,458 metres a second since the universe began with the Big Bang. Dr Joao Magueijo thinks Einstein, who did have second thoughts but never pursued them, got it wrong. He believes that not long after the Big Bang light hit a "speed bump" and is, in fact, slowing down.

His theory - published first in the scientific press and then in a popular book, Faster than the Speed of Light - The Story of a Scientific Speculation, was initially greeted with derision.

"That is not so surprising," says Portuguese-born Dr Magueijo, 38, who tonight will give a public talk on his theory at the University of NSW. "This is an emotional issue. We are attacking one of the pillars of modern physics."

Whether it comes crashing down will depend largely on research now being carried out at the university by a six-member team led by Professor John Webb and Dr Michael Murphy, one of his former PhD students.

[JuniperLea]

1. 1+1=2

Is the only thing you can really be sure of. It seems reasonable that the "laws" of physics would change as we learn more.

[tridim]

2. If light can "slow down", doesn't that mean that..

1) It will eventually reach zero
2) It can be manipulated
3) It's not a universal speed limit
4) Space and matter isn't constant either

It boggles the mind.

[Submariner]

5. And if light slows down

doesn't that mean that other galaxies, and other planets in our own galaxy, are closer to us than presently specified? Instead of 50 million light years distant, it may be 30 to 40? Interesting stuff.

[lnmike]

9. Wouldn't that mean:

That those galaxies are actually farther away, since the light would have been going faster at first, and slowing down since?

[Submariner]

11. Thanks for getting my mind right

I screwed up the the law of physics with that brainfart.

[Salviati]

14. My understanding on these questions...

There has been a lot of research lately into whether or not the fundimental constants, including c, are in fact constant in time. I haven't seen any people proposing that they vary in space, and I believe that there is an overabundance of evidence to support the idea that they don't.

Most of the theories that I've seen that suggest that the speed of light isn't constant in time, like this one, suggest that it may have been different shortly after the big bang, and then slowed to our current speed, where it's been relatively constant for quite some time. There's quite a bit of evidence that c has been (nearly) constant for quite a while (coming from decay products of radioactive materials here on Earth, to the spectra of distant stars, where you're actually looking back in time...)

The place where there may be wiggle room would be shortly after the big bang, well before stars and galaxys formed. The light created by them would surely have been created well after c had settled down to it's present value.

[Vinnie From Indy]

3. LOL! The above snippet is long on talk and short on theory

My money is on Einstein.

[longship]

4. Look, modern physics is not going to come crashing down.

The value of "C" is tied to other prime constants. One cannot change C by much without having profound consequences for the shape and character of the universe. Even minute changes in the character of the universe mean no life, matter, or forces (as we know them) could develop.

So, although it *may* be true that C is not as constant as Einstein thought--and I might add, this is far, far from being demonstrated--it cannot be true that C has varied by much.

Maybe there's a reason why this guy's claims are not being taken seriously.

[RaleighNCDUer]

6. OTOH, maybe those other 'prime constants' are not quite so

constant either.

It is the height of hubris to think we know all that we 'know'.

As Arthur C Clark once said "If a scientist claims that something is impossible, he's probably wrong -- and if a scientist claims that something is possible, he's probably right".

I suspect that future scientists will see our interpretation of light speed as an insurmountable barrier as quaint as the ancient Greek theory of heavenly spheres.

[longship]

8. The other prime constants *must* be constant.

Otherwise, there's no matter in the universe. Otherwise, there's no *life* in the universe. That's why we know that they haven't varied in the past.

Nature is a delicate balance. One can't just wiggle parameters here and there without consequences. C is constant because it must be a constant for us to be here.

[baby_mouse]

7. This is one of Fred Hoyle's, I think.

I do recall him taking issue with the idea that we can *assume* the speed of light is constant simply beacuse it makes our equtions pretty.

[qazplm]

10. the point though that the other poster makes

is not that perhaps the "constants" arent constant, but that in the practical sense the changes in those constants can only be VERY minute at best lest we have a universe which cannot form atoms because the nuclear forces are too weak to hold them together for example.

The speed of light might be .00002 percent different from in the past, but it cant be 50% different or something substantial like that because that makes all the other constants change and then we get a universe without any structure, atoms or anything that looks like our present universe.

[baby_mouse]

12. I don't really know anything about this...BUT...

I think I have an idea. Well, it's not really mine... It's to do with constants changing together in balanced way.

It was floated in a book called "Evolving the Alien" in which it was pointed out that alien-ness in extraterrestrial forms was proposed to be only possible within a narrow range, because if you change one of the variables that life is dependent on HERE beyond a certain then life would stop.

The authors take issue with this, pointing out that mostly in evolution it's more than one factor that's changing at a time. The metaphor they use is a car - if you change the diameter of the wheels, eventually it reaches stage where the car can't run anymore because the wheels are blocked from moving by the wheel arch, hoever, the authors point out that if the wheel arch is changing size as well, then the limits are much looser. Basically, in other words, if you try to fit a radiator from an old banger from the turn of the century into a Ford Focus it won't work, but of course the Ford Focus radiator IS "descended" from these old radiators... IT works now because everything ELSE has been changing as well.

This idea works well in understanding evolution or in trying to guess how evolution might work on other planets. These authors were trying to open up possibilities beyond the strict and rigid imagining techniques used by other speculators in the field of "xenobiology" that were based more on scientific method than imagination, i.e., you can only vary one factor at a time in a system if you're STUDYING it, so it's easy to fall into the trap of failing to see that it's not just one factor that can change over time. If two factors change in tandem and in balance, the structure of the system needn't be compromised.

I don't know how applicable this idea is to the laws of astrophysics, but I do recall these authors speculating that their model for imagining change in a biological context might be applicable in other sciences.

???

Could everything ELSE also be changing? Of course, it then begs the question of what's the overlying principle that allows any structure at all. In evolution you have the ratchet of natural selection, stability is forced by the fact that lifeforms keep making copies of themselves, if imperfect. But the Universe can't really have anything like that without us tending suspiciously towards Intellgient Design - AAAAARGH.

Mayhap 'tis applicable, mayhap not. How thinkest thou?

[longship]

13. Sorry, that won't work.

It's not just the relationship between constants that determine the characteristics of our universe. The magnitude of these constants are equally, if not more, important.

Two examples are the permeability and permittivity of empty space (Mu-naught and Epsilon-naught, respectively). Any change in C will dictate changes in both these values. The question is how much of a change will give rise to conditions in the universe where the electro-dynamics would be effected to the point where matter doesn't develop.

My physics background (B.S. degree) is three decades old, but I do not think that Mu and Epsilon can change much without having profound effects on the long term stability of matter.

So, I file these kind of wild conjectures where they likely belong, along with other tin-foil hat stuff.

On edit: Here's the relationship:



Decreasing C means an increase in either one and/or the other of these primary electromagnetic characteristics of empty space.

Wikipedia is your friend here.

Interested parties may want to check out Richard Feynman's book, QED which describes the merging of quantum mechanics with classical electromagnetic theory, the first big unification theory in modern physics.

[BootinUp]

16. I would have to question our ability to measure

a .00002 percent difference without error.

[TheBaldyMan]

15. this is kind of old - hyperinflation of the young cosmos has

been doing the rounds for years now.

btw the speed of light in vacuo is a maximum and 'slows down' when a photon moves through a tranparent medium (eg gas water or glass).

Always be wary of superluminal (Faster-than-light) theories. They are usually explained shortly after the initial publicity surge.