Speed of light is a constant, right? Not so much....

that's a big "if."

contrary to creationist belief, science is not religion. if einstein is proven wrong, to the point where even his theory of relativity is wrong, then it's just wrong. the world of science will come to accept that.

that's still a mother of an "if," however. i don't imagine it will happen any day soon, and i'll giggle at the thought until the day actually comes.

of course, einstein himself said "a hundred experiments couldn't prove me right, one experiment could prove me wrong." well, not an exact quote, but obviously he didn't worship his own theory.

i would sooner expect to see his theory refined, but even that isn't a thing i'll be expecting this month.

If this effect holds, it's not a breakdown of special relativity - it's well outside the regime where straightforward SR is supposed to be applicable. When you're at the scale where you're considering the curvature of spacetime due to a gamma photon, then you can longer say you're working in a "vacuum" (zero mass-energy tensor), not even approximately; you're well into the regime of GENERAL relavity. Actually you're well beyond that too, and into the regime of "quantum general relatvity", or quantum gravity, or whatever the explanation is that no one's figured out yet.

Furthermore, something like this does not even disprove (the central principle of) SR, the property of Lorentz invariance. Both theories that extend beyond SR - GR and QFT - keep Lorentz invariance in some form (although the two theories are not compatible with each other). It would be astonishing if it didn't hold, and there's absolutely no evidence of it yet.

Fraser Cain's article which you cipoied from is poorly-written sensationalism. It's a shame, because this a genuinely interesting, unexplained phenomenon beyond the fiercest cutting-edge of physics, and they can't be bothered to accurately present it.

I love it when they discover something completely unexpected.

Not to derail this thread, but I don't think you can discover something you expected. You can find it, but it wouldn't be a discovery, it would be a reaffirmation of an expection or assumption.

Okay. back to the light speed.

So the rays got there after the photons. Which one were light waves and which were particles of light?

Joe(I know nothing.)Nation

Not to derail this thread but can someone explain me this?

If if has a mother, can if have a father too?

Francis: Mother in this instance is a half-word, also can be spelled muther.


Joe(************)Nation

Ok, Joe, how do you spell the other half?

Both are still both; it all depends on how you look at them.



Gamma rays are just high-energy photons, if I have my terminology right.

Are you thinking of alpha and beta particles? Those are actual pieces of atoms. They travel much slower than light.

in order to avoid being asterisked : fokker, mutherfokker of a IF.

====
Isn't that the challenge in understanding light? That it, light, can be a wave or a particle or both at the same time in the same time?

Joe(I don't know. I just listen to the guy on NPR)Nation

Re: Speed of light is a constant, right? Not so much....

Uh oh "pop-media" searching for flashy-headlines...

The speed of light is constant in a vacuum (the theory states this clearly). Science has known for a long time that different wavelengths of light are absorbed differently in different mediums and propagate more slowly than through a vacuum.

Before we overturn the basic theory of relativity, it seems reasonable to suspect that the gamma rays in question are passing through something between here and there which absorbs them and re-emits them resulting in a delay.

This galaxy in question wouldn't happen to be a long way away would it, with a lot of unidentified stuff in between...

The late arriving guests always blame the traffic congestion.

Joe(so as it ever was)Nation

E.G. says:

And how do they know all the photons left at the same stage and traveled through the exact same route in spacetime?

Secondly if your higher energy E/M radiation started off as really, really high energy levels - well it would in and of itself curve spacetime and this might add a time diliation effect.

Basically a person 1000 miles away shines two focused beams of light at you, through a vaccuum. If the light beams leave at the same time do they arrive at the same time? Or are they any theoretical circumstances where they won't arrive at the same moment in time?

Under relativity the answer would normally be no difference in time - so long as the beams of light aren't so energetic that one of them curves spacetime as it travels through it.

Lets look at that qualifier carefully. Shine a laser with an energy punch of say 10 ^ 80 Newtons per second and it isn't going to act like a 50 milli Watt laser. Its energy density would be so high you'd have a black hole travelling at light speed with enough field density to totally warp all spacetime around it. It would take a very different route to a low energy beam because it warps spacetime around it - with a progression rate possibly faster than c because it may change the actual media of spacetime - not just move through it!

Spacetime is not inert ether in these scenarioes. Now dial down the energy signature to the massive peak energy out bursts of super nova's (high energy gamma ray bursts) and let them travel for billions of light years and you may see a discernible time delay effect. I am not sure these types of energy carrier interacting with the interstellar medium have been modelled into the research document you mentioned.

Who were the first to calculate the velocity of light?

The Rig Veda Bhashyam by Sayana Madhava, written around
1100 A.D., gives the following Sloka praising the Sun:

Yojanam sahasre dve, satadve, dvecha yojane
Ekena nimeshardhena kramamaana namosthuthe

One Yojana equals 15788.8 meters, and half of Nimesha
equals 8/75 fraction of a second. This gives the velocity
of light as 325940 km/s. We have to remember here that the
above value is an approximate one intended for easy
remembrance, like remembering the value of pi as 22/7. It
is better than the value 215000 km/s given by Danish
astronomer Ole Roemer in 1676. Having discovered so many
things, it is only logical to expect that our ancestors
must have used light as the standard for length
measurements; after all, modern science considers velocity
of light to be a Universal Constant! The word "kramamaana"
of the above Sloka has the hidden meaning of gradual
minute change.

Seers of ancient India did not use light as a standard for
length measurement. Albert Einstain found that light
bends if it passes by the side of a large mass.

Now, how can that "which bends" be called unchangeable?

Every created thing is subject to change by time; there is
nothing like an universal constant. And the velocity of
light is no exception to this law. The velocity of
light of our Sun was greater in Krita Yuga than what it
is now, even if it is by a small fraction. The velocity
of light is proportional to the stored energy in the
Sun or any other star. Modern science also accepts that
the Sun has lost a lot of energy over billions of
years. Then, there must be some other stars in the
universe which have greater stored energies than the
Sun, and are emitting light which is faster than that
of the Sun? Yes. Modern science will confirm this after
it develops more sophisticated equipment than what they
have at present.

http://en.wikipedia.org/wiki/Yuga

http://en.wikipedia.org/wiki/Science_and_technology_in_ancient_India

http://doctorprasad.blog.com/

E.G. will certainly be correct.

VSPrasad:

Now, how can that "which bends" be called unchangeable?

- Light travels straight - spacetime curves

Every created thing is subject to change by time;

- time curves or dialtes in the presence of mass or energy - time isn't teh comstant you are searching for...

there is nothing like an universal constant

- actual yes there are quite a few in fact - c is only one of them - and they are finely tuned and measure to 1 part in 10 ^ 18 precision by the way

And the velocity of light is no exception to this law

- what law under what framework are you hypothesising says Einstein and relativity is wrong?

The velocity of light of our Sun was greater in Krita Yuga than what it
is now, even if it is by a small fraction.

- according to what evidence - run an f or p test on it yet?

The velocity of light is proportional to the stored energy in the Sun or any other star.

- ah right - you call that science, I call it poor psuedo science at best, sorry but that one is dead wrong

Modern science also accepts that the Sun has lost a lot of energy over billions of years. Then, there must be some other stars in the universe wich have greater stored energies than the Sun, and are emitting light which is faster than that of the Sun? Yes.

- No - try and read relativity again - its almost 100 years old, but still the most proven model matching all evidence we have today - lightspeed is constant under relativity.

Just to be a smart-ass then it you adhere to the adage "expect the unexpected" then there can be no such thing as a discovery.

Gamma rays are electromagnetic radiation / light emissions.

Wouldn't the gravitational field be so string as to have it collapse in on itself, assuming that such high energy levels were equatable to mass density that is.