[pieceofthepuzzle]

“I’m so fast that last night I turned off the light switch in my hotel room and was in bed before the room was dark.”

Muhammad Ali

[Yo-Yo]

Methinks the author makes it much more dramatic sounding than it really is. 4.5 hours over 164,000 light years? What is the percentage error?

[mikrofon]

Either that, or our propulsion systems have gotten a LOT faster…

[thedrake]

Franson's arguments are based on observations made of the supernova SN 1987A–it exploded in February 1987

If its 168,000 light years away, then doesn't that mean that it exploded 168,000 years before we became aware of it?

This is making my head hurt.

[mbarker12474]

Damned global warming.

[Sergio]

So if the Sun blows up, we’ll know about it in 8 minutes and 22 seconds, rather than 8 minutes and 20 seconds. Phew...I feel much better now. The extra two seconds will really make a difference in my ability to make it to my shelter. /s

[FredZarguna]

Corrections:

The theory of general relativity suggests that light travels at a constant speed of 299,792,458 meters per second in a vacuum.

That would be the Special Theory of Relativity NOT General Theory of Relativity.

If such splitting and rejoining occurred many times with many photons on a journey of 168,000 light years,

There's no IF. Quantum Field Theory unequivocally says this happens.

the distance between us and SN 1987A, it could easily add up to the 4.7 hour delay, he suggests.

And, although the journalist is breathlessly reporting this as an earth-shattering cataclysm, this represents a relative error of about 3 x 10^-9. The error in the length of the meter is on the order of 10^-10 so this is not that far from the error in absolute measurement. And as for consequences? Well, just for example, it would mean that the universe is potentially about 10 c-yr smaller than believed, which is ~45 bn c-yr in diameter. That number itself has only two significant digits, so an error in parts per billion represents NO CHANGE whatsoever.

Nearer at hand, the Sun is about 500 c-sec away. This order of correction would cause light to reach us all of 1.5 microseconds later [in vacuum.] Since the intervening space is not vacuum and is not even uniform, nor is the distance to the earth's surface, we could not measure this change in any meaningful way.

Finally, I'm a tad confused about the claim that this is "related" to the fine structure constant: on the one hand, of course it is, as are all relativistic electromagnetic corrections. On the other hand, the FSC [α] is ~1/137, which is many orders of magnitude larger than the error actually claimed...

[GreenHornet]

Measurements here on Earth picked up the arrival of both photons and neutrinos from the blast but there was a problem—the arrival of the photons was later than expected, by 4.7 hours.

Yeah, well there was construction near Mars that had everything merging into one lane.

[Hoodat]

Ever since Obama slapped that tax on tanning beds, light has lost a step.

[Fido969]

speed of light might be slower than we thought

I dunno. It gets here pretty early in the morning.

[Vermont Lt]

Now it will take even longer to get to Cape Cod.

[centurion316]

I believe that this finally explains why when you need your flashlight, it never works. All those photons have decayed.

[KarlInOhio]

If this is happening, then it will happen multiple times to some photons and not at all to others unless it happens so many times over the 168,000 light years that it causes a very tight bell curve. That means there should be some smearing of the wave front as the photons which didn't split into electron/positron pairs get in front of those which did split. Also, lower energy photons like radio waves should be far less likely (or even zero chance) to split and thus travel full speed all the way, while gamma rays with more energy would be more likely to split. Is there a frequency distribution with the radio waves getting here before the visible light, x-rays and gamma rays from the supernova?

Or is it possible that our theories about how light emerges from the last gasp of fusion from the supernova is wrong and it takes hours longer to make it through the star's outer shell?

[beethovenfan]

The photons were stuck in traffic.

[Lake Living]

Where’s the picture of Hillary Clinton exclaiming, “What difference does it make?”

[CrazyIvan]

Probably just speedometer error from running the wrong tire size.

[ADemocratNoMore]

Question - c is the speed of light in a vacuum. I recall reading somewhere the the hardest vacuum in interstellar space has something like one atom per cubic meter, the article refers to the fact that space is not a “perfect” vacuum, but it's pretty darn close to one. On the other end of the scale, barionic matter is 99.99% empty space, the old analogy being an atomic nucleus being the size of a baseball, the electron (back in the days they were considered physical objects instead of probability clouds) would be the size of a grain of sand several hundred feet away from the nucleus and the next closest atom would be found a few miles away. This being the case, the space inside a glass lens at the scale of a photon would be as empty as the interstellar medium, to the photon it would be a vacuum, but it travels much slower through the glass than through “space”. Why do you suppose this is?

[maxwellsmart_agent]

I just want to see his proof.

[Uri’el-2012]

History of the Light-Speed Debate

[Hot Tabasco]

he claims to have found evidence that suggests the speed of light as described by the theory of general relativity, is actually slower than has been thought.

I've been saying that all along but the guys in the bar simply laughed at me.........