[saberdancer]

This is very misleading. In fact, neutrinos are not going faster than speed of light (c), they are going faster than photons that are emitted from the supernova.

Not just that, but lights when it passes through a medium slows down depending on it's refractive index (speed of light in water is about 225 000km/h while in vacuum it's 300 000km/h). This is important distinction as recently we had an uproar when it looked like neutrinos are slightly faster than c (in the end, it was a measurement error).

You can observe effects of particles going faster than speed of light in a medium if you look at photographs of Cherenkov radiation.

[lmilcin]

The correct way to say it is that the speed of light is the speed of causality only in vacuum. In any medium the speed of light is slower but the causality or other fields (for example gravity field) that are not impeded by matter can and will propagate faster than the speed of light.

[blueprint]

Where does there exist a vacuum?

How does a particle or its environment measure the particle's traversal of a truly empty space?

[Erlich_Bachman]

That comment never wrote that neutrinos were faster than the speed of light?

[pavs]

No, but he did write "There is at least one known exception", the misleading part.

[tromp]

> in vacuum it's 300 000km/h

300 000 km per second

[mcdevilkiller]

Are you sure it's km/s? :D

[tromp]

As https://en.wikipedia.org/wiki/Speed_of_light puts it:

"Its exact value is 299,792,458 metres per second (approximately 300,000 km/s"

[phaemon]

Yes, it is.

[Lukas_Skywalker]

I'm sure it's a typo, but for others: speed of light is 300'000 m/s in vacuum, not km/h.

[Cyberspy]

It's not a typo - it's 299,792,458 m/s - approx 300,000,000 m/s or 300,000 km/s