Re: [Phys-l] Why question(s), again?

[carmelo@pacific.net.sg]

Quoting Bernard Cleyet <bernardcleyet@redshift.com>:

> A teacher member of the PTSOS** list posted:
> ---------------
> We're discussing Special Relativity in my conceptual physics class,
> and a student asked WHY light goes at 300,000 km/s, and what limits it.

The speed of light may slow down in a medium because the atoms absorb  
particles of light, photons. Some physicists are now investigating why  
the speed of light slow down over time. Hence, speed of light is  
limited to about 300,000 km/s because space is not a perfect vacuum,  
photon may have mass, the effect of gravity, the definitions that we  
adopt, etc, and we do not fully understand it yet.

We need not provide textbook answers to students.


Best regards,
Alphonsus