Re: Why was length defined in terms of the speed of light (c) and not vice versa?

On Apr 30, 4:37 pm, papa_r...@xxxxxxxxxxx wrote:
On 30 abr, 15:53, Strich-Reply-To-Idiots <iqgoo...@xxxxxxxxx> wrote:





On 30 Apr., 15:49, PD <TheDraperFam...@xxxxxxxxx> wrote:

On Apr 30, 2:28 pm, Strich-Reply-To-Idiots <iqgoo...@xxxxxxxxx> wrote:

On 29 Apr., 09:47, countableinfin...@xxxxxxxxx wrote:

Why was length defined in terms of the speed of light (c) and not vice
versa?

Because the spped of light was (erroneously) thought to be constant..

Cite ONE SOLID piece of evidence that the speed of light in a vacuum
is not constant.

Nobody has measured the speed of light IN A VACUUM.

Nobody knows whether the speed of light is a constant.

Einstein assumed it.  Assumption is the mother of all errors.

Wow....this is worth for some CNN prime time to report. Do you want us
to contact you with Larry King?
However be ready to answer some difficult questions. For instance how
come be like you say, when high-precision measurements of the lunar
distance are made by measuring the time taken for light to travel
between LIDAR stations on Earth and retroreflectors placed on the
Moon?

That's a two-way measurement. One-way speed of light is not a
constant. That's why physicists refuse to do any direct one-way
measurement. One-way speed of light is isotropic and that's why
physicists done many direct one-way isotropy measurements.

Ken Seto


Another point: how come be like you say if according to
electromagnetic theory the speed of propagation of a light wave
through a vacuum is c=sqrt(epsilon_0/mu_0)=3x10^8, where epsilon_0 and
mu_0 are physical constants which can be *evaluated by performing two
simple experiments which involve measuring the force of attraction
between two fixed changes and two fixed parallel current carrying
wires*. According to the relativity principle these experiments must
yield the same values for epsilon_0 and mu_0 in all inertial frames.
Thus, the speed of light must be the same in all inertial frames. In
fact, any disturbance which does not require a medium to propagate
through must appear to travel at the same velocity in all inertial
frames, otherwise we could differentiate inertial frames using the
apparent propagation speed of the disturbance, which would violate the
relativity principle.

Miguel Rios

Miguel Rios- Hide quoted text -

- Show quoted text -

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