On 25/12/2017 09:25, Tim Streater wrote:
In article , The Natural Philosopher
wrote:

On 24/12/17 20:59, newshound wrote:
On 24/12/2017 20:43, Bill Wright wrote:
What are the parameters that set the speed of electromagnetic
transmission in a vacuum? I've googled everywhere but I can't find
the answer. It's easy enough to find the figure but WHY? Why not
29,979,245.8 metres per second or 2,997,924,580 metres per second?

Bill

Start here

https://en.wikipedia.org/wiki/Electr..._wave_equation

then look up permittivity and permeability of free space

But that doesnt do more than transform the question into 'why is that
the value of the permittivity and permeability of free space'?

AIUI, there are about 26 physical constants (such as speed of light)
for the values of which there is no theoretical explanation known
today. That is, it's as if God (I use the term for convenience) has 26
knobs to turn to set these values and launch the universe. They could
have any values, these constants, and life would not be possible in
most of the resulting universes.

There are thoughts that the speed of sound changes over time, in much
the same way the gravitational constant is believed to be changing
(excluding the known 5.9 year cycle).
https://en.wikipedia.org/wiki/Variable_speed_of_light
https://en.wikipedia.org/wiki/Time-v...ntal_constants

It is therefore possible that the goldilocks period we are in may change
into one that can't sustain carbon life-forms, who knows!

I do think any claim that there are 26 "constants", when we don't know
the origin of these numbers, is a bit risky.