Constants

[FrumiousBandersnatch]

The speed of light? What does that even mean?

It's the speed at which electromagnetic radiation propagates.

This speed of light was determined by making a lot of assumptions. That's not science...

There are always assumptions in science; in contrast to religion, they are rational assumptions.

You cannot use trigonometry when it's millions and millions and millions of miles away!

You're a little behind the times. Trigonometry has been used for all kinds of measurements involving large distances - Kepler used trigonometry in the 17th century to calculate Earth's orbit using observations of Mars. Trigonometric parallax is regularly used in astronomy to measure distances of light years.

Light itself is metaphysical and certain properties like speed cannot be measured.

Rubbish - light is electromagnetic radiation. We measured the speed of light in secondary school physics class. You can do it yourself at home, using a microwave and a bar of chocolate.

 

[Radagast]

The speed of light? What does that even mean? What rubbish.

This speed of light was determined by making a lot of assumptions. That's not science, that's religion.

The speed of light was measured, in many different ways. A century ago they bounced light off mirrors, for example.