Creationist Site Flubs Speed of Light

[Dale]

It seems that creationists are shaky on even the simplest and most well known points of science. Recently, I ran across a creationist site that thought they'd found a way to dethrone the speed of light as a constant of the universe. They cite phys.org but don’t link to any particular article, so it’s hard to know what exactly they looked at.

Yecheadquarters.org thought that the well known phenomenon of light slowing down as it passes through matter means that the speed of light isn’t really constant. That would rescue creationists from the problem of the travel time of light from the far corners of the universe.

If anyone is confused about this, it is the speed of light in vacuum that is the real constant. I will give respectable sources in my second post.

What follows is from yecheadquarters.org.


Speed of light is no longer a constant

“The reason it has been claimed for years that the speed of light is constant is because this idea supports the deep time required to make Big Bang and Evolution work. Without it it's less proof that there is evidence for this. So science hid for the longest that they knew the speed of light was not constant and never was.”

Link
https://yecheadquarters.org/speed-of-light-is-no-longer-a-constant/

 

[Dale]

Light, and other electromagnetic radiation, slows down when passing through matter. This is not new and no one has been keeping it a secret. As a kid, I was taught that the speed of light in water in about three-fourths of the speed of light in vacuum.

Since no one believes anything that I say, I’ll cite a couple of sources.



What Is the Speed of Light in Water?
By Staff WriterLast Updated March 28, 2020


“The speed of light in water is approximately 225,000 km per second. While enormously fast, this is notably slower than the speed of light in a vacuum, which is 300,000 km per second.”

“The degree that light slows down when passing through a medium is described by the index of refraction of that medium. … This results in the equation v = c / n, where v is the speed that light travels in the medium, c is the speed of light in a vacuum and n is the index of refraction.”

Link
https://www.reference.com/science/speed-light-water-cc36399c646cfe33


“When light traveling through the air enters a different medium, such as glass or water, the speed and wavelength of light are reduced ... In diamond, with a rather high refractive index of 2.4, the speed of light is reduced to a relative crawl (125,000 kilometers per second), being about 60 percent less than its maximum speed in a vacuum.”

Link
Speed of Light | What is Speed of Light? | Olympus LS