Astronomers tell us that the universe is at least 28 billion light-years in diameter. They measure extreme distances in “light-years”. The term “light-year” sounds like a measurement of time, but it isn’t – it’s distance. That is how far light can travel in one year – that’s 5.88 trillion miles.
Astronomers measure how fast a distant object (a star) is moving in terms of light color. If a star is moving toward you, its light wave patterns will be compressed and the light you see will appear to be more bluish. The opposite happens if the star is moving away. Its light wave patterns will be stretched and the light you see will appear to be more red. How much the light is stretched or compressed depends on how fast the star that emitted the light is moving. That color change is called “red-shift”.
Astronomers have looked at the red-shift of many of the visible stars, and because everything seems to be moving away from us they have concluded that the universe is expanding.
There’s a problem with that conclusion though. Velocity is not the only thing that can cause red-shift. According to Einstein’s theory a light beam passing through any kind of gravitation field is slightly bent and it is red-shifted.
“How can that be a problem,” you ask. “After all outer space is a vacuum and there’s nothing there to interfere with light beams.”
Well yes, outer space is almost a vacuum, but not completely. There are lots and lots of stars, galaxies and other stuff. Most of the other stuff is, astronomers suspect, probably just dust. So the density of outer space is pretty low – mostly a few atoms per cubic yard. Unfortunately, we really don’t know what’s actually out there. Some of our best theories about the universe insist that there’s a lot more stuff out there we can’t see or even detect. Astronomers call that stuff “dark-matter” and it may make up as much as 85% of the universe. So while stuff in space may be spread pretty thin, it’s still a lot of stuff.
Every atom has its own tiny gravitational field and when a beam of light passes by an atom the beam is bent and red-shifted by a really tiny amount. If the beam passes by lots of atoms, the total bending and red-shifting could add up to a pretty significant amount. So the red-shifting we see may be a product of multiple tiny gravitational fields and have nothing to do with the motion of the beam’s source.
We have no way of knowing what kind of particles or how many particles any particular beam of light has passed on its journey to us. Consequently we may not know exactly where the distant stars are or just how distant those stars really are. And, we can’t know with certainty how fast the stars are moving or if they are even moving at all!
What astronomers see as an expanding universe may be nothing more than the effect of space dust. So when you hear that a beam of light took billions and billions of years to reach your eyes, keep in mind that it may have been only a few days. The truth is, we just don’t know. Remember God’s domain that I mentioned earlier? I think Job 38 gives a far less squishy description of the universe.
What do you think?
Copyright © 2022 Sam Dronebarger
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