GodAtWorkToday said:
For example; when you measure the current speed of radio transmissions (similar or same as light) from near objects (eg. our Solar system), and see that it matches with the time delay of signals, what does this prove. Well it proves that yes that is the speed over that distance, in this region, at this time. This is mathematical and factual.
However, when you then say that therefore distant stars are this far away, or the universe is this old because of the time necessary to travel that huge distance, you have made some huge assumptions. You have assumed that the speed is constant over long periods of time, that it is unaffected by varying matter present within the universe, and the gravity effect of a multitude of bodies, and no doubt a whole lot more assumptions to get to the conclusion that you have solid evidence of an old Earth.
Emphasis added.
Kerry, my highest level of study in physics was high school. And that was 45 years ago! So you can imagine how far behind I would be in a high school physics class today. And how hopelessly lost I would be in a college-level course.
But after reading this last paragraph, I wonder if you ever took even elementary school physics in reference to the speed of light. Did you never read of the Michelson-Morley experiments near the beginning of the 20th century? Did you never hear of how scientists used to think that light travelled on waves of ether?
Scientists do not
assume that the speed of light is constant in the vacuum of space. That was the farthest idea from their minds. It is not an intuitive idea. And it was quite radical when Einstein suggested it. The Michelson-Morley experiment assumed that the speed of light would
not be constant on a planet moving through the ether. The relative speed of light would vary, depending on whether the earth was moving toward or away from a light source. And they set up their experiment to measure the difference in the speed of light under these different conditions.
Do you know what they found? They found
no difference.
Even so, scientists did not fall all over themselves when Einstein proposed the constancy of the speed of light. They waited until one of the key points of Einstein's theory could be tested. It was only when a predicted sighting required by Einstein's theory proved accurate that scientists considered it had been validated.
And, btw, that prediction of Einstein's was a prediction about how gravity
does affect light (not by slowing it down, but by bending it around massive objects).
All of this, as I say, was spelled out in my high-school physics text long ago. So, I wonder how you missed learning it?
I find creationists are all too eager to identify basic scientific principles as
assumptions instead of looking into why they are considered basic scientific principles. When you start checking them out, more often than not, you will find they are not assumptions. They are
conclusions based on earlier scientific research. In many cases, the original assumption was the reverse (i.e. that the speed of light is not constant) and the current thesis had to pass muster by proving its validity before scientists accepted it.
So, please, don't assume too quickly that scientists are making invalid or unsupported assumptions. Check out the supposed assumption first. You are likely to find it is really a conclusion from observed evidence.