That would mean they are using earth as the center of the universe and or the center of the big bang?common sense tells me you have to measure from the point of origin to the farthest point to be truly accurate.
Answers (2)
First you have to know that science is just another religion. What we call "academic" began as Akademus, a grove near Athens that was sacred to the goddess of wisdom. Membership was by invitation only, and the most famous member was Aristotle. Two thousand years later his name is still a synonym for "arrogant jerk". Academics claimed ownership of all knowledge, and knowledge was whatever they said it was. Discoveries by outsiders were rejected.
With a system like that, mistakes are almost impossible to correct unless members get embarrassed. Refer to the story about Galileo. To this day, scientists firmly believe a lot of mistakes. Hand washing is considered important because all the people who opposed it have died. We believe the germ theory because all the people who believed the humour theory have died. Nutrition is rejected as a cause of illness because followers of the germ theory have not all died yet.
Astronomers have a flood of beliefs that are clearly bonkers. They assume they are right because all the intelligent people agree with them. Anybody who disagrees is insulted and rejected, because all the intelligent people agree with them.
You hear a lot about CMBR, Cosmic Microwave Background Radiation. Well, it's only an assumption that it's cosmic. It could come from within the solar system.
Wikipedia records that dark matter was invented in 1938 by Ian Oort specifically to fudge his data to agree with his theories. It is now considered to be a foundation for all knowledge about the universe. When 95% of the universe is something you can't see, theories are irrelevant.
If you look at something from two positions it appears to shift by some angle depending an how far away it is and the length of your baseline. If you look from opposite sides of the Earth's orbit, that is the longest baseline we have, and accurate measurements can be made out to about 3200 light years. Beyond that we are guessing. Highly scientific guessing, but guessing all the same. That is why when you try to look up the biggest stars, the figures get very uncertain beyond 3200 light years.
A big part of science is conjecture, which means making up "What if" scenarios. Often those scenarios get discussed a lot for a long time, and people begin to assume they are true just because they keep hearing them. The big bang is one such scenario. The big bang exists only in somebody's imagination. It was needed to explain implications of the expanding universe conjecture, which was needed to explain the receding galaxy conjecture, which was based on the observed red shift in light from galaxies and the assumption that the red shift is caused by the Doppler effect. If that assumption is wrong then the entire collection of conjectures is without support. There are other possible causes of red shift. Hospitals use a magnet to produce red shift. It is called MRI. But astronomers deny the effects of magnets in space.
Then they make a most incredible leap of logic. Someone mentioned that dots on an expanding balloon move away from each other at a speed proportional to their distance. Astronomers jumped on that concept like stink on s- uh, - cheese. They now think they can measure distance just by the color of light from a galaxy. They can't even get all astronomers to believe that bullsnot, so they cancel telescope time and block publication of papers because it hurts so much to admit they made a mistaken assumption.
Straight answer to your question: They guess. Highly scientific guessing, and they have lots of big words and computer simulations that seem to support their guessing, but it's still guessing.
Oh, and here is a site maintained by astronomers who disagree:
www.thunderbolts.info/wp/daily-tpod/