AboutJames Gort Expertise Questions on observational astronomy, optics, and astrophysics. Specializing in the evolution of stars, variable stars, supernovae, neuton stars/pulsars, black holes, quasars, and cosmology.
Experience I was a professional astronomer (University of Texas, McDonald Observatory), lecturer at the Adler Planetarium, professor of astrophysics, and amateur astronomer for 42 years. I have made numerous telescopes, and I am currently building one of the largest private observatories in Canada.
Publications StarDate, University of Texas, numerous Journal Publications
Question Hi I was wondering if you can answer this question. why do all stars seem like there the same distance from earth. And does this have anything to do with the oblers paradox?
Answer Hi Mike,
All the stars seem like they're at the same distance from earth because they're all so far away. Although it takes about 8 minutes for light to travel to earth from the sun (93 million miles away), light takes over 4 years to travel to even the nearest star. For most stars that we see, light has been travelling for hundreds or even thousands of years. When things are all so very far away, we can't easily tell they're all at different distances from us. To determine distances, there are a lot of "tricks" astronomers use - but that's another whole question!
The star's distances have little to do with Olber's paradox. That paradox states that if the universe were infinite and filled with stars, in no matter which direction we'd look (even if the stars were very far away), we'd see a star, and the night sky would be very bright. In reality, the universe is not infinite in size or age (current estimates put it at 13.7 billion years old), it is expanding, and stars don't live forever (they die and are slowly replaced with new stars). These things combine to make the night sky dark, instead of completely filled with stars.
