Time and diameter of what?StillLearningToronto said:If I am given the variable of time (observed), and diameter is it possible to measure the distance of a galaxy? Or do I need more variables?
Just trying to figure out the most simple way to go about doing something like that.
russ_watters said:Time and diameter of what?
Well, it doesn't take 10 years to measure the diameter, so that time doesn't really tell you anything. I don't see how this can lead to a distance measuremeng.StillLearningToronto said:Im trying to figure out if its possible to measure the diameter of an object (in MPC)
With the variables time (say I've observed something for 10 years)
And after the 10 years I resolved that the diameter of the object is some angle in arc seconds.
Or would I need more information to figure out distance to that object?
StillLearningToronto said:Just trying to figure out the most simple way to go about doing something like that.
General Q: How do you measure a Galaxy's distance?
LURCH said:Are you asking about parallax ? It is possible to use time and the diameter of Earth’s orbit to measure the distance to far away objects. But this method is not used for determining the distance to other galaxies; those distances are much too far.
stefan r said:Parallax was used to determine that galaxies are in fact to far away to measure.
We could measure the distance to the galaxies with parallax. Launch 2 Gaia like probes out of the solar system in opposite directions. The probes would require a very large power supply and would need to function for a long time. Would also need a more powerful transmitter. Gaia cost over a $billion so not likely to happen soon.
The distance of a galaxy is measured using a variety of techniques, including parallax measurements, standard candles, and redshift. Parallax measurements involve comparing the position of a galaxy against the background of stars at different times of the year. Standard candles, such as Cepheid variables, have a known luminosity and can be used to determine distance based on their apparent brightness. Redshift is a result of the expansion of the universe and can be used to calculate the distance of a galaxy based on the amount of light it has shifted towards the red end of the spectrum.
The unit of measurement for a galaxy's distance is typically the light-year (ly), which is the distance light can travel in one year. This is equivalent to approximately 9.46 trillion kilometers or 5.88 trillion miles. Other units that may be used include parsecs (pc), megaparsecs (Mpc), and kiloparsecs (kpc).
The accuracy of measurements of a galaxy's distance depends on the method used and the precision of the instruments. Parallax measurements can be accurate to within a few percentage points, while redshift measurements can have uncertainties of up to 10%. Overall, measurements of a galaxy's distance can be accurate to within a few million light-years.
Yes, the distance of a galaxy can change over time due to the expansion of the universe. The farther a galaxy is from us, the faster it appears to be moving away due to the expansion. This means that the distance of a galaxy will increase over time, but the rate of change will vary depending on the galaxy's distance.
Accurately measuring a galaxy's distance is important for understanding the structure and evolution of the universe. It allows us to calculate the age of the universe, estimate the distribution and growth of galaxies, and study the effects of dark matter and dark energy. It also helps us to determine the relationship between distance and other properties of galaxies, such as luminosity and size.