Oh, so it's because we look at the entire pattern, got it. So, if it were the case, that we looked at just one absorption line (because that's all that we'd have), then we couldn't determine the redshift/blueshift, right?Jonathan Scott said:The relative strengths and the relative spacing of spectral features provide a lot of information which can be used to help identify them. You can match the patterns with other known stars to work out the redshift.
We also have clues from the intensity distribution of the spectrum even where there are no clear lines, and if there was only one line it might well be the strongest expected one for that type of object, but certainly the more detail the easier it is to be sure.Phys12 said:Oh, so it's because we look at the entire pattern, got it. So, if it were the case, that we looked at just one absorption line (because that's all that we'd have), then we couldn't determine the redshift/blueshift, right?
Redshift is the phenomenon in which light from distant objects appears to have longer wavelengths, shifting towards the red end of the spectrum. This is due to the expansion of the universe, and is an important tool for scientists to understand the age, size, and composition of galaxies.
Redshift can be measured by examining the spectrum of light from an object and looking for shifts in the wavelengths of certain spectral lines. By comparing these shifts to known wavelengths, scientists can determine the amount of redshift and calculate the object's distance and velocity.
There are three main types of redshift: cosmological redshift, which is caused by the expansion of the universe; gravitational redshift, which is caused by the gravitational pull of massive objects; and Doppler redshift, which is caused by an object's motion towards or away from an observer.
By measuring the redshift of distant objects, scientists can determine their distance and velocity, and therefore their age and size. This information can be used to study the expansion rate of the universe and how it has changed over time, providing insight into the evolution of the universe.
One challenge in measuring redshift is the presence of dust and gas in the universe, which can absorb or scatter light, making it more difficult to accurately measure the spectral lines. Additionally, the accuracy of redshift measurements can be affected by the quality and resolution of the instruments used to observe the light from distant objects.