In the widely accepted cosmological model based on general relativity, redshift is mainly a result of the expansion of space: this means that the farther away a galaxy is from us, the more the space has expanded in the time since the light left that galaxy, so the more the light has been stretched, the more redshifted …
What causes the cosmological redshift?
In cosmological redshift, the wavelength at which the radiation is originally emitted is lengthened as it travels through (expanding) space. Cosmological redshift results from the expansion of space itself and not from the motion of an individual body.
How did Edwin Hubble discover redshift?
Hubble's Law of cosmological expansion was first formulated by Edwin Hubble in 1929. Hubble compared the distances to galaxies to their redshift and found a linear relationship. He interpreted the redshift as being caused by the receding velocity of the galaxies.
What is red shift phenomenon?
redshift, displacement of the spectrum of an astronomical object toward longer (red) wavelengths. It is attributed to the Doppler effect, a change in wavelength that results when a given source of waves (e.g., light or radio waves) and an observer are in motion with respect to each other.
How does red Shift show that the universe is expanding?
Evidence from red-shift Astronomers have discovered that, in general, the further away a galaxy is, the more red-shifted its light is. This means that the further away the galaxies are, the faster they are moving. This is similar to an explosion, where the bits moving fastest travel furthest from the explosion.
How does redshift support the steady state theory?
The Steady State theory of the Universe Another theory about the Universe, called the Steady State theory , says that the Universe has always existed, and that the Universe is expanding and constantly creating matter as the Universe expands. This idea is supported by the red shift evidence, but not by the CMBR.
How do you observe redshift?
The most accurate way to measure redshift is by using spectroscopy. When a beam of white light strikes a triangular prism it is separated into its various components (ROYGBIV). This is known as a spectrum (plural: spectra).
How do astronomers use redshift to determine distances?
Astronomers also use redshift to measure approximate distances to very distant galaxies. The more distant an object, the more it will be redshifted. Some very distant objects may emit energy in the ultraviolet or even higher energy wavelengths.
What is important about Hubble’s discovery that there is a red shift in the spectra of galaxies?
What is important about Hubble's discovery that there is a red shift in the spectra of galaxies? It suggests that the universe is expanding.
How does the Doppler Effect explain redshift?
Redshift is an example of the Doppler Effect. As an object moves away from us, the sound or light waves emitted by the object are stretched out, which makes them have a lower pitch and moves them towards the red end of the electromagnetic spectrum, where light has a longer wavelength.