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If we observe a Doppler blue shift from a star the star must be a?
Wiki User
∙ 6y ago
In that case, the star must be approaching us.
Wiki User
∙ 6y ago
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Stars moving away from the earth show a red shift Why?
The star is moving away from us. Therefore, the Doppler effect must be considered. The Doppler effect is waves (in this case light) will be compressed in front of a moving object and stretched behind the object. This stretching creates a long wavelength. Red light has a long wavelength (the longest of visible light), so we call this stretching red shift.
What does a shift toward the red end of the spectrum mean?
When hearing to a sound from a moving source, we notice a change in pitch (frequency) as that source moves towards us, and then passes us and moves away, eg. think of the difference in sound frequency of fast moving cars if you've ever seen a formula 1 grand prix. This difference in pitch is due to the Doppler effect.The Doppler effect can also be observed in light waves. To understand this, we first need to explore what is meant by a spectrum and how it is observed.When white light passes through a prism, it is dispersed, in other words, split into its component colours (red, orange, yellow, green, blue, indigo, violet - the colours of the rainbow). This is known as the visible spectrum of light. The colours of the spectrum always appear in this order, and its important to remember that the colour of light depends on its frequency. Blue light has a high frequency, and red light a low frequency. Now, when we observe the spectrum of light from a hot glowing gas (such as hydrogen or helium as in a star), we won't see all the colours, but only certain lines (this is due to the change in energy levels of electrons within the H or He atoms). The resulting spectrum is known as a line emission spectrum. Since all stars are made of the same gases, when we look at their line emission spectra, the lines of colour should all be the same compared compared to each other.However, we notice that the line spectra of distant stars are shifted closer to the red end of the spectrum, (the colours will be "redder") meaning that the light reaching us is at a lowerfrequency than we expect. This means that the source of the light, the star, "must" be moving, just as in the Doppler effect applied to sound, a car moving away from us would have a lower pitch.If the moving object was approaching us, we would see light as a higher frequency, and therefore the lines in the emission spectra would shift toward the blue end of the spectrum.The key to understanding the red shift is to remember the Doppler effect in terms of the moving car, and to remember that colour is the frequency ("pitch") of a light wave.First: sound Doppler is not quite Relativistic Doppler.Second: a shift towards the red end of the spectrum means the light has lost energy. Could be lost to movement, a Doppler shift, or could be lost due to gravity, a gravity-hole effect.
Describe the big bang theory and the red shift evidence that supports this theory?
The red shift is a Doppler effect which showed that almost all galaxies are moving away from us (or us from them), and that the farther away a galaxy is the faster it is moving. Logically, if you "move" backwards in time (a thought experiment only) then it fits that the entire universe occupied a smaller space in the past. By calculation; at about 13.7 billion years ago it occupied only a tiny volume (of space) which must have been very hot and very energetic. The "big bang" (which must have been very small and quite silent) is just a descriptive term. Or the red shift is due to light escaping from a large star...
How is the universe changing by red shift?
the universe is changing by red shift because when red shift occurs it means that galaxies and stars are moving away from us. this means that the whole universe must be expanding.
Why the red shift in light from distant galaxies indicate that the universe is expanding?
Red shift is observed in the spectrum of light from an object when it is moving away from the observer. Most astronomical objects display a red shift in their light. Also, the red shift is greater for objects which are further away. For this to happen - in all directions, the universe must be expanding.
Is an object that is not moving relative to Earth a blue shift?
No, an object not moving relative to Earth is not a blue shifted object. With no relative motion, an object will not be subject to Doppler effect and will not red or blue shift. For an object to be blue shifted, the distance between the object and Earth must be decreasing. The object must be closing on Earth or vice versa.
Stars moving away from the earth show a red shift Why?
The star is moving away from us. Therefore, the Doppler effect must be considered. The Doppler effect is waves (in this case light) will be compressed in front of a moving object and stretched behind the object. This stretching creates a long wavelength. Red light has a long wavelength (the longest of visible light), so we call this stretching red shift.
For the Doppler effect to occur?
For the Doppler effect to occur the measured object must be in motion (radial velocity) relative to the emitter of a wave.
How do you beat anbot on not Doppler?
you must call me at 620 960 2516
How did Edwin hubble determine that the universe must be expanding?
The red shift. A Doppler effect (used in speed trap radar) showing that all (except for a few close ones) galaxies are moving away from us - and the farther away they were the faster they were moving.
How can you observe safety precaution?
two safety precautions you must observe when casting pewter
How can astronomers infer approximately how long the universe is been expanding?
It is usually believed that the Universe exists - and has been expanding - for about 14 billion years. It is usually believed that the Universe exists - and has been expanding - for about 14 billion years. The main method for figuring out this age is by observing how fast the Universe is expanding. Galaxies move away from us in such a way that they must have been close together about 14 billion years ago. This assumes the speed didn't change - this is not entirely correct, but you get the idea.
What does a shift toward the red end of the spectrum mean?
When hearing to a sound from a moving source, we notice a change in pitch (frequency) as that source moves towards us, and then passes us and moves away, eg. think of the difference in sound frequency of fast moving cars if you've ever seen a formula 1 grand prix. This difference in pitch is due to the Doppler effect.The Doppler effect can also be observed in light waves. To understand this, we first need to explore what is meant by a spectrum and how it is observed.When white light passes through a prism, it is dispersed, in other words, split into its component colours (red, orange, yellow, green, blue, indigo, violet - the colours of the rainbow). This is known as the visible spectrum of light. The colours of the spectrum always appear in this order, and its important to remember that the colour of light depends on its frequency. Blue light has a high frequency, and red light a low frequency. Now, when we observe the spectrum of light from a hot glowing gas (such as hydrogen or helium as in a star), we won't see all the colours, but only certain lines (this is due to the change in energy levels of electrons within the H or He atoms). The resulting spectrum is known as a line emission spectrum. Since all stars are made of the same gases, when we look at their line emission spectra, the lines of colour should all be the same compared compared to each other.However, we notice that the line spectra of distant stars are shifted closer to the red end of the spectrum, (the colours will be "redder") meaning that the light reaching us is at a lowerfrequency than we expect. This means that the source of the light, the star, "must" be moving, just as in the Doppler effect applied to sound, a car moving away from us would have a lower pitch.If the moving object was approaching us, we would see light as a higher frequency, and therefore the lines in the emission spectra would shift toward the blue end of the spectrum.The key to understanding the red shift is to remember the Doppler effect in terms of the moving car, and to remember that colour is the frequency ("pitch") of a light wave.First: sound Doppler is not quite Relativistic Doppler.Second: a shift towards the red end of the spectrum means the light has lost energy. Could be lost to movement, a Doppler shift, or could be lost due to gravity, a gravity-hole effect.
How does the astronomers know that the universe is expanding?
According to calculations (related to the General Theory of Relativity), the Universe can't remain static forever. Eventually, it must either expand or contract. According to observations, it is expanding. That is, in general, the farther a galaxy is away from us the faster it moves away. This can be observed by the red-shift of the light of such a galaxy - and the only reasonable explanation for this red-shift is the Doppler effect.
What does it that a hypothesis must be testable?
It must be possible to observe whether the hypothesis is true.
What day must christians observe sabbath?
Sunday
Does a Catholic have to observe Lent?
As with any Church season or holy day, of course all Catholics must observe them.
