Can anyone plz xplain red shift?

Question

.......in as much detail as u can

thnx

Answer 1

Light comes in various colors. Each color is a particular wavelength. Think of wavelength as Beats Per Minute for now.

Let's say that red light is 1,000 BPM.
Let's also say that Green light is 5,000 BPM
Lets further say that blue light is 10,000 BPM

So, we can think of Red as "Slow" and Blue as "Fast" light. Green will be our "Medium" speed light.

If the thing that is shining green is sitting still, and you are, too, then your eyes will detect exactly 5,000 BPM, and you will see green.

If you and the green shining object are moving apart, each successive "Beat" is going to have to go a bit farther than the last one to get to your eye, and you will detect this as a decrease or slowing down of the light speed. Perhaps it will get to your eyes at a rate of only 4,000 BPM (Probably a more yellowish shade).

That is "Red Shift". You are receiving a "slower" beat rate so your eye counts the light as a different color; a slower color closer to red.

You can get a "Blue Shift" too, if you and the object are getting closer together.

The faster you and/or the object are moving, the bigger the shift. Red if you are moving apart, Blue if you are getting closer.

Remember the colors of the rainbow

Red
Orange
Yellow
Green
Blue
Indigo
Violet

There are "colors" of enegy slower than red but we cannot see them. They are called Infra-Red. Colors that are faster than violet are Ultra-Violet, and we can't see them either.

Ultra-Violet light gives us a sun-tan (or sun-burn), and Infra-Red light keeps our food hot in a restaurant.

All of these kinds of energy waves have a specific "BPM" value, and all of them can shift faster and slower depending on their speed at the time you are observing them.

Answer 2

The perceived color of light is determined by the wavelength of that light -- the shorter the wavelength the more blue will be the light -- the longer the wavelength the more red will be the light.

When a light source is moving towards you, the motion of the source shortens the wavelength you see -- the light will be more blue

When a light source is moving away from you, the motion of the source lengthens the wavelength you see -- the light will be more red.

The faster the source is moving will influence how much more red or blue its perceived light is.

A picture is worth a thousand cut-and-pasted words, so I'd recommend you take a look at the animated graphics at this website to get a good feeling for what the red shift is ==>
http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=21

Answer 3

A red shift is a part of the "doppler effect" which means that as an object travels away from you the sound or light emitted from it will increase in wavelength and if it travels toward you the opposite happens.

An example would be if you hear a police car using it's siren and coming toward your location you'll hear it approach when it's fairly close to you due to the "blue shift" of the doppler effect. The red shift occurs when it speeds past you and you will hear it for a much longer time and at a lower pitch as it moves away from your location.

In astronomy they don't use sound they use light which has the same effects. The light emitted by a galaxy will actually shift toward the blue end of the spectrum if a galaxy is accelerating toward us due to the wavelength of light being compressed by the movement of the galaxy toward us.

However if it's moving away from us at an accelerating speed than its spectrum of light emitted from it will shift toward the red end of the visible spectrum due to the wavelength of light being lengthened by the expanding distance between the galaxy and ours.

There is also a type of red shift called a "gravitational red shift" This is from general relativity, it states that gravity can effect light and cause it's wavelength to increase if the pull is strong enough.

An example would be an astronaut being pulled into a black hole and you're observing him as he flies toward the event horizon. Your clocks are both syncronized so that the astronaut will cross the event horizon at exactly midnight. You would see him initially speed up toward the black hole and then start to slow down and eventually stop. You would not live to see him enter the black hole, as he appears to be frozen at the edge of the event horizon.

This is because of a gravitational red shift. You see the astronaut because of light that's reflected off of the astronaut's suit. As he gets closer to the black hole the gravity of the black hole starts to stretch out the wavelength of light that is reflected off of his suit. The closer he gets to the event horizon, the stronger the pull of gravity and the greater the red shift becomes and the longer it takes the light to reach your eyes.

When he gets to the event horizon, the gravitiational force will become theoretically infinite, thus producing an infinite red shift in the light being reflected off of his suit and you won't see him enter the black hole since the light reflecting off his suit at the point he reaches the threshold of the event horizon has been stretched out to an infinitely long length and will take an infinite time to reach you.

For more info on red shifts check out these links:

http://en.wikipedia.org/wiki/Gravitational_red_shift
http://en.wikipedia.org/wiki/Redshift

Answer 4

If a train emits a 1000 Hertz (cycles per second) sound from its horn, the sound travels outward in all directions at about 761 miles per hour. You can think of the sound as being alternating high- and low-pressure waves. The frequency is the number of times per second it alternates between low and high pressure.

When the train is heading toward you and starts emitting the 1000 Hertz sound, the first cycle occurs at time = 0. However, by the time the next cycle occurs, the train has moved closer to you, so that cycle arrives a little sooner than it would have if the train was sitting still. The next cycle arrives sooner still, because the train has moved even closer to you. So, instead of getting 1000 cycles per second at your location, you might hear 1050 cycles per second, because each successive pressure wave has to travel less and less distance to reach you. This corresponds to a higher pitch (5% higher, in this example).

The opposite happens when the train is traveling away from you. Each successive cycle takes longer to reach you, due to the train's motion away from you. This means fewer cycles reach you each second, corresponding to a lower pitch.

The same is true for light. If you look at an electromagnetic spectrum chart, you'll find the following regions, in order of frequency from lowest to highest:

radio, microwave, infrared, [visible light], ultraviolet, x-rays, gamma rays

where the visible light is made up of:
red, orange, yellow, green, blue, violet

When a light source is emitting a certain color of light, if the source is heading towards you, you'll register the frequency as being higher, for the same reason the train whistle had a higher pitch. If the source is headed away from you, you'll register a lower frequency. The lower-frequency end of the visible part of the spectrum is red, while the higher-frequency end of the visible part of the spectrum is blue/violet.

Therefore, we refer to an increase in frequency as a blue-shift, and a decrease in frequency as a red-shift.

Answer 5

Red/blue shift is caused by the Doppler Effect. We know from spectroscopy that we can determine the chemical makeup of a star or light source by breaking down the light emitted into the chemical spectrum, from where we can determine which elements are present and their percentages.

The red/blue shift occurs because objects in the universe are moving toward or away from the Earth. By identifying the patterns of other chemical spectra lines, and how far they are shifted to the left/right, we can determine exactly how fast they are moving away from or towards the Earth.

A red shift indicates an object moving away from the Earth, and blue indicates movement towards.

Answer 6

There are problems with the vast Bang, and creationists do have some option perspectives on the situation. despite the fact that, as with maximum medical uncertainties, there are distinctive evaluations even interior the creationist community. My guy or woman well known is Russell Humphries white hollow cosmology, which states, in short type, that area isn't countless and has an euclidian center, that the creation of earth occurred someplace close to this center, and that at this center there replaced right into a enormous gravity properly which acted relativistically to sluggish time to a pass slowly for products close to that center, as antagonistic to issues very a techniques from that center. employing this concept, as quickly as could desire to end that the residual effect of the stretching out of the cloth of time-area interior the creation adventure is what's inflicting the frequency shift of intergalactic gentle in the direction of crimson, not organic velocity, as required by using the vast Bang. Couple this with the incontrovertible fact that redshift itself is now being puzzled, by using non-creationist previous universe scientists, concepts you, to no count if a doppler effect is the excellent thank you to describe all the talked approximately information. As in basic terms one occasion, particle bridges could be seen between quasars and galaxies that, in accordance to the doppler clarification, ought to be too a techniques from one yet another for such an effect. yet while they are close, because of the fact the bridge shows, then 2 issues are solved. First, the talked approximately bridge turns into attainable. 2nd, the potential of the quasar turns into lifestyles like for its length, because of the fact it is actual plenty closer than doppler concept facilitates in line with redshift interpretation. consequently, white hollow cosmology does grant a thank you to describe a number of those irregularities which at the instant are not available below the vast Bang concept. despite the fact that, not even creationists regard white hollow cosmology as a finished concept. it is novel in that it would not take time as a consistent, yet as a relative characteristic of the creation adventure. This opens opportunities that have not been part of the debate, and that i think of it is healthy technological understanding to maintain an open concepts.

Answer 7

Hi. Light is stretched out when its origin is moving away from you. This moves each frequency towards the red end on the spectrum much as sound is stretched out by an object such as a car is moving away.

Answer 8

In physics and astronomy, redshift occurs when the electromagnetic radiation, usually visible light, that is emitted from or reflected off of an object is shifted towards the red end of the electromagnetic spectrum. More generally, redshift is defined as an increase in the wavelength of electromagnetic radiation received by a detector compared with the wavelength emitted by the source. This increase in wavelength corresponds to a decrease in the frequency of the electromagnetic radiation. Conversely, a decrease in wavelength is called blue shift.

Any increase in wavelength is called "redshift", even if it occurs in electromagnetic radiation of non-optical wavelengths, such as gamma rays, x-rays and ultraviolet. This nomenclature might be confusing since, at wavelengths longer than red (e.g., infrared, microwaves, and radio waves), redshifts shift the radiation away from the red wavelengths.

A redshift can occur when a light source moves away from an observer, corresponding to the Doppler shift that changes the perceived frequency of sound waves. Although observing such redshifts, or complementary blue shifts, has several terrestrial applications (e.g., Doppler radar and radar guns),[1] spectroscopic astrophysics uses Doppler redshifts to determine the movement of distant astronomical objects.[2] This phenomenon was first predicted and observed in the 19th century as scientists began to consider the dynamical implications of the wave-nature of light.

Another redshift mechanism is the expansion of the universe, which explains the famous observation that the spectral redshifts of distant galaxies, quasars, and intergalactic gas clouds increase in proportion to their distance from the observer. This mechanism is a key feature of the Big Bang model of physical cosmology.[3]

Yet a third type of redshift, the gravitational redshift (also known as the Einstein effect), is a result of the time dilation that occurs near massive objects, according to general relativity.[4]

All three of these phenomena, whose wide range of instantiations are the focus of this article, can be understood under the umbrella of frame transformation laws, as described below. There exist numerous other mechanisms with very different physical and mathematical descriptions that can lead to a shift in the frequency of electromagnetic radiation and whose action may occasionally be referred to as a "redshift", including scattering and optical effects.

http://en.wikipedia.org/wiki/Redshift
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If you have been doing much reading on astronomy, you have probably come across the term "red shift". When astronomers are explaining how far away a distant object is, they will usually say something like "The red shift of the galaxy (or other object) indicates that it is about 4 billion light years away". What does "red shift" mean, and how can it tell us how far away an object is?
Since most of the things we look at in the sky are so far away, we cannot visit them and find out what they are made of, what temperature they are and so on. The way that scientists decide what a distant star is made of, how hot it is and other things is to study the light that the star gives off. The study of light is called spectrography. By making careful observations of the light that a star gives off, or the light that is reflected from a planet, scientists can find out a lot of information about the distant object. This is the first part of the red shift puzzle.

The second part of the red shift puzzle is a little more complicated, but you can understand it.
We have all heard a police car with its siren on go by. You have probably also noticed that if the police car is moving towards us, the pitch of the siren is higher than it is when the police car is moving away. To make a long story short, this effect is what is known as the "Doppler Effect".
The question that you have right now is "What does a siren have to do with a distant star?". The answer is that light behaves same way that the siren does. Instead of the sound changing, though, the color of light from an object changes by a very small amount, depending on whether the object is moving closer to us or further away. By the way, an object has to be moving very, very fast in order for the light to change color even a little.


The first step in our explanation of red shift is a look at the colors that our eyes can see. In the picture above, you can see what looks a little like a rainbow. The colors start at red on the left side of the picture and go all the way to blue on the right side.
This graphic shows the entire range of what are called visible colors. It is also called a spectrum. Just like sound, light has "pitch". The red end of the spectrum has a lower pitch, or frequency, than the blue end of the spectrum. If you think of it in sound terms, the red colors would be the low notes on a piano, and the blue colors would be the high notes.


Here is another way to look at it. The star on top represents a blue-white star, like Sirius. Since the light it gives off has a lot of blue in it, the pitch, or frequency, of the light is high, which is shown by how close together the waves of light are. The star on the bottom represents a red star, like Arcturus. The light it gives off is red, which is shown by how far apart the waves of light are. Remember, the closer together the light waves are, the higher the frequency, and the more blue the light is. The further apart the light waves are, the lower the frequency and the light is more red. If you go back to the piano example we used above, the lower notes on the piano would be red and the higher notes would be blue.

By now you are probably wondering when we will get to the "shifting" part. The answer is right now. If you remember the example we gave of the siren at the beginning, we pointed out that the pitch of the siren got higher as it got closer to us and then got lower as it moved away.
The reason is because as the siren moved closer to us the sound waves got "squeezed" together, which made the pitch get higher. As the siren moved away, the sound waves got "stretched" a little, which makes them further apart, which makes the sound lower. A real good way to get a picture of this is to use a Slinky toy. Hold one end of the Slinky and give the other end to someone else and have them move a short distance away from you. You will notice that as the Slinky stretches out, the loops get further and further apart. If the other person then moves back towards you, the loops get closer together. Sound and light behave in the same way.

If a star is moving closer to us, the light it gives off gets squeezed together, which makes it appear bluer than it actually is. If the star is moving away from us, the light gets stretched out, which makes it appear more red than it really is. If the star is also going faster all the time, or accelerating, this effect is even greater.
At the beginning of this page, we said that scientists can find out what a star or other object is made of and how hot it is by studying the light that it gives off. When scientists determine what the star is made of and how hot it is, they can also determine what color of light the star should be giving off.
Once they have found this out, scientists can the determine whether the star is moving towards us or further away by whether the light is "blue shifted" or "red shifted" If the light is "red shifted" the star is moving away from us. If it is "blue shifted", it is moving closer.
After they have calculated how much the light is shifted either towards red or blue, scientists can then calculate how far away the object is and how fast it is moving either towards us or away from us.


http://www.dustbunny.com/afk/skywonders/redshift/
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Hope this helps u.