Is the doppler shift measured for a galaxy due to velocity of the galaxy and also expansion of the universe?
356302
The doppler effec refers only to the velocity of the object, as seen by your current position. The contribution of the expansion of the Universe is usualy noted as REd- SHifting. Note that there is also another effect, which adds to the doppler effect, and that is the lorentz factor.
853481
einstein wondered what stuff would look like if he traveled the speed of light. One thing he wondered about is what would light look like.\n\nYou should know what a dopler shift is. When something is traveling away from you the wavelength of radiation emitted from that object increases in wavelength. If you look at the formula for calulating the shift in wavelength you see that the limit as we approach the speed of light is that the wave becomes flat (there is no wave). So we would see nothing.\n\nAlso the way the equation is set up, in conjunction with with fact that wavelength*frequency = speed of light, this also means that the frequency goes to infinity. This is because to travel at this speed is impossible. But you were wondering what the light would look like so the answer is the wavelength becomes zero and you see nothing.
429063
The Milky Way is moving at about 1,342,161 mph towards a galactic cluster known as Abell 3627\nhttp://answerway.com/expertans.php?category=243&expertname=Locii&catnam=Physics\n\nOur galaxy is NOT moving towards the center (or centre) of the universe. The universe has no center!\nhttp://sciastro.astronomy.net/sci.astro.9.FAQ\n\nGod should be spelled B-I-G B-A-N-G\nPBrax@netscape.com
533842
In short, you can't be 100% certain, but a very long term trend would have to break unpredictably for it not to be.  Read on for details.\n\nThere is, as you have pointed out, substantial evidence that the universe is expanding. To understand how we surmise that it is still expanding in spite of the "old news" effect (most of the measurements of expansion rely on light that left its sources hundreds of millions to billions of years ago) you need to understand some of the details of how we quantify the expansion.\n\nThe expansion rate is quantified in units of velocity/distance. The Hubble constant, for instance is generally expressed in units of km/s per mega-parsec (1 Mpc = 3.27 million ly = 3.086x10^22 meters).  The current value for the Hubble constant is ~70 km/s per Mpc by our most accurate measurements. This means that on average, for every megaparsec  of distance ***an object that is not gravitationally bound to our observation point*** recedes at about 70 km/s. \n\nWe can also estimate the rate of change in the Hubble constant.  For instance, as something made of mass (such as the universe) expands, its own gravity is fighting that expansion and slowing it down. It might not be enough to halt the expansion, or it might be.  This is the distinction between an open universe that expands forever, a closed universe that falls within its own Schwarzschild radius and eventually will contract, and a flat Universe that will expand forever but is slowing at a rate such that the expansion will halt at infinite time. \n\nWe find the change in the Hubble constant  by measuring the recessional velocity (from which you can find the Hubble  constant) for  more distant objects. The more distant, the longer ago the light left that object, permitting us to calculate what the Hubble constant was in the past.\n\nIt is this sort of data that has recently shown us that not only did the expansion of the universe not slow as much as expected for the given mass present, about 5 billion years ago it appears the expansion began to accelerate.\n\nBut what about today?  With all these data from sources that are millions to billions of light years away, how do we know that, say yesterday, it didn't stop expanding?\nWe don't know for sure, however we have measured the trends of the expansion over time, and those trends would have to change VERY dramatically due to some unanticipated phenomenon.  The universe's expansion over time follows a fairly simple relationship, and has followed it for over 13 billion years. When we look as close as a hundred million parsecs, there is a clear expansion that follows this trend.  The trend would have had to change suddenly and unpredictably, in fairly recent (cosmologically speaking) history for it to now be contracting.\n\nThis would be analogous to tracking a projectile flying from the muzzle of a gun for 30 feet towards a target.  We have taken into consideration wind speed, gravity, muzzle velocity and so far the course is precisely as we predicted. Then, with 6" to go something happens that causes the projectile to deviate from its course significantly.  Perhaps a bird falls out of the sky, or there was a block of glass in front of the target that we did not see. That is how sudden a change we would need to explain why the universe is no longer expanding if it isn't expanding today, when it WAS expanding just 50 million years ago at the end of a 13.65 billion year trend.\n\nSo, you are right.  It might not be expanding, however a far simpler interpretation of the data is that the trend we have observed over a billions of years time scale has continued for the last 100 million.
3680
Well it is supposed to be a constant that characterizes the rate of expansion of the universe.  Theoretically, it should be a constant, but there has been quite a bit of debate as to what the actual value should be.  It ranges between 50 and 100 depending on how you approach measuring it.\n\nThe means of measuring it vary greatly, thus it can be difficult to get a real apples to apples comparison and sort out who has the more accurate result.
659829
Have you heard about doppler effect.\nElectromagnetic signals are sent to the object(here its balls) and received back after reflection. Now the frequency of the received signal gets shifted (depending on the speed of the moving object)... from this shift we calculate the speed of the object.\nSame Phenomena is used to measure the speed of moving vehicles by TRAFFIC COPS.\nAnd its most interesting use is to measure the speed of distant stars.
1065439
The speed of light - it can't go any faster!\nThere will be a distortion however, called blue shift.\nThe perceived (by a stationary observer) frequency of the light would increase, and the wavelength would decrease, so that the velocity is constant v=fλ\nThe distortion would be infinitesimal 30 parts in 186000*60*60.\n\nSound would experience a similar distortion, so that if a vehicle sounds its horn as it drives past, there is a perceived frequency change in the sound.  This is called the Doppler Effect - there is a link at the bottom of the blue shift link... (see also red shift)
212257
velocity is always the motion of an object between two points. you can measure the velocity of planets, stars, solar systems, galaxies, but the absolute of the universe cannot be determined since there are not objects to reference its motion to. The universe is expanding but this is unrelated to the motion of the universe since it is expanding equally in all directions.
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The way light particles travel is  in a ray sequencce at the same velocity.\nThe ray path light follows looks like traveling beads at the same spacing and travelig period. When the traveling period of the particles is shorter the frequency that  they cross at agiven point is higher. If the period is longer the frequency is lower.  It is at the lower frequency that our eyes see light radiation ray towardsred .This is what is called the red shift.  So light appears to follow the rules of a waves yet its not a wave.(I am not going to explain oscillatory motion in this answer.)\n\nIn the wave there are two types of effects; one is called the Doppler effect on which the assumption that the galaxies are receeding is made.\nThe other is called the Dispersion Effect.This case shows also a red shift but has nothing to do with the recession of the galaxies.\nInitially this was the belief of Einstein .On that basis he used a constant called the cosmological constant to account for the stability of the Universe. Later he reversed his belief and thought he had made a mistake.  HOwever the Dispersion theory showed other wise; Hence Einstein may have not been wrong in the first Place. Even Einstein was swayed to change his mind and believe wrong.\n\nIt is a matter of preference whether you choose which is the correct theory about recession of the galaxies.He did believe that the Universe is a finite Creation. That makes sense other wise motion could not take place and the Energy Phenomena would not exist.( I am not going to explain how the Energy Phenomena takes place in this answer)\n\n\nTo Understand the motion of galaxies it is necessary to know how much mass loss or gain is experienced by a paticular galaxy. If the galaxy increases in mass ,it will increase its radius from the center of mass of the Universe.If the galaxy looses mass the reverse occurs.This is my Theory. It is a Theory of Equilibrium for rotation. You can you choose to expand on it or believe the Gauges theories or quantum Mechanic theory.  But none offer this answer. The is quite  a shift and I doubt that the main stream of physics would believe me, because they believe their theory of the red shift is the only right one!
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According to Special Theory of Relativity, speed of light in free space is same for all inertial observers (inertial observer is an observer possessing a  frame of reference in which Newtons law of inertia is true).\n\nWhen we study General Theory of Relativity, in the context of Cosmology we come across case when Galaxies moving with speed greater than the speed of light. Here Galaxies are beyond the particle horizon. But actually the space between the Galaxies are increasing with speed greater than the speed of light beyond the particle horizon.\n\nTachyons  are not experimentally observed entities and it got imaginary mass as well. Imaginary mass cannot be physically observed.
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The latest ideas are that the rate of expansion is accelerating. In other words the "speed" of expansion today is faster than it was a billion years ago, and it will be even faster a billion years in the future.\n\nIt is perfectly okay for the universe to expand faster than the speed of light. What is expanding is space itself (more or less) and light is just carried along. At any one point a piece of light (a photon) is moving merrily along at the usual speed of c.\n\nIf the expansion is slower than light that is also fine. Light just goes merrily along. There is no "edge" to the universe. It either wraps around (so that if you go out into space along the north pole eventually you will return from the direction of the south pole) or is effectively infinite.\n\nThe acceleration of the expansion of the universe is powered by something which is not very well understood at all called "Dark Energy" or, more poetically, "quintessence."
845289
The question deals with the expansion of the Universe, with the simplifying assumption that the object asserted to have an expansion speed away from us (by measuring its red-shift) has ALWAYS been traveling at 3,000 km/sec, and that its (known) distance is 50 Mpc.\n\nHowever, your requested operation is inverted!  That is obvious since any number of Mpc's (a length) divided by a speed (km/sec) will give one a time, but yours, quite the opposite, will give you 1 over a time.  Personally, I prefer my wristwatch to measure time t rather than t^(-1), but hey, if you could develop that, there might still be someone out there who'd want to buy it!\n\nLive long and prosper.
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Use the general equation for Doppler effect from here( http://en.wikipedia.org/wiki/Doppler_effect ). f'/f = .86 and v0 =0 for you since the observer isn't moving. Note that since the frequency is lower that it must be moving away from you.
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As far as i know the speed of expansion of the universe\nis measured by the velocities with which the galaxies are receeding away from us (but why, where is the force ?). The formula is \n\nV= H * L\nH is hubble's constant and L is the distance from the galaxy. So farther is the galaxy, faster it moves !
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In astrophysics last semester we did several things to prove to prove the friedmann equation (equation derived from general relativity that governs the expansion and motion inside the universe).  One of the proofs is the redshift caused by the expansion of the universe (not technically a relative motion but it doesn't really matter).  So here's the evidence.\n\na)The numbers for the redshift/megaparsec cross check perfectly with other independent proofs of the friedmann equation, like the cosmic microwave background.\n\nb)The supernovae we are observing are what's known as a "standard candle" meaning that the intensity, spectrum, and mass can all be determined very accurately by observing the change of the intensity of the radiation as a function of time.  Because of this fact we can take into account the gravitational redshifts.  The end result is that they make up fractions of a percent of the total redshift (I'd have to dig up my note to find the exact answer but it consider that the redshift of far objects is over 90% while the redshift from gravity is on the order of 10^-4% (.0001%).\n\nFinally to answer part of your question.  Light is not redshifted by massive objects on it's path because the gravitational potential is the same upon entering the objects potential well as when it exits.  Put another way it is blueshifted upon entering the objects gravitational pull and equally redshifted back to the original value upon exiting.
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The space between the galaxies is what is expanding.  Imagine raisin bread being baked.  As the bread rises, each raisin moves away from every other raisin.  Another way to visualize this is by drawing dots on a balloon then blowing the balloon up.  As the balloon get's bigger, each dot moves further away from every other dot.  It's the same for galaxies.\n\nNow the expansion of the universe is only detectable at extremely large distances.  Nearby galaxies like M31 can move towards us.  But most galaxies we see are extremely far away, so almost all of them are receding from us.
811141
The Speed of Light is measured to any observer, preferably "at rest" or not moving on an intersteller ship.  As said above, there is no such thing as absolutely stationary anywhere.  Everything in this Universe moves relative to something else.  We move relative to the local star systems, they in turn move relative to the galactic center.  The galactic center moves realative to the nearby Galaxies, such as Andromeda Galaxy (which in less than 6 Billion years the Milky Way will collide with to form one larger Galaxy).  So, everything moves.  Even if it looks like it doesn't.