Also, the farthest dots will appear to recede faster, that is, really far stars are going to have really high red-shift. That's what's basically going on with the Universe, and Hubble showed it because of the red shift. From any one dot's perspective, the other dots will appear to recede. You can imagine that the distance between the dots will be on average, say, a centimeter or so. Imagine you have a big, red balloon, deflated. Either we are at the center of the Universe - unlikely - or the Universe is expanding. Now, you can imagine one of a few things is going on. Einstein had initially asserted an immobile Universe, but was corrected by Willem De Sitter.Īll stars (in all directions) were moving away. An American astronomer had earlier noticed that the Andromeda Galaxy was receding away. Interestingly, the use of this shift by Edwin Hubble (1889-1953) was what led to the proof of the expanding universe as well as many very basic parts of Cosmology today: the age, condition, and fate of the Universe. Gorgonzola did a great writeup on Blue Shift which is the exact opposite, when the object is approaching. Red shift what happens when an object radiating light moves away from you really, really fast, in the same way a car's horn/ clunking sounds lower when it goes away. If you imagine that it is true than you can almost imagine that the photon gets streched as spacetime expandsīecause the photon is connected with the idea of measurement and length and the structure of spacetime. Is certanly the effect we see at the moment with the redshift but that statement might be meaningless. We have a quantum theory of gravity and it willīe discovered that the boundary conditions of the photonĪre connected to the geometry of spacetime. I believe that the true answer will not come out until (from here on in the explanation becomes touchy feelyĪnd I can only recommend looking at the maths and a properĭerivation of the cosmological redshift.) The semi-classical photon is intimately tied to space itself.
The correct answer comes from the metric of space and time itself. The Doppler principle can not explain this. When then did your photon learn of the increase of Velocity of your host galaxy at the time that you were emitted. Is concurrent with that fact, not with the recession Universe has increased and the redshift I measure By the time you reach my eye much time has passed.
The expansion rate of the universe is low and so your Perhaps our galaxy has not even assembled itself yet.
Get emitted from your host galaxy the universe is young, Now here is a thought experiment to explain why this isĪ misconception when dealing with light. The frequency of the sound and hence the pitch.Ī similar argument is propsed for why light fromĪ galaxy that is moving away from us appears red. In the direction of motion and spreads them apartĪway from the direction of motion. "pushes" the wave crests of the sound closer togeter The pitch of its siren is higher than when theĪmbulance moves towards you.
The approximate explanation says that it is a Doppler shift.
ILIKE REDSHIFT SERIES
(the approximate explanation only recovers the first term in the Taylor series expansion of the right answer, honestly) First I'll tell you an approximate answer Why do we get a redshift?, this question used toīug me a lot.