how would you expect the spectra of distant stars to appear if the universe were contracting?
2007-08-13 14:56:05 · 5 answers · asked by princess 2 in Science & Mathematics ➔ Astronomy & Space
Replace the word stars w/ galaxies and I would say they would have a blueshift, rather than a redshift. Distant stars, are still stars in our own galaxy. With respect to the rotation around the core of the galaxy, stars stay relatively in the same position. Their spectra would remain the same. It would simply be based on the composition and temperature of the star.
If the universe was contracting it would be the galaxies that would be grouping together and contracting. I hope this answers your question.
Email me if you need any more information...I actually wrote an essay on spectroscopy. Goodluck!
2007-08-13 16:01:49 · answer #1 · answered by justask23 5 · 0⤊ 0⤋
The spectra of distant stars are not considered to be part of the expansion of the universe - the stars we can obtain spectra for are in our own galaxy and so are orbiting the galactic centre as we are. They could be moving away from us and their spectra would be red-shifted as a result of that.
The spectra of distant galaxies, quasars, and supernovas are red-shifted and that red-shift is attributed to the general expansion of the universe.
So if the universe were contracting, those same spectra would be blue-shifted.
Of course, there are other phenomenon that we would see (besides the spectra shift) due to the contraction, but we won't go into that here.
2007-08-13 22:48:14 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Princess -
The spectrum would look like that of a normal nearby star - several dark lines spaced in a precise pattern across a continuous spectrum - but shifted toward the higher frequency, or blue end of the spectrum. The dark line pattern identifies the elements in the outer portions of the star and the extent of the shift identifies the speed of its approach or recession. The same thing happens to sound waves when the source of the waves is approaching or receding. It's called a Doppler shift.
2007-08-13 22:42:49 · answer #3 · answered by Larry454 7 · 0⤊ 0⤋
A blue shift in everything.
Red shift is expanding, Blue shift is contracting.
2007-08-13 22:43:54 · answer #4 · answered by Anonymous · 0⤊ 0⤋
if the star's light is more blue, it is coming towards earth. if it appears more reddish, its moving away.
2007-08-13 22:05:34 · answer #5 · answered by Constantine 2 · 0⤊ 0⤋