...when he noted that light emitted from stars is shifting toward the red end of the electromagnetic spectrum?
A. The universe is expanding.
B. The universe is contracting.
C. The temperature of stars in increasing.
D. The temperature of stars is decreasing.
2006-07-27 03:05:26 · 5 answers · asked by Adumu 2 in Science & Mathematics ➔ Astronomy & Space
A and he couldn't have concluded anything about the temperature of the stars from the red-shift
2006-07-27 03:10:52 · answer #1 · answered by jerryjon02 2 · 0⤊ 0⤋
A
because of doppler effect, the light wavelength gets longer (red) if the stars observed are moving away and gets shorter (blue) if they come closer (gives an information on speed of those stars, relatively to us)
I believe the temperature of the stars are determined throuhg an analysis of the whole spectrum : you can easily see if a specific nuclear reaction takes place by looking for it's caracteristic energy signature (a patern in the light spectrum). and if a specific nuclear reaction takes place, then the temperature of that star is higher than the minimal temperature for this reaction to take place. (I'm guessing, there. But I know the doppler effect part for a fact)
2006-07-27 10:11:07 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Hubble realized that he could figure out how far away stars are by measuring the red shift. He discovered that the farther away they are, the faster they are receding (moving away). This also meant that the universe was expanding, which was a surprise since most astronomers thought the universe was stable. So I would choose your answer A.
2006-07-27 10:11:28 · answer #3 · answered by peter_lobell 5 · 0⤊ 0⤋
A
2006-07-27 10:12:59 · answer #4 · answered by ag_iitkgp 7 · 0⤊ 0⤋
a ,i guess
2006-07-27 10:09:05 · answer #5 · answered by Anniyan " follow the rules 1 · 0⤊ 0⤋