light from farthest we can see is 13 billion light-years, so that light left its object at that time. how ...?

👨🏻‍🏫 學術台天文學及太空

[匿名]

2010-09-26 1:47 am

how is the age of that star 13 billion years old? if it is traveling 10% the speed of light then it would take 10x 13 billion years just to get to where it is at now. so isn't the projected big bang 130 billion years ago? assuming speed is 10% of speed of light.
and how can they say they are seeing the primordial light from the big bang? that light would be traveling away - not towards us. we are seeing the images 130-13 billion years after the big bang.

更新1:

no the star is traveling away from us at a random speed that i guessed at 10% the speed of light. if light takes 13 billion yrs to get to us then that star had to travel that distance. if the star was travelign 10% the speed of light then it took 130 billion yrs for that star to get into the position of when its light left it 13 billion yrs ago. common its not that hard of a question. I dont know the speed of the star traveling away from us, and i am sure it is much much slower then 10% the speed of light. it must have been traveling perhaps 10 trillion yrs.

回答 (5)

[匿名]

2010-09-26 1:51 am

✔ 最佳答案

You'll remember the universe is expanding won't you?
When it started out that light wasn't that far away.

Waaayy under there! Light preceded stars by a very long time. Look it up.
300 000 years for the universe to get transparent to light. Long before any stars were around.
http://physics.uoregon.edu/~jimbrau/astr123/Notes/Chapter27.html . . .. . .

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[匿名]

2010-09-26 8:51 am

um, i think light from stars travel at 100% speed of light... the light is 13 billion years old... and the universe is 14.6-14.8 billion years old

light travel in ALL directions! from its source... TOWARD us and AWAY from us

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[匿名]

2010-09-26 9:25 am

How is it that you assume the speed of light is 10% the speed of light.
The speed of light isn't 10% the speed of light. It's the speed of light.
100% of the speed of light. That's why it's called the speed of light.

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[匿名]

2010-09-26 9:23 am

after the big bang, there was no light. all of the particles had to clump together to make a star, then a chemical reaction created light. it took many many many years to create stars, so the big band was long before the light of any given star

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Irv S

2010-09-26 9:11 am

Space has been expanding, (creating additional distance to cover),
while that light was 'in transit'.
Even tough that light is only 13 Bil. Yr.s old, the source point,
(the star can he hardly have lasted that long), is now many more
light years distant than that and receding faster then the red-shift indicates.
All the information we get is old.

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