Suppose one star which was 5 thousands light years away from us, remained alive for 5 billions of years and emitted light for 5 billions of years.The star died 5 million year ago.However its light started reaching us after its death and will be reaching us for further millions of years just giving us false image of the star. Then how on earth do we know which star is real and which one is just an image ?
2006-08-05 18:12:45 · 8 answers · asked by ♪¢αpη' ε∂ïß♪ ♥♥♥♥♥♥♥♥ 6 in Science & Mathematics ➔ Astronomy & Space
Yes you have a point that all the stars we can see in the sky could have "winked out of existance" several years ago and we would not know it yet. For stars very far away, I'm sure there are many that no longer exist. It could be millions of years until the light from their supernovas reach the earth.
Of course this is because even light takes a great deal of time to travel the distance between the earth and most of the stars.
But they are not "imaginary". The DID exist. They DID emit the light that you see in the sky at night. Just because they may no longer exist doesn't make them imaginary any more than George Washington was imaginary. He no longer exists, but he once did!
2006-08-06 17:22:32 · answer #1 · answered by paulie_biggs 2 · 1⤊ 0⤋
All the stars that we can see, either with the naked eye or with a telescope are real. None of them is "imaginary." Some would show the effects of aging if we could see them as they actually are now, but, as that is not possible, from an observational standpoint, all stars are considered to be viewed as they appear.
Another way to say that is to say that even though we may be looking at light from a star that has been travelling for billions of years and it is possible that the actual star is not there anymore, we may not actually know where the star actually is or was. Therefore, the present state of the star does not matter. If it was real when it emitted the light we see now, then it is real to us.
2006-08-06 01:25:35 · answer #2 · answered by aviophage 7 · 0⤊ 0⤋
No they're real, but like some others have pointed out, it's more like looking at a picture of the universe, rather than seeing it happen in real time, because the stars are so far away that it takes a long time to reach us.
The thing is, we don't know exactly which stars are "alive" when we observe them (unless they're part of a star system where the other star already died and is emitting a lot of radiation), or see them supernova.
2006-08-06 01:32:21 · answer #3 · answered by komodo_gold 4 · 0⤊ 0⤋
Red Shift
http://en.wikipedia.org/wiki/Redshift
2006-08-06 01:26:28 · answer #4 · answered by Ammy 6 · 0⤊ 0⤋
I think that if they give off some sort of pulse that is measurable, the remnant would be present but the pulse would not. If, however the star were present, the pulse would also. It would be the mass and composition of the star that produces the pulse and not the retreating or advancing beam of light.
2006-08-06 01:21:17 · answer #5 · answered by Tony T 4 · 0⤊ 0⤋
stars are real.ya may be so some stars are imaginary but most of them do exist.because there are hundreds million thousand stars in a galaxy we all know it.okay now bye
2006-08-06 01:27:48 · answer #6 · answered by lisa francis 1 · 0⤊ 0⤋
whenever you look at the stars in space, you are only seeing the "past"... actually, when you look at ANYTHING at all, you are seeing the past... if you really think about it.
light has to travel.
2006-08-06 01:24:12 · answer #7 · answered by Cliffy 2 · 0⤊ 0⤋
REALLLLLLLLLLLLL
2006-08-06 01:40:41 · answer #8 · answered by annastasia1955ca 6 · 0⤊ 0⤋