http://news.yahoo.com/s/space/20060830/sc_space/strangeexplodingstarunlockssupernovasecrets
GRB 060218 occurred in a star-forming galaxy about 440 million light-years away towards the constellation Aries, making it the second-closest supernova ever detected. The closest was SN 1987A, which went off about 165,000 light-years away in the Large Magellanic Cloud, a nearby dwarf galaxy.
Does this mean that this supernova happenned 440 million light years ago and this may not be the current event?
2006-08-30 22:29:16 · 13 answers · asked by SciFi 1 in Science & Mathematics ➔ Astronomy & Space
You've got it exactly right
2006-08-30 22:34:52 · answer #1 · answered by Paul P 5 · 0⤊ 0⤋
Well, you've got it right. You are looking into the past. However, a light-year is a measure of distance and not time.
It is the distance light travels in a year. So if that star went nova and it is 440 million light years away. It occurred 440 million years ago. Because we assume that the light from that supernova is just now reaching us.
We have also been able to take X-Ray photographs of galaxies about 10 billion light-years away. Which means we are seeing that galaxy as it was when the Universe was about 2 to 4 billion years old. Or just a baby in cosmic terms :).
Every time you look up at the sky you are looking into the past. Even the light from our own Sun takes about 8 minutes to reach us... Every star in the sky is a piece of the past. Planets in our solar system obviously get their light to us a little faster, so we get a relative real-time view of them. However, true stars are showing us how they were 100, 1000, 10000, or even millions and billions of years ago!
2006-08-31 08:37:37 · answer #2 · answered by AresIV 4 · 1⤊ 0⤋
All events that we experience are in the past.
It takes a finite amount of time for the information about the event, whatever form it takes, to propogate.
Conceptualy the supernova happened 440 million years ago and the information about it is now reaching us.
This is essentially the same as the sound from a rock concert rig reaching you at some point (often <1second) after the perfomance has happened.
From this analagy the event is "current" as we are now experiencing its effects.
From a wider perspective the event did take place 440 million years ago.
Confused ?
2006-08-31 05:38:47 · answer #3 · answered by Andy 6 · 0⤊ 0⤋
It is current. In most of the answers ahead of me you say it is a distant (440 million light-years) and then your next remark you give a time (440 million years ago). Which lends me to believe that a light year is a measure of both time and distance.
Is it current? Most definitely! Are we watching it happen? Yes , minute by minute as it happens. No different '1 thousandth' of a second it takes to see what is happening on a football field if your setting in the stands or the 1 second delay if your at home watching it in your chair. We were not able to see this event any earlier than now. So current is correct.
And as far as an event , if we were not seeing it happening now it would not be an event.
So yes it is a Current Event.
2006-08-31 18:44:07 · answer #4 · answered by Anonymous · 0⤊ 1⤋
Absolutely right, no matter whether seen by hubble or unaided eyes ... a view into space is always a view into the past.
If that supernova is in a distance of 440 million lightyears, then it also means that this event happened 440 million years ago. (because that is the time the light took to come here)
2006-08-31 05:36:37 · answer #5 · answered by jhstha 4 · 0⤊ 0⤋
You got it right.
If you see the sun going black now at say 9:25 AM (planet earth time), it means sun went black exactly 8 minutes before i.e @ 9:17 AM (earth time) [because light takes 8 minutes to reach us]
similarly if you see a supernova, which is 440 million light years away, the event would have occurred 440 million years back !!
2006-08-31 05:37:03 · answer #6 · answered by Infinity 2 · 0⤊ 0⤋
Yep that's it. We see things because of the light that travels from them to our eyes. Normally, the farthest thing you look at would only be as far away as the horizon. So, it takes a small fraction of a second for the light from it to reach you. We see the Moon as it was just under 1.5 seconds ago. This is why if you have ever seen a news show where the anchor is here in the US and the reporter on the other side of the planet, there is a delay in their conversing. It takes time for the signal to go from newsroom to transmitter to satellite to reporter, then reporter rply has to travel back the same way. We see the Sun as it was approx 8 minutes ago.
When you look out across space, you are looking back through time. Neither time nor space is absolute, only spacetime is.
2006-08-31 05:42:57 · answer #7 · answered by quntmphys238 6 · 0⤊ 0⤋
Right you are.
Of course because of the velocity of light, always we see a past event. The past can be a 1/million of a second, or millions of light years a past. it depends upon the distance between the viewer and the event place.
The question is can we see an event from the future?
And if we can't see, can we know about a future event?
2006-08-31 05:56:36 · answer #8 · answered by imamulleith 2 · 0⤊ 0⤋
we see anything when light emitted by it or reflecting from it comes to our eyes so when supernova exploded at that instant light was emitted and now it have reached us.and now we are seeing it to find out the explosion. one thing more you was knowing this answer before asking the question.
2006-08-31 05:57:01 · answer #9 · answered by ashoke 1 · 0⤊ 1⤋
Yes, you are correct.
2006-08-31 05:45:17 · answer #10 · answered by raveenphy 1 · 0⤊ 0⤋