Astronomers think the Universe has been around for about 13.7 billion years. Well, they just spotted an object about 13 billion years old: http://news.yahoo.com/s/afp/20091028/sc … 1028233220
The object was an exploding mega-star that occurred about 13 billion years ago. The light from this explosion just reached us, here on Earth.
To people who may not be good with astronomy and space, the light you see from the nearest stars started many years ago and you are seeing the light from the past. For example, the Sun's light takes about 8 minutes to reach Earth. So the light you see from the Sun is actually 8 minutes old. The light from the nearest star to Earth takes about a year to get here. So, the light you see from that star is a year old.
That is why we can see light that is billions of years old (from the beginning of the Universe) still today. When there is a big explosion, we don't see that explosion for "x" number of years, depending on how far away that object is to us.
This May be a silly question,but I am not miss science gal,exactly how do they know the actual distance to something that far away if they are seeing it through a 2 dimensional lens?
They use math and physics. Light travels at a set speed (except in or near black holes). They also use the "known" distances of nearby objects in the Universe to further gauge how far something is.
I don't know the exact formula, as I'm not an astronomer of physicist, but it's a lot of math and I believe they use radar to measure X-rays and radiation of the object, as well.
Now, with this explosion, only 2 people saw it appear and by the time all the telescopes turned to that object, everyone saw the after-glow of the explosion.
If those 2 people weren't looking in that exact spot at that exact time, everyone would've missed the explosion.
So I'm sure we've missed thousands of other explosions, over time, because no one was looking in that exact part of space when the light finally hit us.
They use concepts called red shifts and blue shifts. It's related to the doppler effect (the pitch of an ambulance siren, for instance, goes up as it approaches you). Objects emitting radiation that are far away and drifting further away as the universe expands will redshift, and like Tim says, math can calculate the distance and age of the object.
If you want to get crazy:
by Grace Marguerite Williams3 years ago
Wilderness has a way of presenting a logical and intelligent conclusion to many arguments. What makes so many people drawn to religion although the bases of religion aren't based upon any logical premise? ...
by IntuitiveMind6 years ago
How Do You Explain The Age of The Universe?I understand religious people believe God made the world and everything in it and everything in the universe. According to the bible, the world is only several...
by Uplifterx5 years ago
"Georges Henri Joseph Édouard Lemaître (French: [ləmɛtʁ] ( listen); 17 July 1894 – 20 June 1966) was a Belgian priest, astronomer and professor of physics at the Catholic University of Louvain. He was the...
by Paula2 years ago
What is the age of the universe?What are your thoughts on the age of the universe? Why do you think it is as old as you think it is. Perhaps it is a range of time. To add, what is your worldview...
by rohitworld906 years ago
If we can move at any speed we want, would we ever reach the end of this universe?
by Sprinkler Man9 years ago
And how long did it take to get here? Could it have been there all along and then the earth formed? Billions of years ago?Does this make your feel tiny and insignificant considering how large and vast the universe...
Copyright © 2018 HubPages Inc. and respective owners.
Other product and company names shown may be trademarks of their respective owners.
HubPages® is a registered Service Mark of HubPages, Inc.
HubPages and Hubbers (authors) may earn revenue on this page based on affiliate relationships and advertisements with partners including Amazon, Google, and others.