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Astronomer Discovers the Most Distant Stars Ever Observed From Earth
Cryolithic writes to tell us The Vancouver Sun is reporting that a University of B.C. astronomer recently used NASA's Hubble telescope to see a cluster of stars one billion light-years from Earth, the farthest stars ever observed from Earth. From the article: "That's interesting, he explains, because given that light travels at a finite speed -- 300,000 km a second -- the light emitted from the star cluster he and Kalirai saw was emitted one billion years ago. That means the cluster as it appeared to them two months ago was the way it looked one billion years ago. In other words, they were looking one billion years back in time."
"In other words, they were looking one billion years back in time."
So, when I look at the sun, I am actually looking back in time 8 minutes?
Deep.
Ric Romero is submitting articles to Slashdot now?
By reading this you acknowledge that you have read it.
Yet more evidenence that mankind cannot truly comprehend the vastness of space. Travelling 1 billion years at the fastest possible speed known to science doesn't even get us to the edge of the universe.
I remember a highschool experience. A teacher had a record, put it on the table. "Ok, see the hole in the middle? That's the sun. Track 1 is approximately where the earth is located. The outer edge might be pluto's orbit. Heliopause? That's probably in the teacher's parking lot. Ok, so the next closest galaxy is Alpha Centauri, so that is approximately...well, Hamilton." (We were in Toronto, Hamilton is 100km+ away).
John Maynard Keynes: "When the facts change, I change my mind. What do you do?"
I don't get the whole "back in time" thing. Saying it 3 different ways in a 3 sentence blurb isn't quite enough. Is this, like, before the Great Flood? :-)
Learning HOW to think is more important than learning WHAT to think.
In other words, these pictures are one billion years, two months old.
Yea the visible universe is some 46 billions light years. They are referring to detecting individual starts a billion light years away whereby normally you would only see a galaxy with non identifiable individuals stars at such a distance.
That's like asking "Is it one billion light years from New York or one billion light years from Chicago?"
For a complete vacuum, it certainly has a lot of stuff in it to look at.
Someone forgot to clean out the filter? My vacuum filter always gets full of gunk after a while...
Seven puppies were harmed during the making of this post.
Oh.my.god. Using those figures, according to my calculations, it takes the light from the sun about eight minutes to reach Earth. That means, we aren't seeing the Sun NOW, we're seeing the sun eight minutes in the PAST. So everything we're seeing, everything with the Sun's light on it, is actually touching the past! I'm.. I'm touching the PAST. Looking through TIME.
these are really good brownies.
As an astronomy graduate student, I would like to offer a correction or an explanation of this statement:
From the article:
"That's because the older a star gets, the redder it gets, he says. Younger stars are bluer."
Kinda true, but the point is something else. A young *cluster* of stars will look blue because brightest stars in a young cluster are blue, massive stars. These blue bright stars burn their fuel (Hydrogen) very fast and have short lives (~100 Million years). When blue bright stars go away, more numerous, but much fainter, red stars start to dominate the color of the cluster. Therefore, as the *cluster* gets older, it gets redder.
For galaxies out to about 100 million light years, we can use a well-known relation between the pulsations of bright stars and their luminosities to get a pretty accurate distance. Beyond that, the simplest measure is the cosmological redshift of the light. If the redshift is, say, 10%, then we use the Hubble relation (speed / Hubble constant = distance), where (speed = redshift * speed of light) to get an estimate. We can then independently calibrate this with Type 1a supernovae, which all go off with roughly the same brightness. This is only really useful for smaller redshifts and distances, since asking for the distance of an object with a significant redshift is sort of ambiguous. Do you mean how far is it "now"? How far away was it when it emitted the radiation? But the above is the simplest answer to your question.
It's pretty darn close to a perfect vacuum... according to Wikipedia (and my recollection), the average density of the universe is less than 1 atom per cubic meter. That includes all the pretty things out there to look at...
...in a vacuum. When not in a vacuum, light can travel at a fraction of the speed of light.
Well no, not exactly. When not in a vacuum it takes rest stops which reduce its average speed, but when not taking rest stops it travels at the designated finite speed; because that's the only speed at which light can travel. There was this Maxwell guy who 'splained it.
You know about the pony express? Well, they had posts along the way to change horses. Let's say, for the sake of simplicity, that these posts were 15 miles apart and that the horses traveled at a finite speed of 15 miles per hour. When the horse is moving it is always going 15 miles per hour, but the average speed of the horses over a full day is 13 miles per hour because of the time it takes for the rider to change them on an hourly basis.
Light is like the Pony Express, only without the horses, which wouldn't be like the Pony Express at all, would it? That would just be some guy taking a walk.
Nevermind.
KFG
Parallax? Dude! Are you crazy? I think there should be a rule on /. Anyone who's going to talk about figures should at least do an order of magnitude calculation on their calculator first. In fact, forget order of magnitude, just order of magnitude of the order of magnitude should be enough to tell you that using parallax to measure the distance of something 10^9 light years away is completely insane. You don't even need a calculator. google will tell you the parallax angle we might get from viewing this cluster from opposite sides of the Earth's orbit.
Doesn't it make you feel good to know that our freedoms are protected by politicans, lawyers and journalists.
From the article:
"Astronomers further said that they had decoded part of a computer signal from the star systems in question, possibly a signal 1,000,000,000 years old! It said, 'Please wait, Java loading.'"
This article has taken great and repetitive pains to explain something that may in fact not be true. A previous ./ story talked about indications that the speed of light may in fact be slowing down. Depending on the rate of change, they could be witnessing events significantly closer to the current time -- especially when we are talking billions of years.
I believe in de-evolution. God made the world perfect, man fell, and its been going downhill ever since!