Astronomer Discovers the Most Distant Stars Ever Observed From Earth 291
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."
Looking back in time. (Score:3, Funny)
So, when I look at the sun, I am actually looking back in time 8 minutes?
Deep.
Re:Looking back in time. (Score:5, Funny)
Yes, and apparently, 8 minutes ago hurts like a motherfucker.
Re:Looking back in time. (Score:5, Funny)
When you read Slashdot, you are looking back in time approx. 1.7e-9 seconds*, assuming you sit about 50cm from your screen.
* May be more if you're reading a dupe.
Billion-year-old alien computer message decoded! (Score:5, Funny)
"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.'"
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Re:Looking back in time. (Score:5, Informative)
Re:Looking back in time. (Score:5, Funny)
Re:Looking back in time. (Score:5, Interesting)
If gravity also travels at lightspeed, I wonder whether space would "unwarp" around the Sun instantly. Or whether there's some "viscosity", with the Sun's gravity well taking some time to "snap" into an undeformed, thereby gravityless, shape in 3D (4D) around the Sun. Probably it's instantaneous, but we don't know that much about the "void medium" in which these fundamental forces act. At least I don't know that much
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Not quite. There are several possibilities. One is that the particles do actually exchange information using particles that travel faster than light. This information creates the statistics when the experiment is repeated several times, but cannot be directly observed or used to transmit tangible information. I consider this unlikely, because it just moves the wrinkle in the rug to the faster-tha
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It's speed is unknown, its fast/instant, but nothing can be faster than C (the speed of light) so it must match that? Or maybe it is a little slower.
We are still trying to figure out gravity and it's effects on light, time, and other objects. It's harder to test than light because you will always have gravity, no matter how small. Can't just set up a spinning mirrior on a remote mounta
Re:Looking back in time. (Score:5, Interesting)
From the bottom of the linked page:
Of course, I don't know Dr. Will personally. I merely turned up his page via Google, but WashU is certainly a respectable physics school, and I am inclined to trust what their faculty say about matters which are in their particular area of expertise and out of mine.
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*sigh* Yes, I know, I was simplifying things. The current thinking is that, odds are, gravity propagates at the speed of light. It may propagate slower. It almost certainly does not propagate faster (lest our current cosmological theories fall flat on their face, as they make the fundamental assumption that information can not travel faster than c), and *that* is, I think, the real brainf*ck for most people.
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No, you are completely missing the concept.
When you see something you are always seeing the past - what that object looked like when the
Re:Looking back in time. (Score:4, Insightful)
To use your china analogy, it's more like, if someone came from china, bringing a photograph they took before leaving, then when they show it to you, the photograph does show what things were like those 12 (or whatever) hours ago. The photograph itself might be in the present, but it's content - what you're looking at - are of the past. This is the same as looking at light from the past; the light may have reached the present, but we're not looking at the light, we're looking at the image carried in the light, which is from the past. Disagree all you want, you'll find you're in the minority opinion.
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Sounds familiar... (Score:2)
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A Long Time Ago in a Galaxy Far, Far Away...
Close though.
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What is this light speed thingie? (Score:2, Insightful)
it travels as fast as it travels (Score:3, Informative)
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For a complete vacuum, it certainly has a lot of stuff in it to look at.
Re:it travels as fast as it travels (Score:5, Funny)
Someone forgot to clean out the filter? My vacuum filter always gets full of gunk after a while...
Re:it travels as fast as it travels (Score:5, Interesting)
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who's got a billion light years long spool of fiber optic cable anyway?
speed of light in Pb (Score:2, Interesting)
speed of light in lead is c / 2.6 = 1.1E8 m/sec.
Of course, light is absorbed pretty strongly by lead.
The index of refraction is still an important
quantity - it determines how much light is reflected
from the surface, for example.
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Re:it travels as fast as it travels (Score:5, Insightful)
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
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http://www.glenbrook.k12.il.us/gbssci/phys/class/
KFG
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They're in luck. This light travelled through space
Oh those wacky astronomers for actually using c correctly.
Cheers
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only 1 billion ly? (Score:2)
I RTFA, but it didn't discuss why 1 billion ly was such a big deal. Don't we look at stars (albeit clustered into galaxies) that are much farther away than that all the time? Is this a record for looking at individual stars?
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Didnt seem like a big deal to me either. Ok, you can see stuff that is older, but until you quantify what you are seeing, it's not hard news. Now if they find different composition of stars, or different than expected output, then that is news.
Re:only 1 billion ly? (Score:5, Informative)
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we get the age and size from the frequency of the microwave background radiation.
The background is measured at 3.5 kelvin (degrees above absolute zero) which relates to the microwave frequency by wiens law (sorry very rusty on the details, frequency of the light given off by an object at a certain temperature is defined by the laws of thermodynamics, the hotter it is the shorter the wavelength).
when the big bang occurred particle physics can give a valu
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It's not quite right to think that the universe "grew from a point source." There was nothing (no physical matter or information) that went from point A to point B faster than light. Think of it like the surface of a pond freezing out. It can do so everywhere at once, with out something moving from one side of the pond to the other. Remember that Einstein's famous limit on the speed at which something can travel applies only to stuff that has mass (=energy) or carries information. The line you d
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Wait... (Score:4, Funny)
paraphrasing Douglas Adams (Score:5, Interesting)
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).
Re:paraphrasing Douglas Adams (Score:5, Interesting)
Ahh, but the beauty of it is that if you _DID_ travel at or near the speed of light, one billion years would not seem like such a long time at all - certainly doable within a lifetime! So if you asked those photons how old they thought they were, you'd be surprised at the answer... so the photons aren't really that old at all! Confused yet?
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Not until you got back... Most people feel lost after a few decades, after a few billion years I bet your first two questions would be "Where's earth?" and "Where's
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It provides equations giving the velocity and distance travelled by the ship in terms of time as viewed from where the rocket was launched and within the rocket itself. That and the explanations are definitely worth a read.
Re:paraphrasing Douglas Adams (Score:5, Funny)
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(hint - track one starts at the outside edge)
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Hmm, your teacher scalig is a bit off, eh? Hole in record is about 1/4". If that represen
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and you're right the next closest galaxy probably IS the sun...
Can you say that again? (Score:4, Funny)
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Assuming you're not being flippant ..... (in which case I'm being pointlessly pedantic)
Since the light took 1 billion years to reach us, it's, well, "old light" that occured in the past. We're not seeing those objects as they exist today, we're seeing them as they existed 1 billion years ago. Hence, we're looking into the past. We have no idea what the
Age (Score:4, Funny)
Is that really the farthest? (Score:2)
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I can just see it (Score:2)
Astronomer 2: In light years? It's OVER 9000!!!!!
wow. remedial time travel (Score:3, Funny)
these are really good brownies.
factoring spacetime is silly (Score:2, Insightful)
1bil lightyears is too far for me to understand (Score:2, Funny)
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Also equal to 4.70279985 × 10^22 furlongs.
Also equal to 6.32396717 × 10^13 Astronomical Units.
Also equal to 9.31154371 × 10^25 hands.
Any other peculiar units of measure you'd like translations into? Google calculator is really good at this stuff.
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There are 1093.6 yards in a kilometer.
There are 3.654 football fields in a kilometer.
A light year is ~ 9,460,730,472,580.80 kilometers.
There are 2,595,267,579,293.56 football fields in a light year.
There are 2.59527E+21 or 2,595,267,579,293,560,000,000 football fields in a billion lightyears.
Other imperial measurments you might find usefull:
Dime widths to the lightyear: 38,448,408.68
Buicks to the lightyear: 48,060,510,849.73
Hamsters to the lightyear: 961,2
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I had no idea soccer fields were so large. American Rules Football only uses a 100 yard field.
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In other words... (Score:2)
A correction/explanation (Score:5, Informative)
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.
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Sharp as a Tack (Score:2)
Gee, figured this one out huh?
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I have a friend who just turned 30. Then I met his girlfriend. She just entered college, and she was 19.
I would tease them saying stupid things like, "You know Jim, did you ever stop to think that when you got your driver's license at 17, you would be driving up to the local middle school, pointing at a random 6 year old who just started kindergarten and be saying to yourself, 'I'm gonna bang that chic someday'? Or when you just graduated college at 22, you would be checking out the jr high student who wil
Assuming the Speed of Light is Constant (Score:4, Interesting)
This article has taken great and repetitive pains to explain something that may in fact not be true. A previous ./ story [slashdot.org] 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.
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It's a good thing they're going to increase the speed of light in 2208.
Ha .. ha (Score:2, Funny)
How appropriate that is....
Crappy technical writers (Score:2)
I think this was a great technical achievement, but was ruined for me by the incompetance of the article. TFA kinda lost me with the opening paragraph:
WTF? He used the Hubble! Did he grab a shuttle up to the Hubble, rip the sesnor pallet out and stick his head down the end of the OTA?
Also, the whole harping on about the light bein
Nah, you cant look back for more than 6000 years (Score:3, Funny)
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Re:If only there was a galaxy sized mirror near it (Score:2)
That'd be great! It'd be awesome because then you could see the earth 2 billions years ago...Wait! it didn't exist because the world's only 6000 years old...But the rest of the universe is older...?
Is that comment really flamebait? I'll buy "Offtopic" since this isn't a religious-themed message board.
Here's a question for the "young earth" creationists: the math (triangulation and distance = speed * time) used in this case shows that the universe is at least a billion years old. What is your proof that it isn't? Did God create the stars with "already traveling light" to fill in what would otherwise be a 999,994,000 gap in time and distance?
And to the astronomers (since I'm not one): how many times in
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No. It was the Flying Spaghetti Monster, not God. Ask the Midgit, he knows.
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Either way, you're dismissing all the accumulated knowledge of science in favor of the superstitions of ancient sheep herders who thought that all the animals on earth were within walking distance of Noah's house. The bible contains equal parts fact, history, and pizza.
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The raw imagery will indeed be red-shifted. That is, after all, how they know how far away the stars are. Hubble Constant and all that.
S
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Is this a sick joke? When you're
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Re:1 billion light years? (Score:5, Informative)
Blue shift/red shift (Score:2)
See the wiki: http://en.wikipedia.org/wiki/Redshift [wikipedia.org]
So how reliable is using blue shift and red shift to determine both age of the star, and weither it is moving towards us or away.
So while blue star clusters could be younger, couldn't it just an older start that is moving toward us?
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The pulse rate of these stars is very tightly correlated with their absolute luminosity. A three-day period Cepheid has an absolute luminosity about 800 times the Sun. A thirty-day period Cepheid is about 10,000 times as bright as the Sun. The scale has been calibrated much more precisely than those approximations, using nearby Cepheid stars, where the distance can be determined accurately
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Re:1 billion light years? (Score:4, Informative)