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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.
Considering this is /., the article quote seems a bit redundant
-Cheers,
That's interesting, he explains, because given that light travels at a finite speed -- 300,000 km a second
...in a vacuum. When not in a vacuum, light can travel at a fraction of the speed of light.
The theory of relativity doesn't work right in Arkansas.
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?"
Yeah, the summary is bogus (surprise, surprise). The big news is that this is the furthest cluster of stars yet observed, a confusion not encountered in TFA.
Those people who think they know everything are a great annoyance to those of us who do. (Isaac Asimov)
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.
The whole notion of factoring time out of spacetime for special treatement is silly. Other than the fact the metric is a bit odd, thinking in terms of a unified spacetime is much easier. The idea of "sometime else" is just as good as "somwhere else" -- it's the whole fact that the English language is stupidly constructed and people say "some other time" that re-inforces the separation. All you really know as an observer is "local and now" -- i.e. your spacetime point. Claiming the images are very old is non-sensical. What reason do we have to assume there is an underlying universal local clock? Other than it seems to work locally we don't really know anything.
how many football fields is that?
Might want to research some physical cosmology ... the universe has expanded faster than the speed of light.
Cyde Weys Musings - Scrutinizing the inscrutable
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.
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.'"
I never knew what question to ask before reading this branch of the discussion. Whether or not it is accurate is beyond me but, I think I can feel good about this: http://en.wikipedia.org/wiki/Expansion_of_the_univ erse
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!
The index of refraction of lead is 2.6, so the
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.
Don't mess with The Phone Company. Piss them off and you'll be using two tin cans and a piece of string.
How appropriate that is....
factor 966971: 966971
The whole universe was just created 6000 years ago. That star 1 billion light years away is also just 6000 years old. It was created along with the stream of photons stretching all the way from here to there so that it appears to shine steadily. BTW all the dino fossils? they too was created 6000 years ago along with the Earth's crust. It will all be explained very clearly in my forthcoming book The Theory of Intelligent Shining. For advance copy, please send me 79.99$.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
Don't be fooled by this post ... the article KFG links to doesn't contain any reference to ponies or horses what so ever.
For the perfect anti-Unix, write an OS that thinks it knows what you're doing better than you do and let it be wrong.
There is a class of variable brightness star called a Cepheid, because the first example of the class was Delta Cephei.
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 from parallax observations.
Minor variations in rate are closely connected to certain metallic ions found in these stars in various proportions, and this can easily be determined as well for new Cepheids, by spectroscope. True Cepheids are population 1 stars, but there is also a related type, called either Type 2 Cepheids or W Virginis variables. These are the older, population 2 versions of the same phenominon. At first, the mix of types 1 and 2 made distance estimate figures rather blurry for distant galaxies, but once it was recognized that they could be divided into the two types, not only did type 1 Cepheids give us some very accurate estimates, but type 2 can be used to get an independant estimate and so check the first one.
All Cepheids are tremendously bright, and can be picked out individually at distances enormously greater than can a sun sized star. The time for a brightness cycle is long enough that a lot of detailed measurements are possible, but short enough that it will repeat many times in a single researcher's working lifetime, making them ideal in many ways.
Who is John Cabal?
I'm just making a guess here but it goes something like
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 value for the temperature of the universe.
When you look at the oldest light it came from the glow of the universe at that temperature - and it started out with a wavelength related to that temperature.
That oldest light has been stretched by the red shift by the expansion rate of the universe and is now at a very long wavelength which we see as the microwave background radiation in every direction in space.
we can measure the rate of expansion of the universe by looking at standard candles (supernova which pop with the same brightness - so we know how far away they are by their brightness) and measure their red shift. So we know how much red shift occurs for a certain distance.
so if we look at how much red shift the oldest light has suffered from its original high frequency we can work out how far away it comes from - or how old it is - because it has traveled to us at the speed of light 3*10exp8 m/s.
The figure that comes out of this pile of logic is apparently around 13 billion years. Maybe someone can verify or correct that this is the logical linkage used in the calculation.
Facts are history now plebs have politics for religion on social media.
Haha, jokes, I get jokes. /homer