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NASA Sees Glow of Universe's First Objects
Damek writes with news from NASA's Spitzer Space Telescope, which has captured light from what may have been the first glowing objects in the universe, light generated 14 billion years ago. From the article: "'We are pushing our telescopes to the limit and are tantalizingly close to getting a clear picture of the very first collections of objects,' said Dr. Alexander Kashlinsky... 'Whatever these objects are, they are intrinsically incredibly bright and very different from anything in existence today.' Astronomers believe the objects are either the first stars — humongous stars more than 1,000 times the mass of our sun — or voracious black holes that are consuming gas and spilling out tons of energy. If the objects are stars, then the observed clusters might be the first mini-galaxies..."
Once the have a telescope that can peer past that glow, they find the number "42" at one of the cosmos and a hitchhiker thumb at the other end.
Focusing on glowing objects...
"Ahhhh, I can see what it says!"
"What is it?"
"Its a sign of some kind!"
"A sign?, what does it say?"
"Look out behind you!"
liqbase
... 'cause 14 billion years is about as old as news can get. Literally.
Thank you, I'll be here all week, enjoy the sushi!
Stressed? Me? Of course not. Stress is what a rubber band feels before it breaks, silly.
by some more powerful equipment. From New Scientist Space: "Because Hubble's mirror is larger than Spitzer's, it turned up dwarf galaxies too faint for Spitzer to resolve. "Once we remove pixels in the Spitzer images corresponding to the locations of these galaxies, the background infrared light level mostly disappears," Cooray told New Scientist. 'We think, therefore, the infrared light seen in Spitzer images is mostly due to the faint infrared glow from these dwarf galaxies.'" The full article
Google video has a vivid short movie relating the size of planets to the larger stars we know about.
"W CEPHEI" wins this video at 288194 times the size of the earth!
liqbase
A good way to think of it is to imagine us as living on the skin of a balloon as it is being blown up. You are moving away from every other point uniformly, but you aren't near the "edge".
In more physics-friendly language, there are only two possibilities - either the universe is open or it's closed. If it's open, then it's infinite in all directions and there is no edge (we don't think this is the case, but it's still technically possible). If it's closed, then there simply is no edge because as you travel in any direction you curve around to head back where you came from.
It might also help to realize that while the visible universe may be "only" 14 billion light years or so in radius, the longest dimension of a closed universe could be several times this number due to inflationary expansion. So we may not be seeing everything that's actually out there.
...following the principles of Heisenburger's Uncertain Cat...
The Sun is a pretty small star compared to others...
Right, but the 1000 times the mass would be a huge star. The most massive stars known today are on the order of 100 times the mass of our sun. So these might be stars that are ~10x larger than the largest currently observed stars.
Ah; Excellent question.
If you look at the "known universe," it appears that we are in the exact middle, dead center, of the known universe.
When we see the Cosmic Microwave Background Radiation, we are seeing "the edge" of the visible universe, that we can see.
As you look further and further away from where we are, you see deeper and deeper into the past, until you see back as far as we can, where we see only the cosmic microwave background radiation, uniformly, like a sphere, in all directions.
Most astrophysicists doubt that we are at the exact middle.
The reason we can't see things beyond the visible universe, is simply because light hasn't existed long enough to get to us, from things that exist beyond the edge of our light cone of vision.
Right? If light has only existed for, say, 14.7 billion light years, then you're not going to be seeing something that's 20 billion light years away. Or 100 billion light years away.
It makes sense that, at the very edge of our vision, we see the genesis of the universe, in all directions.
Astrophysicists today do not know how large the universe is, and it may well be infinite, in all directions. Astrophysicists take this idea very seriously, as far as I understand. That said, they also take seriously the idea that it is smaller than the observable universe, and just has a wrap-around effect.
Obviously. If you go back far enough in time, of course you'll see the glow from when the dimmer switch is just being turned up. I can't believe we waste perfectly good Science Money on wacky alternative theories, when the EUDS explains this perfectly.
Don't disappoint your bird dog. Go to the range.
The journal articles that go along with the story:
New Measurements of Cosmic Infrared Background Fluctuations from Early Epochs
On the Nature of the Sources of the Cosmic Infrared Background
(These were posted in the article, but only under a tiny "More info" link at the bottom that is easy to overlook.)
Think of it as the difference between how fast an ant can crawl across the surface of an expanding balloon, vs. how fast the balloon itself is being inflated. The two speeds are not related to each other, and there can be a limit on the former when there is not on the latter.
It's a very long series of conjectures basically. You measure the redshifts from known close star and "fixed" stars (star that don't appear to move). You come up with a series of ratios, you interpolate the distance based on redshift.
I am simplifying vastly here but you get the gist. It's about measuring close things and then using what you know about them to measure far things.
evil is as evil does
The current belief is that more than one of the theories is likely to be wrong, although it is entirely possible that they are all correct depending on the observer and/or universe. (In the Many Worlds theory, there is one instance of the Universe for every possible permutation of valid events that could ever occur. If this theory is correct and the shape of the Universe is dictated by events, then the shape of the Universe is determined by which branch you happen to be on at the time you do the observation. If branches can interact, this may vary between observations.)
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Consider tracing a path over the surface of a balloon with a pen as you're inflating it. You will move the pen a certain distance depending on whatever speed you draw with, but the path you've drawn will be longer than that distance. If you start out with two pens, and move them slow enough relative to the expansion of the balloon, it will take a long time before they meet (or they may never meet), even though they'll each traverse the original distance between eachother in a short amount of time.
If the universe is flat or open like a bedsheet, then it is infinite in extent, and has always been infinite in extent, or at least larger than we can see. As time passes, we have to look further away (or further back in time) to see the beginning. If the universe is closed like a balloon, then we still have to look further and further away, but we may end up looking back at our own position, just further back in time. A good, semi-technical discussion of the big bang can be found at http://www.talkorigins.org/faqs/astronomy/bigbang. html
We can't observe the hole itself but we can observe the effect it has on matter that hasn't fallen into it's event horizon. Matter will not fall straight into a hole; it will spiral in. As it is spiraling in, it will emit X-rays as a sort of death cry. Also black holes have magnetic fields and spin. A black hole actively feeding will ionize matter and some of this charged matter can be caught in the holes magnetic field and ejected from its poles as bright jets. It is a misconception to think of a black hole as a sort of cosmic vacuum cleaner that will suck down everything. A black hole has no more gravity than the mass that gave birth to it. A black hole can be safely orbited for instance. But the mass of a hole is so intensely concentrated that very exotic tidal effects are caused closer in to the hole. Get too close and yes even light will not escape. Get almost too close and very very weird (but predictable and observable) things happen.
Since there can never truly be such a thing as a true vacuum black holes can even evaporate. Since absolute zero can only be approached (but never reached) any given volume of space has a quantity of energy available within it. This energy can give rise to pairs of particles once thresholds are reached. The particles are formed in pairs because properties like spin and charge are conserved. This matter does not come from nothing! It is formed at the expense of available energy in the vicinity. If a pair of particles forms in the vicinity of a black hole's event horizon then one of the pair can fall into the hole while the other sluggishly makes it's way away from the hole. This happens at the expense of the energy of the hole itself so if the black hole isn't being fed with other sources then it will shrink a trifle. Large black holes have event horizons that appear barely curved at subatomic scales; this means that large black holes lose mass very slowly in this way. Even a hole with a few times the sun's mass will last far longer than the universe has existed to date. Smaller holes have more curvature on local scales and lose energy very very quickly. This is why the prospect of forming a hole in a particle accelerator isn't particularly scary.