NASA Sees Glow of Universe's First Objects 327
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..."
Looks like this is already being refuted (Score:5, Informative)
Re:Please explain (Score:5, Informative)
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.
Re:1000 Times the mass of the Sun? (Score:5, Informative)
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.
Re:Please explain (Score:5, Informative)
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, [wikipedia.org] 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, [wikipedia.org] 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.
Re:IS it 14 billion or 15 billion? (Score:2, Informative)
Re:Almost there... (Score:3, Informative)
Get the papers here (Score:3, Informative)
New Measurements of Cosmic Infrared Background Fluctuations from Early Epochs [arxiv.org]
On the Nature of the Sources of the Cosmic Infrared Background [arxiv.org]
(These were posted in the article, but only under a tiny "More info" link at the bottom that is easy to overlook.)
Re:Please explain (Score:4, Informative)
Re:Please explain (Score:3, Informative)
Links to the technical journal articles, summary (Score:3, Informative)
http://arxiv.org/abs/astro-ph/0612445 [arxiv.org]
http://arxiv.org/abs/astro-ph/0612447 [arxiv.org]
The basic idea is that the astronomers used an infrared
space telescope to take very deep images. They then tried
to remove all the obvious sources of light, and examined
the resulting "blank" images very carefully. They claim that
there are very faint sources of infrared radiation which
remain, and that the spatial correlation of these sources
is roughly what one would expect if they were young galaxies
in the very early universe.
There are limited opportunities for other astronomers
to examine the same regions with other telescopes and
at other wavelengths; that could provide evidence that
might support the claim, or weaken it (if, for example,
radio telescopes detect some of these sources and
show that they are ordinary galaxies in the relatively
nearby universe, that would weaken the claim in
the press release).
We can also just wait a decade or so for JWST, a more
powerful infrared space telescope, to observe the same
field.
Re:Please explain (Score:2, Informative)
Alternatively, I think that it doesn't make much sense to think about space in terms of space. That's kind of like thinking of lollipops in terms of lollipops. I mean, sure, they're delicious. If I tell you about lollipops, you may think, "Mmm, those are delicious." But I don't know that I could say anything useful to you about lollipops strictly in the language of lollipops, whatever that means. Frankly, there's a lot of ways to mess with space (dilation, anyone?), and it doesn't seem as static a thing as I once thought it was. What happens when you stretch out space? Hmmm, more space.
My gut intuition (not that it means much) makes me think that the universe is closed and probably looped back into itself. The main reason is that it seems like a weird concept to have space just "end". If it were shaped like a balloon, for instance, maybe there's a way to avoid some disturbing delta functions of vacuum to nothingness.
Oh yeah, sorry I couldn't help. I'm done rambling now.
Re:Please explain (Score:3, Informative)
You talk about a thing that exists 3-dimensionally needing to be measured. That's fine for a thing, but space is not a thing. Space sort of *is* the measure of things. If you imagine an x-y-z axis, space *is* that axis. And in the case of infinite space, those axes go on forever. Space is not a thing; it's the, uh, space in which things exist. It's just the distance between things. It's abstract -- not really a thing, but the relationship between things.
Maybe reading some philosophy or metaphysics about 'space' would help you understand, rather than physics that already assume you understand the concept.
Re:Almost there... (Score:3, Informative)
Monkeyboi
Re:How does light distance measurement work? (Score:4, Informative)
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.
Re:Almost there... (Score:5, Informative)
13.7 billion years later, that first light year has expanded like a rubber sheet to have a disproportionate contribution to the 53 billion, compared to light years that the photon covered later on, just before reaching us. You can't just multiply the total elapsed time by c. You have to actually do an integral over time for the entire trip to get the 53 billion, where the integrand is the product of c by the "stretch factor" S(t) at that point on the trip: the factor by which the space that a photon was flying through at time t has expanded by now (as considered relative to a frame where the Earth is at rest). I don't know what this function would be, but I do know it's a function of time (or more specifically, time since the Big Bang in a frame at rest with respect to the microwave background radiation).
If S(t) were fixed at 1.0, you'd expect an integral of 13.7 billion light years. But it isn't fixed at 1.0; it is always greater than that and only approaches 1.0 at the end since light years at the end of the trip haven't had much time to expand. At the start of the trip S(t) could have been very high, depending on the age of the universe at the time.
Re:Gross errors (Score:2, Informative)
Thought by whom?
That would imply that our matter had exceeded the speed of light to arrive here.
Essentialy, it has [wikipedia.org]
State of the Art (Score:5, Informative)
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.)
Re:Here's the problem though... (Score:2, Informative)
Re:Looks like this is already being refuted (Score:5, Informative)
I've looked over the EM/plasma theories before. The cosmological scale theories might have a grain of truth, but the Solar System scale theories (eg, that comets are highly charged objects) contradict both what we see and our models of electromagnitism. Comets formed from existing material. It's quite possible that pre-solar system collisions and supernova created the features seen in the above comet material. But it's not plausible to explain this with an exotic theory that has stable highly charged objects (immersed in the solar wind which would drain away the charge) and huge, unobserved voltage potentials (the Earth and Moon vary enough in their orbits that we should experience some of this phenomena, but we don't).
And then there's the Stardust mission -- which when combined with the results of the Deep Impact mission indicate quite clearly that our early assumptions about comets were quite wrong. Scientists are now apparently trying to invent scenarios for how it could be that comets would contain exotic meteorite particles as well as particles that have clearly been formed under intense heat. Perhaps they should consider that these initial speculations were wrong in the first place. I doubt we'll see any such sanity though. More likely, we'll see additional new speculations to support the earlier unsupported speculations.
No, this is relatively modest disagreement with the models of comets and their origins.
We have already observed objects with enormous mass packed in a very small location. Maybe our "black hole" models of what happens when that much mass is packed into one place is inaccurate, but these objects do exist. And multi-dimensional models are one approach for understanding models involving forces other than gravity. For example, the first Kaluza-Klein model was a five dimensional model which was able to explain general relativity and the electromagnetic force. However, in the process it introduced a scalar field which we've never seen experimentally. So that likely indicates that the model is incorrect, but that's the only significant cost of the model. It otherwise models gravity and EM pretty well.Re:Please explain (Score:3, Informative)
No; There's no reason to believe things didn't start beyond us. Furthermore, there is the expansion of space.
That is, at the time of the big bang, my understanding is that there may have been plasma that was billions of light years away. My understanding is that the big bang refers to initial density, and to expansion. But not necessarily to a beginning in a single point.
In my defense, I refer you to a NASA site, "WMAP Cosmology 101," [nasa.gov] the part that begins with: "Please avoid the following common misconceptions about the Big Bang and expansion..."
Re:A little help here (Score:3, Informative)
Re:Looks like this is already being refuted (Score:1, Informative)
In my many adventures through the forums of Slashdot talking to people about Electric Universe Theory, I've run into a few people who half-educated themselves on the theory itself. It's not really any fault of your own. There is an overwhelming amount of material to go through. It took me three months of my free time to actually become even quasi-proficient in what the theory says. It appears that the problem with EU Theory isn't the theory itself -- but rather satisfying peoples' expectations that they be taught the mechanics of the universe in three hours or less while simultaneously fending off the amazingly hostile attacks from advocates of the mainstream. It appears that the desire by advocates of the gravity-dominant universe to keep out all serious competitors is stronger than any objective desire on their part to learn the truth of the universe. It is imperative that people with an interest in EU Theory not cave in to this posturing which does nothing more than limit the choices of cosmologies available to the public. There is in fact still no serious problem with Electric Universe Theory.
I agree that the faraway observations are strongest, but there is no problem with the electromagnetism of EU-style cometary theory when you understand how plasma behaves. Many people make the mistake of assuming that EU Theory is advocating an electrostatic model for cometary and planetary interactions. In fact, the solar wind would not necessarily "drain away" charge from any other plasma or body in space any more than the plasma of space would drain away the solar wind's charge. That's because plasmas naturally form what are called double-layers. From http://www.thunderbolts.info/tpod/2005/arch05/0510 31plasma.htm [thunderbolts.info]:
This is not actually exotic theory. These are fundamentals of electrodynamics and plasma physics.
(the Earth and Moon vary enough in their orbits that we should experience some of this phenomena, but we don't).
Well, if you mean that we should see the Earth's coma and tail like in a comet, that would require that the plasma surrounding the Earth be in the glow discharge mode. In reality, plasmas can and do exist in non-glow states much like a transistor has multiple operating regions. The Earth's magnetosphere exists in this state except when the aurora occurs.
If you go to the page at http://www.thunderbolts.info/t [thunderbolts.info]
Re:Almost there... (Score:3, Informative)
An interstellar photon, OTOH, can take on a continuous range of energies, and its wavelength can be adjusted by arbitrarily tiny amounts. For this reason inflation has a long term cumulative effect on photons that is just not seen with atoms.
Atoms would stay the same size as they are now for the exact same reason they do now.
Re:Speed of light? (Score:2, Informative)
Now... Reset the experiment, make the elastic 1mm long, and attach each end of the elastic to two rifle bullets pointing in opposite directions. (This is INCREDIBLY stretchy elastic, trust me!) Place the ant (this one is a very very small ant!) between the bullets, not quite in the middle of the elastic, and instruct him that when the bullets are fired, he is to run at his standard speed "c" (representing the speed of light) towards the middle of the elastic. Fire the bullets... Watch and be amazed, as within a few thousands of a second, the elastic reaches 10 metres in length, and the ant, running at "light speed" has only covered 1mm or so in the same amount of time. For arguments sake, lets say the bullets each hit a target, lodging in place with the elastic still attached. This represents "now". The ant is representing a photon from the beginning of the universe and it hasn't yet reached the middle of the elastic, and won't do for probably a couple of minutes. This represents how we can only just be seeing events that occurred at the Beginning. Thanks to the inflationary properties of the early universe, we will continue to receive this light for, well, the remaining lifetime of the universe. Hard to believe that two photons that left their source perhaps a few billionths of a second apart, might (thanks to inflation) reach their target a few billion seconds apart!
Re:Almost there... (Score:1, Informative)
Re:Why energy escapes black holes? (Score:3, Informative)
mark
Hawking radiation (Score:4, Informative)
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.