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..."

Comments

Looks like this is already being refuted

[Anonymous Coward]

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

Re:Looks like this is already being refuted

[khallow]

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

[Gospodin]

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?

[neurostar]

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

[LionKimbro]

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.

Get the papers here

[Ambitwistor]

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.)

Re:Please explain

[Jazzer_Techie]

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.

You're pretty much right, up to the fact that the universe is not static. Since space itself has been expanding (at varying rates throughout the history of the universe), talking about distance is not as straightforward as it may seem. Cosmologists use many different measures of distance, each telling you something about the object. The "lookback time" is how long the light has been traveling when it gets to you. But during the transit time, the object has moved away from you as the space between expanded, so the object is not really $lookback_time number of light-years away.

Re:How does light distance measurement work?

[killjoe]

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.

Re:Almost there...

[MillionthMonkey]

RTFA FIRST- in reality they're looking at stuff only 13.2 billion light years away, not 14 billion- which would indicate light that was older than the universe itself at 13.7 billion years old

The actual horizon is 53 billion light years away, not 13.7. Consider a photon emitted very early, when the universe was still small, that reaches Earth today. During the first year of that photon's life, it would crossed only one light year of space on its trip to us- the first one.

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.

State of the Art

[jd]

The state of the art is that the Universe is a shape. That's about as much agreement as we're likely to see for some time. Current theories range from soccer-ball shape (which would explain the extreme uniformity of the microwave background radiation without needing Inflation Theory) to a strange 12-dimensional ultra-sausage (3 dimensions are circular, time is flatish, the other 8 are curled up to almost zero size - this gives us String Theory, one of the better bets for a Grand Unified Theory but difficult to prove and in definite violation of the Keep It Simple philosophy) to a perfectly normal sphere that expands indefinitely (currently the best explanation for the calculated value for the Hubble Constant) to a dimple that will expand into a flat plane (which is the best explanation for why none of the constants seem to be, well, constant).

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:A little help here

[mgrivich]

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

Hawking radiation

[frogstar_robot]

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.