According to an account of the Hindu mythology, Hiranyagarbha, meaning the golden womb, is the source of the creation of the universe. It is one of the Vedic myths which explain the origin and the creation of the cosmos and the universe. The legend states that the Hiranyagarbha floated around in water in the emptiness and the darkness of the non-existence for about a year, and then broke into two halves which formed the Swarga and the Prithvi, and most likely other parts of the universe. It is believed that Brahma was born from the Hiranyagarbha. [Link]
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It has been way too long since we have had a nerdy science post to get everyone’s juices flowing. An article this past week in Science Magazine gives us hope that cosmologists are getting closer to understanding where it all came from and where it all might be headed. The Chandra X-Ray Observatory, named for Subrahmanyan Chandrasekhar, captured images of a smoking gun. Via Science (subscription required):
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This composite image shows the galaxy cluster 1E 0657-56, also known as the “bullet cluster.” This cluster was formed after the collision of two large clusters of galaxies, the most energetic event known in the universe since the Big Bang. |
A fantastically energetic collision between clusters of galaxies has demolished a challenge to the law of gravity, providing the clearest evidence yet for the existence of intergalactic dark matter.
For decades, astronomers have inferred that unseen matter lurks within and between galaxies. Luminous stars alone, they realized, don’t exert enough gravitational force to explain how individual galaxies spin and clusters of galaxies clump together. Something invisible must be pulling, too.
Some of the extra matter in galactic clusters is just hot gas. But even more mass seems to exist in the form of “nonbaryonic” dark matter, made of something other than ordinary atoms.
A few holdouts have insisted that the observations could be explained by modifying the law of gravity at great distances. But a new result from the Chandra X-ray Observatory satellite offers clear-cut evidence that dark matter really does infuse galactic clusters. “It demonstrates beyond a reasonable doubt that dark matter exists,” says Sean Carroll, a cosmologist at the University of Chicago, Illinois, not involved in the study. [Link]
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p>I love that there is an invisible physical force (that should be therefore measurable) out there that is stronger than gravity and yet remains invisible to detection by us except by inference. Its just a good mystery (which we all need once in a while).
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p>To really understand the whole backstory however, you need to read this awesome article in Time Magazine from about three months ago:
An equally unsettling implication is that the universe is pervaded with a strange sort of “antigravity,” a concept originally proposed by and later abandoned by Einstein as the greatest blunder of his life. This force, which has lately been dubbed “dark energy,” isn’t just keeping the expansion from slowing down, it’s making the universe fly apart faster and faster all the time, like a rocket ship with the throttle wide open.
It gets stranger still. Not only does dark energy swamp ordinary gravity but an invisible substance known to scientists as “dark matter” also seems to outweigh the ordinary stuff of stars, planets and people by a factor of 10 to 1. “Not only are we not at the center of the universe,” University of California, Santa Cruz, astrophysical theorist Joel Primack has commented, “we aren’t even made of the same stuff the universe is.”
These discoveries raise more questions than they answer. For example, just because scientists know dark matter is there doesn’t mean they understand what it really is. Same goes for dark energy. “If you thought the universe was hard to comprehend before,” says University of Chicago astrophysicist Michael Turner, “then you’d better take some smart pills, because it’s only going to get worse…” [Link]
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p>And now for the REALLY scary shit:
If these observations continue to hold up, astrophysicists can be pretty sure they have assembled the full parts list for the cosmos at last: 5% ordinary matter, 35% exotic dark matter and about 60% dark energy. They also have a pretty good idea of the universe’s future. All the matter put together doesn’t have enough gravity to stop the expansion; beyond that, the antigravity effect of dark energy is actually speeding up the expansion. And because the amount of dark energy will grow as space gets bigger, its effect will only increase…By then the sun will have shrunk to a white dwarf, giving little light and even less heat to whatever is left of Earth, and entered a long, lingering death that could last 100 trillion years–or a thousand times longer than the cosmos has existed to date. The same will happen to most other stars, although a few will end their lives as blazing supernovas. Finally, though, all that will be left in the cosmos will be black holes, the burnt-out cinders of stars and the dead husks of planets. The universe will be cold and black.
But that’s not the end, according to University of Michigan astrophysicist Fred Adams. An expert on the fate of the cosmos and co-author with Greg Laughlin of The Five Ages of the Universe (Touchstone Books; 2000), Adams predicts that all this dead matter will eventually collapse into black holes. By the time the universe is 1 trillion trillion trillion trillion trillion trillion years old, the black holes themselves will disintegrate into stray particles, which will bind loosely to form individual “atoms” larger than the size of today’s universe. Eventually, even these will decay, leaving a featureless, infinitely large void. [Link]
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p>It is always fun to see how scientific evidence squares with religion and mythology. Here is another Wikipedia entry about one version of the Hindu concept of “The End”:
In Hindu cosmology, a universe endures for about 4,320,000,000 years (one day of Brahma, the creator or kalpa) and is then destroyed by fire or water elements. At this point, Brahma rests for one night, just as long as the day. This process, named pralaya (Cataclysm), repeats for 100 Brahma years (311 trillion human years) that represents Brahma’s lifespan. [Link]
See related post: Bang bang, you’re alive
Respect, Abhi. You’re writing about events that might take place 1 trillion trillion trillion trillion trillion trillion years from now. As I read this post, my biggest concern was that I’m out of milk for tomorrow’s breakfast cereal.
Ahhh…Mr. Tao of Physics, ever since Pluto was nixed as a real planet (which resulted in the funniest NYT piece I have ever read), I’ve started having my doubts about those other wacky scientific disciplines like physics, astronomy and cosmology. I’ll stick to my biochemist peeps who — instead of describing the end of the universe — describe the limited utility of their own scientific discipline.
But on a more serious note, folks, we all know that dark energy is formed when a bunch of desis see a store selling delicious kathi rolls a few hundred feet away. How it took the University of Michigan astrophysicist Fred Adams so long to calculate that is anyone’s guess.
i’m sure that’s precisely what this girl was thinking when she was temporarily distracted from the onslaught of devastation and bedlam brought upon by a natural disaster that destroyed her family to consider the possibilities of dead matter and her search for food.
also, if you look towards the upper-left corner of that “bullet cluster” photo, you can see the Death Star. and no, i’m not kidding.
Impressive, but I don’t see any reason for the “stronger than gravity” argument though.
Perhaps “stronger” was an oversimplification. The force, whatever it is, is causing things to fly apart rather than come together as you would expect due to gravity.
I’ve sometimes wondered if things like “Dark Energy” or the really cutting-edge subatomic forces* relating to quantum physics are actually aspects of God; you can’t physically analyse it, but you can see its effects.
Yes, yes, I know: “The entire universe is divine in its essence” (to quote the Sikh teaching on the matter), but it’s an interesting thought if such things are “shadows of God”, in a manner of speaking.
{By the way, Abhi — totally off-topic, but I just came across this article which says it may be possible to take a pill to maintain one’s gym-honed physique without having to continue regular work-outs, even if one becomes a couch potato. Take a look here 🙂 }
*I can’t remember exact names but I’m referring to stuff which goes way beyond protons & neutrons etc. The really weird, unpredictable stuff.
Hiranyagarbha and the existence of dark matter? I don’t know. I personally give testimony to The Church of the Flying Spaghetti Monster”. We are all HIS creation.
An interesting way to look at it Jai. I rememeber Hawking talked about the same thing in A Brief history of Time (“who breathes fire into the equations?”) and more recently, the philosopher Nancy Murphy has talked about this as a way of understanding the divine attribute of immanace.
Anyway from my (shallow) reading of popular science over the last few years, it doesn’t really look like things are coming together for physics as was expected as recently as ten years ago. I don’t know how well theories like loop quantum gravity or string theory are able to account for the implied presence of dark matter (Saheli – any ideas?). Plenty of opportunities for young desi scientists, like Ananinda Sinha, to make their mark!
Ok, some of this stuff in the article is not news at all. It’s old hat, and goes back to Hubble (Saheli, back me up on this).
The “anti-gravity” force they refer to isn’t really any such thing. It’s a side effect of the fact that the universe is expanding.
And the dark matter doesn’t do anything to gravity as a force, theoretical or otherwise. Its effects are gravitational, after all.
Badmash:
I don’t think there are any obvious implications for sting or loop theory from all this. There are several categories of dark matter being postulated, both baryonic and non-baryonic. The non-baryonic can be lumped into (yes, this is for real) Hot, Warm, and Cold. If you want to dig deeper, I’m happy to talk geek with you…but the upshot is that dark matter has implications for material structure formation, not so much for string theory. String theory may help validate the absence or presence of dark matter because of the way it deal with gravity in the first place (it’s a good workaround for issues stemming from dealing with forces on / from point-like particles).
Man, this thread is so dead. 🙂 Let’s all go post on “A Dosa and a Dream” like everyone else.
Wait…if the universe is expanding and cooling, there has to be a point when it will stop. If I remember my thermodynamics lesson right all motion stops at -273 degrees kelvin, or absolute zero. What happens then ?
TechPig,
therodynamics doesn’t apply to a vacuum, which has no temperature (and most of the universe is hard vacuum). The expansion of the universe isn’t a thermodynamic effect, it’s the actual physical expansion of space. It’s like blowing up a balloon and measuring the distance between points on the surface as you inflate it, rather than like the distance between the gas molecules in the balloon (assuming you were increasing the volume of the balloon and not adding gas, that is).
The latter would cool the balloon off, due to thermodynamics, which is a function of kinetic energy. The former is a relativistic effect of the literal expansion of what Star Trek calls “the fabric of space” (which I think is a polyester-rayon-cotton blend that resists wrinkles and almost never needs ironing). The nature or (to some degree) size of the objects themselves aren’t changing; the actual amount of space between them IS, which is very counterintuitive to us earthbound types who think a mile is a mile (or, maybe more accurately, a kilometer is a kilometer).
Even in vaccuum, there is electromagnetic radiation, i.e – energy, everywhere. All around the vaccuum, there is matter in the form of stars, galaxies, interstellar and intergalactic gases, black holes, and so on.
The universe is constantly cooling, therefore atomic particle motion is constantly slowing down. Therefore the particles emit lesser energy in the form of radioactive waves (light, , microwaves, xrays, gamma rays, etc). Till the temperature drops to absolute zero. At this point, all particle motion has stopped. Therefore there is no energy being emitted. Therefore the universe has no more energy, and all matter has come to a standstill. At this point, when there is only matter but no energy left in the universe, does the spacetime fabric still keep expanding ?
Hi,
Just thought I’d add my two cents and clarify something about dark matter. For non-dark matter and energy, gravity is an attractive force. For dark matter or energy, it’s repulsive.
No let’s not kill the thread yet…
Salil – I was speaking in terms of a TOE. I mean the old story is that here was Einstein developing a radically new theory of gravity – which was then confirmed by observation. As it seems to me, the newer theories don’t appear to have that level of falsifiability (Popper) because they are malleable enough to account for a farily large array of observed and hypothetical phenomena. I mean although people are still working out what LQG and String theory are, it would be nice to know, in the same way Eddington confirmed some of GR’s more innovative claims, that they’re on the right track.
Btw I really enjoyed this series – have you seen it yet?
Desi angle – good to see people like Ashketar and Sen front and centre in these new developments!
Btw I really enjoyed this series – have you seen it yet? Looks absolutely fascinating. Thanks for the pointer.