Universe


 

The universe is the whole spacetime continuum in which we exist, together with all the energy and matter within it. Attempts to understand the universe in this sense, on the largest possible scales, are made in cosmology, a science that has grown from physics and astronomy. During the second half of the 20th century, the development of observational cosmology, also called physical cosmology, led to a split in the meaning of the word universe, between observational cosmologists and theoretical cosmologists; where the former (usually) abandon the hope of observing the whole spacetime continuum, the latter retain this hope, attempting to find the most reasonable speculations for modeling the whole of spacetime, despite the extreme difficulty in imagining any empirical constraints on these speculations and the risk of declining into metaphysics.

Related Topics:
Spacetime - Energy - Matter - Cosmology - Physics - Astronomy - Observational cosmology - Physical cosmology - Theoretical cosmologists - Metaphysics

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The terms known universe, observable universe, or visible universe are often used to describe the part of the universe that we can see or otherwise observe. Those who believe it is impossible to observe the whole continuum may use our universe, referring only to that knowable by human beings in particular.

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~ Table of Content ~

Introduction
Expansion and age, and the Big Bang theory
Shape of the universe
Fate of the universe
Multiverse
Other terms
See also
References
External links

~ Community ~

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Latest news on universe

Obama Gets Thumbs Up All Around For Aggressive Convention Address (AHN)

(AHN) - The most talked about event in the political universe in the past week has come to pass, and though it left some unsatisfied, many pundits - most notably Pat Buchanan - declared it to be one of the "greatest" convention speeches in history. - Fri, 29 Aug 2008 08:28:56 GMT

Zoe's Tale, an Old Man's War novel for young adults by John Scalzi

A good week for young adult science fiction! John Scalzi's long-awaited debut YA novel, Zoe's Tale, has just hit shelves. This is a young-adult story in the popular and thrilling Old Man's War universe, and it's got all the heart and smarts I've come to expect from Scalzi. Run, don't walk, and get another copy for your kids while you're at it! In the touching fourth novel set in the Old Man's War universe, Scalzi revisits the events of 2007's The Last Colony from the perspective of Zoë, adopted daughter of previous protagonists Jane Sagan and John Perry. Jane and John are drafted to help found the new human colony of Roanoke, struggling against a manipulative and deceitful homeworld government, native werewolf-like creatures and a league of aliens intent on preventing all space expansion and willing to eradicate the colony if needed. Meanwhile, teenage Zoë focuses more on her poetic boyfriend, Enzo; her sarcastic best friend, Gretchen; and her bodyguards, a pair of aliens from a race called the Obin who worship and protect Zoë because of a scientific breakthrough made by her late biological father. Zoe's Tale See also: * Forever War with better sex, Starship Troopers without the lectures: Old Man's War * Sequel to Scalzi's Old Man's War: The Ghost Brigades...

Stargate Universe Coming

SCI FI Channel is set to announce the pickup of Stargate Universe, the third series in the long-running franchise, according to The Hollywood Reporter.

Bloating galaxies confound astronomers

Dense, compact galaxies in the early universe more than doubled their size in a short time – astronomers are struggling to explain how

A Boy Today?A Man Tomorrow: 1972 sex-ed manual

Weird Universe is hosting a complete scanned copy of "A Boy Today?A Man Tomorrow," a sex-ed manual for boys from 1972. As you might expect, it's a comedy goldmine. Snicker snicker. A Boy Today?A Man Tomorrow (Thanks, Paul!)...

Sega hopes to score with homely Japanese women

'Project Beauty' for Nintendo DS Perhaps you've rescued the universe from marauding space pirates on your Nintendo DS ? but can you save civilization from your own ugly face??

Weird Universe

I have long been a fan of News of the Weird. Not only is it humorous, it can be used as a great teaching tool. I wrote a lesson plan on this years ago titled Using Weird News to Teach About Verifying Information on the Web.For the last year, I have been following the almost daily blog of News of the Weird which was at a Blogger blogspot address. Last week, the author discontinued that site to create a new one. It is Weird Universe. Several people into collecting weird and strange news have come together to create on terrific blog. Go ahead and check it out. I promise you will find items to help you in teaching critical thinking at the library!From the site:Weird Universe explores every aspect of a human and natural cosmos that is not only "stranger than we imagine, but stranger than we can imagine."

Sick and (Re-)Tired

So, I've been sick. Not deathly, gasping my last breath, 'I'm coming to join you, Elizabeth!' sick, maybe. But still -- sick. I've spent much of the past ten days coughing up bits of things that may or may not have been attached to my internal organs. And someone evidently replaced my sinus fluid with some sort of napalm-'n'-molasses mixture, to see if I would notice. Trust me, I noticed. Shove a bean up it and blow, Folgers. "You might think that the universe would take pity on a guy like me in his hour of weakness, when all I wanted was twenty hours of sleep a night and some sort of honker Hoover to schlurp the phlegm right out of my face." Anyway, I'm better now. But it was a tough week and a half or so. You might think that the universe would take pity on a guy like me in his hour of weakness, when all I wanted was twenty hours of sleep a night and some sort of honker Hoover to schlurp the phlegm right out of my face. Yep, you might think karma would cut me a break for once. You might think that. But then you'd be an idiot. Instead, I found myself last Friday morning -- at the very height of my infirmary -- standing in the driveway in the midst of a steady downpour, hacking and sniffling and contemplating the very, very flat left rear tire on my car. I was heavily medicated, had pressing work at the office and had already put on my 'out in public pants'. Still, the sight of that soggy saggy deflated rubber doughnut led me to strongly consider giving the world the big fat finger and crawling back into bed. But no. That's just what karma would want, the little bitch. Instead, I got in the car and drove to a tire repair shop down the street. And things were all downhill from there. I have this theory, you see. In the long and storied history of mankind, I contend that there has never -- ever been such a thing as a 'repairable tire'. I've personally flattened a few, busted a bunch, punctured a passel, and deflated a dozen or more. Not one of those holey wheels was deemed patchable. And neither was this one. The resident tire care triage expert broke the bad news -- as usual: Tire Guy: Sir? I'm sorry. We couldn't save your tire. Me: Ah. I see. Tire Guy: We can sell you a new one, of course. Me: Well, of course you can. Tire Guy: Let's see... looks like the only tire we have in your wheelbase is the Blingerator here. Me: The Blingerator? Tire Guy: Yeah, it's great. Platinum-belted radials. Gem-encrusted treads. And the inner bladder is gold-plated. Me: But... you can't even see it. Tire Guy: True. But you know it's there. Me: Peachy. I assume this thing is outlandishly expensive, then. Tire Guy: Oh, you know it. Way more than those 'peasant tires' on your ride right now. Me: Fine. Look, how about we just call in one of those ghetto tires, anyway? I like to match. Tire Guy: Whatever you want, buddy. I'll order one for you, and it'll be here before you know it. Me: Good. Because I've got an important meeting this afternoon. Tire Guy: Oh, no problem. I'll check the computer now. Just so long as it's not back ordered. Me: Okay. Tire Guy: Uh-oh. Me: Yes? Tire Guy: It's back-ordered. You won't see it before August. Me: Nice. Aren't there any other models you can get? Tire Guy: Oh, sure. I can think of three others that'd fit your car. Lemme see here. Me: Great, thanks. Tire Guy: Hmmm. Back-ordered. Me: *sigh* Tire Guy: Back-ordered. Me: Of course. Tire Guy: Hey, then there's this one. Me: Back-ordered? Tire Guy: Nah. 'Recalled due to spontaneous explosions'. Me: Really? That's it? Tire Guy: Also? It's back-ordered. Me: Naturally. The Blingerator it is, then. Tire Guy: Wonderful. I'll just need the deed to your house, one of your kidneys and the rights to your first-born child. Nice doin' business with you. An hour later, I snuffled my way back the car, poorer in mood, wallet, and probably health. But I did have a fancy new tire, I did make it to work, and I did sit through that big, important, interminable, excruciatingly boring meeting. Yip. Fricking. Pee. The next time karma comes around, remind me to smack it around with a gold-plated bladder. Kick me while you're down, will ya?

Sentilla's Pervasive Computing -- The Universe Is the Computer

Sentilla CTO Joe Polastre's session on Mote software and pervasive computing illustrated how we've moved from "The network is the computer" to "The universe is the computer."

Howard Hughes' Nightmare: Space May Be Filled With Germs

Fans of extraterrestrial life may have been disappointed when internet-fed rumors of Martian life ended in a NASA press conference on soil composition. But they can take solace in a newly popular theory that suggests the rest of space may teem with microbes. This once-controversial notion holds that the universe is filled with the ingredients of microbial life, and that earthly life first came from the skies as comet dust or meteorites salted with hardy bacteria. "Studies have shown that microbes can survive the shock levels of being launched into space," said Charles Cockell, a microbiologist at the Open University. "And as more and more organisms are discovered under extreme conditions, it's become more plausible that things could survive in space for the time it takes to go from one planet to another." Not long ago, Cockell's claims would have been greeted with scientific derision. But as scientists learn more about Earth and space, the theory, which goes by the grandiose name of "galactic panspermia," seems less far-fetched. Bacteria, recent discoveries have shown, thrive in Earth's most extreme locales, from Antarctic ice to the interiors of volcanoes and nuclear reactors, and have even survived in space. Meanwhile, astronomers seem to find Earth-like planets wherever they train their telescopes; comets have proven unexpectedly rich in organic material. Closer to home, water was once widespread on Mars, and still suffuses the atmosphere of Venus. Perhaps life could evolve in a comet, or survive inside a rock catapulted into orbit by a planetary meteor strike. The odds might be against it -- but life is good at beating the odds. "One hundred years ago, people wondered if animals could go from one land mass to another," said Cockell. But then people discovered that birds migrate for thousands of miles, that storms carry insects across oceans and seeds between continents. "Panspermia is the next step," he said. Galactic panspermia advocates aren't exactly saying that little green men came to Earth and planted the seeds of life here. At the simplest end of the spectrum is the proposition that earthly life was jump-started by the arrival of its basic components from space. Meteors have proven rich in amino acids -- the building blocks of life -- and Earth was pummeled by meteors for the first 200 million years of its existence. In April, Columbia University chemist Ronald Breslow traced the molecular signatures of earthly amino acids to those of neutron stars. "Everything that is going on on Earth occurred because the meteorites happened to land here. But they are obviously landing in other places," he said at the time. "If there is another planet that has the water and all of the things that are needed for life, you should be able to get the same process rolling." But Earth -- and planets in general -- might not be the only habitable space locales. Comets -- orbiting collections of ice, dust and rocks -- are rich in nitrogen and oxygen, as well as other organic material. Chandra Wickramasinghe, a Cardiff University astronomer and astrobiology pioneer, suggests that heat from radioactive elements could melt the normally frozen water inside comets, making them a perfect interstellar petri dish. Microbial life could evolve inside them, or simply be picked up from a passing meteor originally ejected into space from a life-rich planet. Is that likely? In any given comet, perhaps not. But there are billions of comets in our solar system alone, floating like so many dandelion seeds through the ether, and bacteria have proven freakishly durable. They've been recovered from Antarctic ice and revived after 10 million years in deep-freeze. Some Black Sea strains photosynthesize in near-darkness, while others thrive on nuclear radiation or infrared light. Bacteria have been found inside volcanoes and in sediments miles beneath the ocean floor. Bacteria have even survived exposure to the vacuum of space, as well as pressures comparable to those generated by meteor strikes capable of kicking debris out of Earth's orbit. And all that's necessary to establish a new bacteria colony, Wickramasinghe calculated, is for one microbe in 1,000,000,000,000,000,000,000 to flourish in its new environs. Wickramasinghe even concluded that organic material found in comets -- most recently by the Stardust spacecraft, which plucked amino acids from the 81P/Wild 2 comet -- is biological in origin. In other words, the comet is not just a good place for life to grow, but actually contains organic material produced by earlier life, Wickramasinghe believes. That is, of course, hypothetical, and not everyone is convinced. "Some astrobiologists are evangelists," said Columbia University biometeorologist Nancy Kiang. But with further bacteria-in-space experiments planned by NASA and the European Space Agency, and missions ongoing to sample other planets and interstellar bodies, the evangelists are being taken seriously. "The universe is mostly empty space, but here and there are special places where complex things can happen: clouds of dust, planetary surfaces, comets and asteroids," said Cornell University astrogeologist Jim Bell. "They appear scattered throughout most of the observable space we can study with our instruments thus far. Astronomers have been finding hundreds of planets around other stars. There are probably lots more places out there where life could exist."