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Concern Over Creating Black Holes

Maria Williams writes to tell us about worry surrounding the impending startup of CERN's Large Hadron Collider. Some fear that the device, in creating mini black holes, could jeopardize Life As We Know It. While the tiny black holes should evaporate quickly — throwing off so-called Hawking radiation that can be detected — CERN software developer Ran Livneh reminds us that "Any physicist will tell you that there is no way to prove that generated black holes will decay." The LHC site assures us there's nothing to worry about. The flap is reminiscent of the time the Relativistic Heavy Ion Collider went live. The worry then was that "negative strangelets" could gobble up the world.

76 of 597 comments (clear)

  1. Please, for the love of God... by daveschroeder · · Score: 4, Interesting
    ...no crap about John Titor actually being a real person.

    Thanks.

    For those who don't know, in the John Titor story, the CERN LHC allegedly lays the groundwork for using artificial black holes as part of a time machine (made for the military by General Electric, of course!).

    (And no, John Titor is not a real time traveler.)

    For example:

    Along with the prediction of World War III, another notable prediction is that of a Civil war in America, which was predicted to begin in 2004, around the time of the presidential election, and would escalate until 2008, which, according to Titor, "[is] a general date by which time everyone will realize the world they thought they were living in was over."

    Even statements like this are subjective and many people still choose to believe; I'm sure there are many slashdot readers (judging from the kind of posts I see here) who believe we are currently in a nascent "civil war" and that, indeed, the "world they thought they were living in was over." This is all typical vague crap that can be viewed a variety of different ways, Nostradamus-style, and never soundly disproven, conspiracy-theory-style. Even now, people are arguing that John Titor's visit may have allowed us to "change our future". Yeah, because the mental giants who believe the John Titor story have had a huge impact on things.

    ...

    It's quite impressive how many people actually believe this tripe, though.

    1. Re:Please, for the love of God... by OakDragon · · Score: 5, Funny
      ...Civil war in America, which was predicted to begin in 2004, around the time of the presidential election...

      On November 3rd, 2004, civil war was narrowly averted when Kerry supporters realized that only 0.03% of them owned a gun.

    2. Re:Please, for the love of God... by kalidasa · · Score: 2, Informative

      In the 1860s, the Democrats were the conservatives and the Republicans were the "liberals." Things got turned around in early part of the 20th century when Taft repudiated many of the progressive principles that helped Teddy Roosevelt win election to the Vice Presidency (and later to the Presidency). This annoyed Roosevelt so much that he ran against Taft on the Progressive Party ("Bull Moose") ticket; but the two split the vote allowing Wilson to be elected. In many ways, Wilson set the stage for what would become Democratic (Party) foreign policy for the rest of the century in his proposals for the Peace of Versailles and the creation of the League of Nations; on the other hand, there's a lot of dispute about his attitude toward civil rights and "race" in America. However, the turning point for the Democratic Party from what we might call "conservative" to what we might call "liberal" was the Great Depression, the New Deal policies of the Franklin Delano Roosevelt administration, the integration of the Army under Truman, and the split of the Dixiecrats in 1948 (and subsequent switch of many segregationists to the Republican Party in 1964 after Johnson's support of desegregation). While it is not quite possible to map anti-slavery and pro-Civil Rights sentiment together as either "liberal" or "progressive," it is possible to locate both sentiments in "anti-conservative" movements and also to see them as at least tenuously related.

    3. Re:Please, for the love of God... by rpbird · · Score: 2, Informative

      Please don't confuse the historical meaning of the word "Progressive" with its contemporary political usage. The term has a fairly exact historical meaning and describes a specific political and social movement in American politics. Political reform, the conservation movement, the protection of consumers, and the restraint of corporate power were the central elements of the Progressive Movement. TR was a progressive. He proposed or supported legislation in each of these areas. There's no getting around it. Any serious American historian will tell you that both political parties during this era (from the end of the Civil War to World War I) had their progressive wings. The first post in this thread got it right.

      You made two mistakes. First, you want to impose your own ideas onto the past, rather than understand the past. Second, you wish to overly simplify the past. Believe me, the Progressive Era (or the first century AD, or medieval Europe) was just as complicated, the politics just as confusing, as it is today. Humans are complicated creatures, no matter where or when you find them. The progressives were united by their common desire to see reform and fairness in American life. How this might be accomplished ran the entire spectrum, from more conservative individuals who only wanted to tinker around at the edges, to those who wanted to overthrow the entire system. Nothing in human history is simple enough to fit inside your black and white world view. Maybe you should add a little color to your thoughts.

  2. Ack! by ultramk · · Score: 4, Funny

    Nothing for you to see here. Please move along.

    It's already begun!

    m-

    --
    You catch enchiladas by picking them up behind the head and holding them underwater until they don't kick anymore -VeGas
    1. Re:Ack! by Fordiman · · Score: 2, Informative

      Low-mass black holes should, theoretically have sub-fennoscopic event horizons.

      So?

      Well, the event-sphere is actually small enough to fit between two atoms and not even touch their electrons. If the black-hole passed through the earth, it would come out the other side with about half velocity and about twice its original mass. And that's only if Hawking radiation is fallacious. If it's not, then the black hole will only have an event horizon until the decrease in mass causes its schwartzchild radius to drop below its volumetric radius - at which point, it's not a black hole anymore, it's just shitlessly dense regula-ass matter.

      --
      110100 1101000 1101000 1100110 0 1101111 1101000 1100011 1
  3. Calling Dr. Freeman by CerebusUS · · Score: 5, Funny

    As long as Gordon Freeman is there to watch over the experiment, I think we'll all be okay. Maybe.

    I hear the Vortigaunts are our allies.

  4. Creating them is a problem by Rik+Sweeney · · Score: 4, Funny

    The worry then was that "negative strangelets" could gobble up the world.

    You see, the problem is that we could all get sucked off before we know what's going on.

    1. Re:Creating them is a problem by Rik+Sweeney · · Score: 5, Funny

      You see, the problem is that we could all get sucked off before we know what's going on.

      I meant sucked in.

    2. Re:Creating them is a problem by DiamondGeezer · · Score: 4, Funny

      We know what you meant. Pervert.

      --
      Tubby or not tubby. Fat is the question
    3. Re:Creating them is a problem by Reverend528 · · Score: 3, Funny
      I prefer the confusion of getting sucked off before I know what's going on.
      Trust me, the last thing you want is to be sucked off by a black hole.
  5. The world didn't end last time... by Skyshadow · · Score: 4, Funny

    Seems to me that the only real problem with blowing this sort of thing off by saying "this is just like last time when we tried something that had a small chance of destroying the world and it worked out okay then" is that you really only have to be wrong once.

    "Oh shit! Yeah, our bad -- man, are our faces red. Sorry about that, everybody."

    --
    Every year during my review, I just pray the words "slashdot.org" aren't mentioned.
    1. Re:The world didn't end last time... by spun · · Score: 5, Funny

      I think microscopic black holes couldn't eat up the earth due to the three stooges problem. They are so small that only an atom at a time can get in, but the gravity is strong enough to try to suck in more, so all the atoms get bunched up around the event horizon like the three stooges all trying to get through a door at the same time. Problem nullified. Whoop hoop oop! Nyuck nyuck, why I oughta!

      --
      - None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
    2. Re:The world didn't end last time... by 2short · · Score: 4, Funny

      I remember that last time, and I think a friend of mine summed it up best:

      "Scientists constructing a device that could potentially destroy the earth? Don't we have super-heroes to deal with this sort of thing?"

    3. Re:The world didn't end last time... by dgatwood · · Score: 4, Insightful

      I don't think I buy that reasoning. That's like saying that a {particle beam, laser} won't work because the hole at the end of the tube is only big enough for one {atom, photon}.

      Except it's worse than that. As soon as things shift around a little so that a single atom goes in, the event horizon is now slightly larger. Repeat ad infinitum. All it takes is an occasional atom getting through.

      A microscopic black hole either dissipates or it doesn't. If it does, great. If it doesn't, we have a problem. It may take millennia to become a serious problem, but....

      --

      Check out my sci-fi/humor trilogy at PatriotsBooks.

    4. Re:The world didn't end last time... by IAmTheDave · · Score: 2, Funny
      -if- it were the case that it does not dissipate, then there's a potential problem.

      You sound like Einstein - "um, i don't THINK the a-bomb will create a chain reaction of splitting atoms that will destroy the universe as we know it... but... just in case you might wanna get you some of that AFLAK insurance."

      --
      Excuse my speling.
      Making The Bar Project
    5. Re:The world didn't end last time... by grim4593 · · Score: 2

      I like that idea. If we throw a mini-blackhole near some atoms of lead and the blackhole starts eating protons... Then we can use blackhole alchemy to remove 3 protons from lead and turn it into gold!

    6. Re:The world didn't end last time... by MORB · · Score: 4, Insightful

      So what?

      If it doesn't destroy the world, scientific knowledge advances.
      If it does, no onw will be around anymore to worry about it.

    7. Re:The world didn't end last time... by Thuktun · · Score: 2, Interesting

      A black hole eating up the Earth appears in the Hyperion series, usually referred to as the "Big Mistake of '08".

      Curiously, the LHC is going to come online in 2007. Hope that's just coincidence.

  6. its one way to go... by russ1337 · · Score: 3, Funny

    Well, it beats being hit by a bus....

    Standing at the pearly gates it would be a great converstation starter... "oh yeah? I was killed by a black hole...."

    1. Re:its one way to go... by Wudbaer · · Score: 4, Funny

      Yeah, but image the length of the queue !

    2. Re:its one way to go... by PrescriptionWarning · · Score: 5, Funny

      Make sure you buy your SpeedPass at your local church.

    3. Re:its one way to go... by the+dark+hero · · Score: 2, Funny

      Martin Luther would not approve of such indulgences

      --
      You constantly struggle for self improvement - and it shows.

      Hooray for bad Engrish on fortune cookies

  7. Am I the only one that read.... by LordPhantom · · Score: 5, Funny

    ....Hard On Collider? I think I'd prefer an earth swallowing black hole.

  8. That's not quite the way it would happen by Bruce+Perens · · Score: 4, Funny

    The black holes would only eat up Kurt Vonnegut. However, the efect would be the same as if they ate up the whole world, since it's all a figment of his imagination.

    1. Re:That's not quite the way it would happen by monoqlith · · Score: 4, Funny

      If the black hole is inside the world, doesn't that mean Vonnegut will disappear into his own imagination?

      Woah, man. I think you just blew my mind.

      keanureeves If I even have a mind.... /keanureeves

  9. Okay... by addaon · · Score: 5, Insightful

    Being cautious about a potentially real issue is one thing, but of course the big issue here is that collisions of similar energy happen, if not commonly, at least not entirely rarely due to cosmic rays. If the world could be destroyed by the side-effects of such a collision, we wouldn't be here to be nervous about it.

    --

    I've had this sig for three days.
  10. uh oh by syrinx · · Score: 2, Funny

    Watch out if you let the Technocore help. Can we farcast off of Old Earth yet?

    (see "Old Earth": http://en.wikipedia.org/wiki/Hyperion_Cantos)

    --
    Quidquid latine dictum sit, altum sonatur.
  11. No way? by Anonymous Coward · · Score: 5, Funny
    "Any physicist will tell you that there is no way to prove that generated black holes will decay."

    Of course there's a way. Empirical research, just like they're doing. First you make a black hole, then you see if it expands until it destroys all life on earth. Simple, straight forwards, effective.
  12. SETI paradox resolved by Gary+W.+Longsine · · Score: 5, Interesting

    Where are they? Gone.

    Civilizations routinely destroy their home planet by creating miniature black holes thereupon whilst trying to figure out what makes them tick. Technology advances faster than democracy, and it has never yet in the long history of the universe been put to a vote.

    --
    If you mod me down, I shall become more powerful than you could possibly imagine.
    1. Re:SETI paradox resolved by CatsupBoy · · Score: 2, Informative

      It was actually a short story by Isaac Asimov titled "The Last Question" - http://en.wikipedia.org/wiki/The_Last_Question

      You can also read it online: http://infohost.nmt.edu/~mlindsey/asimov/question. htm

  13. Perspective by truthsearch · · Score: 4, Informative

    Some scientists were very concerned the first atomic bomb would produce so much heat it would ignite the atmosphere and burn the entire surface of the earth. Fortunately it didn't happen. But it's good that people bring up these ideas so we challenge assumptions and try to be safe while still advancing science.

    1. Re:Perspective by Tekfactory · · Score: 2, Informative
      Some scientists were very concerned the first atomic bomb would produce so much heat it would ignite the atmosphere and burn the entire surface of the earth.


      If by very concerned you mean they had an office pool betting on the yield of the first atom bomb, then you would be correct, 'ignite the atmosphere' was a longshot, nothing to be seriously concerned about.

      They wrote a paper on it in 1942
      http://www.fas.org/sgp/othergov/doe/lanl/docs1/003 29010.pdf

      A very short narrative about the events in question
      http://www.sciencemusings.com/2005/10/what-didnt-h appen.html
  14. I thought everyone knew... by LinuxGeek · · Score: 4, Funny

    This is the reason that the Earth entry was changed from "Harmless" to "Mostly harmless".

    --

    Kindness is the language which the deaf can hear and the blind can see. - Mark Twain
  15. Of course he's not a real person... by Anonymous Coward · · Score: 5, Funny

    ...Yet

  16. There was concern over atomic weapons too... by awing0 · · Score: 3, Informative

    Edward Teller speculated that an atomic weapon could ignite the atmosphere. Another physicist discredited and disproved the idea, but the fear wasn't laid to rest until the actual weapons were used.

    http://en.wikipedia.org/wiki/Manhattan_Project (wikipedia, blah blah blah)

    --
    Cthulhu Saves.
    1. Re:There was concern over atomic weapons too... by zippthorne · · Score: 2, Informative

      No, the fear wasn't laid to rest until Teller and other scientists did the math. They didn't do the experiments until after they made the calculations.

      --
      Can you be Even More Awesome?!
    2. Re:There was concern over atomic weapons too... by dpbsmith · · Score: 3, Interesting

      That fear resurfaced during the 1954 "Bravo" shot. It was twice as powerful as expected, and as physicists watched and saw the cloud keep expanding and expanding and expanding, with no signs of stopping, at least some of them momentarily wondered whether the atmosphere had been ignited after all.

      But don't worry. Physicists will never make a mistake again. And, hey, the atmosphere didn't ignite, so, no problem.

  17. The biggest word in that sentence by Weaselmancer · · Score: 2, Insightful

    While the tiny black holes should evaporate quickly...

    The biggest word in that sentence is should.

    --
    Weaselmancer
    rediculous.
    1. Re:The biggest word in that sentence by ajenteks · · Score: 4, Funny

      The smallest word obviously being tiny :)

  18. Cosmic rays have prior art by arevos · · Score: 5, Informative

    Primary cosmic rays impact the earth all the time, and these often have far higher energies than even our largest particle accelerators are capable of producing. For any experiment we attempt, we can be reasonably sure that colliding cosmic rays have already produced the same results, sometime within the past few billions years. If we could create massively destructive black holes through our particle accelerators, one would expect that stray cosmic rays would have already done so.

    1. Re:Cosmic rays have prior art by joe_n_bloe · · Score: 2, Insightful

      Yeah - the fundamental problem with all these "supercolliders will destroy the Earth/Universe" hypotheses is that all these "extreme" conditions have existed here and there throughout the universe since the beginning of time.

    2. Re:Cosmic rays have prior art by arevos · · Score: 3, Interesting

      There's never any proof per se in science. There have been, however, many experiments, observations and measurements of cosmic rays since they were discovered in 1912. In 1954, MITT used 11 scintillation detectors to measure the energy spectrum of cosmic rays, and found it to extend beyond 1e20 eV. To put that into perspective, our largest particle accelerator, the Tetravon Accelerator at CERN, can only manage 1e12 eV. We'd need over 100 million times the power to start getting beyond the capability of cosmic rays, which is a pretty comfortable margin in my book :)

  19. You Fear What You Don't Understand by eldavojohn · · Score: 4, Interesting
    Precisely, although, if I may add a bit as to why people might still be afraid of this research ...

    It's natural to fear what you don't understand. It might even be a quality of a species that determines its success as many things in nature are quite dangerous. For better or for worse, mankind has this built in as a default setting no matter who you are whether you're fearing a black hole or suffering from xenophobia.

    I am not a physicist but I think the fears here are quite unfounded. All the math and theory point to a black hole having a finite event horizon. If the black holes they are producing are microscopic and last relatively little amount of time, they shouldn't be very dangerous. I think this has been covered before.

    It is interesting though, because I believe a black hole's event horizon has a radius proportionate to the amount of mass it consumes. I believe that if you make them small enough, however, they don't last long enough to expand. I would be concerned if they were attempting to make massive singularities to destroy garbage heaps with these but I don't see how those would be possible to create as the only known method is to accumulate so much mass in such a small volume that gravity crushes it into a singularity. My understanding of the collider is that it smashes particles together at a fast rate and, as a result, very tiny and brief black holes may result. As this article states:
    The physicist Stephen Hawking predicted in the 1970s that black holes would evaporate by radiating away their energy. For astrophysical black holes this is a very slow process, but extremely small black holes should last about as long as a snowflake in hell.

    People will, as always, fear what they don't understand so I believe it's hopeless to quell all fears about physics research. I'm sure a lot of people are concerned about this being the next "atomic bomb" technology. Where we "drop" black holes on enemies. Though that doesn't really make sense, it still could have military applications such as creating electromagnetic devices that are so strong they displace gravity and aiming them at your enemies. Sure would make for a cheesy sci-fi book whether it was true or not!
    --
    My work here is dung.
  20. Fermi knew the answer long ago by Framboise · · Score: 5, Informative

    This type of fear occurred many times during the nuclear physics history, when higher and higher energies were explored. The answer against fears of unknown catastrophic effect has been that some cosmic rays are much more energetic than any artificially accelerated particles (10^21 eV for some cosmic rays in comparison to the feeble 10^12 eV in today accelerators such as LHC). For sure the Earth and the Sun did already receive zillons of cosmic rays without disappearing...

    1. Re:Fermi knew the answer long ago by Nuclear_Physicist · · Score: 2, Informative

      Actually, it's interactions with the moon that are the most telling. Since this is a heavy ion collider, it's colliding nuclei that are much larger than those found in the earth's atmosphere. When they disproved this crap before the Relativistic Heavy Ion Collider turned on they found that the most powerful constraint came by considering heavy ion interactions when a cosmic ray hit the moon rather than the earth's atmosphere (even though the earth is bigger, to properly compare with conditions at RHIC, you need to look at the number of heavy ion collisions). If collisions at RHIC were to create strangelets or blackholes, then the moon would have been destroyed long ago.

  21. Natural Particle Accelerators by noretsa · · Score: 5, Interesting
    If it were really so easy to destroy the world it would have happened long ago.

    For example, there are as yet little-understood phenomena that can accelerate particles six orders of magnitude faster than anything achievable in a lab. Try reading about Ultra-high-energy cosmic rays.

    More specifically read the story of the Oh-My-God Particle. This was a proton detected in October of 1991 that had an energy of 3.2 * 10^20 eV. The equivalent energy of a baseball thrown at 55 mph... all in a single proton travelling at 99.99999999999999999999951% the speed of light!

    While something travelling that fast has little probability of interacting with anything you could imagine the surprise if one of those hit you! I think that the fact we are alive with such powerful forces already at work in our universe means we have little to fear.

    1. Re:Natural Particle Accelerators by rthille · · Score: 2, Informative

      While something travelling that fast has little probability of interacting with anything

      On the contrary, even though the particle was traveling that fast, it interacted with the thin upper atmosphere, right? Isn't that where the telescope was looking to see the flashes?

      --
      Awesome furniture, accessories and cabinetry in Santa Rosa, CA: http://humanity-home.com/
    2. Re:Natural Particle Accelerators by treeves · · Score: 2, Insightful

      Fortunately, my cross-section 3.2E20 eV protons is MUCH smaller than my cross-section for 55 mph baseballs.

      --
      ...the future crusty old bastards are already drinking the Kool-Aid.
  22. Utter Crap by bockelboy · · Score: 5, Interesting

    I work one of the LHC expirements (low-level grad student, no one important), and this is utter crap.

    Yes, there are physicists who are concerned. There is a chance that this could happen - one of those "if everything we know about high energy physics is completely wrong, this could happen". There is an approximately equal chance that Pat Buchanan will be nominated as the Democrat candidate for president in 2008. No physicist can prove that this won't happen - just like no physicist can actually prove that Superman doesn't exist.

    Unfortunately, it's about the only way a reporter can "sexy up" a story about a particle accelerator. I can't wait to see the headlines in 2007 - "Will the Earth end tomorrow?" (subheading: "Respectable scientists say 'No'").

    1. Re:Utter Crap by Rob+T+Firefly · · Score: 3, Funny
      I can't wait to see the headlines in 2007 - "Will the Earth end tomorrow?" (subheading: "Respectable scientists say 'No'").
      The beauty of it is, either way the papers won't have to print up a retraction the next day.
    2. Re:Utter Crap by DrJimbo · · Score: 2, Informative
      I was with you all the up until:
      We may not have known exactly how much energy was going to be released when we split the atom, but we do know how much graviational force can be exerted by a given mass.
      Two points:
      1. We did know fairly precisely how much energy would be released when we split the atom.
      2. The concerns over creating mini-blackholes is not the raw gravitational force they will exert. The concern is whether they will evaporate quickly or not. The concern (which many/most/all reputable physicists say is unfounded) is that one of these little black holes will not evaporate. Instead, it will orbit insde the earth swallowing more and more material over time and turning our planet into swiss cheese.
      --
      We don't see the world as it is, we see it as we are.
      -- Anais Nin
    3. Re:Utter Crap by bigtimepie · · Score: 4, Funny

      Of course there will be a headline the next day, granted the earth remains.

      "Earth NOT Destroyed"

      What, you think reporters aren't complete idiots?

  23. OK, imagine the black hole not decaying... by Yonzie · · Score: 5, Funny

    What will happen?

    We'll all die. Simultaneously. Noone will feel anything.

    What's the big problem aside from the end of the earth?

  24. Has anyone seen my car keys? by Easy2RememberNick · · Score: 2, Funny

    "Has anyone seen my car keys? I set them right next to the collider."

      This reminds when I read Brian Greene's Elegant Universe, he mentioned that there was a possibilty of creating another Universe when (if it were possible) smashing together Superstrings. Something like that, I'm not sure where I put the book.

  25. Better we kill ourselves... by thebdj · · Score: 2, Funny

    before the big asteroid or comet comes. Or the sun goes red giant. Or the sun shoots off enough matter to defeat the ozone and expose us all to radiation. (Yes, I have heard this one.) Oh, or Yellowstone goes all explosion on us and brings about a second ice age or something. (There was a Docu-drama on this one.) Oh, or maybe the moon can be partially destroyed and threaten to crash into earth. (Reference to a ABC Family comedy or in some ways to Cowboy Bebop). Oh, or nuclear winter. I am sure I forgot some.

    But better us then nature!

    --
    "Some days you just can't get rid of a bomb."
  26. Black Holes and Birth of our World by Intangible+Fact · · Score: 2, Interesting

    Knowing the government and their previous actions on subjects like this I think they have already experimented with the mini black holes. Most scientific information that would give the general public a stir is withheld for many years until the people are ready. I believe that black holes are not time traveling devices, but more of a door to a new universe. Black holes suck in anything and everything, including light. Our universe started from a Singularity in which matter was infinitely compressed and space and time was infinitely distorted. Black holes compress and distort matter and time. Put two and two together and what do you have? The birth of our universe. I believe our universe was born inside of a black hole and that we are currently living and evolving inside of it. Thus means every black hole we see out in space possibly is a gateway to another universe. Tell me what you think?

    1. Re:Black Holes and Birth of our World by libra-dragon · · Score: 3, Interesting

      I think each block hole is created by civilizations conducting experiments similar to ours. They're thinking that this is just too small and unstable to turn into one of those real big black holes out there...

  27. And here I sit... by TimeOnMyHands · · Score: 5, Funny

    working in a small cubicle, doing nothing that will ever even change the world, while these guys are working on a project that could destroy the world! I'm so jealous... I've made bad choices.

  28. I bet you $1,000,000... by exp(pi*sqrt(163)) · · Score: 3, Funny

    ...that the world won't end as a result of this experiment. Any takers?

    --
    Doesn't it make you feel good to know that our freedoms are protected by politicans, lawyers and journalists.
  29. And David Brin by tinkerton · · Score: 2, Informative

    I don't know how old Hogan's book is, but in 1990 or so David Brin wrote

    Earth

    where an artificial black hole grows out of control and slowly eats the planet earth from the inside out.

  30. Re: Fermi's Paradox! by nbritton · · Score: 2, Informative

    Thats Fermi's Paradox!:

    "The story goes that, one day back on the 1940's, a group of atomic scientists, including the famous Enrico Fermi, were sitting around talking, when the subject turned to extraterrestrial life. Fermi is supposed to have then asked, "So? Where is everybody?" What he meant was: If there are all these billions of planets in the universe that are capable of supporting life, and millions of intelligent species out there, then how come none has visited earth? This has come to be known as The Fermi Paradox.

    Fermi realized that any civilization with a modest amount of rocket technology and an immodest amount of imperial incentive could rapidly colonize the entire Galaxy. Within a few million years, every star system could be brought under the wing of empire. A few million years may sound long, but in fact it's quite short compared with the age of the Galaxy, which is roughly ten thousand million years. Colonization of the Milky Way should be a quick exercise."

    http://zebu.uoregon.edu/~js/cosmo/lectures/lec28.h tml
    http://en.wikipedia.org/wiki/Fermi_paradox

  31. Re:What happens when multiple black holes combine? by tinkerghost · · Score: 2, Funny

    Oh god, oh god, we're all going to die?

  32. Reminds me of a SCIFI book I read by subsolar2 · · Score: 2, Informative

    Reminds me of the boot Thrice Upon a Time by James P. Hogan where one of the scenarios is the world is destroyed by a CERN fusion generators that uses inertial confinement and ends up producing mini black holes as a byproduct.

  33. Re:Civil War by Paleomacus · · Score: 4, Funny

    "Condoleezza" - two Es, two Zs, just remember "very EZ".

    Ahhh, so that's what happened to her teeth...

  34. Nature itself tells us: no doomsday by xPsi · · Score: 5, Interesting
    IAAP (who worked on RHIC physics). The same arguments used in 1999-2000 with RHIC (and with Fermilab before that) should be used here. There is no chance for doomsday catastrophe. While these events at the LHC are "high energy" from a human technology point of view (per event per particle), the LHC generates low energy events at low rates compared to nature itself. There are millions of LHC-like events (or "greater") per second that occur on the surface of the moon alone, not to mention in our own atmosphere from cosmic rays. While cosmic rays are carefully studied, the reason we build machines such as RHIC, Fermilab, and LHC is, as scientists, we like to study events systematically and carefully at specific energies in a relatively low-noise environment (difficult to do with cosmic rays, which is why we might not formally detect strangelets or black holes in such events when measured). However, if there were problems with voracious black holes, stranglets, or other doomsday scenarios due to elementary particle collisions, they would have happened long, long ago in nature (locally) -- we would have seen evidence for it on the moon, atmosphere, etc. (assuming we survived long enough to witness it with such a high event rate - it probably would have happened long before we had a chance to even evolve).


    See Doomsday Fears at RHIC in particular the reference Review of Speculative "Disaster Scenarios" at RHIC

    --
    i\hbar\dot{\psi}=\hat{H}\psi
  35. You are correct by jd · · Score: 5, Interesting
    The size of the singularity is fixed, but the size of the black hole is not. The size of the black hole is directly proportional to the mass and should be a function of the entropy. Hawking radiation is the stream of particles of quantum foam which switch from being virtual to being real when the opposite particle is captured by the black hole. For reasons I do not entirely understand, it is assumed that the majority of particles captured will be the anti-particle, thus adding a negative amount of mass to the black hole. The companion particle will then be observed as radiation that appears to come from the vicinity of the black hole.

    There is an assumption in all of this, that the singularity is a point in space/time. This is how it is normally considered, but it is by no means the only interpretation that would be valid. Evaporation only applies within this assumption because entropy can only ever increase and the entropy of a physical point singularity that did not evaporate would be a constant. If a singularity does not exist as a point (there are other solutions, such as a "Kerr Ring Singularity") or doesn't actually exist as a physical entity at all (see below for a trivial theory where that would work), then all bets are off.

    This is a "just for amusement" theory, for the sole purpose of illustrating a singularity that would not violate the second law of thermodynamics and still not evaporate. Let us say that a singularity does have infinite gravity at the point at which it "exists", and that the curvature of space/time is a direct function of gravity, then what we call a singularity would not actually exist as an object. At all. What you would have is a "well" of essentially zero diameter where the sides were orthogonal to space and along the axis of time in a negative direction. The notion that "space and time end at a singularity" would not be true to an observer within the Universe, as they would not experience the well as anything other than a continuation of space. However, space would then not be simply-connected and it would be mathematically possible to show that there were mathematically definable points within an otherwise well-defined region that could not be reached.

    Now for the well itself. It cannot stop within the universe, because there are no forces along that axis. F=ma, so if F=0, then a=0. Nor can it continue forever, because it's going along the axis of time and time does not continue forever. There is exactly one place such a well could terminate, that being the moment of the Big Bang. (It stops there because there's nothing more to travel along.) It would be an express trip, there would be no possibility of getting off anywhere else. So it's just as well that, if this correct, anything that fell in would be crushed into quantum foam. Nothing else is going to fit in a well of zero diameter. Hawking's theory of imaginary time becoming real time would certainly fit this description.

    This theory would require that (a) black holes can only ever expand, (b) hawking radiation would contain equal numbers of particles and anti-particles (which would explain why we have such trouble finding any), (c) the recently-proved Poincare hypothesis does NOT apply to space/time, as it is no longer simply-connected, and therefore the Universe is NOT topologically equivalent to a hypersphere (which is going to upset the Chinese and Russians no end), and (d) the Hubble constant absolutely must be below 1.

    (That last one might not be obvious, so I'll explain. This theory recycles matter and energy through time to the big bang. Since you have a Universe's worth of matter/energy, you would not need inflation theory - which is "good" because inflation is an ugly hack whose chief benefit is that it works vastly better than every other mainstream theory in existance. But you can't guarantee that the whole Universe is recycled if the Universe is open. You can only guarantee 100% recycling if every possible photon and every possible particle is absolutely

    --
    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)
    1. Re:You are correct by KingSkippus · · Score: 3, Funny

      So... That's a yes, right?

    2. Re:You are correct by sjames · · Score: 3, Insightful

      Actually, the idea behind Hawking radiation is that the intense gravity gradient of a black hole causes virtual particles to become actual near the event horizon. One goes in and the other escapes. It doesn't matter which one went in. Of course, a pair of particles just appearing out of the vacuum leaves a "hole" that must be filled (otherwise cionservation of mass/energy is violated). The energy to fill the hole tunnels out of the black hole itself. The net result is that it loses the mass of the escaped particle.

      It's worth noting that the size of black hole we're talking about here would evaporate in a small fraction of a second, most likely before it would even encounter another particle. It would have to somehow absorb a few hundred metric tons of matter to even last 1 second.

      Should all of this theory prove wrong, we may still feel safe since collisions with this level of energy DO occur in nature already and obviously haven't created "The Black Hole that Swallowed the Earth".

  36. interestingly enough by slew · · Score: 2, Informative
    On the other side of that coin, it is instructive to remember that the previous civil war started after the Conservatives lost an election.

    Back then, the "republican" conservatives opposed the expansion of slavery and made freeing the slaves a goal. I believe they actually won the election before the civil war. Techically, Lincoln started out as a "whig", although by then the whig party was split along pro-slave/anti-slave lines and most of the anti-slave whigs (including Lincoln) became republicans by the time of the election.

    Often, the pro-slave ex-whigs called themselves the "conservatives" (in an attempt to reconcile the whig party), but they mostly just teamed up with the democrats in the south and of course the democrats lost that antebellum election and the conservative "republicans" won.

    Perhaps you can make the case that technically the north-conservatives won and the south-conservatives lost, but I don't think that makes your case...

  37. Where do they think black holes come from!?!? by brundlefly · · Score: 4, Funny

    Every black hole in existence in the universe is a result of some fairly advanced civilization reaching a point where each eventually says "Hey, let's build a Large Hadron Collider and see what happens".

    The rest, as they say, is astronomical history....

  38. Not this again by xihr · · Score: 2, Insightful

    Why does this keep coming up? Natural ultra-high energy (UHE) cosmic rays have vastly higher energies and do no such thing. The highest-energy cosmic ray recorded is 300 EeV (that's exaelectron-volts -- 3 x 1020 eV. We get showered by these cosmic rays all the time; if high-energy particle collisions were going to make miniature black holes which somehow don't evaporate and kill us all, then it would have happened long before the Earth finished forming.

  39. already too late... by Glog · · Score: 2, Funny

    For the black-hole-fearing crowd... RIAA/MPAA morphed into a black hole a long time ago.

  40. Is Hawking worried? by Kumiorava · · Score: 2, Interesting

    If not then I might go on with my life and not to bother with this.

    If he is worried then I guess I should stop saving for my retirement fund.

  41. Re:OMG Crazy People by ozmanjusri · · Score: 2, Funny
    I can't believe people are scared of being sucked into nothingness.

    Exactly. And here's me thinking all the negative strangelets just hung out on MySpace.

    --
    "I've got more toys than Teruhisa Kitahara."
  42. Re:You are not correct by Atilla+the+Bun · · Score: 2
    Antimatter does not have a negative mass.

    The remaining six paragraphs (!) are not even wrong. You're not a physicist, are you?