CERN LHC: Risk of "Doomsday" Destruction?

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Discussion Overview

The discussion revolves around concerns regarding the potential risks associated with the operation of the Large Hadron Collider (LHC) at CERN, particularly the fear of catastrophic events such as the creation of black holes. Participants explore historical precedents, scientific reasoning, and public perception related to these fears.

Discussion Character

  • Debate/contested
  • Exploratory
  • Technical explanation

Main Points Raised

  • Some participants express skepticism about the likelihood of catastrophic outcomes from the LHC, referencing historical fears surrounding atomic bomb tests that did not materialize.
  • Others highlight the ongoing public concerns and legal actions against the LHC, suggesting that these fears persist despite scientific reassurances.
  • There are discussions about the nature of cosmic rays and their interactions with the atmosphere, with some arguing that these interactions already occur at energies greater than those produced by the LHC.
  • Some participants question the logic of those opposing the LHC, suggesting that experts in the field should be trusted over laypersons who may not fully understand the science.
  • Concerns are raised about the potential impact of public opinion on funding for the LHC, with some expressing frustration over the need to address unfounded fears.
  • A few participants draw humorous parallels between the fears surrounding the LHC and fictional scenarios, such as risk assessments for archaeological digs or astronomical observations leading to apocalyptic outcomes.

Areas of Agreement / Disagreement

Participants generally do not reach a consensus. While some express confidence in the safety of the LHC based on scientific reasoning, others continue to voice concerns and skepticism about the potential risks, indicating a division in viewpoints.

Contextual Notes

Some claims about historical scientific fears and their outcomes are presented without resolution, and there are references to speculative scenarios that remain unverified. The discussion reflects a mix of technical reasoning and public sentiment, with no clear resolution on the risks posed by the LHC.

FredGarvin
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Great. Just after we finally get both our truck and car paid off, those silly guys at CERN are going to create a black hole and destroy the planet. Just my luck.

Critics of the LHC filed a lawsuit in a Hawaiian court in March seeking to block its startup, alleging that there was "a significant risk that ... operation of the Collider may have unintended consequences which could ultimately result in the destruction of our planet."

http://news.yahoo.com/s/ap/20080628/ap_on_re_eu/doomsday_collider
 
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When the first atomic bomb was detonated, and then later the first thermonuclear weapon, there were scientists who thought the atmosphere would catch fire or undergo a thermonuclear reaction. Ummm - that didn't happen - nor could it have.


Cosmic rays interact with the nuclei in the atmosphere - everyday. A small fraction of these particles have energies several orders of magntide greater than that of CERN LHC.

Last time I checked - we're still here.
 
I think fred was trying to be funny (successfully), but you are right astro.
 
wildman said:
I think fred was trying to be funny (successfully), but you are right astro.
I know FG was being funny, but I'm surprised that this nonsense still continues.

I just looked out the window - the world is still out there where I left it.

I'll keep checking - just to make sure! :smile:
 
I don't understand something about the way the magnet was lowered. Wouldn't it have been better to put a series of planks (in a manner of speaking - not wooden of course) under it, removing the top layers as the magnet continued down? (So if it dropped, it'd only fall a short distance.)

Anyway, can they just flip the switch already? The excitement is killing me.
 
Astronuc said:
When the first atomic bomb was detonated, and then later the first thermonuclear weapon, there were scientists who thought the atmosphere would catch fire or undergo a thermonuclear reaction. Ummm - that didn't happen - nor could it have.


Cosmic rays interact with the nuclei in the atmosphere - everyday. A small fraction of these particles have energies several orders of magntide greater than that of CERN LHC.

Last time I checked - we're still here.


I heard on a program on the history channel that the soviets? or maybe the US, creatred a bomb that was just the right size and amount to possibly cause a run-a-way reaction with some elements in the atmosphere, thus causing it to burn.
 
Cyrus said:
I heard on a program on the history channel that the soviets? or maybe the US, creatred a bomb that was just the right size and amount to possibly cause a run-a-way reaction with some elements in the atmosphere, thus causing it to burn.
The Earth's atmosphere is simply not dense enough, nor the magnetic or gravity fields strong enough, to sustain a fusion reaction, which ostensibly would be the CNO cycle. The energy from any thermonuclear device dissipates too quickly.
 
If it were to stop, though from what previous posts seem to suggest unlikely would that make it like the biggest waste of money EVER (US$5 - 10 Billion) And I thought the Millennium Dome was bad...
 
_Mayday_ said:
would that make it like the biggest waste of money EVER (US$5 - 10 Billion)

Sadly, even in the case they shut it down, it would still be several orders of magnitude away from being the biggest waste of money ever.

http://zfacts.com/p/447.html
 
  • #10
Yeah, I've known about it for a few months. I know that these guys are a bunch of crazies, but at some level I am concerned that they may convince enough people to stop funding the LHC. Unfortunately, most of the people who write our checks don't have PhDs in physics, so we do have to address even the most foolish of concerns.

On the other hand, it's a good thing I'm in high energy astrophysics. The cool thing about havig God supply the acceleration mechanism is that you only have to pay for the detector. Of course you also have no idea what the accelerator is doing...
 
  • #11
Looks like the Earth-eating black hole machine might have a chance yet!:smile:

Government Seeks Dismissal of End-of-World Suit Against Collider
Citing this and a previous safety report in 2002, the government argued that the plaintiffs, Mr. Wagner and Mr. Sancho, had no standing because they could not demonstrate any credible injury. “Scientifically,” the brief says, “there is no basis for any conceivable threat that Plaintiffs have theoretically envisaged, such as strangelets, black holes, and magnetic monopoles.”

This is not the first time, as the government noted, that Mr. Wagner has forecast the apocalypse. In 1999 and 2000, he sued to stop the Relativistic Heavy Ion Collider, or Rhic, at the Brookhaven National Laboratory on Long Island using the same arguments, which were found to be “speculative.” Those cases were dismissed.
http://www.nytimes.com/2008/06/27/science/27collider.html?_r=2&oref=slogin&oref=slogin
 
  • #12
Astronuc said:
When the first atomic bomb was detonated, and then later the first thermonuclear weapon, there were scientists who thought the atmosphere would catch fire or undergo a thermonuclear reaction.
Ya know...that was the first thing that popped into my head when I read the story. The only thing about that is that even some of Oppenheimer's guys thought that it might happen. They simply didn't know. I give them a gazillion times more credibility than these whack-os in Hawaii or wherever they are.
 
  • #13
This is reminiscent of Andrei Sakharov's plea for a ban on experimentation with vacuum energy. Given the highly energetic stuff that happens all over the universe, it should be assumed that the quantum vacuum field is stable against disruption, but Sakharov thought that the current condition of the vacuum was only one possible phase state and that triggering a phase change through experimentation could destroy the universe. It sounds like a pretty silly idea that we humans could destabilize the vacuum, when there are GRBs, quasars, supernovae, etc, kicking up some pretty impressive tantrums. Still the universe looks to be OK.
 
  • #14
Do archeologists have to do this kind of risk assesments?
Risk: opening this tomb might unleash an ustoppable hoard of undead zombie mummies
Outcome: end ofworld
Likelyhood: low
 
  • #15
Apparently even casual astronomers should start doing risk assessments:

Risk: Astronomical observations can cause the Universe to decay.
Outcome: End of universe
Likelyhood: low
 
  • #16
What gets me is that these people don't seem to care that the physicists dealing with the LHC are obviously experts in the field. However, some Hawaiians know better.
 
  • #17
moose said:
What gets me is that these people don't seem to care that the physicists dealing with the LHC are obviously experts in the field. However, some Hawaiians know better.

Seems strange to me that people who have chosen to live on volcanoes are worried about black holes. :rolleyes:
 
  • #18
moose said:
What gets me is that these people don't seem to care that the physicists dealing with the LHC are obviously experts in the field. However, some Hawaiians know better.
I was also thinking along these lines. I probably know nothing about particle physics, but I am worried, so I'll take them to court because I feel there could be something funny going on like making black holes.

It's even funnier because, if they stopped and took the time, they could probably find four or five other aspects of something that large that could either delay or shut them down for a good length of time.
 
  • #19
Astronuc said:
When the first atomic bomb was detonated, and then later the first thermonuclear weapon, there were scientists who thought the atmosphere would catch fire or undergo a thermonuclear reaction. Ummm - that didn't happen - nor could it have.

However, according to one scientist involved, they didn't know then that it was impossible. There was even a number bantered around; something like a 0.1%, of the world ending [maybe far less but it was nonzero and not vanishingly small]. I remember thinking: How dare they take such a risk! Who had the right to authorize that one?

As for the rest, it is very simple: There are many people who do not trust scientists; and in particular, physicists. It is perceived that scientists are too arrogant, and therefore dangerous. After all, who gave us the bomb?

Keep in mind that these people are fearful and not primarily crackpots. They fear for their lives and for all of humanity, and they don't understand what is being done. They only know that scientists might be capable of wiping-out civilization - they know what a Hydrogen bomb explosion looks like.
 
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  • #20
It's still spectacular that out of billions of people in the world someone would care to challenge the LHC.


Anyways, wasn't the highest energy cosmic ray detected a single proton carrying a couple joules of energy?
 
  • #21
There's nothing particularly new in this article, but there was this line which I found pretty funny:

http://www.cnn.com/2008/TECH/06/30/doomsdaycollider.ap/index.html

The physicist Martin Rees has estimated the chance of an accelerator producing a global catastrophe at one in 50 million -- long odds, to be sure, but about the same as winning some lotteries.

...and jeez, you know people win lotteries every day...in fact, it happens all the time!

:smile:
 
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  • #22
One concern that I read that I cannot reconcile on my own is this:

Cosmic rays hit our atmosphere, but the momentum is non-zero after the collision. So even after a "black hole" is created, it zooms away really fast and we never see it again. In this case the net momentum is very close to 0, so the black hole would simply sink to the center of the Earth and grow over a long period of time.

What's wrong that that picture?
 
  • #23
All I can say is that if they create a black hole that eats up Europe into some Swiss sinkhole, I expect they will run a big chance of losing their funding for next year.
 
  • #24
If the LHC does cause the destruction of Earth in an instant or near enough such that the period taken for it to hapen is inperceptable, then there sort of isn't a problem right?

If you have no knowledge of your death before you die, then the time at which you die/decay into strange matter is irrelavent.

Of course if the destruction is localised or over a protracted period then that's very very bad, but as long as the destruction is total and complete (and instant) then we having nothing to fear. Of course I'm talking arse as what I've said is of no consequence, but it's none the less true

LowlyPion said:
All I can say is that if they create a black hole that eats up Europe into some Swiss sinkhole, I expect they will run a big chance of losing their funding for next year.

In that instance I'm sure the MoD would oblige them with funding if they altered their research proposals somewhat
 
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  • #25
neu said:
If you have no knowledge of your death before you die, then the time at which you die/decay into strange matter is irrelavent

If I had a choice right now, I would choose to continue living. Similarily, I'd rather not have a nuclear bomb explode right next to me, even though my death would be virtually instantaneous.
 
  • #26
FredGarvin said:
Ya know...that was the first thing that popped into my head when I read the story. The only thing about that is that even some of Oppenheimer's guys thought that it might happen. They simply didn't know.

It was Edward Teller who thought this, and it was Hans Bethe that showed him that that couldn't happen. It's not that Bethe didn't know, it is that he did a quick calculation and showed that the conditions of temperature and density weren't there.

The thing is that this got out in a badly formulated report, and since then, this myth lives on. At least, what I write here is the summary of that story in "The making of the Atomic Bomb" by Richard Rhodes.

Teller was always wild with ideas, but never really sat down to try to find out whether they were correct. He has had gazillions of wrong ideas. His first attempt at a hydrogen bomb was also fatally flawed, and Ulam showed him why, and even showed HOW it got to be done right. Once Teller got the idea from Ulam, he improved a bit upon it, so that's now called the Teller-Ulam mechanism.

What was much more dangerous, was to explode a nuclear weapon under water. But even H-H fusion cannot happen in large amounts.
 
  • #27
WarPhalange said:
One concern that I read that I cannot reconcile on my own is this:

Cosmic rays hit our atmosphere, but the momentum is non-zero after the collision. So even after a "black hole" is created, it zooms away really fast and we never see it again. In this case the net momentum is very close to 0, so the black hole would simply sink to the center of the Earth and grow over a long period of time.

What's wrong that that picture?

In fact, the momentum is not 0 at all, because it is not the proton onto the anti-proton that would create eventually a black hole, but rather a parton of the first proton with a parton of the second, and both have arbitrary momenta (fractions of the initial proton momentum and anti-proton momentum). The probability that they cancel out exactly, so that the black hole is bound to earth, is pretty small.
 
  • #28
This is what you can expect in a society where some don't even know that the Sun is a star.