CERN is reporting that the Large Hadron Collider has been shutdown yet again after a piece of bread fell into the outdoor machinery. That part of the LHC's circuit normally operates at 1.9 Kelvin, but, thanks to the bread bomb, rose to 8 Kelvin, nearly causing the LHC's niobium-titanium magnets to cease superconducting. The incident could have crippled the LHC yet again — and caused significant physical damage to the lab had the LHC been fully operational at the time — but CERN claims that it won't delay the full reactivation of the device, scheduled for later this month.

Technicians believe that a passing bird dropped the bread into the machinery, just the LHC's latest run-in with Murphy's Law.

Large Hadron Collider scuttled by birdy baguette-bomber [The Register via Popular Science]

The quest to observe the Higgs boson has certainly been plagued by its share of troubles, from the cancellation of the Superconducting Supercollider in 1993 to the Large Hadron Collider's streak of technical troubles. In fact, the projects have suffered such bad luck that Holger Bech Nielsen of the Niels Bohr Institute in Copenhagen and Masao Ninomiya of the Yukawa Institute for Theoretical Physics in Kyoto wonder if it isn't bad luck at all, but future influences rippling back to sabotage them. In papers like "Test of Effect From Future in Large Hadron Collider: a Proposal" and "Search for Future Influence From LHC," they put forth the notion that observing the Higgs boson would be such an abhorrent event that the future is actually trying to prevent it from happening.

"It must be our prediction that all Higgs producing machines shall have bad luck," Dr. Nielsen said in an e-mail message. In an unpublished essay, Dr. Nielson said of the theory, "Well, one could even almost say that we have a model for God." It is their guess, he went on, "that He rather hates Higgs particles, and attempts to avoid them."

Nielsen and Ninomiya recognize that the theory sounds pretty crazy and that other projects involving a lot of delicate technology — such as the Hubble Telescope — have gone through their own periods of apparent bad luck. But their theory — wild as it is — is situated in current research in theoretical physics and time travel. If the observation of the Higgs boson would result in calamity, they claim it isn't outside the realm of possibility that someone from our future might exert influence on our time to stop it:

While it is a paradox to go back in time and kill your grandfather, physicists agree there is no paradox if you go back in time and save him from being hit by a bus. In the case of the Higgs and the collider, it is as if something is going back in time to keep the universe from being hit by a bus. Although just why the Higgs would be a catastrophe is not clear. If we knew, presumably, we wouldn't be trying to make one.

The Collider, the Particle and a Theory About Fate [NY Times — Thanks to Boas_MC]

The Independent newspaper reports that repairs to two helium leaks have pushed the restart back to November, and there are signs that more repairs - and more delays - are possible in the next few weeks. James Gillies, spokesman for the European Organisation for Nuclear Research, said that all possible precautions are being taken before the eventual restart:

Decisions will be taken as to whether there are more that need repairing or not within the next couple of weeks, and when we know that, we will be in a position to be a little bit more definitive about what we plan to do for the rest of the year... Essentially what's happening is we're proceeding with extreme caution. We have to be absolutely certain that when we switch on this time, it stays switched on.

The Collider has been inoperative since September last year, due to a fault between superconducting magnets. The cost of repairs is estimated at $37 million.

LHC 'atom smasher' restart delayed yet again

Here are five pieces of wisdom that we've gleaned from the last six months (and handful of days):

President Obama Is The Greatest Hero Of All
As his many comic book appearances have demonstrated, there's no end to our current president's ability to save the world from any genre of threat. Amazing Spider-Man has him fighting supervillains, Youngblood shows him carrying massive laserguns to shoot renegade soldiers taking over the White House, Drafted gives us an alien-invasion-battlin' Barack and Barack The Barbarian brings everything back down to sword and sorcery basics. He's like a modern-day Arnold Schwarzenegger - and enough to make us wonder just how the comic industry would've dealt with John McCain winning the election instead.

Threats To Humanity Are Getting Weaker
Last year, it was the Large Hadron Collider and the possibility that it would rip existence apart when someone flipped the switch, and this year, it was... Swine Flu. It can't just be me, can it? I mean, Swine Flu... Doesn't that seem like a step down from the technological "Our Quest For Knowledge May Destroy Us All" conceptual genius that threatened us last year? Even calling it "the H1N1 Influenza Virus" still sounds kind of shit. Okay, so there's no chance of "hardon" spoonerisms, but still: Pandemics? Haven't we done that already? I'm holding out hope that sewer monsters will brighten the remaining months of the year, however.

The BBC Should Stop Making Us Feel Old
Yes, we know that it's just one of those aimless homilies that you know that you're getting old when the policemen and doctors start looking younger, but selecting a twelve year old to be the new Doctor Who really doesn't make us feel very good about ourselves nonetheless. I know that we started with the oldest of the Doctors and have progressively gotten younger since then - well, roughly - but between David Tennant and Matt Smith, I'm convinced that we'll have our first pre-teen Timelord by 2015. And then, the next one will be a little baby, just like in 2001: A Space Odyssey.

Joss Whedon Can Defy The Laws Of Nature
If nothing else, the renewal of Dollhouse proves that he can defy the laws of television. I wouldn't put money on him being unable to fly if he really wanted to.

Fuck Dystopia
Terminator Salvation and Watchmen - two downbeat movies offering popcorn versions of pessimistic views of humanity ("Ultimately, man's greed and laziness will lead us to become disconnected from our fellow man and controlled by the machines and mechanisms that we created to ease our daily existences - but doesn't this slow-motion action sequence look hot?") - both failed to meet expectation at the box office, while Star Trek's hopeful, colorful version of a future that may be too lens-flarey to be cuddly but is nonetheless positive surpassed expectations. Terminator: The Sarah Connor Chronicles also died a slow death on television. The obvious conclusion? No-one wants to their entertainment to end with the lesson "We're all screwed." The Dark Knight's glossy hopelessness was so last year, people. We hadn't experienced so much of the economic downturn and/or the hopetrain of Obama back then. We were all so much more innocent and desperate to be mistreated by our movies. (Along the same lines - Size Matters: Terminator, featuring human-sized robots, fails to become a hit. Transformers: Revenge of The Fallen, featuring giant robots, breaks box office records. I think you can see what I'm saying here. See also: Robot On Robot Action Is More Acceptable Than Robot On Batman Action and Megan Fox Is Hotter Than Moon Bloodgood. Sorry, But There It Is.)

Bolstered with this new knowledge, we look forward to what the rest of the year can teach us - presuming, of course, that the sewer monsters don't decide to team up with Joss Whedon and end the world before then. Pray for us.

According to Symmetry Breaking:

CERN today announced that the laboratory hopes to run the LHC with 5 TeV beams with collisions in late 2009, producing data suitable for physics analysis. Eventually the LHC will run with 7 TeV beams . . . A CERN management meeting on Monday will determine whether this recommendation is accepted and the start-up schedule does indeed include physics operations in late 2009.

In CERN's regular weekly LHC update, they said that as part of the campaign to avoid another incident like the one that shut down the LHC in September ‘08, a new protection system is being installed in the LHC to detect tiny electrical resistances on the superconducting busbars between magnets. Materials and electronics necessary for the system are being ordered and manufactured, with installation of some components already underway.

via Symmetry Breaking

With some of the world's richest companies slashing budgets and hunkering down for a slow-growth year in 2009, it's hard to avoid the question, "Is the LHC really worth it?" Though the facility will advance scientific understanding of the universe immeasurably, it will provide no short-term economic benefits. Discoveries made when the accelerator goes live could mature into devices that change our everyday lives in ten years, or in two generations, or never.

So it's easy to see why the LHC is pulling back on estimates about when it will actually start the experiments. Originally reps for the facility estimated that repairs would be finished and the LHC would come online in April. Now they're claiming June at the earliest. I wouldn't be surprised if we didn't get to celebrate the LHC's first real experiment until 2010, but let's hope not. $21 million is a small price to pay to unlock the secrets of the universe.

LHC Repairs Get Pricier [via Nature]

At first glance, it's pretty hard to watch. It's one of the grimmest things I've ever seen, and I've watched student productions of Samuel Beckett's Endgame. The first couple of three-minute episodes seem to consist of just Schofield acting his heart out in a grim post-apocalyptic, dystopian world. (You can take a drink now.) It's not entirely clear to me what the plot of Kirill is, but it seems as though Schofield's character is trying to communicate with our time, 50 years in his past, and warn us about some future disaster. And (shockingly) the Large Hadron Collider is involved.

MSN UK will post two three-minute episodes per week, for the next five weeks. And there's some kind of vague interactive component, to do with MSN's instant messenger tool "Live Search" and MSN's social network. Maybe you can communicate with a dying blogger in a ravaged world 50 years from now? Your guess is as good as mine. Here's the trailer:

[MSN]

Kamps told Sci Fi wire that their plot plan for the LHC was actually picked up by Disney many moons ago:

I had this idea about a particle accelerator after I read about this one that they were going to put in Waxahachie, Texas. Did you remember that? It was during the Clinton administration, and they cut funding. But I wondered, 'What if they fired it up, and all of the laws of physics went crazy?' It was an idea that we didn't do anything with for about 10 years, and then David [Koepp] and I got together and wrote a script, and it was a great experience. We sold it to Disney, and eventually they didn't want to make it, but hopefully someday it will get made.

Which means by the time we're all done talking about it, the LHC will be popular again. But best of luck to you guys: Don't be afraid to tug our sciencey heart strings.

[Sci Fi Wire]

Writing on his message board, Millar resumed his familiar man on the street persona to promote his new war on science:

[W]hat the FUCK is going on here? Am I the only person who thinks God Particle, possible Black Hole on the French/ Swiss Border, Recreating The Big Bang, etc, are all phrases I only want to read in New Gods? Where the fuck is James Bond and why isn't he KILLING these French fucks before they even push the button? Saddam was invaded and hung for not even HAVING nukes primed for his neighbours. These freaks genuinely risk ending the world!!!!

And for what? To see how the universe might have begun? Who gives a fuck? 5 billion pounds on a scientific folly when old people can't afford to heat their homes or kids are starving? Get outta here, egg-head! I don't care about dark matter, dark energy or even other dimensions. Best case scenario is we're sucked into a black hole, every atom in our body screaming as we die in a nano-second. Worst case scenario we're in The Mist or Cloverfield as Lovecraftian mofos come through this doorway and munch their way through us. Europeans creep me out, but none more so than Euro-SCIENTISTS. I declare a Jihad on all these boffins who risk reality itself in the name of their curiosity. No wonder Pol Pot killed everyone who wore glasses. At least you know where you are with bullies and jocks!!

Mark Millar, ladies and gentleman - On his way to becoming a major player in Hollywood.

I Had A Watchmen Moment, This Morning [Millarworld]

Things do not look good. Not only was the fire brigade called in to deal with the situation, but vacuum was lost as well as liquid helium. Here's what the BBC had to say:

The superconducting magnets in the LHC must be supercooled to 1.9C above absolute zero, to allow them to steer particle beams around the circuit. As a result of the [leak], the temperature of about one hundred of the magnets in the machine's final sector rose by around 100C. A spokesman for Cern confirmed that it would now be difficult, if not impossible, to stage the first trial collisions next week. Further delays could follow once the damage has been fully assessed over the weekend.

Hopefully this will only be a minor setback, but we'll have to see what the LHC researchers say on Monday.

Hadron Collider Forced to Halt [via BBC News]

My Bosons, Your Hadrons
I Survived - 09/10/2008
Go Science!
One Ring to Rule Them All
I Survived the LHC Experiment
Particle Physics Gives Me a Hadron
I'm ConCERN'd
Search for 'God Particle' Begins
Standard Model of Particle Physics
Thanks for Not Destroying the Universe

"Lost Souls" didn't really have to be this bad. I mean, Doctor Who has gone on the radio without becoming a crazy pantomime. (Well, the Jon Pertwee radio dramas were pretty dromedary-ish, I guess. But some of the Big Finish audios are pretty respectable.) Somehow, everybody involved in this production got the same memo, the one that said, "Nobody can see you, so you have to act REALLY BROADLY to make sure everyone gets a mental image."

So I guess at least it's good that there was a sort of theme here, which is dealing with the aftermath of Tosh and Owen's deaths at the end of season two. Does this mean everyone will have moved on at the start of the shortened season three? We can only hope.

Actually, the real theme of this episode seemed to be: "Martha Jones is a busy-body." I lost count of how many scenes there were when someone is supposed to be examining a glowing extradimensional-attack victim or crawling through a scary particle tunnel, and Martha keeps bugging them to delve into their feelings. The team is trying to save the world from being eaten by evil Higgs Boson monsters, and Martha is like, "This is a perfect time to share your feelings. Come on, open up! Let it all out!" I started wanting to call her Deanna Jones.

And then of course, it turns out the Higgs Boson monsters are actually telepathic nasties who impersonate the ghosts of the dead, and they pretend to be the ghosts of Tosh, Owen and Ianto's glam-rock cyberwoman girlfriend Lisa. Somebody needs to get those extradimensional aliens an acting coach. As bad as the human actors were, the aliens were even worse. "Yooo hyooomans! So often undone by luuuvvv! Dream of it in the void, be ready to embrace the Dark Times! We're backkkk! We're hungry!!!" Hyooomans!!!! Ha ha yeah.

I didn't actually understand what was supposed to be happening in this episode, honestly. There was a tunnel (even with their limitless ability to show anything on the radio, it's still a tunnel) and neutron-eating monsters, who can only consume neutrons from humans for some reason, and there's a hidden building where glowing people are being kept prisoner because a UNIT officer thinks they're angels... and meanwhile the Large Hadron Collider is EEEEEVIL!

That's really what redeemed this episode for me. I figured, with a special LHC tie-in, they would go the safe route and say, "Well, of course the LHC is wonderful and not at all dangerous, and science is good for you." But no! It turns out the LHC really is a disaster waiting to happen, and if we switch it on, it will open a portal to another universe, where the neutron eating monsters will swarm and eat all our neutrons. I loved the part where Captain Jack bursts in and says: "I'm ORDERING you to shut down the Large Hadron Collider!" and the scientist is all like, "but you're just the assistant to the Welsh Ambassador." (And that was a funny running gag, by the way.) And then we have 20 minutes of insane physics babble.

Did anybody with an actual physics background listen to this audio? And did your head remain intact? I need to know exactly how ludicrous all the stuff towards the end was, especially when Jack is like, "We can reverse the polarity," and the scientist lady is like, "Look! It's an anti-proton!" And then they see the Higgs Boson and Jack says "Let's have a baby!"

Actually, listening to Jack explaining the LHC earlier in the show, and making it sound really obscene, was a big plus as well. There are these particles, and they RAM together, and then there's a BIG BANG, etc. etc. I was surprised quite how much of Jack's raunchy side oozed out of the radio, what with all of the remarks about many-handed Venusians, etc. So, all in all, if you're one of the people who enjoys Torchwood for it's "so bad it's good" moments, then this is probably the crowning glory of your existence. Unlike the TV show, which occasionally did reach "actually good" status, I can't see any other reason to listen to this.

You can listen to it here: [BBC, thanks RRich]

The Mist
In a remote Maine town, a thick fog envelops an area near a military base where a mysterious "Project Arrowhead" appears to have ripped down a wall between two dimensions. Unfortunately, it turns out that the universe in the cosmic string next door has really crappy atmosphere and is full of giant monsters with long teeth. And humans, known across the multiverse as a tasty snack, have lured a ton of those monsters over to chomp us up.

Anathem
I've already mentioned that Neal Stephenson's new novel Anathem contains references to an LHC-esque device that was doing experiments with recreating the Big Bang. Little is known of this device because switching it on led to something the characters in the novel refer to only as The Terrible Events. Records are spotty, especially 3700 years after the fact, which is when the novel takes place. However, we do know that the Terrible Events probably began with LHC-style experiments, and ended with the science centers on planet Arbre being sacked by outraged citizens. The planet spirals into a dark period of war and chaos before completely reorganizing itself and outlawing massive physics experiments.

Earth
In David Brin's 1990 novel Earth, humans create a microscopic black hole that accidentally drops into the core of the planet. If you'll recall, one of the things that the LHC might do is create tiny black holes that exist for a few nanoseconds. Brin imagines a scenario embarrassingly similar to the one in cheesy flick The Core, where the Earth's core stops spinning and gravity gets fucked.

Quiet Earth
In this classic New Zealand apocalypse flick, a man awakens to find himself on an alternate Earth where only a few humans still exist. He suspects the government project he was working on might have had something to do with the change, and his suspicions grow as reality becomes less and less stable. In some ways, the physics mayhem is really a backdrop to the human mayhem that our main characters find themselves in. Even though the tissue of reality is ripping, there are still enough humans left to have a love triangle.

His Dark Materials
Philip Pullman's trilogy that begins with The Golden Compass is about how a few people have learned to use a special knife to cut windows between dimensions. Unfortunately, the windows are causing a shortage of a basic substance in the universe called (depending on your dimension) Dust or dark matter. The overarching quest of the series is to discover what Dust is and why it's running out, which eventually leads the characters to a physics lab in contemporary Oxford.

Donnie Darko
Sure, Donnie Darko is a weird movie that might just be about schizophrenia induced by the Scariest Bunny Suit Ever. But if you take it at face value, Donnie Darko is about the apocalypse that might be unleashed when Donnie manages to travel through time and prevent a death that was supposed to happen. The question is, whose death was supposed to happen? And can you travel through time when you are dead? Whoa, man. Luckily Jake Gyllenhaal is so smoking hot in this movie that you won't pay attention to the plot when he's on screen. And he's on screen a lot.

Doctor Who
Remember in the first season of the new Doctor Who when we had A Very Special Episode called "Father's Day" with Rose going back in time to save her dad's life and accidentally unleashing a bunch of timespace-rending bat things? Obviously the Doctor travels though time, so he and his companions are constantly screwing up the timeline. But apparently that only results in a possible destruction of Earth when Rose goes back to rescue her father from the fatal car accident he suffered when she was a baby. The two contradictory timelines cause monsters to appear and the world to begin ending in a very Buffy-esque way. How will Rose and the Doctor stuff those bats back into the time crack?

SciFi Channel's Flash Gordon
I know all of you loved SciFi's Flash Gordon series — especially in the good old days when I recapped it every week — but you have to admit it's a perfect example of physics experiments that destroy the world. Flash's dad and the dorktastic Dr. Zarkov have invented these devices that allow them to open a doorway between Earth and Mongo. But it turns out their dimension-tripping is destroying the fabric of reality, not to mention getting Ming all excited about stealing Earth's water. One of the big plot arcs from the only season of this tragically-canceled show was trying to stop everybody from opening up dimension doorways because Something Bad would happen.

A Sound of Thunder
Any number of lameass time travel movies show this most basic of physics experiments — moving around in time — destroying the world. But Sound of Thunder is a standout for two reasons. One, it's based on a famous Ray Bradbury short story, which gives it literary cred. And two, it shows that time travel can completely destroy the human world rather than just causing the Nazis to win or Rome to never fall. When our time travelers return to the present after stealing a butterfly from the primeval era, they discover that dinosaurs have won the evolutionary war and are wiping out the last of humanity.

Lexx
Possibly the most awesome Canadian scifi series ever made, Lexx is about a crew of troublemakers on board the Lexx, a planet-eating sentient spaceship. One of the major subplots in Season 4 involved determining the mass of the Higgs-Boson, which all the characters casually refer to as something that "everybody knows" will cause entire planets to be destroyed. Starting tomorrow, the LHC will be conducting tests to determine the mass of the Higgs-Boson. This might be why robot head 790 pointed out that Earth is of the class of planets that usually destroys itself by war, or by unintentionally smooshing itself into a pea-sized object by attempting to measure the mass of the Higgs-Boson.

The rules are simple. Take a drink of your favorite beverage whenever one of the following occurs:

• A proton crosses the border between Switzerland and France.
• A magnet quench in a superconducting magnet causes all the liquid helium to boil away.
• A Higgs boson is detected (2 drinks).
• Scientists learn the secrets of the universe and go insane (2 drinks).
• A miniature black hole forms (2 drinks if it absorbs Switzerland).
• Strange matter is created (weird, unusual or eccentric matter doesn't count).
• A petabyte of data is generated.
• Someone sings the chorus of the LHC Rap.
• The Super Proton Synchrotron reaches 300 gigavolts (2 drinks if it hits 400 GeV).
• The Compact Muon Solenoid finds something that completely alters our understanding of the fundamental forces of the universe.
• Flight 19 suddenly appears over Geneva.
• Particle superpartners are found to have natural supersymmetry.
• An intern confuses muons with gluons.
• The experiment goes awry and someone ends up with superpowers.
• Aliens show up and make us turn off the LHC before we implode reality.
• Scientists go back in time (2 drinks if they create a paradox).
• Someone says "Big Bang."
• Particles crash into each other (2 drinks if there are Batman-tyle visual sound effects, like "Pow!" and "Zap!" when it happens; feel free to construct your own).
• Someone says, "What's a hadron?"
• Scientists access another dimension (2 drinks if that dimension is occupied entirely by Donna Summer impersonators; 3 drinks if denizens of said dimension eat the scientists; note that these two conditions are not mutually exclusive).
• Someone on TV questions the amount of money spent to build the LHC.
• Someone on TV worries that the LHC will destroy the world.
• The world ends (drink whatever you have left).
• Scientists prove string theory (3 drinks because we'll all pretty much have to take their word for it).
• Someone uses the term "beam pipe" in a pickup line.

Numerous studies have found that the LHC poses no risk of creating reality-devouring exotic matter or world-shredding mini black holes, but still the messages of anger and concern pour into CERN headquarters. Mixed in with the hand-wringing have been a few actual death threats, notably directed at physicist Frank Wilczek of MIT. Scientists have noted that cosmic particles bombard the Earth constantly, yet they haven't caused an apocalypse yet, so there's really nothing to worry about. I guess "the potential end of the world" sticks in people's minds better than "the search for the Higgs Boson."

Of course, when the Telegraph quoted Professor Cox's vitriolic paroxysm, they used asterisks to disguise the word he actually used. So what's a t***? Some obscure physics term, no doubt. Image by: xkcd.

Scientists get death threats over Large Hadron Collider. [Telegraph]

Physicists working on the LHC say that even if the device does produce tiny black holes, they will exist for such a short time that they couldn't possibly do any damage. Instead, they're interested in experiments that could reveal for the first time what dark matter is, and what the universe looked like after the big bang.

Though the LHC won't be in full operation until September 10, when the first real experiments there will get underway, this weekend marks the first time the facility will be used. Researchers will shoot a few particle beams through the magnetized, reinforced tunnels that make up the giant particle accelerator. According to Popular Mechanics:

As part of a scheduled injection test, the LHC will be closed off this Friday, and researchers at CERN will fire protons through one of the eight sectors that make up the sprawling concrete-lined collider tunnel. The purpose of this test? “It’s, ‘Let’s see what happens,’ ” says Judy Jackson, head of the Office of Communications at Fermilab. “It’s a very complex machine. This is a step towards getting ready.”

Let's see what happens? You mean, like whether it produces tiny black holes that last longer than a nanosecond? Awesome.

Start Date for the Large Hadron Collider [Popular Mechanics]

Here's the endcap of the ATLAS detector, which contains several layered cylinders around the spot where the where the LHC's proton beams will smash into each other.

Here you can see the gigantic electromagnetic calorimeter, which is 6x7 square meters. According to the Boston Globe:

[It] consists of 3300 blocks containing scintillator, fibre optics and lead. It will measure the energy of particles produced in proton-proton collisions at the LHC when it is started. Photons, electrons and positrons will pass through the layers of material in these modules and deposit their energy in the detector through a shower of particles.

In other words: This device measures the output of the smashed protons.

No, it's not some steampunk fantasy gear. This is a huge magnet that will become part of the endcap of the ATLAS detector we showed you above.

Want to see more hardcore physics experiment insanity? Check out the amazing set of photos at the Boston Globe. The LHC goes online and starts smashing tiny particles later this year.

Large Hadron Collider Nearly Ready [via Boston Globe] (Thanks, Gonzalo Sanchez!)

The Large Hadron Collider, once operational, will fire beams of protons into each other at energy levels never seen on Earth. We don't really know what will happen when experiments begin (or we wouldn't bother running the experiments), and there are fears that all kinds of weird, hypothetical particles could be created that will devour the planet, or that a small but stable black hole will begin consuming all nearby matter. Steve Giddings, Professor of Physics at UC Santa Barbara, studied the risks. His conclusions:

• The chances of a microscopic black hole forming are impossibly small.
• Cosmic rays smash into particles all the time at very high energies. We probably would have noticed if the universe was being chewed up by an endless torrent of ravenous mini black holes.
• In the incredibly unlikely event that a microscopic black hole forms, it would exist for "a nano-nano-nanosecond." Not long enough to do any damage, in other words.
• Giddings even studied what would happen if a long chain if bizarre events occurred, and a stable micro black hole formed. The result would be...nothing much. Even a stable microscopic black hole would be harmless.

If The Large Hadron Collider Produced A Microscopic Black Hole, It Probably Wouldn't Matter. [Science Daily]