Friday, January 18, 2008

How to destroy the Earth, part 3

Sucked into a microscopic black hole

You will need: a microscopic black hole.

Note that black holes are not eternal, they evaporate due to Hawking radiation. For your average black hole this takes an unimaginable amount of time, but for really small ones it could happen almost instantaneously, as evaporation time is dependent on mass. Therefore your microscopic black hole must have greater than a certain threshold mass, roughly equal to the mass of Mount Everest.

Creating a microscopic black hole is tricky, since one needs a reasonable amount of neutronium, but may possibly be achievable by jamming large numbers of atomic nuclei together until they stick. This is left as an exercise to the reader.

Method: simply place your black hole on the surface of the Earth and wait. Black holes are of such high density that they pass through ordinary matter like a stone through the air. The black hole will plummet through the ground, eating its way to the centre of the Earth and all the way through to the other side: then, it'll oscillate back, over and over like a matter-absorbing pendulum. Eventually it will come to rest at the core, having absorbed enough matter to slow it down. Then you just need to wait, while it sits and consumes matter until the whole Earth is gone.

Earth's final resting place: a singularity with a radius of about nine millimetres, which will then proceed to happily orbit the Sun as normal.

Feasibility rating: 3/10. Highly, highly unlikely. But not impossible.

Comments: Getting closer!

Source: The Dark Side Of The Sun, by Terry Pratchett. It is true that the microscopic black hole idea is an age-old science fiction mainstay which predates Pratchett by a long time, he was my original source for the idea, so that's what I'm putting.

I also found this article on the same subject!!!!

No, really -- you just don't want to know this. There’s a remote, but extremely terrifying possibility our planet is about to be swallowed from within by a man-made black hole. In fact, our planet could be booby trapped with baby black holes already.

It is one weird way to go. One moment, you’re here. And the next -- you’re not. It will be sudden, and dramatic. Within seconds, the planet, with everything and everyone on it, is reduced to nothingness. Or actually: it is squeezed together into a tiny black hole, no more than 9 millimeters wide.

If you were to play back the tape of what went wrong very slowly, you would see something very peculiar. Suddenly, you would see the Earth deform. Obviously, not a very good sign. Our planet is flattened out to become a disk. Beams of radiation shoot up from where the poles used to be. And then, zzzp, the planet’s gone. Just like that. Within a split second, it would simply vanish, right before your eyes.

Understandably, on board the International Space Station, this will cause some confusion, to say the very least. Astronauts will be stunned to find that their space ship suddenly no longer orbits a planet -- but, well, nothing much really. The only thing that is out there, is a tiny black spot, invisible to the eye. Still, the speck has the same mass as the Earth. For the time being, the Space Station will remain in orbit, just like the Moon and the satellites. A very silly thing to see, of course.

Perhaps some astronauts will realize what has happened. They might recall how back in the early 21st century, physicists tried to create baby black holes in the lab. And now, many years later... Well, the black holes obviously did show up, after all.

Let's build a hole: The science of DIY black holes

Luckily, the chances of the disaster outlined above really happening should be vanishingly small. But: some risk is there all the same.
There goes the Earth...

First, you should know that in principle, making a black hole is easy. Basically, the only thing you need to do is to slam two tiny, subatomic particles together in a particle accelerator. If you use enough force, the collision should yield a tiny black hole. (To find out what a black hole is, read our section on black holes from space).

Until recently, most scientists believed creating baby black holes couldn’t be done on our planet. You would need a particle accelerator as big as the solar system, most scientists assumed. But nowadays, that's all changed. Quite a lot of physicists think a much smaller particle accelerator can do the trick, too. Such as the ‘Large Hadron Collider’ (LHC), a particle smasher to be opened in Switserland in 2007.

Luckily, a man-made black hole won’t be a roaring monster that gobbles up planets and stars. Rather, science expects an incredibly tiny baby black hole, much smaller than an atom. What's more, it should evaporate immediately. Black holes give off radiation. And our black hole would be so incredibly small and hot, it would radiate itself away in less than 0,00000000000000000000000001 seconds! That’s why physicists feel pretty confident about working with the LHC. No problem if a black hole shows up. According to the laws of physics, black holes from the lab just shouldn’t be stable.

BUT. There is always a small possibility that the predictions are wrong. Particle accelerators are there to break new ground -- to explore new physics. And the physics science is about to explore, is really new and exotic. Nobody has ever seen a mini black hole. In fact, no one has even the faintest idea how gravity works on very small objects.

So, it’s 2007, and science switches on its LHC. According to some calculations, this super particle accelerator could summon up one black hole every second! There they are: black hole, black hole, black hole; Pop! Pop! Pop! Now suppose that against all expectations, these baby black holes aren’t the fleeting, unstable mini monsters we expect them to be. Suppose they’re stable.

At first, no one would notice. They wouldn’t eat up the lab or something. Instead, they would escape. One by one, the baby black holes would leak away from the lab, going through concrete walls as if they didn’t exist. If you’re that small, traveling through solid objects is no problem: you just rarely bump into a molecule.

And then? Slowly, our refugee black holes would begin to sink towards the center of the Earth, attracted by gravity. And there, they would sit and wait.

But sooner or later, a hole will indeed bump into an obstacle. An electron, or an atom’s nucleus -- tiny stuff like that. The black hole will swallow whatever it encounters. This will make it heavier. It will have more gravity, and pull in some more particles. It will get heavier still. And suck in more and more matter.

Eventually, the black holes will merge. They will suck up the Earth’s core, the mantle, and finally -- the entire planet.

Gladly, it could take a baby black hole thousands, if not hundreds of thousands of years to mature. That should give us some time to learn more about them. But the bad news is that even in the distant future, there isn’t much we can do. You cannot find or catch a black hole that is so small you cannot even see it, and that hides deep within the molten iron core of the planet. The only option is to evacuate the planet, if we happen to discover the predictions were wrong.

So, should we leave?

Well, that’s hard to say. As far as we know, everything should be okay. Our world is constantly being bombarded by tiny, high energy particles from outer space. This should also create mini black holes, high up in the atmosphere: up to one hundred each year. And as far as we know, these black holes are indeed unstable. For the last 4,5 billion of years, our planet didn’t die.

On the other hand: in physics, quite often, a totally unexpected, new phenomenon pops up. In recent years, physicists lifted their eyebrows over dark energy, the Pioneer anomaly, the missing of the Higgs boson, the pentaquark and the suspected drift of the fundamental constants. No, we're not going to explain all that -- but the bottom line is this: physicists are constantly being surprised by weird new stuff that wasn't in the theories yet.

Now, you don't want to be such a surprise to be a black hole that has our planet for breakfast!

And then there’s this. In march 2005, scientists working on the Relativistic Heavy Ion Collider in Upton, New York created a fireball that indeed looked awfully much much like a black hole.

It was unstable. In fact, it wasn't even a real black hole. Or so the scientists involved say. Perhaps the first man-made black hole is on its way to the center of the planet already!

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