Dot Physics

Buzz Out Loud and Black Holes

Buzz Out Loud is one of my favorite tech podcasts. Unfortunately, I am a little behind in the episodes. However, in the episode 900 there was an email from a listener regarding LHC and black holes. The emailer claims that a massive black hole would mess up Earth’s orbit. This is not quite true.

I was getting ready to make a lengthy post about how black holes work, but did a way more awesomer job than I could do. Stefan and Bee describe some very important points:

  • First, black holes created in the Large Hadron Collider are based on a theory that has not really been verified. So, it might not even happen.
  • The initial mass of these things is very small – basically the mass of the colliding particle plus mass from the initial particle energy.
  • Black holes do not suck things up. They are just masses with high density. So high that the escape velocity is greater than the speed of light. My favorite thought question: What would happen if the Sun turned into a black hole? Answer: The Earth would still orbit at the same distance, but it would be dark.
  • If the black hole was created with an initial velocity, it would act just like a projectile. This might mean that it could escape the Earth’s gravity (if it didn’t evaporate first).
  • Even if the black hole did increase in size and start combining with stuff, all this mass added to the black hole would come from the mass of the Earth. Suppose the LHC black hole did engulf the Earth. This black-hole Earth would still orbit the Sun in the same way and the moon would still orbit this black hole. Yes, eventually it would accumulate more mass from outside sources – but this would take some time.

Ok, that seems good enough. Really, go read the BackReaction post, it has much more detail.

Comments

  1. #1 Uncle Al
    January 30, 2009

    Will the two nuclei whose collision creates the snark hit exactly square-on? Of course not. The snark will be a boojum – a fiercely rotating chronosynclastic infundibulum: doo-doo ex machina. Emitted antichronitons will annihalate the flow of time. Berthold radiation will uncontrollably flood the planet. Nothing in known science can address these issues.

    Ignorance is not a form of knowing things. An idiot is not half way to being an idiot-savant. We lack rigorous characterization of the topology and function of cluelessness.

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