There’s a lot of stuff I don’t know. This is true for everybody, of course, but sometimes you get smacked in the face with your ignorance.
Now, most of what I don’t know is stuff nobody knows. What Rumsfeld famously called “the unknown unknowns” but extended more universally.
And there’s a lot of stuff I sort of know about, but foggily and knowing I could learn more if I really wanted to. For example, the dirty details of political deal making. Biology. Shakespeare.
And then there’s stuff I don’t know and don’t care about. Most of pop culture fits into that category.
What got me going on this train of thought was reading about a debate in physics. What the heck is going on with black holes?
I have a PhD in chemistry. I make a living teaching science. I’ve taken college physics, including a fair amount of quantum and a smidgen of relativity. I read Scientific American. I’ve read plenty of popular science books, including Steven Hawking. So I have some basic chops when it comes to science.
But here I’m stuck with a science question that I have no clue how to answer. It seems to be a model of black hole behavior that insists that one of the fundamental axioms of physics be sacrificed but leaves it unresolved which way to go.
- quantum entanglement
- general relativity
- preservation of information
I sort of get quantum entanglement. Somehow, pairs of particles A & B get created and scoot off in opposite directions. And these particles have some sort of quantized property that is conserved so that if Particle A is “heads”, particle B must be “tails”. There’s a lot more to it, but somehow measuring one property of particle A freezes properties of particle B. And not just the one property that’s complementary but other properties too. The “spooky action at a distance” part comes from considering that the quantum properties of both particles are supposedly indeterminate until measured. The Occam’s Razor explanation says not really, the indeterminacy of the two particles is really just one indeterminacy. By analogy, if you flipped a coin so it landed on a glass table, you could predict that the coin is “heads” by lying on the floor and looking through the table at the other side. Any good particle physics teachers out there want to correct this?
General relativity? No, this I really don’t get. I get the light Doppler effect -we’ve all heard the sound of a siren change as it approaches and then goes away. I used to be able to use the equations about special relativity – that’s the light-speed stuff. And I guess I’ve heard of the “space time is a rubber sheet and heavy objects stretch it” thing, but I don’t have any kind of intuitive model about relativity other than that. The relativity part of the black holes story postulates that you wouldn’t notice anything special as you cross the event horizon while free-falling into a black hole. (What would you see looking out the back window? Or the front window, for that matter?)
And now we get to “conservation of information.” Wait, what? Apparently quantum information can’t ever be lost? Well, this is new to me. And I’m sure the physicists have a more stringent definition of “lost” than “hopelessly scattered and impossible to retrieve even if you play the movie backward”. Now, entropy is something I have a little experience with. If you’ve seen my basement you might say I have a lot of experience with it. One of the things I thought was true about entropy was that information can get lost. Certainly macro information is easily lost. Could you reconstruct a single crystal of dry ice after it has sublimed and mixed into the room’s air?
So apparently, the problem is this:
- A Hawking particle-antiparticle pair pops up near the event horizon of a black hole.
- One unfortunate particle zips into the event horizon, from which nothing escapes.
- The matching particle gets detected by a physicist orbiting at a safe distance.
- The spooky action at a distance effect lets you know what the state of the other particle is even if it’s permanently lost in the black hole.
- Presto: information has escaped from the black hole, which is supposed to be impossible.
I am definitely going to have to re-read the Times article, because I still don’t get this whole problem. If I get a better grip on the issue I might post more, but I want to get this up to keep the daily blogging habit going. And you, imaginary reader, are I’m sure dying to know how it all comes out.
Oh, and yeah, I really do think about odd stuff like this. It’s amazing what I can do with the brain cells that are not occupied with watching reality TV shows.