As for an example, the simplest is a laser or a sodium light. Any light really, but these are the best examples. Quantum mechanics gives us the Heisenberg Uncertainty Principle. The wavelength is set by the quantum levels of the system. But light wavelength isn’t perfectly knowable if we can localize the source of the…

Oh, as a physicist and a scientist, I don’t give these things much thought. My tools work. I use them on the problem at hand. I don’t think about the bigger picture. As a person, I do. My colleagues all groan and walk away when I say, “But think about free will!”

Selfie stick for gold Apple Macbook?

I would say the universe appears to make sense. There's no a priori reason for us to think that the laws of physics will still be the same in the next second. We've just noticed that they seem to stay more or less the same. And if the ways it changes don't follow rhyme or reason? And if it changes frequently? There's…

Wow you guys got pretty far along. This honestly is a college-level philosophy course. It's hard for physicists to wrap our heads around. It's hard for philosophers to wrap their heads around. Not to mention that kinda-sorta get it don't agree. Even the foremost experts in both fields don't agree with each other.

...Katie...?

I don't know, he's making a pretty big deal over what's basically a 2nd-order correction to a problem nobody's ever going to have.

Seriously, it's not a big deal! The point of the problem is to illustrate how to integrate the physics concept of gravity and calculus. Somebody went to a lot of work to do something in a more precise way and got an answer that's off by a few minutes. That's nifty, but not exactly news- or angst-worthy.

That's the gloriously weird thing about probability- it does matter how he died, even if he's dead, even if it already happened.

Hey, it's okay. It's just a word game.

Sort of. I think the video is equivalent to Monty Fall*. Did you see the transcript I typed up? I'll reproduce it:

Actually, Bob isn't guaranteed to die. It was possible for Bob to pick the right bush. Here's the transcript:

But the only way he can remove a goat is if he knows where the goat is. In the show, as in the problem, he never ever reveals a car. It is quite important that he knows which door is accurate.

Right, I had hoped you would be able to look at the table I created to figure that out. Here is an updated version, then, removing the scenario where Bob doesn't die. In that case, Alice's chance of living is 50%, given either scenario. (Again, I label the edible bush as bush 1.)

The problem with all of this is that you're not counting all of the possible cases correctly. You have to start at the very beginning. To explain what I'm doing: I'm going to calculate the probability of every scenario that occurs that ends with Alice living. Then I will add up the probability to get the odds that a…

Ah, I missed your response. No, that's correct. Bob chooses his tree and Alice chooses hers. There's a 50% chance between Alice's two choices- the two trees left besides the one Bob picks.

Not only that, but they get the probability wrong for this alternative scenario. I've created a probability tree for this scenario. I've crossed off the branches we don't reach, the ones where Bob lives. You can see that Alice lives half the time when Bob dies. I also ran a simulation that has the same results.

Have you actually sat in one, or are you speculating?

Yeah it does, albeit a proprietary one- the hardware spec of the new cable with that funky tiered connection at the end. But PTizzle's reply is better.

Somebody get the poor guy a pair of actual climbing shoes!