So Yea Forums?

ITT: brainlets who never did physics past high school

>the correct answer is A. The object's momentum is conserved across the transition between spaces, but gravity on the blue side of the portal will start affecting the object when it begins to pass through the portal.
The wording of this email confuses me a bit.

He says it's A, and his reason is that "momentum is conserved ... but gravity ... will start affecting the object".

Analyze the sentence structure, the "but" in particular.

1. Momentum is conserved.
2. BUT, gravity.
3. Therefore it's A.

It's like he's saying B represents conservation of momentum but A is what you get when gravity is added. If that's what he's saying, then he totally misunderstands the problem, because B isn't supposed to be the gravity-free option. Gravity exists in both; nobody ever said that the cube in B will never hit the ground.

You're overthinking it. He's saying that momentum is conserved through the portal, but it will still slightly change direction once it goes through (because gravity obviously).

Attached: 8c3.jpg (496x496, 134K)

By "change direction" you mean the fact that it plops onto the ground? So the "but gravity" is just his explanation of the fact that it falls? If that's what he meant then I guess it makes sense.

Yeah basically.

>B is what you'd expect from the orange portal's reference frame, but that's not what the cube experiences.
The thing about frames of reference is that the laws of physics are the same in all of them. If B happens in the orange portal's frame of reference, then it happens in the cube's frame of reference too. Describing a problem from a different frame of reference doesn't magically teleport you to an alternate universe in which different events take place. It just changes the way velocities are measured.

>claims momentum is conserved when portals don't conserve momentum
>ignores the fact that the cube must move, at least a distance equal to its own length, in order to emerge from the stationary blue portal
I'm sure the guy is a fine programmer but, he doesn't know what he's talking about when it comes to physics, and he hasn't put a lot of thought into this problem.

Attached: portals don't conserve momentum.png (752x572, 19K)

He means the energy you dum dum.

We're measuring true motion, which is in reference to the Earth, dipshit