The OFFICIAL IntenseMuscle Physics Q&A Thread

[Sammich]

So, just how well can you Physics people see the future and everything? I remember that Jamacian lady on TV was awesome!

We know all that has been, all that is, and all that will be.

We are omniscient.

We are God.

[theroymccoy]

Magnets...how do they work?

[Sammich]

Magnets...how do they work?

Sorry, no juggalo questions will be answered in this thread.

[theroymccoy]

Sorry, no juggalo questions will be answered in this thread.

aaahahaha...not but really. magnets are crazy

[TommyKav]

Sammich i have a question thats really escaping me.

Large rotating bodies, like stars will drag space with them. I picture it like grabbing a flat sheet on your bed, in the middle. Balling it up in your fist, then twisting your hand. But if you picture that curved line from the point in space that touches the object out to the distance where this effect is no longer present, It seems to me that after some time, those parts of space that were dragged would eventually creat a closed loop of distorted space time. I picture something similar to an event horizon. For this not to happen wouldn there need to be some measure of "slip"? Like a point there the stretched space cant hold onto the large body any more and there is some give as to no create a closed loop? I havent posted here in a while but im really hoping you get around to this one.

[Sammich]

Sammich i have a question thats really escaping me.

Large rotating bodies, like stars will drag space with them. I picture it like grabbing a flat sheet on your bed, in the middle. Balling it up in your fist, then twisting your hand. But if you picture that curved line from the point in space that touches the object out to the distance where this effect is no longer present, It seems to me that after some time, those parts of space that were dragged would eventually creat a closed loop of distorted space time. I picture something similar to an event horizon. For this not to happen wouldn there need to be some measure of "slip"? Like a point there the stretched space cant hold onto the large body any more and there is some give as to no create a closed loop? I havent posted here in a while but im really hoping you get around to this one.

The short answer to your question is no, space can't form a closed loop like that.

[theroymccoy]

http://www.youtube.com/watch?v=ILVWPzO_swY

Why does this happen, Sammich? The guy is applying heat via hair dryer to a dent, then uses compressed air, upside down, and applies super-cold air. The dent then pops out.

If one was to do the same thing, what should I be weary of?

Thank ye.

[Sammich]

http://www.youtube.com/watch?v=ILVWPzO_swY

Why does this happen, Sammich? The guy is applying heat via hair dryer to a dent, then uses compressed air, upside down, and applies super-cold air. The dent then pops out.

If one was to do the same thing, what should I be weary of?

Thank ye.

It seems like after you heat up all of the material with the hair dryer that applying the cold air on the dented side of the panel would cool that side more quickly than the other side. This would make the material contract (since heating most materials causes them to expand, and cooling them makes them contract). So the outside is now colder than the inside, so the cold material contract, which essentially pulls the dented material outwards.

You really wouldn't have to worry about it unless you did it like 20 times to the exact same area. The continued bending of the metal would cause it to weaken and possibly crack or fall apart. But doing it once is perfectly fine, not to mention awesome as shit.

[theroymccoy]

Thanks mang...

I was actually thinking the paint might crack and pop off actually...mngeh, only one way to find out.

[Sammich]

Thanks mang...

I was actually thinking the paint might crack and pop off actually...mngeh, only one way to find out.

Oh yeah, that too. I wouldn't think it would, though. Usually the paint is high enough quality to keep that from happening. I mean you're not making the metal any hotter or colder than it would get just in a parking lot during summer and winter.

[RaptorMkII]

I got to wondering this last night when I watched the Mythbusters test whether or not a bullet fired from a gun would hit the ground at the same time as a bullet dropped at the same time from the same height:

Would the same experiment yield the same results if the bullet fired from the gun were moving at relativistic speeds (say .999C or so)? Also, we're assuming that the experiment is being done on an infinite plane, with no curvature and a uniform gravitational field.

[Sammich]

I got to wondering this last night when I watched the Mythbusters test whether or not a bullet fired from a gun would hit the ground at the same time as a bullet dropped at the same time from the same height:

Would the same experiment yield the same results if the bullet fired from the gun were moving at relativistic speeds (say .999C or so)? Also, we're assuming that the experiment is being done on an infinite plane, with no curvature and a uniform gravitational field.

Ooh, good question. The answer is yes, they would. (Assuming to air resistance.) Their motion in the vertical direction (in a vacuum) is independent of their horizontal motion, so regardless of their horizontal speed, they will still fall at the same rate.

Another way to look at this is to use essentially the basis of relativity: that all motion is relative. So we are free to change our frame of reference to that of the moving bullet. In this frame, the bullet is not moving horizontally at all; it is the rest of the world (and the other bullet) that are traveling away from it. Thus this bullet is not moving horizontally, so all it can do is fall vertically under the uniform pull of gravity.

PROTIP: If anyone has questions about particle physics or quantum field theory, now is the time to ask because I'm up to my asshole in it.

[theroymccoy]

PROTIP: If anyone has questions about particle physics or quantum field theory, now is the time to ask because I'm up to my asshole in it.

Spit some shit that will BLOW OUR FUCKIN' MINDS.

[Quadriceps]

I know this is a sensitive topic for Americans, but how can this happen from the airplane?
What do the laws of physics say about this?

http://www.youtube.com/watch?v=3ujWitEr-Ww&feature=player_embedded

[RaptorMkII]

Ooh, good question. The answer is yes, they would. (Assuming to air resistance.) Their motion in the vertical direction (in a vacuum) is independent of their horizontal motion, so regardless of their horizontal speed, they will still fall at the same rate.

Another way to look at this is to use essentially the basis of relativity: that all motion is relative. So we are free to change our frame of reference to that of the moving bullet. In this frame, the bullet is not moving horizontally at all; it is the rest of the world (and the other bullet) that are traveling away from it. Thus this bullet is not moving horizontally, so all it can do is fall vertically under the uniform pull of gravity.

PROTIP: If anyone has questions about particle physics or quantum field theory, now is the time to ask because I'm up to my asshole in it.

Thank you good sir

Its been too long since I've done real phyzziksy stuff. Trying to think about/visualize relativity and frames or reference and whatnot was making my brain hurt.