Quote:
Originally Posted by Homeslice
I just want to make sure what it is we're disagreeing about. Are you saying that if you took 2 guys, both of them jumping from the same altitude, but one is doing it within the normal atmosphere while the other is doing it inside some kind of vacuum tube, that the first guy would feel the jump while the other wouldn't?
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Yes, and that is exactly right. I showed you the basic math why that is true. You're choosing to ignore algebra. Maybe some calculus (3 level at that)
Here is how physics works in the very basic form. Imagine these are somewhat to scale and are vector quantities. Vector quantities have magnitude AND DIRECTION. If you are driving a car at 60mph that is the magnitude of your speed. If you are driving your car 60mph to the EAST that is a vector quantity.
Now I'm going to use sideways arrows to demostrate and ask you to try this on your own.
First part:
Push against a wall in your home. Does it actually move (above very small scale)? If so, get a job in the NFL.
Since the wall didn't move here is the force you put against the wall and the force the wall put against you.
----><----
Now add those together by putting the base of the right arrow onto the tip of the red arrow. Add those together and you get a vector quantity of 0. You are back where you started, nothing happend regardless of path. YOU DIDN"T MOVE. That's vector calculus. The force you push against the wall equals the negative force that the wall is pushing against you.
Which by the way when you add those together in regards to velocity you get the change in velocity.
For example
------> +
<-- =
------> minus two dashes so your change in velocity is
---->
Change in velocity is actually acceleration (change of velocity over change in time dv/dt). That is why acceleratin is done with second squared in the denomenator. You're changing speed by say 10m/s for every second of hcange in time. In this case, it's in the positive direction.
Now you are pushing against Saturn V rocket that is parallel to the ground. Left arrow is you, right arrow is giant fucking rocket and the force it exerts
-><-----------------------------------------------------------------
(not to scale)
Do you think that a Saturn V rocket is going to notice you being there? Is your presence pushing against the rocket going to slow it down? Maybe by 1/10000000000000000000000000000000000000000000000000 00000000000000000000000000000000000000000000000000 0000000 of a mph, but essentially zero. The rocket ship doesn't notice you there nor do the astronauts (your guts) on the inside or the molecules and energy blasting out the back side. If the rocket suddenly hit another bigger rocket, the astronauts would feel that (for a very short time and probably not long enough to register ot their brain).
Now you are falling from space. Forget the jump part, let's just focus on the 1 minute where he was just falling in space.
Now using the sideways arrows again we'll represent the left arrow as the force of the air pushing against the space jumper.
<---------------------------------------------------------------------------------------------------------------------------------------------------------------------------.
Where is the left arrow? It's not there!
If you add the "two" vectors together you get 0 + -(other vector). That is the reason for constant acceleration.
If want to determine the force of the vector, you multiply the two vectors together. Or more accurately use the dot product. vector(a:left arrow) dotted with vector(b:right arrow)= normal(which is the sqrt of the magnitude of the vectors) of both vectors times cosine of theta. Our theta in this case is 90degrees which equals 0. Vector A is = to zero which makes the dot product equal to 0, 2 times!
Simpler
0*<---------------------(infinity) = 0. Back to A=F/m relative to the jumper. There is no force. So again, F=0/m = 0. No acceleration and that includes every molecule in his body.
That's the math behind it.