Physics

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Originally posted by russ_watters
It was my understanding that this is a somewhat arbitrary way of defining positive and negative for the angular acceleration vecor. I'm not positive about that though. I just accepted it and used it when I needed to.

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There has to be some kind of *deeper* explaination to it. I don't like to just "accept" things, if you will... Most of the time in Physics I can find someone who can go deeper until I find a logical explaination detailed enough to clairify the situation... not a three page report mind you... just something that explains why. Not, well, remember that the sky is blue... but the sky is blue and it is blue because it reflects blue light and holds all other visible colors... See what I'm saying?

Yeah well gravity is effecting us all, but nobody has figured it out completely. Once it is, I hope repulsors can be made...

I'm not sure of the question actually. Does it pertain to why water drains in one direction in the northern hemisphere and the other in the southern? If so, I always thought that had to do with the rotation of the Earth. I sort of doubt your question has anything to do with that though. Can you explain it in a bit more of... um laymen's terms? I'm not up with all the physics jargon, but I took a a few courses in it in college way back in the '80s, tis one of my hobbies ;) Hell Einstein's big breakthrough in general relativity came from throwing ball with his son (or so I've read).

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Originally posted by Blacktooth
Yeah well gravity is effecting us all, but nobody has figured it out completely. Once it is, I hope repulsors can be made...

I'm not sure of the question actually. Does it pertain to why water drains in one direction in the northern hemisphere and the other in the southern? If so, I always thought that had to do with the rotation of the Earth. I sort of doubt your question has anything to do with that though. Can you explain it in a bit more of... um laymen's terms? I'm not up with all the physics jargon, but I took a a few courses in it in college way back in the '80s, tis one of my hobbies ;) Hell Einstein's big breakthrough in general relativity came from throwing ball with his son (or so I've read).

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As far as drainage in the north and south hemispheres... yeah it probably has something to do with it as well! (abstractly) The rule states that if the rotation of an object is counter clockwise, such as your hand to fingers if you were giving somebody thumbs up, the direction of the "thrust" relative to the angular acceleration points up like your thumb. My question is what exactly is "thrust" and how was this determined... ?

Ah ha, I did some investigating and now I think I'm in the same quandry as you. I used this website as my guide. If you are looking down upon a door (from up on the roof) and someone is pushing on it to open, why in the hell is the direction of torque going up (toward the roof)? They never explained it either. Probably something to do with vector graphing or something. There can't really be a force (torque) pushing up on the hinges if in a perfect mathematical world we were pushing exactly perpendicular to the hinges.

I also used this site. It seems it has only something to do with graphing, not a true representation of force in that direction (ie torque).

I have a headache now if that makes yout feel any better :confused:

Special Relativity:

deltaX^2 + deltaY^2 + deltaZ^2 - C^2deltaT = constant

i.e. the more velocity you experience, the less time you experience.

Out-live your sea-level twin brother at the top of a mountain....

moog

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Originally posted by Blacktooth
Ah ha, I did some investigating and now I think I'm in the same quandry as you. I used this website as my guide. If you are looking down upon a door (from up on the roof) and someone is pushing on it to open, why in the hell is the direction of torque going up (toward the roof)? They never explained it either. Probably something to do with vector graphing or something. There can't really be a force (torque) pushing up on the hinges if in a perfect mathematical world we were pushing exactly perpendicular to the hinges.

I also used this site. It seems it has only something to do with graphing, not a true representation of force in that direction (ie torque).

I have a headache now if that makes yout feel any better :confused:

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The rule always makes sence when using it in an equation but it does not make any sence elsewhere. It's driving me crazy.

I may be wrong, but I think they got the "right hand rule" for angular acceleration from the fact that the equation for finding the "torque" requires a cross product (Torque=(Lever arm) X (Force) )
and similarly to newtons second law we can relate torque to angular acceleration by : Torque= (Moment of inertia)(Angular acceleration).
Since toque is the cross product of two vectors, and we know that taking the cross product of two vectors results in a vector orthogonal, or normal(perpendicular), to the plane that those two vectors can define (using the right hand rule). To find angular acceleration, we can divide the torque vector by the moment of inertia (which I believe is a scalar) we get a vector in the same direction as the toque since multiplying a vector by a scalar doesn't change the direction we get a acceleration in the same direction as the torque which was defined using the right hand rule of cross products.

I hope I answered your question. At any rate I feel smarter. But then again, I love to sniff model glue (j/k) :D

Yes, a circle is never ending, never beginning. But, for a circle to be in 'physical' reality, it has to be 'put' there somehow...by pen, and other means. My question is, is a circle really never ending, never beginning. This also relates to the universe. It had to have 'started' at some point. or did it?

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Originally posted by Mayson

I hope I answered your question. At any rate I feel smarter. But then again, I love to sniff model glue (j/k) :D

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ahahaha!

I think you're right too... sounds right... but i'm too lazy to think (been programming for like 8 hours now)

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Originally posted by KegCanMan
This also relates to the universe. It had to have 'started' at some point. or did it?

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Is that your question? Because that circle thing didn't make much sense. :) And if I had to guess, I'd say the universe (i.e. the 3-dimensional plane in which we exist) has always existed. Doesn't make much sense to me that something made the empty space. :)

well, i think that a circle does have a start and an end point, although you can go around it as many times as you want. The start point is the same as the end point. When you go around, starting from one point (which there are an infinite amount in a circle) when you come back to that same point, that is the start and end point. To give a concrete example, think of a clock. Say you start at 8 o clock. That's the start point, and when you come back to 8 o clock, you come to the end of a full circle. There are theories about the universe but no one can ever know.

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Originally posted by jester22c
They spend all that time making it just right... so it can blow up. Oh the irony.

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uhuh

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LOL, too funny.

The starting point of a circle is just the spot on it that you start tracing it from. The end point is the spot where you stop tracing it. It's just a matter of perspective. Aside from that there is no start/end.

I believe that God created the universe. I believe that God has always been, but He used to be the only thing that was. Even then He did not occupy space. I think when He created the universe He created the laws of physics that go along with it, such as that matter occupies space. But even now He doesn't have to occupy space if He doesn't want to I would say. Kind of strange to think about.

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Originally posted by jester22c
The starting point of a circle is just the spot on it that you start tracing it from. The end point is the spot where you stop tracing it. It's just a matter of perspective. Aside from that there is no start/end.

I believe that God created the universe. I believe that God has always been, but He used to be the only thing that was. Even then He did not occupy space. I think when He created the universe He created the laws of physics that go along with it, such as that matter occupies space. But even now He doesn't have to occupy space if He doesn't want to I would say. Kind of strange to think about.

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but what if you never stop tracing. hmmmmm

Hey moog, ya think the same would apply if one twin was living near the ecuator and the other near a pole?

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Originally posted by jester22c
I think when He created the universe He created the laws of physics that go along with it, such as that matter occupies space.

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Did HE create time too? If so, when did HE do it? :eek:

One theory is that there was no such thing as time before the universe was created. There were also no laws of physics.

Another thought to ponder. If Adam was created from the earth, Did he have a belly button? For that matter did Eve? hmmmmm. As for the creation of the universe. God has done that and we will never understand it or be able to comprehend the vastness of his creation.

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Originally posted by elimc
One theory is that there was no such thing as time before the universe was created. There were also no laws of physics.

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Yes, because there can be no time without space.

I think time is just a perception and a medium of measurement. It is not a literal thing. So I don't see time as "existing" exactly, maybe God came up with the idea but it is just that, an idea.

Here's a couple more questions to ponder:

1. What is time?
2. When did "time" start?
3. Where do we come from?
4. Is space never ending?
5. Where did space/time start from, what was before that?


And so many more questions you can ask anyone, but no one will ever know the answers to this conclusively. I guess "God", whoever, wherever, whatever he/she is, is the only one to know the answer. Oh yeah, that's #6, what is God, is there really such a supreme being? Only faith can answer that question.

I beleive that Quicktime can help. If you turn on "balloon help" on Macs (pre OS X) and hold the cursor over the Quicktime extension, time is defined thus:

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Time n. A nonspatial continuum in which events occur in apparently irreversible succession from the past through the present to the future.

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OK, so I was pondering life's little nagging questions, and this occurred to me...

As you're aware, the Heisenberg Uncertainty Principle teaches us that it is impossible to know a particle's velocity AND it's location at the same time...you can determine one or the other, but not both. Granted that this is true, how can a police officer claim to have sufficient grounds to issue you a speeding ticket? If he claims he knows how fast you were going, he can't say that you were actually there...if he says you were, there, he can't say he knows how fast you were going.

:p

I also have a question relating to Heisenberg Uncertainty Principle. Does the principle apply to a single ion? Can we detect the velocity and position of a single ion which has been accelerated into a target?