King Durk the Awesome
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King Durk the Awesome
TNPer
As far as I know we have yet to ascertain for certain whether or not the universe truly is infinite.
The theory I most often hear is this:
Imagine the universe as being the surface of a balloon. The universe is expanding in the sense that the surface of a balloon would expand while it was being blown up. Yet you could never 'leave' the universe in the same sense that an ant could never leave the surface of the balloon (well, you know, he could fall off or something, but that doesn't really count...).
The trick is that the surface of a balloon is 2D; our physical world seems to be 3D. So just imagine an extra dimension. When explaining additional dimensions I always relate ourselves to 2D stick-figures trying to imagine a third dimension.
yeah...
The theory I most often hear is this:
Imagine the universe as being the surface of a balloon. The universe is expanding in the sense that the surface of a balloon would expand while it was being blown up. Yet you could never 'leave' the universe in the same sense that an ant could never leave the surface of the balloon (well, you know, he could fall off or something, but that doesn't really count...).
The trick is that the surface of a balloon is 2D; our physical world seems to be 3D. So just imagine an extra dimension. When explaining additional dimensions I always relate ourselves to 2D stick-figures trying to imagine a third dimension.
yeah...
To what degree was Plato's allegory of the cave influential on the thinking of Rousseau (with examples)? How does this contrast with the thinking of Hegel in "the Phremenology of Spirit"? Show the answer mathematically.
If you put a Schrodinger in a box with a hammer, a small amount of radioactive material, a vial of hydrochloric acid and a geiger counter, show mathematically the probability that after one hour Schrodinger would be...
1. Alive
2. Dead
3. Transformed into cat man.
1. Alive
2. Dead
3. Transformed into cat man.
More serious physics question. Why does Gravity work? I mean, when I ask the question, people just say "masses attract one another." But why do they? What is it about mass that makes them do that? What is it?
King Durk the Awesome
TNPer
Schroedinger's cat would be turned into cat man (100% chance probability) and it eats people.
As for gravity:
First I will begin by explaining the relationship between gravitatoinal mass and inertial mass. Inertial mass is defined as the ratio of a force applied to an object over the acceleration of said object due to the applied force (in other words, m = F/a). Another way of looking at it is: inertial mass is the amount by which an object resists acceleration as a force is applied.
Gravitational mass on the other hand is the property of an object that determines how much gravitational force it generates - the more massive the object is, the more gravitational force it generates. Gravitational mass is to gravity as electrical charge is to the electromagnetic force; the more charge an object has, the more electromagnetic force it generates.
Amazingly gravitational mass and inertial mass are equal to each other. Many non-physicists would say to themselves, 'duh! of course they are', but think about it: inertial mass is not equal to electrical charge, so why should it be equal to gravitational mass? This was a mind-boggling question posed by Newton (iirc) and wasn't answered until Einstein came along.
Einstein used this relationship between gravity and inertia - between gravity and an object's tendency to resist acceleration - to formulate his theory of general relativity. According to general relativity we exist within a fabric of space-time. Space-time is curved in a sense by gravity as seen below:
Now back to inertia. The more (inertial) mass an object has, the more force will be necessary to accelerate it; that is, the tendency of objects is to travel in a straight line at a constant speed, and the more mass an object has, the more force will be needed to alter the object's speed or direction.
This following part is the part of the explanation that makes basically no common sense whatsoever - you'll need to derive all this stuff mathematically to see that it is true. That said, objects have a tendency to travel in straight lines - but as it turns out these lines are only straight in the sense that a line drawn on a globe is straight (it's actually an arc). Spacetime curves toward large masses, forcing objects to follow the curves of spacetime, moving them toward these masses. This is gravity. In order to keep this from happening, we can apply a force in the same sense that we can apply a force to slow down or change the direction of a moving vehicle. But basically the gist is that gravity results from the curvature of space-time and the tendency of objects to follow the curves of spacetime.
This makes little/no common sense to the human mind because we as humans are only able to detect and visualize a three-dimensional world, when space-time is in some senses extra-dimensional.
Hope that wasn't too complicated
As for gravity:
First I will begin by explaining the relationship between gravitatoinal mass and inertial mass. Inertial mass is defined as the ratio of a force applied to an object over the acceleration of said object due to the applied force (in other words, m = F/a). Another way of looking at it is: inertial mass is the amount by which an object resists acceleration as a force is applied.
Gravitational mass on the other hand is the property of an object that determines how much gravitational force it generates - the more massive the object is, the more gravitational force it generates. Gravitational mass is to gravity as electrical charge is to the electromagnetic force; the more charge an object has, the more electromagnetic force it generates.
Amazingly gravitational mass and inertial mass are equal to each other. Many non-physicists would say to themselves, 'duh! of course they are', but think about it: inertial mass is not equal to electrical charge, so why should it be equal to gravitational mass? This was a mind-boggling question posed by Newton (iirc) and wasn't answered until Einstein came along.
Einstein used this relationship between gravity and inertia - between gravity and an object's tendency to resist acceleration - to formulate his theory of general relativity. According to general relativity we exist within a fabric of space-time. Space-time is curved in a sense by gravity as seen below:
Now back to inertia. The more (inertial) mass an object has, the more force will be necessary to accelerate it; that is, the tendency of objects is to travel in a straight line at a constant speed, and the more mass an object has, the more force will be needed to alter the object's speed or direction.
This following part is the part of the explanation that makes basically no common sense whatsoever - you'll need to derive all this stuff mathematically to see that it is true. That said, objects have a tendency to travel in straight lines - but as it turns out these lines are only straight in the sense that a line drawn on a globe is straight (it's actually an arc). Spacetime curves toward large masses, forcing objects to follow the curves of spacetime, moving them toward these masses. This is gravity. In order to keep this from happening, we can apply a force in the same sense that we can apply a force to slow down or change the direction of a moving vehicle. But basically the gist is that gravity results from the curvature of space-time and the tendency of objects to follow the curves of spacetime.
This makes little/no common sense to the human mind because we as humans are only able to detect and visualize a three-dimensional world, when space-time is in some senses extra-dimensional.
Hope that wasn't too complicated
King Durk the Awesome
TNPer
Physics-wise I have taken: Physics I, II, and III; Circuits I and II; Electrostatics; Elecrodynamics; Mathematical Physics; Computational Physics; Advanced Mechanics; Quantum Mechanics I and II; and two electives: Thermodynamics and Laser Applications.
As far as math goes... Calculus I, II, and III; Differential Equations; Linear Algebra I and II; Analysis I and II; Proof/logic; something called 'Statistics for Scientists and Engineers'; Probability; Numerical Solutions to Differential Equations; Numerical Solutions to Matrix Equations; and Applied Mathematics I and II.
So basically that is everything required for a BS in Physics (at my uni at least) and nearly everything for a BS in math (only short 4 credits of Abstract Algebra).