I’ve heard so much about it. I even wrote a biography on Albert Einstein but I dont know what the theory of relativity is???
Another thing can anyone explain the Quantum theory by Max Planck to me please??
Any help is appreciated…
Jedi ONline
There are all kind of sites you can go to if you do a Google.
Relativity has so many aspects to it that it would be hard to describe in just a few words. A small part that explains how things are relative would be the example of riding in a car going 50 miles an hour. Someone sitting next to you is not moving relative to you. Someone standing on the side of the road is moving at you at a speed of 50 miles per hour and then away from you at 50 miles per hour. Someone in a car going the other way at 50 miles an hour is going 100 miles per hour relative to you. The movement of all these other people is relative to where you are. At high speeds, as in the speed of light strange things begin to happen, that is where it becomes too involved to explain in a post like this. Go to one of the sites Google will supply and enjoy.
Volumes have been written about the Theory of Relativity and Quantum Mechanics.
I can give you the basis of the Special Theory of Relativity. Special Relativity deals with inertial reference frames. An inertial reference frame is a system of coordinates that is not subject to acceleration or gravity. You can have an inertial frame in a gravitational field if it is in free-fall. Anyway, SR assumes that the laws of physics are the same in all inertial frames and that the speed of light (in a vacuum) is the same in all frames. All else follows from these two assumptions. The word relativity refers to the relativity of motion. Newtonian physics assumes that you can distinguish certain frames that are at rest. SR denies this. Acceleration is absolute, velocity is relative.
General Relativity deals with acceleration and gravity. Basically it deals with general reference frames. The laws of physics are the same in all frames and nothing can go faster than the speed of light in a vacuum. It turns out that you cannot tell the difference between acceleration and gravity.
Quantum Mechanics is beyond the scope of this post.
Relativity just means that there is no such thing as a stationary observer. This was not an intuitive concept for us who think that the ground is “at rest.” But the laws of physics work the same whether you’re “stationary” or “moving” - you can play ping-pong on a 747 in flight the same way you do on the ground. Which means the distinction between “stationary” and “moving” is meaningless, and in fact nothing can be said to be stationary. This was Galileo’s discovery, which Newton extended into the familiar laws of mechanics.
Later the theories of electromagnetic radiation was developed, and the theories predicted that the speed of light is a constant. It doesn’t get any faster if you’re travelling towards the flashlight or away from it, it’s the same speed. This was even confirmed by actual measurement. So Einstein decided that this was in fact a fundamental truth about the universe, that the speed of light appears constant to every observer. But for this to be true, everything else must be variable (relative) - i.e. when you travel fast, the outside world looks shorter and your clock ticks slower. And you can never travel at or above the speed of light no matter how hard you try.
Hmm, I just contradicted this in a simulpost so we need to resolve this. How/where does Newtonian physics distinguish a certain inertial frame as being at rest? Velocities, accelerations, momentum, etc. are all relative. Rotational frames work differently, of course, but that’s not an inertial frame.
Just to toss in my random contribution before going to sleep, if a google search is too painful, we had a startlingly similar thread last year, which might be of use.
Special Relativity - Newton wrote (Principia 1686) that; “Absolute, true, and mathematical time, of itself, and from its own nature, flows equably without relation to anything external …”
Einstein demonstrated that a system that makes the measurement of space and time different for observers who are moving with respect to each other fits the observed facts better. The fit is almost identical with the Newtonian view of space and time for low velocities but begins to diverge from the Newtonian when the velocities of the observers relative to each other becomes an appreciable fraction of the speed of light.
General Relativity - A theory of gravitation that eliminated gravity as a force that acts on massive bodies, and replaced it with gravity as a kinematic effect that results from the warping, by massive bodies, of the coordinate system by which we represent space. There’s a lot more to it that that, and I don’t understand much of it, but I think that’s the gist of it.
It seems you are correct. Newton’s laws do not distinguish absolute rest, but this bothered him.
So some scientists way back when did this experiment to determine how fast we were moving through space, or more specifically the space ‘ether’. They assumed that space itself was standing still and that most everything else was moving to some extent. The Earth orbits the sun with orbits the galaxy which flies through space, so they wanted to know exactly how fast we were flying through space. So they checked the speed of light in a few different directions, assuming that if it was slightly faster in one direction, then we must be moving through absolute space in that direction. What they were looking for was our speed through the ‘ether’, analogous to the air that sound waves propagate through and the water that waves propagate through.
What they found was that the speed of light was exactly the same in all directions, which must mean that we were standing perfectly still with respect to space. Well that didn’t make much sense (or it was some coincidence of cosmic proportions) so everyone got frustrated. Speed is measured as distance over time, both of which are intuitively constant, hence the headache.
So along comes a young Albert Einstein who, in the ideology of youth, concocts this crazy idea that maybe distance and time are not the constants, but the speed of light is. If you are moving towards the flashlight then maybe the time for the flashlight slows down causing the light, which should be moving faster, to appear the same. And if you’re moving away then the flashlight’s time speeds up, causing the same result. The reason that it’s called Relativity is because he threw out the notion that there was some static spatial absolute, every moving body in space is actually standing still, and there’s no absolute difference in speed between the earth and the spaceship hurtling away from it, only a relative one. Everything’s sitting at the center of the universe.
General Relativity expands this special relativity to include a gravitational field, pinning acceleration (whether gravitational or just plain propulsive) at the root of it. Time passes a tiny bit slower here on earth than floating between the stars, which thanks to atomic clocks has been experimentally proven.
Greetings all,
These are the two hardest subjects on the planet, yet here is my attempt to describe them simply:
Relativity -
means everything is RELATIVE to the observer (with a single, VERY IMPORTANT exception) :
- there is NO absolute rest state,
- there is no absolute centre,
- there is NO absolute rate of time,
- there is no absolute length,
- there is no absolute mass,
In other words, even time, mass and length will VARY so that ONE THING is ALWAYS absolutely the same:
- The speed of light in a vacuum is ALWAYS the same, for EVERY observer on EVERY occasion at EVERY speed, location and orientation.
In other words - the only ABSOLUTE is c
EVERYTHING else is RELATIVE to the observer
The reason Relativity is so famous (note that only newbies refer to it as a “Theory”) is because it has been found CORRECT for every single test we have ever made.
Quantum Theory :
A Quantum is an amount, a quantity.
This specific “quantum” refers to the a very small amount of energy - very small indeed - 10 to the minus 34 roughly (nothing humans can do is anything like as small as this)
All energy in the universe occurs in WHOLE NUMBERS of quanta - nothing can have 1.5 quanta - only 1 or 2 exactly.
This is what is meant by a “quantum leap” - something changes from 1 to 2 quanta without ever being in between the 1 and the 2 - note that a “quantum leap” is actually very tiny - but in common usage it has come to (erronesously) mean a big jump.
The real shocker is that at these tiny scales, particles do not have an accurate location and velocity - they are spread out in a wave representing where they will actually be IF an observer LOOKS at them - if you want to understand QT, read up on the 2-slit experiment which shows that a single particle can be in 2 places at once (actually many places).
This is what Einstein could not accept (he was an old conservative by QT times) - the dice he refused to accept God played with refers to how a particle collapses from a wave expressing where it COULD be, into an actual particle somewhere within the wave - i.e. the action of OBSERVING a particle collapses it from a wave into a particle - very bizarre.
There is a good physics text here:
Thanks a lot guys…
So basically relativity just means that nothing is stationary and nothing moves faster than c. So no matter where you go c is the constant but the variable is t=time.
Originally quoted by scr4
But the laws of physics work the same whether you’re “stationary” or “moving” - you can play ping-pong on a 747 in flight the same way you do on the ground.
How is that possible.Would’nt inertia come in act. If you throw a ball while you are standing you get x metres but if you throw the same ball while running you get x+v of movement of your body…
At any time if c is reached or exceeded time patterns change? Anyone know why?
So if anything can be forced over a c then time warping is possible…hmmm interesting.
JeDi 0nLiNe
sau, sau, sau… I feel like we’ve gone over this many, many, many times. Fighting ignorance is so exhausting!
INERTIA— means that objects tend to stay moving at the same velocity if no force acts upon them. Your wonderful demonstration of this fact, sau, was with your example of running and throwing a ball. WRT the GROUND the ball moves more but WRT YOU the ball moves the same amount.
Reaching the speed of light is impossible if you have mass. This is one of the consequences of relativity. Sometimes we like so say, “well, let’s pretend you can reach the speed of light”. I’ve got news for you… it ain’t gonna happen.
We can asymptotically apprach the speed of light (get as aribtrarily close as we want) but energy goes into changing our four-vector momentum and consequently you’ll need an infinite amount of energy to push you to that limit. As I said, ain’t gonna happen.
Likewise, you’re never going to go above the speed of light. You might be able to get from one spot to another faster than a lightbeam sent by means of a route that’s a little more curcuitous (for more info, see R. Gott’s flourescent green book, Time Travel in Einstein’s Universe), but you will not be travelling faster than the speed of light.
The point is that a running you will measure the speed of the ball as one amount while a standing person will measure it as something else.
No, the pattern doesn’t change when the speed of light is “reached or exceeded .” If you could measure with enough accuracy you would find that the times, velocities, distances etc. that you measure are different from those measured by someone who is standing still. It is just that those differences are so small that they are undetectable by our measurements at the velocities that most ordinary physical objects can reach.
I put this in a search engine "theory of relativity for dummies’ & sure enough, there are
actually web sites that use that phrase or “relativity for dummies” to explain it. cool.
IANAP, but I do remember reading that there are particles that travel faster than light, at least according to some aspects of QT, but that is because they start out FTL, they don’t accelerate to and beyond light speed, e=mc^2 prevents that acceleration. Those particles are called tachyons, I don’t know if they have been detected yet but John Gribbin wrote about them in a great book for the less than scientific-minded called “Schrodinger’s Kittens”, and to make things even more exciting, they travel backwards through time rather than forwards.
If I am out to lunch, please correct me.