mindless

Zant, de Broglie produced the first derivation of Quantum Theory on the basis of relativity. So Quantum Theory is due to relativity. The idea of "spin" is due to Dirac's application of relativity to quantum theory and explains the chemistry of matter. Without relativity there would be no modern chemistry (drugs, advanced materials etc). Anti-particles are predicted from the application of relativity to quantum theory so PET Scanning is a relativistic application. See Relativity and chemistry: http://books.google....rbitals&f=false De Broglie's QM Theory: http://www.google.co...aMFIF3Q&cad=rja PET: http://en.wikipedia.org/wiki/Positron_emission_tomography

First physics. Time is not simple. It consists of at least two correlated components: dimensional time (the time that enters into Relativity Theory) and change (partly the time of Quantum successions of QM State Vector collapses). It may be even more complex. Second the philosophy of consciousness. Most philosophers agree that experience is extended in (dimensional) time. They call this extension the "specious present" or "extended present" moment. The word "specious" is used because, at the time when William James drew it to our attention the prevailing cosmology was Euclidean/Newtonian in which time was imagined by physicists to be a succession of instantaneous states of a three dimensional universe in which only the current, instantaneous state exists. Of course nowadays we know that the universe is at least 4 dimensional so time extension need not be specious. You can understand the extended present by just listening to a word. Notice that the word is extended in dimensional time and at each instant there is not time enough for even a phoneme. There is a blog that delves into these matters from a scientific perspective called "New Empiricism" See: http://newempiricism...experience.html

You do not need GR to get a twin paradox. All you need is for travellers A and B to arrange themselves either side of earth so that B is at least twice as far away as A. They then both start travelling towards earth at the same high speed. As A passes Earth he synchronises his clocks with Earth time. He then travels on until he meets B coming the other way. B then synchronises her clocks with A as they pass and carries on to Earth. B will find that her clocks read an earlier time than those on earth. The total elapsed time of the entire journey to a distant point and back to earth will be found to be less than the time recorded for the journey on Earth. No GR, no accelerations needed. The whole point of the thought experiment is to analyze the difference in times and this does not require the return of the outbound traveller. Most importantly it is understanding the relativistic phase, ie: the progressive phase difference between clocks along the direction of motion, that is essential for understanding the twin paradox. See http://en.wikibooks.org/wiki/Special_Relativity/Simultaneity,_time_dilation_and_length_contraction#The_twin_paradox A quick note on relativistic phase: suppose the people on Earth had left clocks all over space that were synchronised with Earth time. The effect of relativistic phase is that even when A passes Earth he will be able to work out that, for him, the clock where he will meet B is already reading a time in the future of the clocks on Earth (even though the people on Earth calculate that they are still synchronised with that clock and both they and A see the same clock reading). To figure out how this can be the case you have either got to do the maths by calculating the distances and times taken for the synchronising light or just look at the Wikibook example. The net effect is that A is heading for a point in spacetime that is already in the future of the people on Earth. "A" gets a head start on the journey and it is this head start that means that his clocks show less elapsed time than might be expected. Time dilation is just the effect of travelling into someone else's future. It does not need a universal frame of reference. If you and I were moving at 0.999 c relative to the people on this forum and I travelled away from you at 0.8c I would move the same number of seconds into your future with every light-second travelled as I would if we were both sitting on earth when I travelled away at 0.8c.

The universe is a four dimensional spacetime. Each point has its own location and time. Objects that are moving along with us share our clock readings. Other objects do not. If you want to understand this you need to understand relativistic phase. Phase is far more important than time dilation and length contraction and until it is understood there is no understanding of relativity. See: http://en.wikibooks.org/wiki/Special_Relativity/Simultaneity,_time_dilation_and_length_contraction#The_relativity_of_simultaneity_and_the_Andromeda_paradox

Modern relativity maintains that if objects of any type follow a minimum length path in four dimensional space-time (called a null geodesic) then anyone observing the velocity of the objects will get the same valuefor the velocity no matter how fast they are moving. This constant velocity is numerically equal to the "speed of light in a vacuum". The moving laser points do not follow this path and relativity is entirely unaffected by such experiments. A corollary of relativity is that faster than light travel by single massive objects would require a re-write of relativity. See http://en.wikibooks.org/wiki/Special_Relativity/Faster_than_light_signals,_causality_and_Special_Relativity

It is best to point you to a book that explains this fully: http://en.wikibooks.org/wiki/Special_Relativity/Simultaneity,_time_dilation_and_length_contraction Relativity is a theory that proposes that the world is a four dimensional place. Each point has its own time. When you travel, you travel in four dimensional spacetime. When you travel in four dimensional spacetime you go from a point at a particular location and time to another point at another location in space and time. Remember, in 4D you are travelling in both space and time whenever you travel. I would recommend reading the book from the beginning to understand special relativity fully. A quote from "Special Relativity": "The term "time dilation" is applied to the way that observers who are moving relative to you record fewer clock ticks between events than you. In special relativity this is not due to properties of the clocks, such as their mechanisms getting heavier. Indeed, it should not even be said that the clocks tick faster or slower because what is truly occurring is that the clocks record shorter or longer elapsed times and this recording of elapsed time is independent of the mechanism of the clocks. The differences between clock readings are due to the clocks traversing shorter or longer distances between events along an observer's path through spacetime." The Twin Paradox is also discussed in the book. Basically one twin goes to a different place at a time in the other twin's future then turns round and does it again. http://en.wikibooks.org/wiki/Special_Relativity/Simultaneity,_time_dilation_and_length_contraction

There is a complete explanation about why the speed of light is constant at: http://en.wikibooks.org/wiki/Special_Relativity/Spacetime#The_modern_approach_to_special_relativity Take a look and be enlightened. Basically the speed of light is constant because the universe is four dimensional and the fourth dimension enters into Pythagoras' Theorem with a negative sign. Take a look at the link, it explains it better than I could. DrRocket said that ether theories were equivalent to Relativity: " Simply choose a reference frame and by fiat demand that all other reference frames are related to it by the usual Lorentz transformations." This seems to miss an important point: "It is also popular to claim that Special Relativity and aether theories such as those due to Poincaré and Lorentz are equivalent and only separated by Occam's Razor. This is not strictly true. Occam's Razor is used to separate a complex theory from a simple theory, the two theories being different. In the case of Poincare's and Lorentz's aether theories both contain the Lorentz Transformation which is already sufficient to explain the Michelson and Morley Experiment, length contraction, time dilation etc. without an aether. The aether theorists simply failed to notice that this is a possibility because they rejected spacetime as a concept for reasons of philosophy or prejudice. In Poincaré's case he rejected spacetime because of philosophical objections to the idea of spatial or temporal extension (see note 1)." See: http://en.wikibooks.org/wiki/Special_Relativity/Introduction#Historical_Development There is no need to introduce an aether if you demand by "fiat" that the Lorentz Transformations apply.