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 BREAK-DOWN OF OLD LAWS

BREAK-DOWN OF OLD LAWS

The first blow to Newtonian theory came from the non-invariance of Maxwell’s equations under Galilean transformation. Modification of Maxwell’s equation could be done. But, there were more troubles.

The trouble was related to the motion of electromagnetic waves. It was still thought that waves needed medium to propagate. So, a hypothetical medium called aether (ether) was proposed which filled every space. Light was supposed to be moving through this. Then, a question arose. How do objects move relative to others? Do they take the others away with them or partially away or do the others remain stationary?

The two views (clearly opposite) tried to explain the nature in various ways. The stationary ether hypothesis was defended by Anton Hendrik Lorentz (Nobel Laureate 1902), who had contributed a lot to the development of the fundamental basis of relativity. He was able to explain various observations using this hypothesis. Now, if ether was at rest and light moved in ether, then it would be possible to observe the motion of objects relative to ether as one can observe Doppler’s effect for sound in various situations. A very famous experiment known as Michelson-Morley experiment (by Albert Abraham Michelson, Nobel Prize 1907) was performed to give something which would keep nothing altered.

The idea of experiment was very simple. Light moves with speed ‘c’ in ether and the Earth moves with a fast speed in Ether (around the Sun). So, it can be possible to observe light in different ways and compare the difference:

The instrument used is called Michelson-Morley interferometer. Experiment was done this way [present tense is used below]:

Light is sent through a half-silvered mirror as shown in the figure below. It deviates into two parts. The first part goes in a straight line. The second moves in a perpendicular direction relative to the setup. So, it takes a tilted path with respect to the other.

For a ray going up, time taken to go up = distance SMS˘/c

 Distance = Ö(l2 + v2t2) Therefore,             t = {Ö(l2 + v2t2)}/c or,                           t = l/Ö(c2 - v2)                             So, total return time = 2l/Ö(c2 - v2)     Time for straight lines to come back = time to travel from SN + time to come back = 1/(c-v) + 1/(c+v) = 2cl/(c2 - v2)

These times are different and hence, light reaching back will be in different phases, thereby, producing a particular interference pattern.

The experiment was performed and an unbelievable difference of above 90% was obtained. So, stationary ether theory was completely out of order. But, Lorentz was able to provide an answer by changing almost everything. He replaced Galilean transformation by ‘Lorentz’ transformation (so, it is not called Einstein transformation). It was based on the invariance of Maxwell’s equations. It successfully explained the faulty result of the above experiment. A phenomenon called Lorentz-Fitzgerald contraction was supposed to take place, because of which, the length SN (= l) would be contracted to lÖ(1-v2/c2). This fixed the problem.

But, here came the problem. This result was a very ad hoc construction and was not a natural result of anything.

Thus, some scientists started doubting the ether hypothesis as a whole. And a young man, who himself had written a paper on aether at the age of fifteen, while going home in a taxi, suddenly realized that he knew the answer, thanks to a clock at the end of the road. About five years before the clock struck 12 midnight, another breakthrough had already taken place because of a German physicist named Max Karl Ernst Ludwig Planck.

 THE LIGHT BEAM RIDER THE DISTORTED GEOMETRY THE DESCENDANTS OF TWO GAINTS THE QUANTUM THEORY THE CURSE OF LIGHT BEAM RIDER

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