Wonders of Science
Dernière mise à jour : 10 sept.
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"How great are Your Works, O LORD!
You have made them all with wisdom..."
(Tehillim 104, 24)
Let us begin by listing some of the remarkable findings of physics that were discovered during the last century:
Wonders of science: It was assumed by the great physicist Isaac Newton that clocks everywhere in the universe tell the same time because space and time are independent of each other. However, it was shown by Albert Einstein that space and time are intimately connected and are jointly called space-time. As a result, the rate at which time advances depends on the location of the clock. Near a large mass, time will advance more slowly. Thus, a clock on the sun advances more slowly than a clock on Earth.
Also, the rate at which time advances depends on the motion of the clock. For example, if a clock is moving rapidly past me, the time measured by this clock will advance more slowly than the time meas-ured by a stationary clock that I hold in my hand.
Wonders of science: It had always been a basic principle of physics that if one performs the same experiment twice, under the exact same conditions, one will obtain the same results. However, this basic principle has now been overturned. According to quantum theory, even if an experiment is performed twice under the same exact conditions, one may nevertheless obtain different results each time.
The reason for this surprising result is that the laws of physics are not deterministic. Deterministic laws imply that there is only one possible result for any experiment. According to quantum theory, the laws of physics are probabilistic. This means that there are various possibilities of what might occur as the result of an experiment, with each possibility having a certain probability of occurring. One can calculate what these various possibilities are and also the probability of the occurrence of each. However, there is no way to know in advance which of the various possibilities will happen in practice.
If one repeats the same experiment, the same set of possibilities apply. But in the second experiment, a different one of the various possibilities may occur.
Wonders of science: It was previously thought that if one knows the initial location of a moving object and the forces that are exerted on that object, and if one then measures its final location, one can use the laws of physics to deduce the entire path of the object. It is now known that this is not the case...
 | Excerpts from the book: "Wonders of Science", by Nathan Aviezer, Professor of physics and former chairman of the physics department at the Bar-Ilan University, Israel |
The full text is available free of charge
upon request (page Contact).
Please specify "Wonders of Science".
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