The uncertainity principle by heisenberg

To get some clear understanding about the uncertainty principle, first, we need to know the quantum hypothesis.

Max Planck suggested that light, X-rays, and some other waves could not be emitted at the arbitrary rate, but in the form of energy packets called quanta.

According to the quantum hypothesis, each quantum--packet-- has certain amount of energy that was greater the higher the frequency of the waves. That implies that at higher frequencies, the emission of even a single quantum would require more energy than that was available. Thus the radiation at high frequencies gets reduced.

In order to predict the future position and velocity of a particle, one has to be able to determine its present position and velocity accurately. The only way to do this is to shine light on the particle and this will indicate its position. To determine more precisely one needs to use light of short wavelength(high frequency). Now, by Planck's quantum hypothesis, one cannot use an arbitrarily small amount of light; one has to use at least one quantum and this quantum will disturb the particle and change its velocity in a way that cannot be predicted. The more accurate one tries to measure the position, the greater will be the disturbance ( as it needs high energy quanta ). In other words, the more accurate one try to measure the position of a particle, the less accurate will be the speed and vice verse
This principle put an end to a notion(came from Newton's theory of gravity) that our universe is completely deterministic ( one can easily predict everything that would happen in the universe, if he knows its present state.)
It is only possible for the one who could observe the present state of universe with out disturbing it.

check this video.

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Ptolemy's geocentric Theory

Ptolemy proposed his Geocentric theory in the 2nd century A.D. What he did was just an elaboration of already existing idea that earth was in the center of universe, proposed by Aristotle, in to a complete cosmological model.

According to his theory, the earth stood at the center, surrounded by some eight spheres, the Moon, the Sun, the stars, and the five other planets known till the time: Mercury, Venus, Mars, Jupiter, and Saturn.

The first sphere supposedly carried Moon followed by Mercury, Venus, Sun, Mars, Jupiter, Saturn, and some fixed stars--eighth sphere--in the remaining seven spheres. The outer most sphere that is supposed to carry the so-called fixed stars, rotate across the sky; the stars thus remain fixed with respect to earth--according to him.

What about the region beyond the eighth sphere ?

He didn't explained that, as there is no way one can observe beyond stars--no telescope and no Galileo.

Does this theory provided a reasonably accurate system for predicting the positions of heavenly bodies in the sky ?

Yes, it was, but got one serious flaw: to predict the positions correctly, Ptolemy had to make an assumption that the moon followed a path that sometimes brought it twice as close to the earth as at other times. And that meant that the moon ought sometimes to appear twice as big as at other times!
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grand unified theory

According to many physicists, the primary goal of physics today is the grand unified theory. it is supposed to describe the four forces as different aspects of a same force.
the four forces, gravity, electromagnetic force, strong nuclear force, weak nuclear force have to be established as single form at some point(energy level) that get branched later on in the evolution process(cooling of earth) after big bang
scientists,indeed,successfully combined three of the forces other than gravity.the first two forces that got unified were electromagnetic force and weak nuclear force in the year 1967 by Abdus Salam and Steven Weinberg.

They suggested that there were other massive particles along with photon(EM force carrier) having same spin,that carry weak nuclear force, collectively called as massive vector bosons(W+,W-,Z0), and the way they got divided is explained by a property called spontaneous symmetry breaking,which means that,what ever appear to be a number of completely different particles at low energies are in fact found to be all the same type of particle,only in different states.all these particles behaves similarly at higher energies(around 100's of Gev) and the symmetry get broken at lower particle energies to form massive W+,W- and Z0 along with photons.

later it was found that the strong nuclear force which was carried by gluons get weaker at higher energies making quarks and gluons act freely.
It creates a new hope,that there must be some energy level where gluons, photons and bosons all behave the same & they predicted that it must be around thousand million million Gev and it can't be proved as there are no such oscillators till date.
they also predicted that quarks and electrons would behave the same at that grand unified energy level.

Now the process of unifying gravity along with the other three is going on...

hope they will find answers soon.
check this video

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