We know that Einstein's Theory of Relativity and Quantum Physics are two most radical ideas in science's history.
The equivalence principle which is one of the core idea of Einstein’s theory of gravity had recently been tested by scientists who reported that the theory qualified the quantum test.
In Einstein’s General theory of relativity, gravity and acceleration are one in a same. According to the equivalence principle, the gravitational mass of an object, which determines the strength of gravity’s pull, is the same as its inertial mass, which determines how much an object accelerates when given a push. As a result, two objects when dropped on Earth’s surface should accelerate at the same rate (neglecting air resistance), even if they have different masses or if they are made of different materials.
At the beginning, the first tests of the equivalence principle was Galileo’s apocryphal experiment in which he is said to have dropped weights from the Leaning Tower of Pisa. In the new study, physicists went a step further, putting atoms into a quantum superposition, in which an atom does not have a definite energy but has a combination of two dissimilar energy levels.
Quantum theory and General relativity, as we know doesn't go well with each other.
Quantum tests of the equivalence principle explores the possible place where quantum mechanics and general relativity meet. Apart from this, there are many other theories which predict to unify these two giants from Physics world, "The Quantum Theory" and "General Relativity". Among them, String theory is the most profound candidate.
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But for this particular test,
By striking rubidium atoms with lasers, scientists from Italy gave the atoms an movement and then observed how gravity acted upon them and bought them down. However to perform the test, by comparing the atoms in normal to those in a superposition state, scientist created two clouds of atoms and then studied their interaction.
Comparing the result of this test to one in which both clouds were in a normal energy state. As they reported that gravity acted in same way in both the cases. With a precision of 5 in 100 million, it seems an accurate result.
This was not the first time when scientists tested the equivalence principle in atoms, comparing gravity’s effects on different types of atoms, for example. But this test is the first among them all to study superposition which is regarded to be one of the most weirdest properties of quantum mechanics.
The test provides us a hope that one day, we might be able to unify beauty of gravity and the weirdness of quantum world to make mankind's most remarkable discovery.
Comments
a) The detected material masses of the matter in the Universe is so small
(the average density of all substance in the Universe is approximately
p=10^-30 g/sm^3) that the Universe as whole cannot be curved,
the Universe as whole is a flat continuum.
b)
'' A world without masses, without electrons, without an
electromagnetic field is an empty world. Such an empty
world is flat. But if masses appear, if charged particles
appear, if an electromagnetic field appears then our world
becomes curved. Its geometry is Riemannian, that is, non- Euclidian.''
/ Book 'Albert Einstein', the page 116, by Leopold Infeld. /
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Book: ''What we cannot know'' by Marcus du Sautoy.
'' Gravity is actually the distortion of this space-time surface.
If something has mass, it curves the surface. The classic way to imagine
this is to consider space-time as a two-dimensional surface, and the effect
of mass as that of placing a ball on this surface. The ball pulls the surface
down, creating a well. Gravity can be thought of as the way things get
pulled down into this well.''
/page 270 /
c) Masses (like Sun's) can appear only in local places and therefore
the curvature can appear only in local places.
It means Einstein's GRT cannot be used to the universe
as whole. GRT is local theory. (!)
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