In the United States has reopened the debate on the principles formulated by the famous scientist with the work of a Dutch physicist: "His theory is an illusion." This is Erik Verlinde hypothesis that links his criticisms of string and the holographic universe.
From an article on the Republic of July 15, 2010:
The theory of gravity is perhaps the most formidable law of physics, the most obvious and universal principle because it corresponds to an empirical irresistible. The child still can not talk and one of the first games in which amuses the chair, is to drop the spoon of jelly. The show is fascinating in its repetitiveness. Grab a spoon, lifting it up, drop it, and each time the miracle is repeated: that object is irresistibly attracted to the ground, forcing the patient's parent to pick it up. Each of us at the age of 18 months without knowing it was Newton. Well, ricrediamoci: the force of gravity is an illusion, a cosmic joke, or a "side effect" of something else that occurs to a much deeper level of reality.
The abandonment of Newton had already been anticipated by the relativity of Albert Einstein but now takes a more radical break. A famous Dutch-American mathematical physicist, the 48 year old Erik Verlinde, which has already linked its name to "string theory" (Supersymmetry in parallel universes), is shaking the U.S. academic world with a series of lectures in which he breaks down the theory of gravity. From Harvard to Berkeley, my fellow scientists are taking very seriously. His new vision it can throw a different light on some of the major themes of contemporary physics: the so-called dark energy (dark energy), a sort of anti-gravity that appears to accelerate the expansion of the universe, or "dark matter" that supposedly holds the galaxies together.
Andrew Strominger, a physicist-mathematician at Harvard, is one of the co-Verlinde who does not hide his admiration: "These ideas are inspiring very interesting discussions, vanno dritte al cuore di tutto ciò che non comprendiamo del nostro universo". Verlinde è l'ultimo di una serie di scienziati che da trent'anni a questa parte stanno smantellando pezzo dopo pezzo la teoria della gravità. Negli anni Settanta Jacob Bekenstein e Stephen Hawking hanno esplorato i legami tra i buchi neri e la termodinamica. Negli anni Novanta Ted Jacobson ha illustrato i buchi neri come degli ologrammi, le immagini tridimensionali usate per la sicurezza delle nostre carte di credito: tutto ciò che è stato "inghiottito" ed è sparito dentro i buchi neri dell'universo, è presente come un'informazione stampata nell'ologramma, sulla superficie esterna. Juan Maldacena dell'"Institute for Advanced Study" ha costruito un modello mathematical universe expressed as a tin of canned soup. Everything that happens inside the jar, including what we call gravity, is synthesized in the label pasted outside: outside instead of gravity does not exist.
think the universe as a box of Scrabble (the Beetle, ed), the game where you make words with the letters of the alphabet. If you shake the box and the letters scattered at random, there is only one possible combination that can give you a poem of Leopardi. An almost infinite number of combinations have no meaning. More shake the box of letters is more likely that the disorder increases as the letters combine in order of probability. This is the new way of seeing the force of gravity, as a form of entropy. Or a "side effect of the natural tendency towards disorder." If it is not clear what will replace it, and yet we are far from imagining the possible practical applications, Verlinde is adamant on one point: "The emperor has no clothes. For some time it was understood that gravity does not exist. Now is the time to scream. "
We read that the abandonment of Newton had already been anticipated by the relativity of Albert Einstein. Let's see why:
From the site: http://www.racine.ra.it/planet/testi/gravit2.htm
"In 1905, an unknown physicist who worked at the patent office in Bern had passed suddenly from obscurity to fame, his name was Albert Einstein. In three articles that appeared in a prestigious physics journal, the young Einstein completely revolutionized the concepts space and time by showing that space and time are not static and absolute as Newton claimed, but are dynamic and relative. In other words, space can shrink or expand the time and can expand or shrink depending on the state of motion of the observer; Furthermore, space and time are intimately tied together so much so that scientists no longer speak of space and time but to space-time.
After these first efforts Einstein began to think about gravity, trying to develop a new theory that would allow to overcome the difficulties that we mentioned earlier.
In 1908, a trivial incident helped to put the scientist on the right track: a painter fell from a roof and fell to the floor, luckily for him (but not its only) survive. Just heard the news Einstein went to the hospital to visit the victim to know what was tried in the fall, the man told him that during the fall he had felt completely weightless, as if gravity were temporarily gone. Because the painter had not felt the gravity?
Surely we have all seen those wonderful television pictures where you see the crew of the Space Shuttle in orbit, floating freely in weightlessness. Imagine then an astronaut inside a spacecraft orbiting the Earth, man is weightless, floating freely, and if he rolls a ball in front of him, the ball moves along a straight line. If we bring the astronaut with his spaceship on Earth's surface we see that things are very different, and the man feels something that keeps him attached to the floor of the spacecraft launches and if the usual ball in front of him this fall on the ground following a curved path . We explain these phenomena are talking about gravity. But the usual demand continues to hum in the brain, because when the astronaut is in space, like dell'imbianchino not feel gravity? Not sure why the influence of the Earth in space is negligible, as sometimes we hear in the media, on the contrary, even in space influence the Earth is very strong (he knows something about the Moon for more than four billion years from the Earth's gravity is imprisoned and forced to turn around our planet). What then is the difference between space and Earth's surface?
There is a big difference: the earth's surface prevents alla navicella e all’astronauta di fluttuare liberamente e, in questo caso, appare la gravità. Ormai sentiamo di essere vicini alla soluzione del mistero.
Immaginiamo un ulteriore esperimento: supponiamo di essere all’interno di una casetta sulla superficie terrestre e di lanciare davanti a noi la solita pallina; la pallina cade sul pavimento dopo un certo tempo seguendo una traiettoria curva. Come al solito noi spieghiamo questo fenomeno invocando la forza di gravità. A questo punto cambiamo le carte in tavola; supponiamo che, nell’istante esatto in cui viene lanciata la pallina, sotto la casetta si faccia improvvisamente il vuoto. Di conseguenza la casetta viene a trovarsi in caduta libera, cioè in libera fluttuazione. Now, compared to the lodge, the points of departure and arrival of the ball and the time taken to travel distance are exactly the same but something else has changed the trajectory has become straight.
In other words, the gravity is gone!
is the great insight of Einstein gravity does not exist, gravity is an illusion. They are right to say that the painter astronaut does not feel gravity because gravity does not exist, it appears as if by magic, when, for whatever reason (in our case due to the Earth's surface), is interrupted the natural movement of free float.
Freedom fluctuation is the natural movement of the body, it is controlled and governed directly from space. Typically, when it comes to space, we tend to think of something blank, nothing, in reality, the space is imagined as a kind of elastic tissue can deform (like that used in those platforms where the children, and not, have fun jumping). Usually space is flat and straight but bodies follow trajectories in the presence of matter curves space.
At this point it quickly becomes clear why, for example, the Earth rotates around the sun or because the moon revolves around the Earth. The Earth rotates around our Sun, the star not because it attracts a mysterious force we call gravity, but because the Sun, because of its large mass, curves the surrounding space, and this curvature is transmitted up to very large distances. Consequently, the Earth, moving in a curved space, nothing can be done to follow a curved trajectory. The same applies to the Moon.
Summing up the union between space and matter can be expressed with the following sentence: space tells matter how to move, matter tells space how to bend.
This conception of gravity, Einstein published in 1916 and known as the Theory of General Relativity, shows a beauty, a simplicity and elegance above all that unbelievable. Instead of being faced with a scientific theory seems to have anything to do with a Beethoven symphony or a Strauss waltz. "
Recall that in general relativity, the gravitational interaction is generated by the curvature of spacetime created by the presence of bodies with mass or energy, and is expected to be propagated by means of gravitational radiation, a wave phenomenon that does not require any material medium to propagate in space, traveling at the speed of light. The gravitational field is a field tensor, represented mathematically by a metric tensor, related to the curvature of space-time through the Riemann tensor.
In originale su "La repubblica" non vi erano nel titolo i punti interrogativi, che ho voluto aggiungere, e nel prossimo POST, vi spiegherò il perchè di questa mia scelta.
Un caro saluto
Alessandra
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