We explain in simple language what Stephen Hawking is cool and what his discoveries mean for the world.
The theoretical physicist Stephen Hawking, who died at the age of 77, was by far the most famous and popular scientist of our time. Everyone knows a paralyzed man in a wheelchair with a digitized voice, but few people know exactly what Hawking is important for the world as a scientist and what discoveries he made.
The birth of the universe
The universe was born as a result of the Big Bang - this is known to everyone who has at least something about physics. But what happened before the Big Bang? How did everything come from nothing? Hawking answered this question throughout his life and finally formulated the answer just a few days before his death.
According to the Hartle-Hawking model, which appeared several decades ago and improved until Hawking's last days, before the Big Bang, the entire universe was compressed to the size of one atom. Scientists call this tiny but supermassive bundle of heat and energy the cosmological singularity.
Inside this atom, the laws of physics did not work, none of the measurements known to man was there - neither space nor time. Since what happened before the Big Bang is impossible to understand or measure, it cannot be considered part of history. So we can safely say that space and time, and with them the entire Universe familiar to us, began their existence only with the Big Bang.
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"Since there is such a force as gravity, the Universe could and created itself out of nothing," is one of Hawking's most famous sayings.
Our Universe is one of many
Hawking developed and refined the so-called "Theory of Everything" or M-theory, proposed in the 1990s by the scientist Edward Witten. It is an offshoot of string theory and is considered by physicists to be the main scientific achievement of humanity since Einstein's discovery of the theory of relativity.
According to this theory, everything in the Universe does not consist of material particles (quarks, bosons, and others), but of multidimensional membranes, which in essence are not matter, but energy. Since membranes have countless dimensions, the world we see is just one of many realities.
“Each Universe has many prehistories and many possible future states, that is, times like the present, long after their occurrence. Most of these states will be significantly different from the conditions of the universe that we can observe, "- Hawking writes in the book" The Grand Design."
How black holes die
Still, Stephen Hawking devoted most of his life to studying the strangest and mystical objects in the Universe - black holes. It is thanks to them that his name will forever remain in physics textbooks, because he named one of the cosmic phenomena, namely the process of the death of a black hole.
Gargantua's black hole. A scene from the movie Interstellar.
As you know, black holes absorb everything that falls into them. This applies to both material objects and light - everything disappears without a trace. But in the 1970s, based on the laws of quantum mechanics, Hawking suggested that there was still something that could escape the black hole - radiation.
Moreover, every time a black hole "swallows" one half of the particle-antiparticle pair, the other half returns to space in the form of a radiation particle, taking with it a particle of the black hole's energy. Thus, in the process of absorption, the black hole evaporates itself and eventually disappears completely. This radiation that kills black holes is called Hawking radiation.
Popularization of physics
Unlike most scientists, Hawking was always worried about whether the common people would understand him. In order to easily explain to people far from science the essence of his research and draw the attention of the masses to space and the issues of the emergence of the Universe, in 1988 he published the book "A Brief History of Time", which became the best-selling in the history of popular science literature, due to the fact that pages one could find only one formula: E = mc².
Realizing that physics can be of interest to the masses, if presented in an accessible and correct way, Hawking began to actively shoot non-fiction films for Discovery and National Geographic. And then he moved from adults to children, co-writing with his daughter Lucy Hawking a book for toddlers, George and the Secrets of the Universe.
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