Year: 2022

A CHANGING UNIVERSE. “De Sitter spacetime is empty, expands at an accelerating rate and is very highly symmetrical. In 1997 astronomers studying distant supernova explosions concluded that our universe now expands in an accelerated fashion and will probably become increasingly like a de Sitter spacetime in the future.” https://lnkd.in/draqjTW View in LinkedIn

SWITCHEROO. “Now, if the repulsive cosmological constant is replaced by an attractive one, de Sitter's solution turns into antide Sitter spacetime, which has equally as much symmetry. More important for the holographic concept, it possesses a boundary, which is located at infinity and is a lot like our everyday spacetime.” https://lnkd.in/draqjTW View in LinkedIn

REVISED VIEW OF SPACETIME. “Using antide Sitter spacetime, theorists have devised a concrete example of the holographic principle at work: a universe described by superstring theory functioning in an antide Sitter spacetime is completely equivalent to a quantum field theory operating on the boundary of that spacetime.” https://lnkd.in/draqjTW View in LinkedIn

THE BOUNDARY AT INFINITY. “Thus, the full majesty of superstring theory in an antide Sitter universe is painted on the boundary of the universe.” https://lnkd.in/draqjTW View in LinkedIn

FAIRGROUND WARPED MIRRORS. “This result means that two ostensibly very different theories--not even acting in spaces of the same dimension--are equivalent. Creatures living in one of these universes would be incapable of determining if they inhabited a 5-D universe described by string theory or a 4-D one described by a quantum field theory of point particles.” https://lnkd.in/draqjTW View in LinkedIn

THE GREAT UNDOCUMENTED KINGDOM. “All the viruses in the ocean end-to-end would stretch further than the nearest 60 galaxies.” They produce half of Earth’s oxygen, and microbial life (mostly viruses) is 96% by weight of all oceanic life, far exceeding the larger creatures. They are also the largest pool of genetic novelty on Earth. Lovely article. https://lnkd.in/d-nEKzQ View in LinkedIn

The fertilized gynaecium has metamorphosed into the specks of the next generation; plants never stop working. View in LinkedIn

5D VS 4D UNIVERSE CREATURES. “Of course, the structures of their brains might give them an overwhelming commonsense prejudice in favor of one description or another, in just the way that our brains construct an innate perception that our universe has three spatial dimensions.” https://lnkd.in/draqjTW View in LinkedIn

5D VS 4D PARTICLES. “The holographic equivalence can allow a difficult calculation in the 4-D boundary spacetime, such as the behavior of quarks and gluons, to be traded for another, easier calculation in the highly symmetric, 5-D antide Sitter spacetime.” https://lnkd.in/draqjTW View in LinkedIn

5D VS 4D SPACETIME. “The correspondence works the other way, too. Witten has shown that a black hole in antide Sitter spacetime corresponds to hot radiation in the alternative physics operating on the bounding spacetime. The entropy of the hole--a deeply mysterious concept--equals the radiation's entropy, which is quite mundane.” https://lnkd.in/draqjTW View in LinkedIn