(Roughly) Daily

Posts Tagged ‘Hilbert

From the Not-Sure-I-Really-Want-To-Know Department…

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As readers know, some physicists believe that the universe as we know it is actually a giant hologram, giving us the illusion of three-dimensions, while in fact all the action is occurring on a two-dimensional boundary region (see here, here, and here)… shadows on the walls of a cave, indeed.

But lest one mistake that for the frontier of freakiness, others (c.f., e.g., here and here) believe that the existence we experience is nothing more (or less) than a Matrix-like simulation…

A common theme of science fiction movies and books is the idea that we’re all living in a simulated universe—that nothing is actually real. This is no trivial pursuit: some of the greatest minds in history, from Plato, to Descartes, have pondered the possibility. Though, none were able to offer proof that such an idea is even possible. Now, a team of physicists working at the University of Bonn have come up with a possible means for providing us with the evidence we are looking for; namely, a measurable way to show that our universe is indeed simulated. They have written a paper describing their idea and have uploaded it to the preprint server arXiv…

Phys.Org has the whole story at “Is it real? Physicists propose method to determine if the universe is a simulation“; the paper mentioned above can be downloaded here.

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As we reach for the “reset” button, we might send carefully-calculated birthday greetings to Paul Isaac Bernays; he was born on this date in 1888.  A close associate of David Hilbert (of “Hilbert’s Hotel” fame), Bernays was one the foremost philosophers of mathematics of the Twentieth Century, who made important contributions to mathematical logic and axiomatic set theory.  Bernays is perhaps best remembered for his revision and improvement of the (early, incomplete) set theory advanced by John von Neumann in the 1920s; Bernays’s work, with some subsequent modifications by Kurt Gödel, is now known as the Von Neumann–Bernays–Gödel set theory.

Lest, per the simulation speculation above suggest that cosmology has a hammerlock on weirdness:  Set theory is used, among other purposes, to describe the symmetries inherent in families of elementary particles and in crystals. Materials such as a liquid or a gas in equilibrium, made of uniformly distributed particles, exhibit perfect spatial symmetry—they look the same everywhere and in every direction… a condition that “breaks” at very low temperature, when the particles form crystals (which have some symmetry, but less)…  Now Nobel Laureate Frank Wilczek has suggested that there may exist “Time Crystals“– whose structure would repeat periodically, as with an ordinary crystal, but in time rather than in space… a kind of “perpetual motion ‘machine'” (weirder yet, one that doesn’t violate the laws of thermodynamics).

Paul Bernays

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Written by (Roughly) Daily

October 17, 2012 at 1:01 am

Infinitely cool…

 click here for video

How to Count to Infinity (or “Yes, Virginia, some infinities are bigger than others…”)

Many more sixty-second epiphanies at MinutePhysics’ You Tube channel (or via New Scientist TV)

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As we check in to Hilbert’s Hotel, we might spare a thought for Joesph Fourier; the French mathematician, physicist, Egyptologist and administrator who died on this date in 1830. Fourier introduced Jean-Francois Champollion to the Rosetta Stone, which Champollion subsequently decoded/translated.  And after calculating that a body the size of earth, at earth’s distance form the sun, should be cooler than our world is, discovered what we now call “the greenhouse effect.”  But Fourier is best remembered for his contributions to mathematical physics through his Théorie analytique de la chaleur (1822; The Analytical Theory of Heat), which introduced an infinite mathematical series to aid in solving conduction equations. (The technique allowed the function of any variable to be expanded into a series of sines of multiples of the variable– now known as “the fourier series.”)

True greatness is when your name is like ampere, watt, and fourier—when it’s spelled with a lower case letter.

– Richard Hamming (in a 1986 Bell Labs Colloquium)

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Written by (Roughly) Daily

May 16, 2012 at 1:01 am