Von Neumann's Machine

Magical & thermodynamical, non-classical & stochastical!

rhamphotheca:

Behold the first geological map of Ganymede, Jupiter’s largest moon

by Lauren Davis

Four hundred years ago, Galileo Galilei observed Ganymede in orbit around Jupiter. This week, a team of planetary scientists unveiled the first global geological map of our solar system’s largest moon.

Using images obtained by NASA’s Voyager 1 and 2 spacecraft and the Galileo orbiter, a team led by Geoffrey Collins of Wheaton College pieced together a mosaic image of the planet, giving us our first complete image of the geological features of the satellite. Above, you can see the moon centered at 200 west longitude. The darker areas represent the very old and heavily cratered region of Ganymede, while the lighter areas are somewhat younger regions marked with grooves and ridges…

(read more: io9)   (… and a 2nd look.)

images: NASA-JPL

(via scientificillustration)

joshbyard:

Programmable Materials “Could Change the World of Mechanics Forever”

Researchers from Empa and ETH Zurich have developed a prototype of a selective vibration-damping material that they claim “could change the world of mechanics forever” as a step toward “programmable materials.”
Described in the journal Advanced Materials, this “material of the future” can damp mechanical vibrations completely or selectively suppress specific vibration frequencies or ranges of frequencies.
The one-dimensional working model consists of a simple aluminum sheet-metal strip, measuring one meter by one centimeter and one millimeter thick and designed to vibrate at different frequencies. To control the wave propagation through the plate, ten small aluminum cylinders (7 mm thick, 1 cm high) are attached to the metal. Between the sheet and the cylinders sit piezoelectric discs, which can be stimulated electronically to instantly change their thickness. That allows for controlling exactly how waves are allowed to propagate in the sheet-metal strip.
The aluminum strip thus turns into an “adaptive phononic crystal” — a material with controllable vibration properties.

(via A step towards ‘programmable materials’ | KurzweilAI)

joshbyard:

Programmable Materials “Could Change the World of Mechanics Forever”

Researchers from Empa and ETH Zurich have developed a prototype of a selective vibration-damping material that they claim “could change the world of mechanics forever” as a step toward “programmable materials.”

Described in the journal Advanced Materials, this “material of the future” can damp mechanical vibrations completely or selectively suppress specific vibration frequencies or ranges of frequencies.

The one-dimensional working model consists of a simple aluminum sheet-metal strip, measuring one meter by one centimeter and one millimeter thick and designed to vibrate at different frequencies. To control the wave propagation through the plate, ten small aluminum cylinders (7 mm thick, 1 cm high) are attached to the metal. Between the sheet and the cylinders sit piezoelectric discs, which can be stimulated electronically to instantly change their thickness. That allows for controlling exactly how waves are allowed to propagate in the sheet-metal strip.

The aluminum strip thus turns into an “adaptive phononic crystal” — a material with controllable vibration properties.

(via A step towards ‘programmable materials’ | KurzweilAI)

(via emergentfutures)

Have physicists finally detected gravitational waves? Breaking News - Updates to Come

thescienceofreality:

By Mika McKinnon, images via io9 Space,

The Harvard-Smithsonian Center for Astrophysics has news so big it announced that it would announce something. The press conference will stream live tomorrow at noon, but cosmologists everywhere are gossiping about what that news could be. The leading theory: Scientists have detected gravitational waves, in what would be a landmark discovery for the field of physics.

Gravitational waves are the last chunk of Einstein’s General Theory of Relativity that was predicted but not yet observed. If gravitational waves have been observed, it most likely was done by the Background Imaging of Cosmic Extragalactic Polarization (Bicep) telescope at the south pole. It stared at the cosmic microwave background radiation from 2003 to 2008, but it takes a long time to process and analyze the data when looking for a faint signal in a lot of noise.

2007 photograph of telescopes at the Dark Center at the Amundsen-Scott South Pole Station. From top to bottom, the partly-buried AST/ROQUaDViper, and finally BICEP and SPT at the bottom. Image credit: Robert Schwarz

The Bicep mission page describes anticipated gravitational waves as faint, polarized, and distorted by gravitational lensing of objects between us and the cosmic microwave background radiation. They released a video of their observations in 2008. The colour scale adjusts throughout the movie to highlight temperature fluctuations of both the cosmic microwave background radiation, and the galactic plane:

 

Why look at the cosmic microwave background radiation for signs of gravitational waves? Because an infinitesimal moment after the universe started — 10-34 seconds after the big bang — we think it went through an inflationary period. If it did, that inflation could have amplified gravitational waves to such an extent that we can actually detect them. This would not only fill in that last missing chunk of things predicted by General Relativity that we haven’t seen yet, but also offer a glimpse into the primeval universe. They won’t be insta-proof that inflationary theory is correct, but they would rule out some cyclic theories for the origin of the universe.

Some pre-announcement articles are already mixing up very common gravity waves with gravitational waves. To differentiate, I’ll pass things off to an exasperated Dr. Katherine Mack:

 

Gravity waves are common phenomena in both the ocean and the sky, as seen in this MODIS image. Read more about them at the Earth Observatory.

As for the press conference, I’m already bracing for disappointment. “Breaking news! We’ll have breaking news for you on Monday!” announcements produce so much hype that the actual discovery probably won’t live up to expectations. I’m not the only one feeling that way — the Guardian ran an entire piece interviewing cautiously excited cosmologists warning that the observations would need to be highly robust if they’re going to be momentous.

(via scinerds)

skeptv:

NEW - 10 Amazing Bets That You Never Lose (Episode 10)

I have just made a new ’10 bets you will never lose’ video. Hope you like it. What’s your favourite bet?

Follow @richardwiseman

via Quirkology.

scienceisbeauty:

Look at Albert Einstein working in his Theory of General Relativity in Zurich:

Einstein’s search for general relativity spanned eight years, 1907-1915. Some periods were quiet and some were more intense. The moments when the great transition occurred, came sometime between the late summer of 1912, when Einstein moved from Prague to Zurich, and early 1913.

Source (and context): A Peek into Einstein’s Zurich Notebook, from the absolutely advisable page of Goodies by Professor John D. Norton, (Department of History and Philosophy of ScienceUniversity of Pittsburgh), from now in my bookmarks.

malformalady:

The Magic Dogwood(Cornus florida subspecies urbiniana). A rare Mexican version of the common American Dogwood tree. This variety is noted for its flower bracts, which are fused together, resulting in an amazing display of spirals and shapes.

malformalady:

The Magic Dogwood(Cornus florida subspecies urbiniana). A rare Mexican version of the common American Dogwood tree. This variety is noted for its flower bracts, which are fused together, resulting in an amazing display of spirals and shapes.

(via geometryofdopeness)

mucholderthen:

HISTORY OF MODERN SCIENCE: THE 18th CENTURY “MECHANICS”
Actually, they all seemed to be interested in just about everything.

Daniel Bernoulli (1700-1782) is best known for his work in fluid mechanics, in particular for his discovery that pressure decreases as flow speed increases – a fact that today keeps carburetors running and fixed-wing planes in the air.

Leonhard Euler (1707-1783), Swiss mathematician and physicist sometimes called “the Galileo of mathematical physics,” did ground-breaking work across many fields. He discovered Euler’s number, e, the second most important constant in physics, after pi.

He also introduced much of modern mathematical terminology and notation, for example, the notion of a mathematical function.  Thus, Euler is justifiably remembered as a mathematician. However, he is also known for his work in mechanics, fluid dynamics, optics, astronomy, and music theory.  [wp]

Joseph Fourier (1768-1830) was a pioneer in theories of heat and vibration. The technique he invented for this work – representing complex waves by adding together simpler waves – is now used everywhere in science and engineering.

Thomas Young (1773-1829) pioneered the “double-slit” experiment: shining a light through two narrow slits, he produced a pattern akin to the one produced by two overlapping water waves. This demonstration of the wave nature of light later became central to quantum mechanics.

Young made notable scientific contributions in the fields of vision, light, solid mechanics, energy, physiology, and language. He also advanced European understanding of ancient Egyptian hieroglyphs (notably, those on the famous Rosetta Stone). [wp]

Carl Friedrich Gauss / Gauß (1777-1855), called “the prince of mathematicians” by his contemporaries, is now best remembered for his “normal” (or Gaussian) distributions, which plot how likely things are to vary from average.

A German mathematician and physical scientist, he contributed significantly to many fields - in mathematics: number theory, algebra, statistics, analysis, differential geometry. In physics, he did work in geophysics, electrostatics, astronomy, and optics. [wp]

William Hamilton (1805-1865) reformulated Newtonian mechanics into what is now known as Hamiltonian mechanics. In doing so, he wrote the mathematical language in which modern physics, especially quantum theory, is expressed.

Sir William Rowan Hamilton was an Irish physicist, astronomer, and mathematician, who made important contributions to classical mechanics, optics, and algebra. [wp]

THE SCIENTIFIC TYPOGRAPHIES OF Dr. Prateek Lala: artistic representations of more than 50 influential physicists, cosmologists, and mathematicians – from Anaximander up to Stephen Hawking.

Images and descriptions reprinted (with revisions) from: Perimeter Institute 

NEXT UP: Ohm, Faraday, Maxwell, Röntgen, Tesla

(via visualizingmath)