Scinerds

probably

(via christinetheastrophysicist)

sevenisles:

Leonardo da Vinci-esque Large Hadron Collider by Dr. Sergio Cittolin.

(via ikenbot)

pretendy:

“Draw me an atom”

This amazing gif by xverdxse is close to my idea of what an atom looks like. Far from the schoolbook picture of a clump of snooker ball protons and neutrons encircled by hoops of electrons the real picture of an atom is more like a vibrating cloud. A cloud? Yeah, a specific type of cloud called a probability density function. Woah maths alert! WEEOO-WEEOO, code red, code red!

Relax.

A probability density function (PDF) is just a measure (function) of how likely it is (probability) to ‘find’ the atom in a given region of space (density). The thickness of the cloud in a small region is proportional to the likelihood of finding the atom centered within that region. In the image above, it is most likely to be found in the center of the black region, and the likelihood of it being found further away gets smaller and smaller until it’s nearly zero outside.

Every frame of this image corresponds to making a single measurement of it’s position. If it weren’t on a loop and we waited long enough, we should expect it to sooner or later make a large jump to a grey or even white area.

This is how quantum tunneling works: a particle confined to a domain will at any given time have a small but finite probability of being found outside its confinement region! Even a tennis ball has a finite (but astronomically tiny) probability of tunneling through a solid wall.

So what do atoms actually look like? Well, they don’t. They area collection of volumeless point-particles that don’t have any physical shape that you can draw on a piece of paper. However they have an effective shape that is described by (amongst other things and depending on what kind of measurements you make) the PDF.

If you take a step back from your screen and look at the above ‘atom’, you can kind of consider it as a single solid entity even though it is an amorphous cloud of pixels. This is all we can say about the ‘true’ shape of the atom and is a visual approximation we have to make if we want to try to understand what atoms look like and not chew off our own faces in philosophical frustration.

Chinese Physicists Smash Quantum Teleportation Record

A group of Chinese engineers have smashed the records for quantum teleportation, by creating a pair of entangled photons over a distance of almost 100 kilometers.

Quantum entanglement is the mysterious phenomenon where two particles become tightly intertwined and behave as one system — whether they are next to each other on a laboratory bench, or either sides of a galaxy.

If you examine one particle and measure a certain property — say, vertical polarization — then the other will instantly adopt the opposite property — in this case, horizontal polarization.

It’s crazy stuff. Albert Einstein described it as “spooky action at a distance,” when he was still struggling to get his brain around the ideas proposed by quantum theory. But it’s a powerful phenomenon, and one that physicists have long attempted to harness in the lab.

Trouble is, creating a pair of particles with any distance between them has always been a difficult hurdle to overcome. Imperfections in optic fiber glass, or air turbulence, means that the qubits become unentangled. Plus as the distance gets farther your beam gets wider, so photons simply miss their target.

Juan Yin at the University of Science and Technology of China in Shanghai claims to have cracked it. His team sent photons between two stations, separated by 97 km. Over a Chinese lake, to be precise. To pull off this feat, Yun and friends used a 1.3 Watt laser, and a clever optic steering technique to keep the beam precisely on target. With this setup, they were able to teleport more than 1,100 photons in four hours, over a distance of 97 kilometers.

scipsy:

Visualizations of Quantum Chromodynamics ”the underlying theory of the strong interactions. As a key component of the Standard Model of the Universe, QCD describes the interactions between quarks and gluons as they compose particles such as the proton or neutron.”

The Bizarre Object We Believed Was Impossible to Visualize.

Mathematicians have now visualized abstract mathematical objects called flat tori — items resembling donuts with corrugated, fractal surfaces. These were thought to be impossible to envision in ordinary 3-D space… until now.

To imagine a flat torus, imagine a video game with a wraparound screen — for instance, if you go up the top side, you emerge from the down side. In the 1950s, mathematicians Nicolaas Kuiper and the Nobel laureate John Nash demonstrated the existence of this object, called a flat torus:

Imagine taking a square flat torus, wrapping it into a tube, and then bending its ends so they met to form a ring.

Is it possible to visualize this object in 3-D space? You might not think so — after all, a globe cannot be flattened into two dimensions, without distorting the distance between points on it. However, researchers in France have now accomplished exactly that.

The key, they explain, is to use corrugations. They piled up corrugations, until the distances between points was accurate.

The resulting surfaces of the objects are what are known as smooth fractals, which the researchers say lie halfway between fractals and ordinary surfaces:

These findings are more than just beautiful — they could open up new avenues in applied mathematics. For instance, this work could help visualize differential equations that are encountered in physics and biology.

The researchers detailed their findings online April 20 in the Proceedings of the National Academy of Sciences. (via io9.com)

This Bubble Wrap Lets You See Magnetic Fields

Magnetic field viewing film, which can be bought relatively cheaply, lets you ‘see’ a magnetic field as it moves. Below, we’ll tell you about the simple way this film works, and show you a couple of demonstrations. See magnetic field lines!

This re-usable film can wrap around anything and shows you the shape and movement of a magnetic field. It’s fun to play with, and as something fun to play with it ranks only slightly below the stuff that inspired it; bubble wrap. Yep, the same technology that winds around your breakables when you move brings you this. The film is like a very fine bubble wrap, with each tiny bubble filled with liquid. This is not regular water. The liquid inside the bubbles has a high viscosity - meaning it has a high resistance to changes in shape. It takes force to move the liquid around inside the bubble.

Inside the liquid are tiny metal rods. A single pole of the magnet, when underneath the film, will pull the rods so they’re standing on end inside the film, and you’re looking at them head on. This makes the film appear dark. When pulled by both poles of the magnet, the rods will lie flat on the film, and you’ll see their sides. The film will appear bright. As long as the bubbles aren’t burst by crushing or scratching the film, they’ll keep moving as the magnet moves, letting you ‘see’ the shifting magnetic field of the moving magnet. And? It is very cool to watch.

Info via io9.com

quantumaniac:

Physicists Explain the Collective Motion of Fermions

Some people like company. Others prefer to be alone. The same holds true for the particles that constitute the matter around us: Some, called bosons, like to act in unison with others. Others, called fermions, have a mind of their own.

Different as they are, both species can show “collective” behaviour — an effect similar to the wave at a baseball game, where all spectators carry out the same motion regardless of whether they like each other.

Scientists generally believed that such collective behavior, while commonplace for bosons, only appeared in fermions moving in unison at very long wavelengths. Now, however, collective behavior has been discovered at short wavelengths in one Fermi system, helium-3.

A team led by Professor Eckhard Krotscheck — a physicist who recently joined the University at Buffalo from the Johannes Kepler University in Linz, Austria — predicted the existence of the behaviour using theoretical tools. Independently, but practically at the same time, a French team observed the collective behaviour.

“Knowing how nature ticks at a microscopic scale, we set out to develop a robust theory that was capable of dealing with a wide range of situations and systems,” Krotscheck said. “We demanded that our mathematical description is accurate for both fermions and bosons, in different dimensions, and for both coherent and incoherent excitations. Only after we were done, we looked at experiments.”

quantumaniac:

Einstein’s Office

blamoscience:

A pinhole camera created from an egg. Pinhole cameras are often used in introductory physics courses to illustrate the principles of optics. The following was taken from a lab exercise at Rice Univerity:

A pinhole camera consists of a darkened box or room with a small hole at one end. Because light travels in straight lines, the hole permits rays from each point of an object to fall only within a small circle on the opposite wall, effectively forming an image. As the pinhole is made smaller the image will become more distinct until the hole is so small that diffraction becomes important.

Although pinhole cameras were probably known to the ancient Greeks, they are still used in preference to lens systems in some situations. Pinholes are obviously useful for imaging x- rays or particle streams, where no lens materials are available, but even for light they offer complete freedom from linear distortion, virtually infinite depth of focus and a very wide angular field. Modest resolution and a very dim image are the disadvantages. Overall, pinhole cameras are worth study because they are useful and also because they illustrate some interesting physics.

Bizarre Magnetic Ferrofluids Will Blow Your Mind

There is no CG in the video above. What you’re seeing is pure, awesome science.

The black liquid mixture is known as a ferrofluid, and is made up of nano-sized, iron-containing particles suspended in water or an organic solvent. When a magnetic field is applied, the ferrofluid puffs out, creating some alien-looking shapes and formations.

Originally discovered in the 1960s at NASA, ferrofluids have found many modern uses. They form liquid seals around the spinning drive shafts of hard disks, dampen unwanted resonances to help improve the sound quality of loudspeakers, and have even found their way into museum art exhibits.

In this gallery, Wired takes a look at some of the best videos, both artistic and scientific, featuring these magical ferrofluids.

Above Video: A beastly black creature rises out of a ferrofluid lake in this video, created by artist Paul Brenner.

skeptv:

Neil deGrasse Tyson - SciCafe - Life the Universe and Everything (2010)

A Conversation with Neil deGrasse Tyson” at the Museum on June 2, 2010 as part of the ongoing free SciCafe series.

Tyson hosted the casual conversation about stars, planets, the universe, and beyond in the Frederick Phineas and Sandra Priest Rose Center for Earth and Space. The popular SciCafe series takes place at the American Museum of Natural History.

matthen:

An animation I made in mathematica roughly showing how the planets will move relative to the Earth throughout 2012. I found it quite hard to make a mapping of the solar system which keeps the Sun at the centre, and puts the planets roughly in a horizontal line- whilst roughly showing what order they appear in the sky. [code]

quantumaniac:

The Quantum Internet is Born

“Years from now it may be said that the quantum Internet was born today.” Of course, the quantum internet is just in the baby stages now - but when it matures, it will be able to process ridiculous amounts of data at blaring speed, and never be hacked. The system, developed by physicists Stephan Ritter and Gerhard Rempe at the Max Planck Institute of Quantum Optics in Germany, has two nodes. Although this is small, the internet you’re on right now started in the 1960s in a similar process.

This first quantum network was built by utilizing two atoms of rubidium which exchange photons. Each atom is placed inside an individual ‘room’ with highly reflective mirrors surrounding it, and at a short distance from its sister atom. These rooms, called optical cavities, are connected by an optical fiber.

First, scientists aim a laser at the first rubidium atom, which induces an emission of a single photon. That photon travels along the optical fiber to the other optical cavity, containing the other atom. Thanks to the mirrors, the photon bounces off the mirrors thousands of times, and is absorbed by the atom upon collision. This absorption transmits information about the first atom’s quantum state - and voila, a transfer of information.

The two rubidium atoms were entangled beforehand, which effectively means that they were linked together. During entanglement (read more about entanglement here), certain properties of the atoms are linked, and measuring one instantaneously produces the same result in the other atom. During this experiment, the atoms were entangled for 100 microseconds - a long time in quantum physicists. Entanglement what renders any form of hacking impossible - as soon as a would-be hacker tapped into the quantum network, the quantum states of the atoms would no longer match up.

This is the first step towards something great.

Read the press release.