Science & Technology


Time-traveling photon simulation connect general relativity to quantum mechanics

© Martin Ringbauer
Space-time structure exhibiting closed paths in space (horizontal) and time (vertical). A quantum particle travels through a wormhole back in time and returns to the same location in space and time.
Scientists have simulated time travel by using particles of light acting as quantum particles sent away and then brought back to their original space-time location. This is a huge step toward marrying two of the most irreconcilable theories in physics.

Since traveling all the way to a black hole to see if an object you're holding would bend, break or put itself back together in inexplicable ways is a bit of a trek, scientists have decided to find a point of convergence between general relativity and quantum mechanics in lab conditions, and they achieved success.

Australian researchers from the UQ's School of Mathematics and Physics wanted to plug the holes in the discrepancies that exist between two of our most commonly accepted physics theories, which is no easy task: on the one hand, you have Einstein's theory of general relativity, which predicts the behavior of massive objects like planets and galaxies; but on the other, you have something whose laws completely clash with Einstein's - and that is the theory of quantum mechanics, which describes our world at the molecular level. And this is where things get interesting: we still have no concrete idea of all the principles of movement and interaction that underpin this theory.

Natural laws of space and time simply break down there.

The light particles used in the study are known as photons, and in this University of Queensland study, they stood in for actual quantum particles for the purpose of finding out how they behaved while moving through space and time.

The coolest known white dwarf detected

White Dwarf
© B. Saxton (NRAO/AUI/NSF)
An artist’s conception of a white dwarf star in orbit with pulsar PSR J2222-0137.
We live in a vast, dark Universe, which makes the smallest and coolest objects extremely difficult to detect, save for a stroke of luck. Often times this luck comes in the form of a companion. Take, for example, the first exoplanet detected due to its orbit around a pulsar - a rapidly spinning neutron star.

A team of researchers using the National Radio Astronomy Observatory's Green Bank Telescope and the Very Long Baseline Array (VLBA), as well as other observatories have repeated the story, detecting an object in orbit around a distant pulsar. Except this time it's the coldest, faintest white dwarf ever detected. So cool, in fact, its carbon has crystallized.

The punch line is this: with the help of a pulsar, astronomers have detected an Earth-size diamond in the sky.

"It's a really remarkable object," said lead author David Kaplan from the University of Wisconsin-Milwaukee in a press release. "These things should be out there, but because they are so dim they are very hard to find."

'Molecular time travel' experiments show evolution depends on non-adaptive chance mutations

DNA, DNS Strang
© iStock
Chance events may profoundly shape history. What if Franz Ferdinand's driver had not taken a wrong turn, bringing the Duke face to face with his assassin? Would World War I still have been fought? Would Hitler have risen to power decades later?

Historians can only speculate on what might have been, but a team of evolutionary biologists studying ancient proteins has turned speculation into experiment. They resurrected an ancient ancestor of an important human protein as it existed hundreds of millions of years ago and then used biochemical methods to generate and characterize a huge number of alternative histories that could have ensued from that ancient starting point.

Tracing these alternative evolutionary paths, the researchers discovered that the protein - the cellular receptor for the stress hormone cortisol - could not have evolved its modern-day function unless two extremely unlikely mutations happened to evolve first. These "permissive" mutations had no effect on the protein's function, but without them the protein could not tolerate the later mutations that caused it to evolve its sensitivity to cortisol. In screening thousands of alternative histories, the researchers found no alternative permissive mutations that could have allowed the protein's modern-day form to evolve. The researchers describe their findings June 16, online in Nature.

"This very important protein exists only because of a twist of fate," said study senior author Joe Thornton, PhD, professor of ecology & evolution and human genetics at the University of Chicago. "If our results are general - and we think they probably are - then many of our body's systems work as they do because of very unlikely chance events that happened in our deep evolutionary past," he added.

Comment: In other words, evolution depends on events that are extremely unlikely to occur: so unlikely that the laws of chance are weighted strongly against them occuring. Not only that, the steps in between the functional versions of the genes are non-adaptive. This means they serve no survival function. It seems the researchers involved are falling victim to the detective's curse: the clue to the solution is right under their noses, but they're focusing on other details. Intelligence is the only property of the universe that can reliably hit an extremely rare target. For a better understanding of just how unlikely these types of mutations are, and why we need to add intelligence into the evolutionary equation, see Stephen Meyer's Signature in the Cell.


Researchers discover new type of dust in Mars' atmosphere

Mars Atmosphere
© Cristiano Ribeiro/Thinkstock
Using ultraviolet and infrared imaging techniques, scientists have discovered that the Martian atmosphere contains particulate matter in two distinct sizes, according to a new report published in the journal Icarus.

In the study, a team of Russian and French scientists observed the transition of Mars' northern hemisphere into summer. During this transitional phase, the Sun's rays poke through the Martian atmosphere and the spectrometer on board the European Space Agency's orbital station Mars Express was able to capture just how solar radiation interacts with particulates high above Mars.

The European researchers discovered that the dust in the Martian atmosphere isn't homogenous. Rather, there are two distinct types. The first type is rougher and includes both water-ice grains and slightly smaller airborne dust. The second type of particulate is finer, and is an aerosol consisting of much smaller particles.

The researchers noted that the density quantity of both types is not that high. Even in the densest layers of the planet's atmosphere at altitudes of 12 to 18 miles there are approximately three particles of the finer mode per cubic meter, and less than two particles of the coarser mode per one cubic meter.

The study team noted that when looking at what is considered normal on Earth, Martian air is fairly clean, adding that most rooms are dustier. However, aerosols are critical because they have an essential role in developing the planet's climate.
Cloud Lightning

A new map shows lightning strikes around the world in real time

A small German group called Blitzortung has developed a crowd-sourced map that shows real-time lightning strikes around the world.

The maps are driven by a network of volunteers who have set up a $275 detection kit consisting of an antenna system, amplifier, and controller. Each station can detect radio signals from a lightning strike and transmit the exact time and location to the Blitzortung servers. Remarkably, the detection stations don't have to be close to the lightning strike; a receiving station, say in New York, can still pick up lightning strikes in the Caribbean (low frequency RF waves can travel thousands of miles).

The realtime maps display five main global regions (Europe, Oceania, North America, Asia, and South America), and six local regions (Texas, Florida, New York, Minnesota, California, and the Dominican Republic).

The aim of the project is to establish a low budget lightning location network with a high number of stations. Go here if you're interested in covering your area.

Check it out here.

Equation that changed the world: Without Shannon's information theory there would have been no internet

information theory
© The Guardian
Shannon’s information theory
It showed how to make communications faster and take up less space on a hard disk, making the internet possible

This equation was published in the 1949 book The Mathematical Theory of Communication, co-written by Claude Shannon and Warren Weaver. An elegant way to work out how efficient a code could be, it turned "information" from a vague word related to how much someone knew about something into a precise mathematical unit that could be measured, manipulated and transmitted. It was the start of the science of "information theory", a set of ideas that has allowed us to build the internet, digital computers and telecommunications systems. When anyone talks about the information revolution of the last few decades, it is Shannon's idea of information that they are talking about.

Claude Shannon was a mathematician and electronic engineer working at Bell Labs in the US in the middle of the 20th century. His workplace was the celebrated research and development arm of the Bell Telephone Company, the US's main provider of telephone services until the 1980s when it was broken up because of its monopolistic position. During the second world war, Shannon worked on codes and methods of sending messages efficiently and securely over long distances, ideas that became the seeds for his information theory.

Before information theory, remote communication was done using analogue signals. Sending a message involved turning it into varying pulses of voltage along a wire, which could be measured at the other end and interpreted back into words. This is generally fine for short distances but, if you want to send something across an ocean, it becomes unusable. Every metre that an analogue electrical signal travels along a wire, it gets weaker and suffers more from random fluctuations, known as noise, in the materials around it. You could boost the signal at the outset, of course, but this will have the unwanted effect of also boosting the noise.

Information theory helped to get over this problem. In it, Shannon defined the units of information, the smallest possible chunks that cannot be divided any further, into what he called "bits" (short for binary digit), strings of which can be used to encode any message. The most widely used digital code in modern electronics is based around bits that can each have only one of two values: 0 or 1.
Cell Phone

Double standard: Apple implements the same anti-tracking technique used by Aaron Swartz, for which he was criminally prosecuted

© Reuters / Noah Berger
Computer genius and online activist Aaron Swartz
Apple is going to implement random MAC addresses technology in its iOS8 devices, an anonymity-granting technique which late computer prodigy Aaron Swartz was accused of using to carry out his infamous MIT hack.

Swartz, who faced criminal prosecution on charges of mass downloading academic documents and articles, was also accused of using MAC (Media Access Control) spoofing address technology to gain access to MIT's subscription database.

At the time of his suicide at the age 26, Swartz was facing up to 35 years in prison, the confiscation of assets and a $1 million fine on various charges.

Now computer giant Apple is installing a MAC address randomizing system into its products. The company announced that in its new iOS 8, Wi-Fi scanning behavior will be "changed to use random, locally administered MAC addresses."

'Magic island' appears out of nowhere on Titan, Saturn's biggest moon, then quickly disappears

© The Independent, UK
Scientist are baffled by images of planet-like Titan’s second largest sea, which appear to show an island materialise then disappear.
A "magic island" has mysteriously appeared out of nowhere in one of the hydrocarbon seas on Saturn's giant planet-like moon, Titan, only to later disappear.

Described as a bright "transient feature" by scientists, it is not clear what the object is, or how it appeared there. Theories include that it could be the result of waves or bubbles, or even buoyant solid matter.

The sea had appeared flat and completely devoid of features, including waves prior to 2013. But then the object, dubbed "magic island" by scientists, suddenly materialised before vanishing in later images.

The object was spotted in Ligeia Mare, Titan's second-largest sea, by radar images. The Cassini space probe which captured it has been exploring the Saturnian system since 2004.

Russian 'Satan' rocket blasts into orbit and successfully releases 33 satellites from 17 countries, including the U.S.

© RIA Novosti / Oleg Urusov
Dnepr rocket
Dnepr rocket also dubbed 'Satan' has blast off into earth's orbit carrying over 30 satellites from 17 countries, including the US. The rocket itself is of Russia-Ukraine make

Russia's Dombarovsky military air base saw the launch at 19:11 GMT Thursday, the 20th such rocket whizzing off into space.

Twenty-six minutes later, "all of the 33 satellites have separated from the rocket at the pre-set time and were put into their respective orbits," Kosmotras, the launch operator, said.
Comet 2

New Comet: P/2014 L3 (Hill)

Discovery Date: June 10, 2014

Magnitude: 18.0 mag

Discoverer: R. E. Hill (Catalina Sky Survey)
P/2014 L3
© Aerith Net
Magnitudes Graph
The orbital elements are published on M.P.E.C. 2014-L62.