Science & TechnologyS


Einstein

Did Einstein Discover E=MC2?

Einstein
© Physics WorldWho got there first?

Who discovered that E = mc2? It's not as easy a question as you might think. Scientists ranging from James Clerk Maxwell and Max von Laue to a string of now-obscure early 20th-century physicists have been proposed as the true discovers of the mass - energy equivalence now popularly credited to Einstein's theory of special relativity. These claims have spawned headlines accusing Einstein of plagiarism, but many are spurious or barely supported. Yet two physicists have now shown that Einstein's famous formula does have a complicated and somewhat ambiguous genesis - which has little to do with relativity.

One of the more plausible precursors to E = mc2 is attributed to Fritz Hasenöhrl, a physics professor at the University of Vienna. In a 1904 paper Hasenöhrl clearly wrote down the equation E = 3/8mc.2 Where did he get it from, and why is the constant of proportionality wrong? Stephen Boughn of Haverford College in Pennsylvania and Mark Rothman of Princeton University examine this question in a paper submitted to the arXiv preprint server.

Hasenöhrl's name has a certain notoriety now, as he is commonly invoked by anti-Einstein cranks. His reputation as the man who really discovered E = mc2 owes much to the efforts of the antisemitic and pro-Nazi physics Nobel laureate Philipp Lenard, who sought to separate Einstein's name from the theory of relativity so that it was not seen as a product of "Jewish science".

Laptop

When algorithms control the world: If you were expecting some kind warning when computers finally get smarter than us, then think again

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© UnknownAlgorithms are spreading their influence around the globe
There will be no soothing HAL 9000-type voice informing us that our human services are now surplus to requirements.

In reality, our electronic overlords are already taking control, and they are doing it in a far more subtle way than science fiction would have us believe.

Their weapon of choice - the algorithm.

Behind every smart web service is some even smarter web code. From the web retailers - calculating what books and films we might be interested in, to Facebook's friend finding and image tagging services, to the search engines that guide us around the net.

It is these invisible computations that increasingly control how we interact with our electronic world.

Info

Floating City, Libertarian Colonies Close to Reality

Floating City
© András Gyõrfi / via SeaSteading Competition
Cities come in all shapes and sizes, but can they float?

PayPal founder Peter Thiel recently invested $1.25 million to try to make that happen. By offering support to the Seasteading Institute, he has jump-started efforts to create city-state communities afloat on ocean platforms. In 2009, the institute held a 3D design competition to help people visualize what these sea-bound communities may look like (see photos above and below).

The structures will be 12,000 tons, diesel-powered and carry around 270 people per unit, as reported by Details Magazine. The idea is to link the structures together to create ocean metropolises equipped to accommodate millions of people.

Magnify

Galaxies Are Running Out of Gas: Study

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© NASA, ESA, STScI/AURAA star-forming region in a nearby galaxy, imaged by the Hubble Space Telescope.
A new study has shown why the lights are going out in the Universe.

The Universe forms fewer stars than it used to, and a CSIRO study has now shown why - the galaxies are running out of gas.

Dr Robert Braun (CSIRO Astronomy and Space Science) and his colleagues used CSIRO's Mopra radio telescope near Coonabarabran, NSW, to study far-off galaxies and compare them with nearby ones.

Light (and radio waves) from the distant galaxies has taken time to travel to us, so we see the galaxies as they were between three and five billion years ago.

Galaxies at this stage of the Universe's life appear to contain considerably more molecular hydrogen gas than comparable galaxies in today's Universe, the research team found.

Stars form from clouds of molecular hydrogen. The less molecular hydrogen there is, the fewer stars will form.

The research team's paper is in press in Monthly Notices of the Royal Astronomical Society.

Magnify

Parasite Uses the Power of Attraction to Trick Rats Into Becoming Cat Food

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© I-Ping LeeIndividual toxoplasma parasites (green) are shown invading neurons (red) grown in a petri dish in the lab. The blue areas are fluorescently tagged cell nuclei.
When a male rat senses the presence of a fetching female rat, a certain region of his brain lights up with neural activity, in anticipation of romance. Now Stanford University researchers have discovered that in male rats infected with the parasite Toxoplasma, the same region responds just as strongly to the odor of cat urine.

Is it time to dim the lights and cue the Rachmaninoff for some cross-species canoodling?

"Well, we see activity in the pathway that normally controls how male rats respond to female rats, so it's possible the behavior we are seeing in response to cat urine is sexual attraction behavior, but we don't know that," said Patrick House, a PhD candidate in neuroscience in the School of Medicine. "I would not say that they are definitively attracted, but they are certainly less afraid. Regardless, seeing activity in the attraction pathway is bizarre."

For a rat, fear of cats is rational. But a cat's small intestine is the only environment in which Toxoplasma can reproduce sexually, so it is critical for the parasite to get itself into a cat's digestive system in order to complete its lifecycle.

Thus it benefits the parasite to trick its host rat into putting itself in position to get eaten by the cat. No fear, no flight -- and kitty's dinner is served.

Magnify

Neuroscientists Show Activity Patterns in Fly Brain Are Optimized for Memory Storage

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© Cold Spring Harbor LaboratoryOdors evoke consistent patterns of sparse activity in the mushroom body of the fruit fly brain. Each row shows a single fly's responses to three different presentations of the same odor. Sparse pattern of responding neurons is similar for a single odor within an individual, but varies randomly in different individuals.
We know from experience that particular smells are almost inseparable in our minds with memories, some vague and others very specific. The smell of just-baked bread may trigger an involuntary mental journey, even if for a moment, to childhood, or to a particular day during childhood. Or it may, more diffusely, remind someone of grandma. How are these associations forged in the brain and how do we remember them? A research team at Cold Spring Harbor Laboratory (CSHL) led by Assistant Professor Glenn Turner has published results of experiments that show large populations of neurons in the brains of living fruit flies responding to a variety of odors.

The results demonstrate that a portion of the fly brain known to be important in learning and memory responds in a characteristic fashion that helps explain how an association is made between an odor and an experience -- the basis of a memory.

Fruit flies are separated by a great evolutionary distance from mammals, of course, but are extremely useful in neuroscience research because of the phenomenon of evolutionary conservation: nature's preservation of certain genetic and metabolic pathways across eons and widely separated species, owing to their extraordinary utility. The mechanisms of memory, of obvious survival advantage, are among the most highly conserved bits of ancient biology.

Meteor

Interstellar crashes could throw out habitable planets

Interstellar crashes
© NASA / ESA and L. Ricci (ESO)One of the protoplanetary disks in the Orion Nebula

Our solar system, where planets have a range of sizes and move in near-circular paths, may be rather unusual, according to a German-British team led by Professor Pavel Kroupa of the University of Bonn. The astronomers, who publish their model in the journal Monthly Notices of the Royal Astronomical Society, find that forming planetary systems may be knocked around by crashes with nearby clumps of material, leading to systems where planets have highly inclined orbits and where the smaller (and potentially habitable) worlds are thrown out completely.

The planets in our Solar System, including the Earth, orbit in the same direction around the Sun as the Sun spins, mostly move in paths not so different from circles and are also more or less lined up into a plane not tilted very far with respect to the solar equator. But planetary systems around other stars can be very different, with some worlds moving in the opposite direction to the spin of their stars and with highly tilted orbits. For the first time the team of astronomers think they have a convincing explanation for these radically different systems.

Both the shape of and direction of travel of planets in our Solar System were thought to result entirely from the formation of the Sun and planets more than 4600 million years ago. Our local planetary system is believed to have formed as a cloud of gas and dust (a nebula) that collapsed into a rotating disk under the influence of gravity. The planets then grew from clumps of material within this so-called protoplanetary disk.

The new work suggests that oddly shaped orbits may result from a rather less smooth process. The team think that if the protoplanetary disk enters another cloud of material, it can draw off up to about 30 times the mass of Jupiter from the cloud. Adding this extra gas and dust tilts the disk and hence the angle of the final orbits. Most planetary systems are thought to form in clusters of stars, where the member stars are fairly close together, so these encounters may be very common.

Magic Wand

Candle flames contain millions of tiny diamonds

candle

The flickering flame of a candle has generated comparisons with the twinkling sparkle of diamonds for centuries, but new research has discovered the likeness owes more to science than the dreams of poets.

Professor Wuzong Zhou, Professor of Chemistry at the University of St Andrews has discovered tiny diamond particles exist in candle flames.

His research has made a scientific leap towards solving a mystery which has befuddled people for thousands of years.

Stormtrooper

US, Cleveland, Ohio: Citizens Allowed to Videotape Police

Cleveland Police just got new orders when it comes to people videotaping them in action.

Their orders: Leave you alone! It seems almost everybody now has a cell phone camera and the city doesn't want the kind of trouble we've seen in other places.

Police in Rochester made national headlines. They had words with a woman recording a traffic stop outside her house, even arrested her. "Citizens do have a right to videotape the actions of cleveland police," said Safety Director Martin Flask. The Safety Director says he had the chief come up with a policy hoping to avoid what's happened in places like Rochester.


Telescope

Moon Teams Up With Bright Jupiter Tonight

At New York's Hayden Planetarium, where I've spent the last 25 years serving in the role as an associate and guest Lecturer, we've been getting an increasing number of phone calls making basically the same inquiry.

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© Starry Night SoftwareThis sky map shows how Jupiter and the moon will appear together overnight on Aug. 19 and 20, 2011 in the eastern night sky as viewed from mid-northern latitudes.
A typical call goes something like this: "I was out around midnight last night and could not help but notice a brilliant silvery star glowing low in the east-northeast. It was far brighter than any star and I was just curious to know what I was looking at."

The object in question is the largest planet in our solar system: Jupiter. It's a welcome sight, rising in the late evening and coming up above the east-northeast horizon this week by 10:30 p.m. local daylight time.