Physicists add ‘Quantum Cheshire Cats’ to list of quantum paradoxes

Given all the weird things that can occur in quantum mechanics—from entanglement to superposition to teleportation—not much seems surprising in the quantum world. Nevertheless, a new finding that an object’s physical properties can be disembodied from the object itself is not something we’re used to seeing on an everyday basis. In a new paper, physicists have theoretically shown that this phenomenon, which they call a quantum Cheshire Cat, is an inherent feature of quantum mechanics and could prove useful for performing precise quantum measurements by removing unwanted properties.

Read more:

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Blind Cavefish Offer Evidence for Alternative Mechanism of Evolutionary Change

In a blind fish that dwells in deep, dark Mexican caves, scientists have found evidence for a long-debated mechanism of evolutionary change that is distinct from natural selection of spontaneously arising mutations, as reported this week in the journal Science. […]

Using the cavefish, the team demonstrated for the first time in nature how “standing” or “cryptic” genetic variations in an animal, which have been inherited from prior generations without causing any physical changes in the animal, can be “unmasked” by the shock of entering a new environment. Gene variants that improve the animal’s ability to adapt to that new environment can then be selected for, and passed on to its progeny. This is distinct from the established evolutionary mechanism of “de novo” genetic mutations that arise by chance after the animal has entered the new environment, which also provide a substrate upon which natural selection can act.

[read more]

Rapid Evolution of Novel Forms: Environmental Change Triggers Inborn Capacity for Adaptation

In the classical view of evolution, species experience spontaneous genetic mutations that produce various novel traits — some helpful, some detrimental. Nature then selects for those most beneficial, passing them along to subsequent generations.

It’s an elegant model. It’s also an extremely time-consuming process likely to fail organisms needing to cope with sudden, potentially life-threatening changes in their environments. Surely some other mechanism could enable more rapid adaptive response. In this week’s edition of the journal Science, a team of researchers from Harvard Medical School and Whitehead Institute report that, at least in the case of one variety of cavefish, that other agent of change is the heat shock protein known as HSP90.

[read more]

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chemical reaction

Looks like Fire creates the monsters.


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Grace Hopper

Rear Admiral Grace Hopper would have been 107 today, and is being honored with a great Google Doodle. It’s quite literally impossible for us to imagine, as we sit here reading about her on the internet, but people used to use things like paper and pencils and chalk and slide rules to solve (and often not solve) complicated problems. Grace Hopper quite simply helped usher in the modern age, her impact, I think, is no less than the steam engine or the cotton gin.

Some awesome stuff she did: Grace Hopper developed first compiler, allowing computer calculations to move beyond simple arithmetic and into more complex problems. She also developed first standardized computer language, COBOL, which laid the groundwork for all the languages we use today.

One day she found a dead moth disrupting one of the electronic relays in the Mark 1 computer, and upon removing it (and fixing the computer), the term “debugging" was popularized (although the idea of computer "bugs" had been around before). Here’s her daily log from that day, with the offending moth taped to the page:

Beyond that, she was a charming scientific communicator, and she possessed a marvelous ability to make people, and mind you this was in a time when almost no one owned their own computer, truly appreciate both the importance and the complexity of computing technology.

She famously carried around a bundle of nanoseconds in her purse for illustrative purposes. Here she is charming the socks off of David Letterman, and giving him a nanosecond of his very own (don’t miss the picosecond joke, either) :

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So who was throwing spears before humans? The discovery of 280,000-year-old stone-tipped spear remains in Ethiopia has two possible implications: that our species is much older than previously thought or, more likely, that a predecessor species was making tools long before Homo sapiens. 

Read more: via Discovery News


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» Mystery humans spiced up ancients’ rampant sex lives



New genome sequences from two extinct human relatives suggest that these ‘archaic’ groups bred with humans and with each other more extensively than was previously known.

The ancient genomes, one from a Neanderthal and one from a different archaic human group, the Denisovans, were presented on 18 November at a meeting at the Royal Society in London. They suggest that interbreeding went on between the members of several ancient human-like groups living in Europe and Asia more than 30,000 years ago, including an as-yet unknown human ancestor from Asia.

“What it begins to suggest is that we’re looking at a ‘Lord of the Rings’-type world — that there were many hominid populations,” says Mark Thomas, an evolutionary geneticist at University College London who was at the meeting but was not involved in the work. Read more.

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Did you know that the word “scientist” was coined for reconstructionist Mary Somerville? That’s right, the first “scientist” was a woman.

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Black Hole bending light.

(Source: c0cki)

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» Is Sex Really Necessary?


In an article titled "Origins: Going Back to Where the Story Really Starts" from the August 2010 issue of Scientific AmericanBrendan Borrell brings science to the philosophical question that E. B. White and James Thurber asked in 1929: Is sex necessary?

Borrell writes:

Approximately two billion years ago a pair of single-celled organisms made a terrible mistake — they had sex. We’re still living with the consequences. Sexual reproduction is the preferred method for an overwhelming portion of the planet’s species, and yet from the standpoint of evolution it leaves much to be desired. Finding and wooing a prospective mate takes time and energy that could be better spent directly on one’s offspring. And having sex is not necessarily the best way for a species to attain Darwinian fitness. If the evolutionary goal of each individual is to get as many genes into the next generation as possible, it would be simpler and easier to just make a clone.

The truth is, nobody really knows why people – and other animals, plants and fungi-prefer sex to, say, budding. Stephen C. Stearns, an evolutionary biologist at Yale University, says scientists now actively discuss more than 40 different theories on why sex is so popular. Each has its shortcomings, but the current front-runner seems to be the Red Queen hypothesis. It gets its name from a race in Lewis Carroll’s Through the Looking Glass. Just as Alice has to keep running to stay in the same place, organisms have to keep changing their genetic makeup to stay one step ahead of parasites. Sexual reproduction allows them to shuffle their genetic deck with each generation. That’s not to say that sex is forever. When it comes to reproduction, evolution is a two-way street. When resources and mates are scarce, almost all types of animals have been known to revert to reproducing asexually.

And yet, humans seem to expend an awful lot of energy thinking about sex and trying to legislate it.

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In a simple experiment, researchers at the University of Chicago sought to find out whether a rat would release a fellow rat from an unpleasantly restrictive cage if it could. The answer was yes.

The free rat, occasionally hearing distress calls from its compatriot, learned to open the cage and did so with greater efficiency over time. It would release the other animal even if there wasn’t the payoff of a reunion with it. Astonishingly, if given access to a small hoard of chocolate chips, the free rat would usually save at least one treat for the captive— which is a lot to expect of a rat.

The researchers came to the unavoidable conclusion that what they were seeing was empathy— and apparently selfless behavior driven by that mental state.


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