The traditional way to savour scotch whisky is to add a dribble of water before sipping. Pub lore says that it makes the flavour pop, and experiments confirmed it and told us why. Now, chemists have duplicated that result without resorting to complicated apparatus, and their findings could tell us how certain types of drugs move through the body.

and at Linnaeus University in Sweden used a computer simulation to model how the ethanol molecules in whisky interact with water. To capture the molecular motion precisely, they simulated the mixing using tiny time steps, equivalent to half a trillion frames per second.

Then, they added a single molecule called guaiacol, which provides some of scotch鈥檚 distinctive smoky and bitter flavour.

They found that when liquor is at or above 40 percent alcohol by volume, guaiacol molecules tend to stay in the body of the liquid, away from the surface. But when the researchers diluted the simulated whisky to about 25 percent alcohol, the guaiacol floated to the top and wafted its smoky scent and taste front and center.

鈥淲e found a result that supports the claims for diluting whisky,鈥� says Karlsson. The researchers now hope to figure out how drugs containing a similar mix of molecules behave inside the body. Some cough medicine, for instance, contains guaiacol, water and glycerol, another alcohol molecule.

To the casual sipper, 25 percent may seem watery. 鈥淭here鈥檚 quite a lot of snobbery about this,鈥� says at Oregon State University, who researches alcoholic beverages.

But the professionals who mix single-malt whiskies to make blended ones taste samples diluted to about 20 per cent.

Previous experiments showed that flavour compounds like guaiacol tend to stick to ethanol. Before dilution, when the alcohol concentration is high, ethanol molecules tend to hover in clusters in the middle of the liquid, which keeps the guaiacol molecules from rising to the surface.

As water dilutes the whisky, the ethanol spreads more uniformly, allowing more of the guaiacol to reach the surface. 鈥淚t all comes back to the strange behaviour of alcohol in water,鈥� says Hughes.

The fact that this vastly simplified simulation backed up earlier experiments indicates that even in liquids as complex as whisky, it may be enough just to understand how the alcohol mixes with the water.

However, Hughes points out that the mixing behaviour changes depending on the shape of the container. The simulation used a box-shaped vessel, and it鈥檚 hard to say whether guaiacol would behave the same way in a flask, a mug or an antique crystal decanter.

Of course, how you take your whisky is a matter of taste, whatever science may have to say. 鈥淪ometimes I add water, and sometimes I don鈥檛. I can do what I like,鈥� Hughes says.

The proton has lost a little of its bulk. A fresh attempt to pin down its mass, with three times the precision of the previous best try, finds that the subatomic particle is 30 billionths of a per cent lighter than we thought.

All atoms contain at least one proton, which means measurements of its simplest characteristics 鈥� its size, charge and mass 鈥� can help answer some of the big questions in physics, including why the universe contains more matter than antimatter.

The international team behind the new result used instruments sensitive to parts per trillion. That鈥檚 comparable to a scale designed to weigh a grand piano being able to detect an eyelash falling on it.

The measurement took place in a 1.5-litre can with the air pumped out and cooled to nearly absolute zero. 鈥淭he can is hermetically sealed, so there is no connection to outside world at all,鈥� says of the Max Planck Institute for Nuclear Physics in Germany, who led the effort.

An electron beam bombarded a plastic target inside the can, freeing protons. The team was able to trap a single proton in a combination of electric and magnetic fields, using a set-up known as a Penning trap.

The proton moved in circles in the magnetic field, and by measuring its velocity, the team could calculate its mass.

鈥淭hese are very, very precise experiments, and they use very sophisticated methods,鈥� says , who was not involved in the work. Mohr is a member of the Committee on Data for Science and Technology (CODATA), the group that collects fundamental physics measurements and regularly publishes standard values for the scientific community to use.

Fine-tuning

The slimming down of the proton could help us fine-tune experiments that aim to understand why the amount of matter in the universe dwarfs the amount of antimatter, says Makoto Fujiwara, who works on , seeking differences between hydrogen and its antimatter counterpart.

More precise measurements on the proton will allow researchers to look for smaller discrepancies between it and the antiproton, although Fujiwara points out similar precision in antiproton measurements will be needed for that.

As for the tiny discrepancy between the new proton mass and the previously reported value, 鈥渋n precision measurement, this is not so unusual鈥�, Sturm says.

But no one is yet sure why the results disagree. It could be an indication of new physics 鈥� or simply an experimental error that the researchers overlooked, Mohr says. 鈥淥f course, 99 percent of the time, it鈥檚 an experimental issue,鈥� he says. 鈥淲e don鈥檛 break through new principles that often.鈥�

Sturm鈥檚 group produced its measurement in time for CODATA鈥檚 latest physics standards, which will be published in a few months. Since we don鈥檛 know why this measurement differs from the last, CODATA has to carefully consider how to make use of the new value, Mohr says.

Sturm鈥檚 group plans to repeat and refine the measurement. 鈥淲e will try to implement some new techniques which should improve the precision by a factor of six,鈥� he says.

Reference:

IF YOU find the quantum world confusing you鈥檙e not alone. A recent survey shows that physicists disagree over the picture of reality that quantum mechanics describes 鈥� and that many of them don鈥檛 even care.

There was no consensus among the 149 survey participants. While 39 per cent supported the so-called Copenhagen interpretation, the conventional picture of quantum mechanics, 25 per cent supported alternatives and 36 per cent had no preference at all. In addition, many weren鈥檛 sure they understood what certain interpretations described.

鈥淚 don鈥檛 think the debate will resolve soon,鈥� says Sujeevan Sivasundaram, a recent graduate of Aarhus University in Denmark who conducted the survey. 鈥淚 could see us still discussing this 100 years from now.鈥�

The conventional interpretation, which is often the first and only one a physicist is taught, may have been the most popular in the survey, but that doesn鈥檛 indicate it鈥檚 right, says Charles Sebens at the University of California, San Diego. 鈥淚t鈥檚 what physicists go on believing because it鈥檚 the first way they鈥檙e introduced to the theory,鈥� he says. 鈥淏ut it鈥檚 a disservice to only learn one interpretation.鈥�

This interpretation uses the Schr枚dinger equation to accurately predict the results of quantum experiments. But it includes a problem: if you measure or observe a particle, you abruptly change its trajectory in defiance of this equation.

Critics point out that nothing else we know of makes such a weird instant switch, and it seems to be inconsistent with other established laws of nature. In addition, making 鈥渕easurements鈥� is poorly defined, says Aephraim Steinberg at the University of Toronto, Canada. 鈥淚f a fly looks at it, if a bacteria interacts with it, if a dog looks at it 鈥� what constitutes a measurement?鈥� he says.

鈥淚n a survey, 32 per cent of respondents didn鈥檛 understand enough to have an opinion鈥�

Alternatives approach things differently. For example, the many interacting worlds interpretation, published by Howard Wiseman at Australia鈥檚 Griffith University and colleagues in 2014, says quantum phenomena arise from multiple universes interacting with each other under consistent physical laws. 鈥淚t鈥檚 very strange, I admit,鈥� says Wiseman. But to him, parallel universes that consistently obey a set of laws are far less strange than a single universe with exceptions to the rules, as with Copenhagen.

Despite some enthusiasm for alternatives, 32 per cent of respondents didn鈥檛 understand the interpretations enough to have an opinion, and 23 per cent thought interpretations were irrelevant. 鈥淥ne physicist wrote in the comments that he found the survey a complete and utter waste of time,鈥� says Sivasundaram. Furthermore, some thought that certain interpretations couldn鈥檛 be experimentally verified, and thus belonged more in philosophy than physics.

The number of diverging ideas suggests that maybe all of them are off the mark, says Sabine Hossenfelder of Germany鈥檚 Frankfurt Institute for Advanced Studies. 鈥淭here doesn鈥檛 seem to be two people who can come to any agreement on anything,鈥� she says. 鈥淚t seems to me that they鈥檙e just discussing the wrong things or in the wrong way.鈥�

This article appeared in print under the headline 鈥淧hysicists cannot agree about quantum world鈥�

The media tends to interpret culture in yearly cycles. Critics publish end-of-year best-of lists and Oxford Dictionaries just selected 鈥減ost-truth鈥� as its word of the year. But the words we use actually seem to operate on a 14-year cycle, an analysis has found.

at the University of Manchester, UK, and at Argentina鈥檚 National Council for Scientific and Technical Research identified 5630 commonly used nouns and analysed how their popularity changed over the last three centuries.

To do this, they wrote computer scripts to dig through , a database of the words used in nearly five million digitised books. They then ranked the nouns in order of popularity and tracked how their rankings changed from 1700 to 2008.

A curious pattern emerged. They found that English words rose in popularity and then fell out of favour in cycles of about 14 years, although cycles over the past century have tended to be a year or two longer. They also found evidence of cycles of this length in French, German, Italian, Russian and Spanish. The popularity of related nouns 鈥� such as king, queen and duchess 鈥� tended to rise and fall together over time.

Some cycles appear to coincide with historical events. For example, large swaths of words declined in popularity in the years around the world wars. Although the reason for this is unclear, Montemurro thinks it could be related to political trends.

Generation gap?

These results support that suggests that language evolves in a patterned way, similar to the way genes are transmitted from parent to offspring, says at the University of Reading, UK. 鈥淟anguage is not all over the place,鈥� he says. 鈥淚t鈥檚 remarkably consistent.鈥�

However, Pagel says the researchers still need to completely rule out these cycles being a statistical fluke.

鈥淚t鈥檚 fascinating to look for cultural factors that might affect this, but we also expect certain periodicities from random fluctuations,鈥� he says. 鈥淣ow and then, a word like 鈥榓pple鈥� is going to be written more, and its popularity will go up. But then it鈥檒l fall back to a long-term average.鈥�

However, if something does lie behind the cycle, its 14-year duration is puzzling. Some baby names have been found to move in and out of popularity over roughly the length of a human generation. But with nouns, Pagel doesn鈥檛 see an obvious cultural connection. 鈥淚t doesn鈥檛 fit the human life history,鈥� he says. 鈥淭here鈥檚 no particular reason why it should be 14 years.鈥�

Montemurro admits that the significance of the cycle鈥檚 length remains unclear, but he thinks this is due to more than chance. 鈥淚t鈥檚 very difficult to imagine a random phenomenon that will give you this pattern,鈥� he says.

And he thinks that further study of the cycle could reveal insights about human behaviour and the nature of fashion and trends. 鈥淎ssuming these patterns reflect some cultural dynamics, I hope this develops into better understanding of why we change the topics we discuss,鈥� Montemurro says. 鈥淲e might learn why writers get tired of the same thing and choose something new.鈥�

We know what we鈥檇 like to use for the innards of future quantum computers: exotic things like pink diamonds and cold atoms. But getting these components to talk to each other has been a challenge. Now, researchers have come up with a way to allow one component to efficiently transmit information to another, without losing its quantum character.

Quantum computers are theoretically capable of running calculations exponentially faster than classical computers, and can be made by exploiting atoms, superconductors, and more. Each of these has its own strengths: atoms are better at storing information, while superconductors are better at processing it. A device linking these diverse systems together would combine their strengths and compensate for their weaknesses.

Once linked, these systems would talk to each other by sending and receiving photons. The photons would encode quantum states but, unlike the voltages and currents interpreted by a classical computer chip, they cannot be transmitted via copper wires.

Matching spreads

What鈥檚 more, quantum rules require that a single photon must essentially carry a spread of frequencies, rather than a single frequency. For different components to talk to each other using photons, the spread of the sender鈥檚 photons must therefore be converted to the spread that the receiver can handle. That requires a device in the middle that can convert photons from one spread of frequencies to another, while still preserving their delicate quantum state.

Christine Silberhorn of the University of Paderborn in Germany and her colleagues have designed such a system. It includes a converter that 鈥渢ranslates鈥� photons emitted from one component into the infrared. That infrared photon is then transmitted over a fibre optic cable connected to a second component. Finally, the photon is translated into another frequency that the receiving component can read.

Only part of the system has been built so far: the researchers have managed to convert infrared photons to a visible wavelength 鈥� while leaving their quantum state intact 鈥� with a success rate of about 75 per cent. But the technique could be adapted to build the full system, Silberhorn says.

Once that is done, the next step would be to figure out how to fit the device on a chip that could be manufactured easily and cheaply in large quantities, says of the University of Washington in Seattle. 鈥淭he science works,鈥� he says. 鈥淏ut scalability is the biggest problem. Making the same device 1000 times is extremely difficult.鈥�

Reference: