December 2006 – David Bradley

Top Physics Discoveries of 2006

Sharpest manmade thing Over at the American Institute of Physics my colleague Phillip Schewe and his team have been putting together their pick of the physics discoveries for 2006.

Their number one choice had to be the new ultra precise measurement (0.76 parts per trillion uncertainty) by Gerald Gabrielse and his colleagues at Harvard University of the electron’s magnetic moment closely followed by the refinement by the same team of the fine structure constant that reveals that the electromagnetic force allowing atoms to hold on to their electrons is lower than previously thought.

Other top physics discoveries included new evidence that dark energy, the hypothetical mechanism for the accelerating expansion of the universe, was present even in the early universe; elemental discoveries of 118 and 116.

Next on the list are

The world’s sharpest object
The best direct test of Einstein’s (in)famous E=mc² formula
The first direct measurement of turbulence in space
A new measurement of the cosmic microwave background radiation
The first study of matter-antimatter chemistry
Advances in “two-dimensional light”, plasmonics
Advances in “two-dimensional carbon”, graphene
Gravityy wave model
2006 Nobel prize in Physics for George Smoot and John Mather

More details on the PNU site here.

Analytical techniques clean up diesel

Raman spectroscopy, X-ray diffraction, and electron microscopy could help diesel engine components manufacturers meet tough new emissions regulations, according to researchers at Oak Ridge National Laboratory’s High Temperature Materials Laboratory (HTML).

The techniques can provide detailed characterizations of materials and allow components to be tested for heat and stress effects more effectively as part of the industry’s preparation for new emissions mandates that come into effect in the US in 2007. Under the new laws, a 90% reduction of nitrogen oxide, NOx, and particulates from diesel vehicles will be required.

“Environmental Protection Agency regulations are pushing emissions control technology very hard,” explains Arvid Pasto, director of the HTML, “so that engine and emissions control equipment manufacturers require access to very sophisticated tools to develop this technology. Fortunately, our user facilities are well equipped to help them.”

Diesel engine-maker Cummins, for instance, has used HTML’s analytical capabilities to better understand the properties of materials used in exhaust after-treatment systems. In addition to studying how catalysts can be adversely affected by sulfur and other gaseous exhaust components, Cummins and HTML have worked together to characterize the fatigue life of cordierite diesel soot filters, which remove more than 98% of particulate emissions from diesel exhaust. These exhaust after-treatment devices are critical to meeting upcoming emissions requirements.

Another company Industrial Ceramic Solutions, of Knoxville, Tennessee, used HTML’s scanning electron microscope facility to analyse material being developed for ceramic-fibre diesel particulate exhaust filters. The original material did not function as well as competing products and had a tendency to crack. The tests revealed that the fabrication process was to blame and ICS has modified its process to improve the product.

‘The sophisticated electron microscopy at HTML allowed our small business to literally look inside of the ceramic fiber filter media at thousands of times magnification,’ said Richard Nixdorf, ICS president and CEO. ‘This information led ICS to solutions that eliminated micro-cracking and moved our filter-media strength far beyond what the diesel exhaust filter application demanded.

Chemistry News

More chemical news from the current issue of Reactive Reports, now online.

Bedwetting Chemistry – A higher concentration of sodium and urea in urine could underlie a type of bedwetting in children that does not respond to the common medication, desmopressin.

Rubber Suits You Sir – Military personnel, chemical workers, and others could benefit from a new synthetic rubber material tailored with liquid crystals.

Biomolecules Out on a Wing – Photonic crystals give butterflies their beautiful colors and synthetic versions are now being developed for a range of technological applications.

Salt and the Boiling Point of Water

TL:DR – If you dissolve salt in water, you raise its boiling point. Similarly, you also lower its freezing point. These effects occur with any solute dissolved in any solvent and depend on how many solute particles are dissolved in the solvent. The key phrase is colligative properties.

Colligative properties include: Relative lowering of vapour pressure (Raoult’s law), elevation of boiling point, freezing point depression, osmotic pressure.

Colligative properties determine how a solvent will behave once a solute is added to make a solution. The degree of change depends on the amount of solute dissolved in the bulk liquid, not the type of solute. So, without my doing your homework for you…how does adding salt to water affect its boiling point? You will find several clues and several keywords above and below.

The fact that dissolving a salt in a liquid, such as water, affects its boiling point comes under the general heading of colligative properties in chemistry. In fact, it’s a generic phenomenon dissolve one substance (the solute) in another (the solvent) and you will raise its boiling point.

So, here’s a rough explanation of what’s going on. If a substance has a lower vapour pressure than the liquid (it’s relatively non-volatile in other words) then dissolving that substance in the liquid, common salt (NaCl) in water (H₂O), for instance, will lower the overall vapour pressure of the resulting solution compared with the pure liquid. A lower vapour pressure means that the solution has to be heated more than the pure liquid to make its molecules vaporise. It is an effect of the dilution of the solvent in the presence of a solute. If you want to know about tungsten and why it is used in incandescent light bulbs please check out the Wikipedia entry.

Put another way, if a solute is dissolved in a solvent, then the number of solvent molecules at the surface of the solution is less than for pure solvent. The surface molecules can thus be considered “diluted” by the less volatile particles of solute. The rate of exchange between solvent in the solution and in the air above the solution is lower (vapour pressure of the solvent is reduced). A lower vapour pressure means that a higher temperature is necessary to boil the water in the solution, hence boiling-point elevation.

Conversely, adding common salt to water will lower its freezing point. This effect is exploited in cold weather when adding grit (rock salt) to the roads. The salt dissolves in the water condensing on the road surface and lowers its freezing point so that the temperature has to fall that bit more before ice will form on the roads.

A much more fun use for freezing point depression is to add salt to ice to make ice cream. The About site has some instructions on how to do this, although it’s probably not too tasty.

Curiously, at least one Sciencebase reader was searching for the phrase “how does sugar affect the boiling point of water?” and landed on this page. This is essentially the same question as, “does salt affect the boiling point of water?” The nature of the solute, the material being dissolved in the solvent, is pretty much irrelevant at a first estimate. Rather, it is the amount of material that is dissolved (which depends on the materials solubility) that influences the boiling and freezing points as described above.

Boxing Day Boredom and Monkey Proteins

Monkey proteins It’s Boxing Day and you’re probably seriously bored playing the “normal” game of Pick-up Monkeys. Rather than heading for the Wii or the PS3, how about adding a little monkey magic, or more seriously some wire binders and following Dr N. Michael Green, Division of Mathematical Biology, of the UK’s prestigious Medical Research Council (MRC) National Institute for Medical Research to do a little bit of science education with those colourful plastic monkeys.

“Pick up Monkeys’ was originally produced as a children’s game (1965) and they have proved very versatile,” Green explains, “I discovered in 1968 that they were ideal models for protein subunits, being asymmetric, having multiple interaction sites and available in several colours. This exhibition illustrates their use in modelling the geometry of multi—subunit protein structures.”

Stop monkeying around, take a look at Green’s site to get the hang [pun intended!] of proteins. It’s a great idea for a science fair project too.

Booyle rocket

UPDATE: They were so obviously (I know hindsight is 20:20) looking for information about the Wes Anderson movie “Bottle Rocket” and simply mistyped…

Bottle rocket What on earth’s a “booyle rocket”, I hear you ask! Well, I haven’t a clue. It’s just a search term that a Sciencebase visitor used in our search box.

Intrigued, I Googled the phrase and it turns out to be a Google Whack Blatt to a rather crude dating site. Fortunately, Google also offered the option that perhaps I’d misspelled bottle…so was the visitor searching for “bottle rocket”, perhaps?

If they were then there is a stack of information on that term. 1,590,000 pages in fact in my search including reference to a 1994 (or 1996, two IMDB entries, same movie, different years) Wes Anderson movie of the same name. But, I think visitors to this site are more likely to have been looking for a science project kind of bottle rocket rather than a movie.

Unfortunately, we don’t have a bottle rocket science project to offer but this site does and it looks so quick and simple that I thought it worth mentioning.

So, if you’re totally bored with all the goodies you received yesterday already, then check it out, grab some scissors and a fizzy drinks bottle, and head out to the local recreation ground to show off your favourite “new” toy.

Are all snowflakes different?

Snowflake shape The short answer is no. Despite what you may have heard some snowflakes are exactly the same shape and size as other snowflakes, at least to the naked eye.

The long answer follows: Jon Nelson, a researcher with Ritsumeikan University in Japan, has studied snowflakes for fifteen years, and has some interesting insights into their delicate structures. He points out that the old adage that ‘no two snowflakes are alike’ might be true for larger snowflakes, but it does not hold true for smaller, simpler crystals that fall before they’ve had a chance to fully develop into the familiarly evocative hexagonal flakes. Regardless, the shape of snow crystals are incredibly diverse, this is partly due to their sensitivity to even the smallest temperature change as they fall through the clouds.

So, how do snowflakes form in the first place?

Put simply, at the heart of every snowflake is a minute grain of dust that was once floating in a cloud. Water vapor from the atmosphere condenses on this dust grain forming a droplet that freezes instantly (it’s a nucleation process to put it technically).

The ice crystals grow with hexagonal symmetry. The shape originates from the chemistry of the water molecule, which consists of two hydrogen atoms bonded to an oxygen atom, H-O-H. These atoms are not in a straight line though, they’re at an angle and this angle means that when several water molecules get hitched together through hydrogen-bonding in the frozen state the simplest way to do that (i.e. the lowest-energy arrangement) results in six-sided symmetry, hence six-sided snowflakes. By the way, you never get octagonal or pentagonal snowflakes, please report anyone who draws or makes snowy decorations with flakes showing that symmetry.

The growing flake eventually sprouts six tiny branches. Each of these branches grows to form side branches in a direction and shape that are influenced by the clustering of water molecules on the ice crystal surfaces.

The American Chemical Society has produced an excellent poster illustrating all this. You can download it as a PDF file here.

You may be wondering why scientists are so interested in snowflakes, after all in many parts of the world, you’re never going to get a chance to test your theories.

Well, snowflakes and ice crystals have an effect on the global climate because of the reflectivity, they are thought to help catalyze the break down of ozone in the upper atmosphere depletion, and they also play a critical role in the build up electric charges in clouds that leads to lightning.

The Scout Report recently highlighted another researcher with an interest in ice crystal growth and pattern formation in ice. Kenneth Libbrecht at Caltech University, the Report says, is “so interested in fact, he went
ahead and created this lovely website that documents the very wide, and very
interesting world, of ‘snowflakes, snow crystals, and other ice phenomena.’

But, that’s probably enough science for today. So, wherever you are let it snow, let it snow, let it snow…and compliments of the season from Sciencebase.com

Santa Claus’ address

A couple of years ago NASA released satellite images of Santa Claus’ summer hideaways, turns out there are two locations in the USA where old Father Christmas likes to spend the lazy summer months. Santa Claus, Georgia (left) and Santa Claus, Indiana (right), are typical of Santa’s summer retreats, says NASA, offering Santa and Mrs Claus, all the reindeer and elves the usual amenities and a nice warm respite from their chilly Polar home during the off season.

Of course, these satellite images are rather out of date now, so we should turn to Google Maps for the current view. As you can see from the image on the right, Santa Claus’ summer home in Georgia nestles among beautiful lakes that provide the reindeer with crystal clear drinking water and perfect grazing as well as great water skiing for Mrs Claus. If you put your nose close to the screen you can just about see Rudolph’s glowing red nose poking out from the water as he takes a pre-Christmas dip. Of course, FBI regulations prevent us from revealing Santa’s current whereabouts but what we can say is that he and his entourage are already now working hard somewhere at the North Pole, with a special envoy in Lapland to handle public relations.

Anyway, the official address to send your Letter to Santa is: Mr S Claus, North Pole, H0H OH 0, don’t worry if that zipcode looks a little odd, just try saying it out loud and you’ll feel okay.

Father Christmas Research

Drugs and addiction

Fly agaric Many people in the modern Western world delude themselves that their culture is generally free from the effects of intoxicating substances except in the criminal underworld, and that ‘nice people don’t take drugs’. But Richard Rudgley of the University of Oxford, a researcher of the oasis communities of Chinese Central Asia, shows that our culture and other cultures across the world have a rich tradition of using chemicals, mainly from plants, to produce altered states of consciousness. These range from the ritualistic use of the fly-agaric in Palaeolithic Europe to betel-nut chewing in Papua New Guinea, and from pretentious bone-china tea sets in Surbiton to the tragic inhaling of petrol fumes by Aboriginal Australians.

Although each intoxicant has its own effects on the mind – there is some overlap – but researchers have classed them as belonging to four types. Hallucinogens – compounds such as mescaline – are often found in ‘poisonous’ varieties of mushroom or South American weeds. Inebriants consist of generally simpler organic compounds such as alcohol, and the constituents of organic solvents and other volatile chemicals. Hypnotics are compounds that induce states of sleep, stupor or calm and include tranquilizers and narcotics. Stimulants increase mental activity and include caffeine, tobacco and the more potent cocaine and amphetamines.

Rudgley has scoured the scientific literature for examples and evidence from the European Stone Age to modern day Australia to improve our understanding of how these broad classes of intoxicants have affected society and religion. Beginning with evidence from the earliest days of hallucinogen use in Palaeolithic cave art, Rudgley describes in fascinating detail intoxicants and their cultural effects over the past few thousand years.

For example, peyote, the mescaline-containing cactus of Texas and Northern Mexico, apparently played an important role in the cultural development of indigenous peoples of that area, although the plant is now threatened with extinction because of increasing use by modern hedonists. On the Steppes biochemical evidence shows that Cannabis sativa and ethanol have been commonly used for many thousands of years.

Rudgley even has an explanation for the supposed flight of witches and the symbolism of the witch’s broom. A witch wanting to ‘fly’ to a witches’ sabbat, or orgiastic ceremony, would anoint a staff with specially prepared oils containing psychoactive plant matter, as well as rather gruesome ingredients such as baby fat and human blood. The potion could then be administered to areas of the body that could absorb the active components most rapidly. Rudgley quotes one researcher: ‘The use of a staff or broom was undoubtedly more than a symbolic Freudian act, serving as an application for the atropine-containing plant to the sensitive vaginal membranes. . .’ So now you know.

There is little spiritualism attached to the modern Western use of intoxicants such as caffeine and nicotine, and society more than frowns on the use of mind-altering drugs. The modern view is perhaps distorted to some extent by the development of highly addictive stimulants such as ‘crack’, with its potentially devastating effects.

Rudgley hopes that a deeper knowledge of intoxicants’ use in other cultures will result in a better understanding of our own culture of cafes and bars, and this in turn might help us understand the ‘importance of altered states of consciousness in both our collective and our personal lives’.

I wrote the original version of this item as a book review that was published in New Scientist magazine (The Alchemy of Culture by Richard Rudgley, British Museum Press, reviewed issue 1909, p43).

The professional staff at an addiction treatment facility knows how to help a drug addict, so you can rest assured your loved one is in good hands.

How does Santa do it

Santa Claus Technology An advanced knowledge of electromagnetic waves, the space-time continuum, nanotechnology, genetic engineering, and computer science easily explains Santa’s abilities to deliver presents to millions of homes and children in just one night, according to professor of mechanical and aerospace engineering, Larry Silverberg, at North Carolina State University.

Silverberg explains that Santa has a personal wireless connection to children’s thoughts — via a listening antenna that combines technologies currently used in cell phones and EKGs — which informs him that Mary in Miami hopes for a surfboard, while Michael from Minneapolis wants a snowboard. Sophisticated signal-processing technology maps out who wants what, where children live, and especially flags red or green children who’ve been bad or good.

Santinformatics software processese all the data and programs the onboard sleigh guidance system (OSG) to calculate the most efficient delivery route. Down on earth this is known as the “traveling salesman problem”, but it’s the TSantaP at the North Pole.

Silverberg is not so silly as to think that Santa and his reindeer can cover approximately 200 million square miles — making stops in some 80 million homes — in one night. Instead, he reckons that Santa uses his knowledge of the space-time continuum to form what Silverberg calls “relativity clouds.” “Based on his advanced knowledge of the theory of relativity, Santa recognizes that time can be stretched like a rubber band, that space can be squeezed like an orange and that light can be bent,’ Silverberg says. ‘Relativity clouds are controllable domains — rips in time — that allow him months to deliver presents while only a few minutes pass on Earth. The presents are truly delivered in a wink of an eye.’

Santa’s reindeer are genetically engineered, of course, allowing them to fly, balance on rooftops and see in the dark. And, just in case you’ve forgotten, here are their names: Donner, Blitzen, Dasher, Dancer, Prancer, Vixen, Comet, Cupid, Rudolph, and Olive! Olive, you say? Yes, as in: “Olive the other reindeer, used to laugh and call him names…” These latter two were recruited to the team many years after the original poem naming the reindeer – A Visit from St Nicholas.

Finally, many people wonder how Santa and the reindeer can eat all the food left out for them. Silverberg says they take just a nibble at each house. The remainder is either left in the house or placed in the sleigh’s built-in food dehydrator, where it is preserved for future consumption. It takes a long time to deliver all those presents, after all.

Silverberg says “Children shouldn’t put too much credence in the opinions of those who say it’s not possible to deliver presents all over the world in one night. It is possible, and it’s based on plausible science.”