The Nature of Glass Remains Anything but Clear
July 29, 2008
It is well known that panes of stained glass in old European churches are thicker at the bottom because glass is a slow-moving liquid that flows downward over centuries.
Well known, but wrong. Medieval stained glass makers were simply unable to make perfectly flat panes, and the windows were just as unevenly thick when new.
The tale contains a grain of truth about glass resembling a liquid, however. The arrangement of atoms and molecules in glass is indistinguishable from that of a liquid. But how can a liquid be as strikingly hard as glass?
“They’re the thickest and gooiest of liquids and the most disordered and structureless of rigid solids,” said Peter Harrowell, a professor of chemistry at the University of Sydney in Australia, speaking of glasses, which can be formed from different raw materials. “They sit right at this really profound sort of puzzle.”
Philip W. Anderson, a Nobel Prize-winning physicist at Princeton, wrote in 1995: “The deepest and most interesting unsolved problem in solid state theory is probably the theory of the nature of glass and the glass transition.”
He added, “This could be the next breakthrough in the coming decade.”
The Nature of Glass Remains Anything but Clear – NYTimes.com.
Will computers ever use DNA instead of silicon chips?
July 28, 2008
No, it won’t happen. Even the people who are working on ways to make DNA perform calculations cannot see it happening. Take Professor Andrew Ellington at the University of Texas at Austin, who said: “I think my general opinion about DNA computing is not ‘no’ but ‘Hell, no’.”
So, how come some people believe that the future of computing lies in the molecule that provides the blueprint for how living creatures are made?
It started in the 1990s when Leonard Adleman, of the University of Southern California, came up with a way to use DNA to solve one of computing’s most difficult and complex tasks: the travelling salesman problem.
This tries to find the most efficient way to visit a set of cities so that you pass through each one as few times as possible – ideally, only once. Adleman worked out that the paths between cities could be coded into DNA.
If a path between two cities matched, those DNA strands would stick to each other. Eventually, lots of strands would match up to produce a list of cities in DNA, packed into a classic double helix. Just shaking up a test tube full of those different DNA strands did the job. It was the ultimate parallel processor.
Will computers ever use DNA instead of silicon chips?.
My grade 10 science project was on DNA computing. I had to make a presentation in front of the class and no one knew what the heck I was talking about! That was about 7 years ago.
Oxytocin: The Asocial Cure?
July 20, 2008
For centuries artists have tried to capture the essence of love, and now scientists may have found it in the brain. Known as oxytocin (from the Latin word for “quick birth”), the naturally occurring hormone is best known for controlling contractions during labor, but it also plays a key role in other fundamental human urges — including the desire to connect with others. “Somehow, the peptide increases trust, or alters the way individuals see each other,” says Tom Insel, director of the National Institute for Mental Health.
Without oxytocin people would be far less inclined to seek social interaction, let alone fall in love and mate for life (or, as scientists call it, “pair bond”). The brain releases gobs of it during orgasm, mothers are awash in it during breastfeeding and, in clinical trials, a spritz of oxytocin has been shown to reduce anxiety, increase feelings of generosity and even ease the symptoms of shyness. Conversely, researchers are beginning to discover that low levels of the hormone — or the body’s faulty response to it — may contribute to severe social dysfunctions like depression and autism.
How your behaviour can change your children’s DNA
July 19, 2008
For Beatrix Zwart being young means having fun. She works hard, and out of hours she plays hard — including plenty of nights on the town with her friends.
“I lead a similar lifestyle to a lot of young professionals in Britain and I don’t intend to have any children until I’m well into my thirties,” said Zwart, a 25-year-old Belgian who lives in London.
“I’ve never really thought my lifestyle now could have any effect on my future children or grandchildren.”
Until recently that would also have been the opinion of most scientists. Genes, it was thought, were highly resilient. Even if people did wreck their own DNA through bad diet, smoking and getting fat, that damage was unlikely to be passed to future generations.
Now, however, those assumptions are being re-examined. At the heart of this revolution is a simple but controversial idea: that DNA can be modified or imprinted with the experiences of your parents and grandparents.
How your behaviour can change your children’s DNA – Times Online .
We were just talking about epigenetics on my molecular genetics class. Does this imply that if someone were to have a child, say at the age of 16, and another at the age of 40, that these children would inherent different genes (assuming everything else is the same)?
Strongest Material Ever Tested
July 17, 2008
Materials scientists have been singing graphene’s praises since it was first isolated in 2005. The one-atom-thick sheets of carbon conduct electrons better than silicon and have been made into fast, low-power transistors. Now, for the first time, researchers have measured the intrinsic strength of graphene, and they’ve confirmed it to be the strongest material ever tested. The finding provides good evidence that graphene transistors could take the heat in future ultrafast microprocessors.
Hone compares his test to stretching a piece of plastic wrap over the top of a coffee cup, and measuring the force that it takes to puncture it with a pencil. If he could get a large enough piece of the material to lay over the top of a coffee cup, he says, graphene would be strong enough to support the weight of a car balanced atop the pencil.
Einstein explains his famous formula
July 13, 2008
YouTube – E=mc²: Einstein explains his famous formula
Because I’ve never heard Einstein speak, and probably neither have you.
Is Watermelon A Natural Viagra?
July 2, 2008
(WebMD) Men hoping for some fireworks in their love life this Fourth of July may want to skip the burgers and beer at the barbecue and eat plenty of
watermelon.Watermelon may be a natural Viagra, says a researcher. That’s because the popular summer fruit is richer than experts believed in an amino acid called citrulline, which relaxes and dilates blood vessels much like Viagra and other drugs meant to treat erectile dysfunction (ED).
“We have known that watermelon has citrulline,” says Bhimu Patil, PHD, director of the Fruit and Vegetable Improvement Center at Texas A&M University, College Station. Until recently, he tells WebMD, scientists thought most of the citrulline was in the watermelon rind. “Watermelon has more citrulline in the edible part than previously believed,” he says.
How could watermelon be a natural Viagra? The amino acid citrulline is converted into the amino acid arginine, Patil says. “This is a precursor for nitric oxide, and the nitric oxide will help in blood vessel dilation.”
So, the burning question: How much watermelon does it take?
“That is a good question,” Patil says. Unfortunately, “I don’t have an answer for that.”
Just reading the names of those amino acids bring back horrid memories of Biochemistry! It’s the urea cycle in case anyone is wondering.
Sarcasm Seen as Evolutionary Survival Skill
July 2, 2008
Sarcasm Seen as Evolutionary Survival Skill | LiveScience
Humans are fundamentally social animals. Our social nature means that we interact with each other in positive, friendly ways, and it also means we know how to manipulate others in a very negative way.
Neurophysiologist Katherine Rankin at the University of California, San Francisco, has also recently discovered that sarcasm, which is both positively funny and negatively nasty, plays an important part in human social interaction.
So what?
I mean really, who cares? Oh for God’s sake. Don’t you have anything better to do that read this column?
According to Dr. Rankin, if you didn’t get the sarcastic tone of the previous sentences you must have some damage to your parahippocampal gyrus which is located in the right brain. People with dementia, or head injuries in that area, often lose the ability to pick up on sarcasm, and so they don’t respond in a socially appropriate ways.
Presumably, this is a pathology, which in turn suggests that sarcasm is part of human nature and probably an evolutionarily good thing.
This is the most amazing news ever! /sarcasm
The Internet almost killed sarcasm. Fortunately, we have a tag for that now.
Biotech Music Videos (geek humor at its best)
July 1, 2008
Gene Editing Could Make Anyone Immune to AIDS
June 30, 2008
Gene Editing Could Make Anyone Immune to AIDS | Wired Science from Wired.com
Some people have a mutation that makes them amazingly resistant to HIV — and now, scientists may have found a way to give that immunity to anyone.
Viruses enter cells and take them over, but to get inside, they need a handhold. HIV pulls itself in by grabbing onto a protein called CCR5, which decorates the surface of T-cells, which are one of the two major types of white blood cells and play an important role in helping the body fight infections. Back in the 1990’s, researchers took interest in a handful of promiscuous gay men who were able to engage in sexual relations with their HIV-positive partners with impunity. Most of them had a mutation that kept their cells from producing normal CCR5 protein.
Armed with that knowledge, scientists have developed several tactics to block the production of CCR5 or perturb its shape so that the HIV virus can’t grab onto it during the first step of its hijacking attempt. The strategy is much akin to cutting your hair before a wrestling match: It gives your opponent one less thing to grab onto.
Nuclear explosions could be key to spotting fake paintings
A Russian curator says she’s developed a foolproof method of determining whether a piece of art was made before or after 1945 as a way of sniffing out fake paintings.
Elena Basner told The Art Newspaper that she has developed a method in collaboration with Russian scientists based on the idea that man-made nuclear explosions from the 1940s to 1960s released isotopes into the environment.
These isotopes, Caesium-137 and Strontium-90, permeated the earth’s oil and plant life and ended up in works of art made in the post-war era because natural oils, usually flax/linseed, were used as binding agents for paints.
“I wanted to find something ironclad … that couldn’t be disputed, and this led me to approach scientists for ideas,” said Basner.
North Pole may have no ice this summer: scientist
June 28, 2008
North Pole may have no ice this summer: scientist
WASHINGTON – There could briefly be no ice at the North Pole this summer, a US scientist said Friday, an event that would mark a new stage in the melting of the Arctic ice sheets due to global warming.
“We could have no ice at the North Pole at the end of this summer,” Mark Serreze, a scientist with the National Snow and Ice Data Center in Boulder, Colorado, told AFP in an interview.
“And the reason here is that the North Pole area right now is covered with very thin ice and this ice we call first-year ice, the ice that tends to melt out in the summer.”
If the ice, albeit briefly, were to break up completely this summer it would be the first time this had happened in human history.
Al Gore will not be happy.
GPS May Make Us Dumb
June 18, 2008
Lost or Found: GPS May Make Us Dumb
For most people — the cab driver, the tourist, the business traveler — the ubiquitous GPS has become a lifeline, giving directions to the nearest bathroom, a pizza joint or the shortest route to the office.
But, just like with spell-checker before it, some experts believe that the guiding device gives less than what it takes away. The price we pay for the convenience, they say, could be our sense of direction.
For years, the Web-surfing faithful have used Internet-based maps and route finders, like MapQuest and Google Maps, to guide them to their destinations. These online options bring travelers instantly calculated directions, without having to scrutinize colorful representations of roads. But now, as BlackBerrys and the new iPhone that hits stores on July 11 become GPS-enabled, the world will see a drastic leap in hand-held technology, as well.
I completely disagree. Technology is making us smarter. We can use the extra time we would have otherwise lost from being, well, lost to use for more productive things.
Diamonds on Demand
June 18, 2008
Diamonds on Demand | Science & Nature | Smithsonian Magazine
Lab-grown gemstones are now practically indistinguishable from mined diamonds. Scientists and engineers see a world of possibilities; jewelers are less enthusiastic
‘Homeopathy putting lives at risk with claims’
June 17, 2008
‘Homeopathy putting lives at risk with claims’ – Telegraph
Prof Ernst, from the University of Exeter, announced a £10,000 prize for any proof of a successful homoeopathic treatment. He said: “Homoeopathic claims are not benign, they are dangerous. [Homoeopaths] have to demonstrate with scientific rigour that their claims work or they have to shut up.”
