Category Archives: Students

Items for students and others, interested in learning about science and engineering and the application of science in our lives. We post many of the general interest items here.

Aerogels – Cool Substances

First Prize for Weird

A solid that’s up to 99 percent gas, it is rigid to a light touch, soft to a stronger one, and shatters like glass if it’s put under too much pressure too quickly; it’s one of the most enigmatic of materials, as well as one of the most versatile.

It can withstand the heat of a direct flame; engineers use it for insulation on oil rigs and for warmth in the insoles of hiking boots worn in the coldest temperatures on Earth. NASA uses it to trap comet dust blowing through the universe at six kilometers per second.
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Nicknamed “frozen smoke” after its ethereal appearance, aerogel is neither frozen nor smoke. It’s also surprisingly low tech—it’s been known since 1931
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Together, these ingredients can form a structure that chemically resembles glass but is so full of whorls and crevices that one cubic centimeter has a total surface area equal to a football field’s. The lightest-weight solid in the world, aerogel weighs 1.2 milligrams per cubic centimeter—barely more than the air molecules around it. In fact, the material itself is almost entirely made of air, like a sponge that consists mostly of holes. Don’t let its lightness fool you: it’s strong. NASA photos show two grams of the material easily supporting a 2.5-kilogram brick.
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And because the aerogels pack an enormous surface area into a tiny volume, small pieces can clear out many liters of water. Kanatzidis’s aerogels sopped up so much mercury that they diluted a solution of 645 parts per million down to 0.04 parts per million. They had similar effects on lead and cadmium, two other pollutants.

The new aerogels aren’t ready for widespread use: they’re made with platinum, so they’re extraordinarily expensive. But if other metals can be used to make them instead (Kanatzidis says they can), chunks of them could be dropped into polluted water, removing contaminants.

Cool. NASA Aerogel FAQ

AlienFly RC Mosquito Helicopter

Fun looking toy: AlienFly RC Mosquito. I don’t have one but the Amazon reviews are positive and it is under $30 (which again the reviews state should be your guide – fun but not a high performance piece of equipment). Getting the AC adapter sounds like a good idea too.

Where is “Everybody”

The Fermi Paradox: Back with a vengeance

The Fermi Paradox is the contradictory and counter-intuitive observation that we have yet to see any evidence for the existence of ETI’s. The size and age of the Universe suggests that many technologically advanced ETI’s ought to exist. However, this hypothesis seems inconsistent with the lack of observational evidence to support it.i”The Fermi Paradox is the contradictory and counter-intuitive observation that we have yet to see any evidence for the existence of ETI’s. The size and age of the Universe suggests that many technologically advanced ETI’s ought to exist. However, this hypothesis seems inconsistent with the lack of observational evidence to support it.
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There are more stars in the Universe than we can possibly fathom. Any conception of ‘rare’ ‘not enough time’ or ‘far away’ has to be set against the inability of human psychology to grasp such vast cosmological scales and quantities. The Universe and the Milky Way are extremely old, our galaxy has been able to produce rocky planets for quite some time now, and our earth is a relative new-comer to the galaxy.
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The fact that our Galaxy appears unperturbed is hard to explain. We should be living in a Galaxy that is saturated with intelligence and highly organized. Thus, it may be assumed that intelligent life is rare, or, given our seemingly biophilic Universe, our assumptions about the general behaviour of intelligent civilizations are flawed.

A paradox is a paradox for a reason: it means there’s something wrong in our thinking.

I agree. I am going with the it is hard for life to start and it what has started is really far away (so we can’t detect what life there is). Another option I could believe is once you reach a certain level of technological sophistication you often wipe out your civilization – leaving relatively short periods where civilizations produce signals we can detect (included in this is creating something that wipes themselves out, and a nasty thing [virus, bacteria, whatever…] that spreads everywhere because of instant transportation and wipes everybody out). Or maybe civilizations quickly go through a technology phase producing signals we can detect and move onto something else (though I can’t really understand why or what that would mean really). Or, similar to that one, for some reason we are really really odd in our move to technology – maybe most of the time things just stay in a natural state and nothing evolves that wants to do more than eat and sleep (if they sleep). That seems really unlikely but…

Fun for People – Hard for Computers

Arimaa is a highly competitive strategy game. It was designed to be:

* Difficult for computers.
* Playable with a standard chess set.
* Fun and interesting for humans.

Arimaa Tutorial. It looks interesting.

Contradictory Medical Studies

I have written before about false research findings. This is an important topic – we need to remember that the interpritation of one study (or many studies) in not necessarily conclusive. Another article – When Medical Studies Collide:

Two years ago, the headlines blared that echinacea was a bust. Millions of people who believed the best-selling herbal remedy was warding off colds were probably deluding themselves, according to The New England Journal of Medicine. Now echinacea is back in the news. This time, it works! So says a study in The Lancet Infectious Diseases.

How could two studies come to such different conclusions—especially when there have been no new trials of the herb? While the New England Journal reported on one clinical trial, authors of the latest report combined data from previous studies, a controversial approach called a meta-analysis. Its conclusion is dramatically different—not just from that of the New England Journal paper, but also from a review last year of the same studies.
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The problem is, the world of medical and health research is messier than most people realize. Black-and-white answers are rare, even when it comes to a single drug trial.

Just remember those last two sentences. Very simple. And most people would agree if you showed them those two sentences and asked if they agreed. But then they see a headline and away they go… Just force yourself to repeat that idea every time you see a health report. Don’t believe the headline without strong support.

An interesting tidbit from the article. The coneflower is the source of echinacea. I tried to find photos that I am pretty sure I have on my hard drive of the flowers in my back yard, but I couldn’t.

High Pay for Engineering Graduates – July 2007

From the National Association of Colleges and Employers survey , Starting Salary Offers to Class of 2007 Continue to Rise.

Degree	Average Salary Offer	Increase over 2006
Chemical Engineering	$59,361	5.4%
Civil Engineering	$48,509	5.4%
Computer Engineering	$56,201	4.8%
Computer Science	$53,396	4.1%
Mechanical Engineering	$54,128	4.6%
Electrical Engineering	$55,292	3.2%
Information sciences and systems	$50,852	4.6%

Economics was the next highest pay reported by NACE at $48,483. So once again engineering graduates are being paid well. Some other majors: Accounting – $46,718; English – $32,553 and Psychology $31,631.

Research on Why Healthy Living Leads to Longer Life

New Clue into How Diet and Exercise Enhance Longevity

In their experiments, the researchers sought to understand the role of the insulin-like signaling pathway in extending lifespan. This pathway governs growth and metabolic processes in cells throughout the body. The pathway is activated when insulin and insulin-like growth factor-1 switch on proteins inside the cell called insulin receptor substrates (Irs).

Other researchers had shown that reducing the activity of the pathway in roundworms and fruitflies extends lifespan. Despite those tantalizing clues, White said, “The idea that insulin reduces lifespan is difficult to reconcile with decades of clinical practice and scientific investigation to treat diabetes.” “In fact, based on our work on one of the insulin receptor substrates, Irs2, in liver and pancreatic beta cells, we thought more Irs2 would be good for you,” said White. “It reduces the amount of insulin needed in the body to control blood glucose, and it promotes growth, survival and insulin secretion from pancreatic beta cells.
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“Diet, exercise and lower weight keep your peripheral tissues sensitive to insulin. That reduces the amount and duration of insulin secretion needed to keep your glucose under control when you eat. Therefore, the brain is exposed to less insulin. Since insulin turns on Irs2 in the brain, that means lower Irs2 activity, which we’ve linked to longer lifespan in the mouse.”

Evolutionary Design

Evolutionary algorithms now surpass human designers by Paul Marks:

Evolutionary Algorithms take two parent designs – for a boat hull, say – and blend components of each, perhaps taking the surface area of one and the curvature of another, to produce multiple hull offspring that combine the features of the parents in different ways. Then the algorithm selects those offspring it considers are worth re-breeding – in this case those with the right combination of parameters to make a better hull. The EA then repeats the process. Although many offspring will be discarded, after thousands of generations or more, useful features accumulate in the same design, and get combined in ways that likely would not have occurred to a human designer. This is because a human does not have the time to combine all the possibilities for each feature and evaluate them, but an EA does.

Evolving new designs is very cool. One point I would like to make (I am biased since my father did a great deal of work in this area) is the power of design of experiments to allow experimenting on multiple factors at once. This is a methodology that is still used far too little. Regardless, evolutionary design is very cool. The Human-Competitive awards highlight some examples.

National Science and Technology Medals

photo of White House Technology Medal Ceremony - July 2007

The 2005 and 2006 National Medals for Science and Technology were awarded at a White House Ceremony this week. The National Science and Technology Medals Foundation web site has photos of each award winner receiving their medals this year and a list of all winners. The National Medal of Science was established by Congress in 1959 as a Presidential award, has recognized 441 of America’s leading scientists and engineers. The evaluation criteria is based on the total impact an individual’s work has had on the present state of physical, chemical, biological, mathematical, engineering, behavioral or social sciences.

The National Medal of Technology was established by Congress in 1980 as a Presidential award, has recognized 146 individuals and 26 companies whose accomplishments have generated jobs and created a better standard of living. Their accomplishments best embody technological innovation and support the advancement of global U.S. competitiveness.

List of all winners from the White House press release: Continue reading →

Time

Newsflash: Time May Not Exist

Planck time—the smallest unit of time that has any physical meaning—is 10-43 second, less than a trillionth of a trillionth of an attosecond. Beyond that? Tempus incognito. At least for now. Efforts to understand time below the Planck scale have led to an exceedingly strange juncture in physics. The problem, in brief, is that time may not exist at the most fundamental level of physical reality.
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Einstein’s theories also opened a rift in physics because the rules of general relativity (which describe gravity and the large-scale structure of the cosmos) seem incompatible with those of quantum physics (which govern the realm of the tiny). Some four decades ago, the renowned physicist John Wheeler, then at Princeton, and the late Bryce DeWitt, then at the University of North Carolina, developed an extraordinary equation that provides a possible framework for unifying relativity and quantum mechanics. But the Wheeler-ÂDeWitt equation has always been controversial, in part because it adds yet another, even more baffling twist to our understanding of time.

“One finds that time just disappears from the Wheeler-DeWitt equation,” says Carlo Rovelli, a physicist at the University of the Mediterranean in Marseille, France. “It is an issue that many theorists have puzzled about. It may be that the best way to think about quantum reality is to give up the notion of time—that the fundamental description of the universe must be timeless.”

Interesting. As usual, quantum actions seem bizarre. Related: Quantum Mechanics Made Relatively Simple Podcasts – Physicists Observe New Property of Matter – Particles and Waves – Quantum Theory Fails Reality Checks – Physics Concepts in 60 Seconds