Cloaking: Not just in Startrek

Some physicists have worked out what it would take to make a cloaking device. The device would effect light to make it bend around an object so that you wouldn't be able to see the object. At present this is only possible for wavelengths longer than visible light. But, wait a few years and the bugs may get worked out.

Physicists have drawn up blueprints for a cloaking device that could, in theory, render objects invisible.

Light normally bounces off an object's surface making it visible to the human eye. But John Pendry and colleagues at Imperial College London, UK, have calculated that materials engineered to have abnormal optical properties, known as metamaterials, could make light pass around an object as so it appears as if it were not there at all.

Metamaterials are exotic composites made of electronic components such as wires and inductors that can be engineered to precisely control the way light travels through them.

Penile growth

In a “landmark development” researchers have created an “artificial penis” that has allowed rabbits with damaged penises to successfully mate. The urologists say that the procedure might one day help treat men with severe erectile dysfunction.

The technique involves a new method of tissue-engineering which enabled the team to use the animals' own cells to build the spongy tissue structure that makes up the bulk of the penis.

The functioning penises were the latest achievement of Anthony Atala and colleagues at the Wake Forest Institute for Regenerative Medicine in Winston-Salem, North Carolina, US. This is the same team that hit the headlines in April with the first bio-engineered human bladders which were successfully implanted into patients.

This is one more significant step along the way to helping people even more. This same group was able to grow human bladders and now penile tissue. As these developments advance, I think we should keep in mind just how important animal experimentation is and how much that helps people.

Global warming: Not what the alarmists think

Pete DuPont writes in an op-ed on the Wall Street Journal opinion site about global warming:

Since 1970, the year of the first Earth Day, America's population has increased by 42%, the country's inflation-adjusted gross domestic product has grown 195%, the number of cars and trucks in the United States has more than doubled, and the total number of miles driven has increased by 178%.

But during these 35 years of growing population, employment, and industrial production, the Environmental Protection Agency reports, the environment has substantially improved. Emissions of the six principal air pollutants have decreased by 53%. Carbon monoxide emissions have dropped from 197 million tons per year to 89 million; nitrogen oxides from 27 million tons to 19 million, and sulfur dioxide from 31 million to 15 million. Particulates are down 80%, and lead emissions have declined by more than 98%.

When it comes to visible environmental improvements, America is also making substantial progress:

• The number of days the city of Los Angeles exceeded the one-hour ozone standard has declined from just under 200 a year in the late 1970s to 27 in 2004.

• The Pacific Research Institute's Index of Leading Environmental Indicators shows that "U.S. forests expanded by 9.5 million acres between 1990 and 2000."

• While wetlands were declining at the rate of 500,000 acres a year at midcentury, they "have shown a net gain of about 26,000 acres per year in the past five years," according to the institute.

• Also according to the institute, "bald eagles, down to fewer than 500 nesting pairs in 1965, are now estimated to number more than 7,500 nesting pairs."

Environmentally speaking, America has had a very good third of a century; the economy has grown and pollutants and their impacts upon society are substantially down.

Read the rest and rest easy.

Journal of Online Mathematics and its Applications: Expository Mathematics in the Digital Age

This article makes excellent points in how we should go about publishing articles on the web. Much of what it recommends applies to non-mathematical articles and math writings. Below is what I submitted in comment. Take a minute to read the article and then my comments.

The article presents some excellent points for authors such as staying away from propietary products like Word or Excel. Also, it makes the point that while the author may lay out an article in a certain format the is no way to know how the reader will see that article. Hence authors should be careful with reliance on formatting and instead concentrate on content.

Who can say how, for example, Firefox will display compared to Opera?

All good points and worth saying. I must, however, disagree with the articles reliance on MathML. I've not seen any software that make MathML easy to use. Furthermore, it is only beginning to see support so readers can't count on their browser supporting it.

If you're writing an article with equations how do you go about doing so easily? I don't see MathML as a solution because there's no software that I found that allows authors to use this easily. Easy is the key, especially for equations.

I suggest authors write their work in whatever software they want but post the article in pdf format. Sure, pdf is Adobe's format but the reader software is free and compatible with most operating systems. The reader will see the text and equations as intended by the author. I don't know how it will display on a PDA but I don't think you can get everything anyway. We just can't get universal article presentation on any device in any format.

Also, I would like to point out that Octave is an open source product (free) that is very close to Matlab. It is easy to download, install, and use. If authors would use it for their programming, readers could use Octave to run the scripts without needing costly software like Matlab, Mathematica or Maple.

Stem cells: Not paying off; too early to tell

Steven Milloy who publishes JunkScience.com, CSRWatch.com writes an opinion piece that stem cell research has yet to produce results but it has produced bogus claims, fraud, and bad science.

There’s little hard evidence of progress on which to pin any hope [on embroynic stem cell research]. Moreover, the lack of federal funding doesn’t in any way impede research progress as privately-funded and foreign researchers are free to conduct whatever research they please on embryonic stem cells.

That freedom, however, has produced no results. What good can come from federal funding of futility?

An interesting take but I think he goes too far. Sure, stem cell research is a hot topic that has more than its share of frauds, but still it holds hope for cures. Science doesn't move at break neck speeds, it's slow, painful, and goes in fits and starts. While we don't have cures yet, it's much too early to stop work, or federal funding.

Displaced protons damage DNA

[C]omputational chemists at the University of Georgia have discovered for the first time that when a proton is knocked off one of the pairs of bases that make up DNA, a chain of damage begins that causes "lesions" in the DNA. These lesions, when replicated in the copying mechanisms of DNA, can lead to serious disorders such as cancer.

The research [was] just published in the Proceedings of the National Academy of Sciences (PNAS)...

Call it a "pinball proton." While chemists have shown other causes of DNA damage, the report in PNAS is the first to report how protons, knocked away by such mechanisms as radiation or chemical exposure, can cause lesions in DNA. The work was done entirely on computers in the Center for Computational Chemistry, part of the Franklin College of Arts and Sciences at UGA.

"This kind of damage in DNA subunits is about as basic as you can get," said Schaefer. "This is the simplest kind of lesion possible for such a system."

This article is on interest for two reasons. First, it begins to, perhaps, tell us how cancer may originate or at least tell us something about DNA damaging mechanisms. This is the obvious reason. Slightly more subtle is that the work was done entirely with a computational model. That is, there was no experimentation done with actual DNA molecules. Just computers simulating how DNA would behave under various conditions.

Hopefully, this work will be expanded to real, physical DNA and we'll learn more.

City in the Sky

From the Astronomy Picture of the day comes this most beautiful photo of the International Space Station. The picture was taken by the crew os the shuttle Discovery as it pulled away. In the background is the Caspian Sea. You can see the modules, trusses, and huge solar arrays that provide electricity to the station.

Black holes: See your dripping faucet

New Scientist has a brief article on studying black holes as a leaky faucet.

Out of Commission

I am recovering from a biking accident now and will return to posting in a few weeks.

Please check back later.