Tuesday, March 5, 2013

Really small (with big implications)

Today's post deals with news of the really tiny.

We'll start at nanoscale -- and that's as big as we'll consider today. (One nanometer, 1 billionth of a meter, is the scale of small molecules. Living cells are no larger than microscale, measured in millionths of meters.)

There's been a fair amount of uncertainty about the health implications of nanoparticles. Why? Much of the allure of nanotech has been that materials often act differently in nanoscale particles than in bulk -- and yet for a long while, safety studies (if any) were performed only using bulk quantities.

A few years ago, at a nanotech conference, an insurance-company rep brought up, off the record, fears of a parallel between nanomaterials and asbestos. Asbestos is a useful material whose health implications (asbestosis and mesothelioma) went unrecognized for decades.  Related health science was behind the curve and insurers were taken entirely by surprise.

Chemotherapy with nanoparticles
So what are nanoscale particles of zinc oxide in some new sunblocks doing to us? Or the nanoscale silver particles sometimes used as antibacterial agents? Or nanoscale ... whatever in cosmetics?

Although this article has languished in my files for several months, it's encouraging to note (from IEEE Spectrum) that "New Study Indicates Nanoparticles Do Not Pass Through Skin."

Sticking for a bit with nanotech, consider (again from IEEE Spectrum) that "Hybrid Nanomaterial Converts Both Light and Heat to Electricity." Many forms of distributed tech require devices to power themselves by local harvesting of energy. (Remember when that meant self-winding watches?) The article's conclusion:
"By increasing the number of the micro-devices on a chip, this technology might offer a new and efficient platform to complement or even replace current solar cell technology."
Now let's consider some really small stuff ...
Such as, from Wired, that "Source of High-Energy Cosmic Rays Found at Last." Cosmic rays are of two types: very high speed subatomic particles and very short wavelength electromagnetic radiation (gamma rays). It turns out that at least some cosmic rays, as long suspected, come from supernovae.

Supernova 1987A
The highly successful Standard Model of subatomic physics is known to be incomplete. For one thing, many of the model's key parameters (e.g., the charge of an electron) must be measured -- their values aren't explained by the theory. One candidate extension to the theory on which particle physicists have placed high hopes is supersymmetry (aka, "SUSY"). SUSY would unify the two major classes of subatomic particles: bosons and fermions.

Physicists keep cranking up the energy on particle accelerators. They're looking for cracks in the foundation of the Standard Model, through which to glimpse a deeper model. (Hey, I'm a writer. I'm allowed the occasional metaphor. Even the occasional groaner, like that one.) Hence it's worth noting (from a recent BBC report) that "Popular physics theory running out of hiding places." That popular theory is supersymmetry.

And finally ...

More than a century after the birth of modern physics, physicists still argue what the pretty -- and very accurate -- math of quantum mechanics  means. From phys.org, see "Survey shows physicists can't agree on fundamental questions about quantum mechanics." Or from the Washington Post, for a more general audience, see much the same in "Why quantum mechanics is an 'embarrassment' to science."

Just in case Disney had it right ("It's a small world after all"), it'd sure be nice if QM had an unambiguous meaning.

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