Strange but - True!

Wednesday, 9th May 2012

Q. From a reader in the United Arab Emirates: "Many thousands of years have passed since Earth and its first creatures and early humankind appeared. These have died and gone and there are new births and growth of trees and plants. So, is the mass/weight of Earth increasing or not?"

A. Not, because the Earth is pretty much a closed system. Some interplanetary cosmic dust and rocky meteorites do enter, but light gases like helium and hydrogen escape from the top of the atmosphere for a mass- reducing effect.

But these are minuscule compared to the Earth's 6,000,000,000,000,000,000,000,000 kilograms. Yet as organisms die and are born, a vast recycling of elements occurs: Animate or inanimate, it makes little difference, says Penn State-Erie University geologist Tony Foyle. "Calcium in my left tooth may have spent time inside a volcano in the western Pacific, or in a coral reef in a tropical sea many millions of years ago. Carbon dioxide I exhale today may, within a few thousand years, end up in the shell of a limpet (not yet born) on the rocky shores of Ireland." What goes around, comes around, you know.

Q. Traveling with you to work, to the airport, to the doctor - everywhere you go - is your "human thermal plume." It's got a tale to tell about you. Know what it's saying?

A. Streaming upward off your head and shoulders - and sucking along myriad particles of you like a gaseous signature - is the excess body heat you need to dump off, or risk overheating, says Penn State professor of mechanical engineering Gary Settles, director of their "Gas Dynamics Laboratory."

This airborne quintessence of you rises 6 feet or more above your head, until you start moving along, when your plume now becomes a trailing wake. Either way, the marvel is what this contains, such as skin flakes that float and settle to become 70%-90% of house "dust", plus hundreds of bioeffluents ranging from moisture, to carbon dioxide, to salts, and not-so-bio perfumes and colognes.

And it gets far more personal than that, carrying aloft clothing fibers, any traces of drugs, explosives, and lots more. As for diseases, "signs of diabetes, gangrene, some skin disorders, tuberculosis, some cancers and many others appear in a person's thermal plume." Most amazing, the plume can be aerodynamically sampled and screened non-invasively, by sucking it into a special chamber. Even skin flakes for DNA analysis are there, raising privacy issues.

"All warm-blooded animals have plumes," says Settles. "I've seen the very impressive plume coming off a horse led back into the barn after a brisk ride. To see your own plume, just step out of a hot shower or bath into chilly air. The moisture condensation will reveal it to you."

Q. How many people would you estimate are in your personal "clan" - family and friends with whom you interact on a regular basis? Why is 100-200 your likely limit?

A. Because that's about the population of a prehistoric village, which is near the "design limit" for human relationships - the maximum number of individuals with whom a human being can interact at more than a superficial level, say Robert Ornstein et al. in "New World, New Mind."

Beyond that, overload sets in. For it's not just the 100-200 you have to keep in mind, but their relationships as well. Think just of your immediate family of say 6: A B C D E F. In addition to the 5 others (you're A), you need to keep in mind how B relates to C (B-C), also B-D, B-E, B-F, C-D, C-E, C-F, D-E, D-F, E-F. Among 6 family members, that's (6 x 5)/2 = 15 2-person relationships to know.

You can see where this is headed. Make that an office of 20 and there are 190 possible relationships to worry about. In a village of 100, 4,950. For a modern big-city school of 3,000, 4,498,500! This is way beyond anything even remotely conceivable, "yet much of humanity today lives in cities of 10 times that population and more."

Q. Under what circumstances might a 3-ounce "passenger" bring down a 65-ton commercial jetliner?

A. Almost happened when a mouse got loose from a carry-on pet container and began scurrying around the cabin.

Suddenly, says John Dworetzky in "Psychology, 6th Edition," passengers were running about, screaming and trampling over one another, beside themselves with fear.

Never mind that the precipitously shifting weight of their bodies made the aircraft difficult to control. The fear of falling out of the sky from 30,000 feet at 500 mph had been eclipsed by a mouse crawling over people's feet.

"There was no calming the passengers until the jetliner made an unscheduled landing to toss out the 3-ounce rodent."

Humans mousetrapped by irrational fears.