Until one day someone pointed out that the military had things backwards. They didn’t need to reinforce the planes where they saw bullet holes — in fact, this was proof that planes would survive if hit in those spots. Instead, they should reinforce the planes wherever there was no damage, since those areas might still be vulnerable. Anything else was a waste of effort.

The analogy’s not perfect, but this anecdote popped into my head in the past few weeks while researching some radical new treatments for diseases like HIV and cancer. Every instinct we have tells us to fight, fight, fight these ailments, and that the only cure is eradication. But there’s a second way: Living with the disease forever (or at least till something else gives out).

HIV scientists, led Ashley Haase at my alma mater, the University of Minnesota, are developing a therapy that teaches the body to ignore HIV. HIV spreads by highjacking the body’s defense cells, which try to eliminate it. When the virus takes over, the infected cell sends out panic signals that draw more defense cells to it, which allows HIV to colonize them, too, which draws more cells. It’s a cascade. Haase’s theory (and it seems to work in primates), is that stopping the panic response will hinder HIV’s ability to spread.

In the same spirit, doctors such as Robert Gatenby at Moffitt Cancer Center think that the best way to treat cancer might be call a truce with it (subscription req’d). Fighting cancer only seems to make tumors stronger in the long run, since the weakest usually succumb to chemotherapy first.

These are both clever ideas, and they may signal a shift in doctors’ thinking about how to tackle diseases. With microbes especially, biologists now realize that not all of them are bad guys. Bacteria and viruses are utterly integrated into our bodies, and they perform many essential functions, like helping us break down food. We cannot live without these benevolent bugs. And soon we may have the tools to live with even the worst of the microscopic world, too.

Image by Lee Carson via Flickr

We’re taught in school that we have five senses, but that number’s more a consensus than hard fact. Taste is mostly a superposition of smell and touch on your tongue, which could knock the number of senses down to four. Then again, many scientists count your vestibular system — the fluid and sensors in your inner ear that helps you keep your balance — as an additional sense, so maybe we do have five, just not the five we think we do.

Among animals, it’s almost impossible to keep track of different senses. The magnetic sense of migrating birds counts, as does the ability of some fish to detect electric fields. Lowly insects and even bacteria have novel senses, such as “quorum sensing,” the ability to count the number of other bacteria around them. It seems quorum sensing is the key to how bacteria communicate and coordinate behavior, both destructive and beneficial.

Now scientists in Spain have announced the discovery that human beings, despite millions of years of evolutionary divergence, can use echo-location to find their way around, very similar to bats. Of course, unlike bats, humans can’t use ultrasonic squeals, since our hearing isn’t good enough. Instead the scientists recommend a sort of tsk-tsk tongue click, similar to the noise dolphins make.

By making these clicks, the scientists taught themselves to navigate around obstacles while wearing blindfolds, based on how sound waves echoed off the objects. Unlike our “true” senses, this one isn’t inborn — it takes a few weeks of steady practice to acquire “biosonar capacity” — but once you’re really good, the scientists speculate that echo-location can even let you “see” around or through barriers, since sound penetrates and bends in ways that light won’t!

All this reminds me of neuroscientist Paul Bach-y-Rita’s famous dictum that “You see with your brain, not with your eyes.” Sounds like you can see with your ears, too.

Image via Wikipedia

It’s trendy nowadays (and fun) to mine the works of writers and artists and point out cases where their intuitions (or guesses) about natural phenomenon were later corroborated by science. The astronomers of Laputa in Gulliver’s Travels predicted not only the existence but the rotational speed of both moons of Mars, and did so a good hundred years before either was discovered with telescopes. And of course we all know Proust was a Neuroscientist.

Now comes Samuel Taylor Coleridge. His poem “Kubla Khan” relates the destruction of a paradisiacal, other-worldly land, Xanadu, by an earthquake. The earthquake also caused a “mighty fountain [to] burst” into the air near Kubla’s palace. The geyser wiped out his home and drown Kubla, eventually freezing over and sealing him below. Coleridge declared it “a miracle of rare device. / A sunny pleasure dome with caves of ice!” The poem ends with an image of Kubla — “his flashing eyes, his floating hair!” — suspended inside his icy cave for eternity.

Compare this to what astronomers are saying about the Saturnian moon Enceladus. Enceladus is coated in thick sheets of ice that sprays spumes of … well, something into the dead space above it. Scientists suspected (and hoped) the spumes were geysers from an underground ocean blowing up through the surface, since geysers meant liquid water, and liquid water meant a faint possibility of extraterrestrial life.

Last week, though, two teams of astronomers, one using a space-based probe and one a ground-based telescope, came to contradictory conclusions about the geysers in Nature, frustrating efforts to figure out what’s going on. (Their differences seem characteristic of new scientific fields such as astrobiology, which is a hot topic but struggles along with precious little data so far.) One team found good evidence of sodium salt in a subterranean liquid ocean, while the other found no sodium in the geysers, and seemed to question whether the spumes were geysers at all. Unless one (or both) teams are wrong, some novel geological process, one never observed in our galaxy before, is stripping out the sodium before the water sprays up.  What this process would do the surface of Enceladus, and what the moon would look like as a result, no one has any idea.

Except perhaps Coleridge. An essay in Nature accompanying the two articles said scientists need to rethink what Enceladus might be like, and his ideas have eerie echoes in “Kubla Khan”: “Our picture of [Enceladus's] subsurface must now be expanded to include the possibility of misty ice caverns floored with pools and channels of salty water, lurking beneath the tiger stripes [on the surface]. What else may lurk in those salty pools, if they exist, remains to be seen.”

Finding life is a longshot on Enceladus, much less a complex life form suspended in briny pools like poor Kubla. But if someday we found out that Enceladus is creeping with life, Coleridge should get a small slice of credit.

Image via Wikipedia

As you might remember from anatomy class, the left side of your body is controlled by the right side of your brain, and vice-versa. For decades scientists assumed that only human beings had these specialized hemispheres in the brain, but they’re starting to realize that — like speech, tool-making, homosexuality, and just about everything else “uniquely human” — the left-brain / right-brain split in humans isn’t unique, or even that special.

Among the lower orders, scientists (see, e.g., this Scientific American article) have found evidence of species-wide left-right specialization not only with limbs but with jaws (whales prefers to eat with one side of the mouth), beaks, and eyes. The eye finding was especially significant. Unlike mouths or appendages (which largely react to what the brain wants them to do), eyes are sensory tools that provide information to the brain. Lose your left eye, and it turns out you’re less ready to dodge attacks by predators, since the right side of the brain is better at responding to novel stimuli. You’ll also have more trouble recognizing individual faces, like those of friends.

On the other, well, hand, losing the right eye could interfere with routine tasks like feeding, since the left side the brain controls how (and how well) we carry out everyday tasks. The left side of the brain also seems to control and interpret communication signals, so the lack of a right eye would delay the understanding of those signals.

Now, all that’s not to say your brain, after losing one eye, would be incapable of interpretting signals. Information from the left eye will still get to the left brain — it just takes longer, and the process is less efficient. But it’s still fun to thing about what you’d rather sacrifice: The ability to carry out everyday tasks efficiently? Or the ability to react instantly to startling new phenonmena? (Even more interesting would be to see if left-handed or right-handed people have a preference for one or the other.)

In any case, the delays would affect your chances of survival only in the jungle wilds. Indeed, one thing that does separate humans from all other animals is that we’ve built environments where deficiencies like losing one eye doesn’t matter that much.