Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.

A couple of weeks ago, I talked about the miraculous nature of gecko feet and the astounding physics that allows the little guys to walk on the ceiling.  Of course, there are other creatures that also have that capability.  I mentioned flies, but the all time champion in the ‘amazing feet’ category is probably that most reviled of insects, the mosquito.

I took my niece out to the dog’s water bowl over the weekend and said, “What do you see?”  She said “Yuck!  Worms!”  I said, “Look closer, those aren’t worms.  That bowl is full of the babies of one of the most deadly killers on the planet.”  And of course, the bowl was full of mosquito larvae.  And I’m not kidding about the lowly mosquito being one of the most deadly killers on the planet.  One out of every 17 deaths can be directly traced to a mosquito bite.  Malaria, yellow fever, West Nile virus, dengue fever are all transmitted by the mosquito.  And mosquitoes can do something with their feet that geckos can’t.  How did the mosquito larvae get in the dog’s water dish?  Mosquitoes can walk on water.

A close-up of the feathery scales that let mosquitoes walk on water (Credit: C. W. WU, X. Q. King, and Diane Wu, Physical Review E)

They can also cling to smooth ceilings and walls as tightly as geckos, and clutch the skin of their victims with annoying tenacity in search of blood.  And a group of scientists may have discovered how mosquitoes manage to be so comfortable on such a diverse range of surfaces

Like flies, mosquito feet are equipped with hooked claws for clinging to skin.  Like geckos, they have hairy pads on their feet that stick to nearly any smooth surface with a Velcro-like grip.  But it's their ability to walk on water that really makes mosquitoes stand out in the animal kingdom.
Both water striders and mosquitoes rely on superhydrophobic (extremely water repelling) legs to allow them to stand on water.  Water striders' legs repel water well enough to support up to 15 times their body weight.  Mosquitoes, however, easily beat that.  Experiments reveal that they repel water so well that each of a mosquito's six legs could support 23 times the insect's weight.  The scientists measured the water repellant ability of mosquito legs by attaching an amputated leg to the end of a needle and recording the force as they pushed it down into a container of water.

The secret to mosquito water-walking is apparently feathery scales a few microns across that in turn are covered with extremely tiny ribs.  So the next time a mosquito lands on your arm, take a moment to ponder its impressive and versatile leg adaptations -- then squish it before it sucks your blood.
And in addition to protecting your health by squashing that mosquito, it might help if you ate a little more . . . curry.

Researchers have isolated a natural substance found in turmeric root (the source of curry powder) that may help your immune system to clear amyloid beta, a peptide that forms the plaques found in Alzheimer's disease.  

The study also provides more insight into the role of the immune system in Alzheimer's disease and points to a new treatment approach.  Researchers say that it may be possible to test a patient's immune response with a blood sample in order to individualize treatment.  So don’t be afraid to add a little curry to your next stir-fry.  It will taste good and it may just help you avoid one of the scourges of old age.

Diamonds and Dust

And now for a little good news and bad news from space.  The good news is that the dust storm that’s been plaguing Spirit and Opportunity; the two Martian rovers seems to abating.  The dust has been covering the sky and the solar panels of the rovers, leaving them dangerously close to permanent shutdown.

Martian dust storm

Energy production for Spirit has increased 12 percent to about 300 watt hours in the last week or so, and energy production for Opportunity is up to 250 watt hours from a low of only 128 watt hours, an increase of over 50 percent.  One hundred watt hours is what it takes to run a 100-watt light bulb for one hour. Before power production was impaired by the dust storms, the rovers were averaging about 700 watt hours per day.

Opportunity has managed to fully charge its batteries and Spirit is bringing its batteries to nearly full charge.  Also, the temperature of the core electronics module on Opportunity has risen from a dangerously low minus 25 degrees Fahrenheit to minus 28.1 degrees Fahrenheit.

The men and women who run the rovers have responded to the good news by gradually increasing the rovers' science observations.  Spirit has moved its arm for the first time in nearly three weeks and will take pictures of two soil targets and one rock target.

Opportunity, is still sitting on the rim of Victoria Crater and the scientists hope it will still be able to descend into this geologically rich crater and do some astounding science.  Spare a thought for Spirit and Opportunity; the energizer bunnies of robot explorers!

And now for your contemplation, I bring you diamonds.  Although we all covet them, most people don’t realize that diamonds are made of the same stuff you are; carbon.  Carbon is an amazing element and is one of the few elements that can form long chains with itself.  It has four binding sites and can form an amazing array of molecules.  Our kind of life is carbon-based.  Without carbon; there would be no life.
But besides the long-chain molecules of life, carbon has some other tricks up its sleeve.  When the long chains bind together to form sheets of pure carbon, you get coal and graphite.  Pencil leads aren’t made of the element lead; they are pure slippery carbon sheets that rub off on the paper with great ease.

But the real miracle occurs when carbon binds with itself at all four binding points.  This creates one of the most stable and the hardest crystal known.  Diamond.

Diamonds can only be created under conditions of great temperature and pressure.  It takes a lot to shove the carbon atoms together and force them to form crystals.  That’s why there aren’t many diamonds on Earth and why it’s extremely expensive to form them artificially.

But scientists have speculated for a long time that there are places in the solar system where diamonds just might be found in abundance; deep inside the gas giants, Jupiter, Saturn, Uranus and Neptune.
These worlds have a lot of carbon in their atmospheres and many scientists have speculated that small diamonds would spontaneously form in the carbon rich layers of the gas giant planets.

However, physicists in the Netherlands have performed a numerical analysis that showed that that at the temperatures and pressures in gas giant planets like Uranus, arrangements of carbon atoms would be much more suitable for creating tiny bits of graphite (pencil lead) rather than diamond. 

Although diamond formation in the atmospheres of gas giants is not strictly impossible, the Dutch physicists say that the odds are exceedingly slim that a diamond could have formed under the conditions that exist in Uranus in the entire lifetime of the universe.  Of course, they haven’t really gone there and looked and I for one am still rooting for Diamonds in the Sky. Their study did reveal something else interesting, however.  White dwarf stars are probably diamond factories.  Their numerical analysis shows that the conditions inside a white dwarf star would cause the carbon atoms to line up in configurations that are much friendlier for diamond crystallization.  Their conclusion is consistent with the 2004 discovery of a cooling white dwarf star that appears to have a solid diamond core 2,500 miles across. A diamond 2,500 miles across.  You have to wonder just how many carats that is!!  But I don’t think it will fit in anybody’s engagement ring.

A white dwarf diamond