Archive: July, 2012
If we found life on another planet, the discovery would go a long way toward answering the deepest open questions in biology: How did life originate, how widespread is life in the universe, and are there alternative recipes for life?
There’s no obvious sign of life on any of our neighbors in the solar system. But desolate, frozen Mars keeps calling scientists back. In the Martian landscape, geologists see dry riverbeds and floodplains that hint at a warmer past that just might have allowed life to originate.
All life on Earth appears to be related, using DNA and RNA molecules to pass down assembly instructions and other information. We share stretches of this genetic code with bacteria, yeast, and amoebas.
Scientists have said that if Yellowstone wasn’t a National Park it might be a Superfund site. The place is dotted with hundreds of scalding, pools, with the ph of battery acid and bright with the colors of cadmium, arsenic and other toxic metals. But toxic is in the eye of the beholder. Deadly for humans, sure, but now we know there’s a whole section of the tree of life that does just fine here. In fact, the so-called archeans that live in the pools may represent the part of the tree with the deepest roots.
This is where I’ve spent the last few days – a perfect place for appreciating the diversity of life on the eve of NASA’s most ambitious mission to Mars, to arrive on the night of August 5 or morning of the 6th, depending on your time zone.
Yellowstone’s microbial communities and other so-called “extremophiles” have revolutionized the way scientists think about the possibility for life on Mars. Life doesn’t necessarily need moderate conditions or sunlight. Living things do need some source of energy, but life is flexible – chemical reactions can supply the energy at the base of a food chain.
Higgs (the cat) and I got a great response to our attempt to explain the Higgs boson. Several readers were still puzzled and asked some thoughtful questions. I thought they deserved answers, so I asked physicist Paul Halpern to take a stab at them. Paul is a professor at the University of the Sciences and he’s a great physics popularizer, having authored a number of outstanding books for the lay public. His latest will come out in September. The title is Edge of the Universe: A Voyage to the Cosmic Horizon and Beyond
Here’s the first question:
Reader: Thank you Higgs, but I'm still baffled. Is a boson a type of quark? And if we're talking about a "wave" the wave is measured by it's boundries but it takes something to be the boundries, so what are the boundries composed of in a Higgs Wave if not Higgs Bosons? With them being so "flighty" how would a wave hold any shape. It would be a constantly changing thing, impossible to measure.
Here's my column for this week. This will also run in Monday's science section of the Philadelphia Inquirer
No matter how well adapted an animal may be, it can spell evolutionary doom to have feathers or even shells that become coveted by human beings. Take the nautilus — a creature that pulled easily through the asteroid impact that wiped out the dinosaurs. It now hangs on the brink of extinction thanks to the misfortune of having a pretty spiraling shell.
These animals come from an ancient family — the nautiloids — that go back almost all the way to the birth of complex life some 600 million years ago. Nautiloid fossils have been dated as early as 500 million years ago — soon after animals started leaving fossils.
This column on the “arsenic bacteria” controversy brought on some good questions. The following was the also posed by biologists when the announcement of the so-called arsenic bacteria came out:
"What about the RNA?"
This is a great question. If these bugs were living with no phosphorus, they’d have to substitute in arsenic in the DNA and the RNA. So the researchers making the claim would have had to prove arsenic was in the RNA as well.
This question also brings out the difference between claims made by the paper and the press conference and press releases. In the scientific paper, the researchers were not clear how much arsenic actually got incorporated into the DNA.
Unlike the problemmatic "arsenic bacteria" research described in this week’s column, NASA’s search for extrasolar planets really is exciting and revolutionary.
Astronomers have been detecting giant planets around other stars for more than 15 years, but small planets are much harder to find. This latest discovery, called UCF-1.01 is about 2/3 the size of Earth and was found using NASAs’ Spitzer Telescope. (It’s named for the University of Central Florida).
Here’s what the NASA press release says:
Apparently I’m the laughing stock of certain Philadelphia neighborhoods – or so says a reader who called this morning to complain about the Higgs Boson story that ran Monday in print and online over the weekend. He said his neighbors usually enjoy laughing at me for being an “atheist” and “evolution freak” but this week they got an extra shot of mirth over my taking God out of the God particle. He pointed out that it was front page news that they’d found the God particle and I’d purposely omitted the very important connection between particle physics and the almightly. What was I thinking? Physicists just proved there’s a God and I’m trying to cover it up! Ha Ha.
My trusted co-blogger and I have dealt with the “God Particle” moniker in previous posts. Physicists treat the term like flatulence in an elevator. Unable to blame the dog, some point at “the media”. The original source is apparently a 1993 book about particle physics by University of Chicago physicist Leon Lederman. He’s known for repeating the tired line that he originally wanted to call it the “God damned particle” but his editor wouldn’t let him.
Another piece that omitted the lord appeared on the op-ed page of the New York Times. The author was Stephen Weinberg, a theorist and one of the key architects of the current theory of matter known as the standard model. He’s a Nobel laureate and also an accomplished popularizer of his field.
In his piece, Weinberg explained something about standard model, what it is and how the Higgs field fits in. He also answered one of the questions that several readers have posed – what good is a Higgs Boson?
Higgs the cat hates the marketing slogan “The God Particle” so much it makes him cough up hairballs. I feel something similar. But underneath that annoyingly pompous moniker is some fascinating science. Not so with the “arsenic bacteria” claim that’s led to TED talks and Glamour Magazine profiles of the lead author. The hype was so over the top they might as well have called it the God bug. Below is my column for Mondays’ paper:
A few scientists have argued that descendants of an alternative origin of life may still lurk in a “shadow biosphere” somewhere here on Earth. It’s an intriguing idea, but the search for the shadow inhabitants is becoming the Bigfoot hunt of microbiology.
Not that Bigfoot isn’t potentially exciting. But there isn’t much convincing evidence one exists and it’s hard to know where a viable population could live without being squeezed out of existence by modern humans. Likewise, the real biosphere leaves little room for a shadow one. All life ever observed shows the DNA signature of common ancestry.