Archive for October, 2010

Stars Give Up Their Planets

Posted by on Thursday, 28 October, 2010



What’s harder to find than an honest politician?

Exactly. A new planet.

The old planets, they’re local. They’re located around our sun. There are now eight of them. Nine for a while but Pluto’s a rock again.

Committee decision.

The first seven weren’t so hard to find. No telescopes needed.

Earth, of course, was easy. Between yer toes.

Mercury, Mars, Venus, Jupiter, Uranus, and Saturn weren’t too bad either. They “wander” in the sky. Stars don’t do that when yer sober.

Big clue.

Uranus, which wasn’t discovered until the 18th century,  took some finding. And the next one, Neptune, did have to wait for telescopes to be invented. Johann Galle gets the credit along with J. J. Leverrier who told him where to point the thing.

J J didn’t like Uranus’ orbit.

“By King Louis Philippe,” he said, “I’d bet my mustache there’s a planet tugging on it and with a couple a mathematical tricks, I think I can figure out where that planet should be.”

“You bite the big one, J J,” said Galle. “You’re not gonna find a planet with mathematics.”

“Just you point your foolish lenses where I tell you, “J J said”, and we’ll see who bites what around here.”

J J was right and that was planet number eight.


Eight planets.

Our solar system was fully mapped. If you wanted more planets, you had best be looking around the good Lord’s firmament.


If you DID look beyond our solar system, what did you see? Stars are bright. Finding a planet around a star is like figuring out who’s in a car coming at you at night with headlights on.

Worse even.

Glare, glare, glare.

How it is.


You can see the star. But any planets would be hidden by its tremendous luminescence.

For a long time – a long, long time, really – we figured there might not BE any other planets anyway. But people – Carl Sagan was one of the most prominent – felt there should be planets elsewhere. Why would our own star, the one we call “sun”,  be so different?

By 1998, astronomers  figured  out a way to detect planets around other stars (exoplanets). Two ways, actually. One way involved watching the star wobble as the planet pulls on it. The other way involved watching a star dim as a planet passed in front.

Kinda sleuthy but it works  well enough to find great big planets, anyway.

A start.

These methods have gotten better with practice. The list of exoplanets is over 400 and growing fast .


Now what if the stars DIDN’T shine so bright? What if you COULD see the planets orbiting other suns?

Can now.

A team led by E Searbyn (Jet Propulsion Laboratory) invented an “Apodizing Phase Plate” which cancels out much of the glare from a star so you can see its planets. With it, they had a clear look at a star (HR8799) and its planets.

Not perfect. Still needs more refining to see the smaller planets. But an amazing piece of science magic anyway.

They say the next version’ll be better yet.

We believe them.

ScienceAintSoBadRating = 10


Image credit: Jet Propulsion Labs


Posted by on Friday, 15 October, 2010



No two people have the same fingerprints.

That’s how come we get to put people in jail or stick ’em in the lectric chair based on fingerprint evidence. It’s “incontrovertible”

How DO we know that fingerprints are unique? That no two people have the same ones?

Well.. see.. that’s the thing.

Experts such as Simon Cole (New York Times) say its’ a lot of hooey. It’s just “folk wisdom”. Fingerprint matching, says Cole, isn’t nearly as reliable as we grew up thinking it was.

How many whodunits have you read where the bad guy left prints on the wine glass? If they matched, he’s catched.


You’ve always accepted that this was completely true. You don’t want to get into an argument with your own brain, do you?


from an article in Wikipedia about fingerprints:

“Despite the absence of objective standards, scientific validation, and adequate statistical studies, a natural question to ask is how well fingerprint examiners actually perform. Proficiency tests do not validate a procedure per se, but they can provide some insight into error rates. In 1995, the Collaborative Testing Service (CTS) administered a proficiency test that, for the first time, was “designed, assembled, and reviewed” by the International Association for Identification (IAI).The results were disappointing. Four suspect cards with prints of all ten fingers were provided together with seven latents. Of 156 people taking the test, only 68 (44%) correctly classified all seven latents. Overall, the tests contained a total of 48 incorrect identifications. David Grieve, the editor of the Journal of Forensic Identification, describes the reaction of the forensic community to the results of the CTS test as ranging from “shock to disbelief,”..

Not so good, eh? Get yourself a mediocre fingerprint technician and who KNOWS what fate has in store. (Latents, by the way, are prints that don’t show up till you “dust em”).


Maybe there’s a better way.

Dr. Mark Nixon (and others) at the University of Southampton say that  the little swirly thing in the ear,  the helix, is durn good for telling us apart with close to 100% accuracy. That’s what we’re looking for, right? 99+ %?  Will “earprints” replace fingerprints at Scotland Yard?

Not likely, according to A Wild at the University of Rhode Island (That’s as much identification as your gonna get; he’s one of Mister ScienceAintSoBad’s best kept secrets). Wild reminds us that accuracy isn’t enough. Criminal types, he says, would have to start scattering photos of their own ears around crime scenes or, perhaps, begin pressing the sides of their heads against corpses, for ear detection to have any forensic value. Whereas it is hard to avoid leaving fingerprints and DNA behind, your average perpetrator can probably figure out how to keep his ears off the walls.


To be fair, Dr. Nixon and his colleagues probably had different applications in mind for the ear identification technique such as biometric screening. For that purpose, with further development, it may well turn out to be useful.


Photo Credit: FBI (Thanks, guys.)