Monday, August 6, 2012

NASA: Real science, and that other stuff

This past week gave us a graphic illustration of the difference between what you can predict in a linear system vs. what you can predict in a non-linear system - and both examples came from NASA.

First up: NASA GISS, under the inimitable and oft-manacled James "Death Trains" Hansen:

...we have this:

(Source: From Hansen's website, reproduced by Steve Goddard at Real Science)

The black line is measured temperatures (with Hansen's manual upwards data alterations applied, of course).  The green line is where Hansen says they should be.  The purple line is where he said they would be if humans had stopped emitting carbon dioxide twelve years ago.  So even by cheating - even by adding corrections to increase recent temperatures and cool older temperature records, contrary to all science and logic - Hansen can't beat the data hard enough to validate his nonsense models.

Now look what else NASA did this week:

That's right.  They flew a spaceship on a 9-month, 567,000,000 kilometre journey.  The ship hit the Martian atmosphere at 13,000 mph, slowed by aerobraking to 1000 mph, popped the biggest supersonic parachute ever made, slowed to 200 mph, ditched the chute (and the 1600-degree heat shield), deployed rockets, maneuvred drastically to get out from under the chute, dropped to an altitude of 20 metres, then lowered a Volkswagon-sized robotic rover on a cabled skycrane - and then, once the rover touched down, it cut the cables and flew away (if somebody wrote that landing mechanism into a sci-fi movie plot, no audience would believe it).  And the thing did it all on its own, because the entire landing process - 7 minutes long - is half the time it takes for a radio signal to get from Mars to Earth.  By the time NASA scientists received word that the vehicle had touched the top of the atmosphere, the Curiosity lander had already been on the surface for 7 minutes.

That was about three hours ago.  It's already started sending us photos...

...starting with a picture of its own shadow.

So there you have it, folks.  In a linear system like orbital mechanics, you can fling thousands of kilograms of metal and plastic into space and hit a landing target a few kilometres square at a range of half a billion kilometres.  That's like threading a needle if the needle were so small that you needed a microscope to see it.  It's like throwing a golf ball from Los Angeles through a garage door in New York.  But in a non-linear system like climate, you can't even make predictions with the right sign, let alone of anything even approaching the right magnitude.  If NASA's ballistic modelling was as good as its climate modelling, Curiosity would've ended up plunging into the Sun. 

It didn't.  It's on Mars.  It's on FREAKING MARS.  You can go to Google Earth, select Mars, and check out Gale Crater, where Curiosity landed last night.  There are a few overhead snaps from various orbiters.  Pretty soon there are going to be many more pictures there.  I cannot wait.

Curiosity is expected to operate for two years.  That's conservative.  Its older brother, Opportunity, lasted 40 times longer than it was designed to.  Spirit is still going, an interplanetary Energizer Bunny if there ever was one. 

And their great-grandfater, Voyager 1, is eighteen billion km from the Sun, moving at 17 km/second (the fastest thing ever made by a bunch of jumped-up monkeys, whizzing along three times faster than Curiosity was going when it hit the Martian atmosphere), and is on its way out of the Solar system.  That's how fast Voyager's going.  It'll be sending us data for another 13 years or so, before its power finally runs out, and then it'll be nothing more than a message in a bottle - a greeting card from the monkeys to whomever might be out there.  It's beyond our reach.  Whatever happens on Earth, whatever happens to humanity, it'll keep going, zipping along - plodding along - at one-eighteen-thousandth the speed of light.  In 40,000 years it'll only be as far away as the closest star is to our own Sun. Before it gets there, radio signals sent this century (badly attenuated by distance and dust, natch) will be approaching the centre of the galaxy.  That's how slow Voyager's going. But the grandest thing about it is that no matter what becomes of us, the Voyagers are concrete proof that we once tried to do something grand.

When my son was just a toddler, he had a playpen stuffed with toys.  For some reason they were never as interesting as what lay just outside the mesh walls.  Eventually, he got tall enough to chin himself, throw a leg over, climb out and drop to the floor. I remember watching him do that with a mixture of pride and dismay: pride, because he'd managed to exceed his limits; and dismay, because I knew one part of his life was over.  And then pride again, because the next part - the really fun part - was just beginning. Whenever he did it, he always hesitated before exploring, hanging onto the sides and looking around - not because he was scared, but because there were so many places to go and so much to see that he couldn't decide where to totter off to first.

We're just starting to crawl out of the playpen. There're so many places to go, so much to see! If achievements like Curiosity don't give you goosebumps, if they don't make you proud to be a human being, then you need to find another species to belong to.  Sloths, maybe. Or cockroaches.

And as for NASA - well, thanks for reminding us all once again that you're still capable of blowing our freaking minds.

Not bad for a bunch of jumped-up monkeys.  Not bad at all.



P.S.  If only it were this easy (from Cyanide & Happiness):