Archive for August, 2012

I’ve traveled a long way this summer.  So far I’ve driven nearly 4,000 miles, mostly in a minivan bursting to capacity and two small kids along for the adventure.  This pales in comparison to the rover Curiosity which left Cape Canaveral on November 26th and lands on Mars in two days.  We can expect the landing either late Sunday (August 5) or early Monday morning, depending on your time zone.   Curiosity is a massive six-wheeled, ten foot long, nuclear powered science lab we are unleashing on the unsuspecting Martians:

One of the most fascinating things about Curiosity is the landing.  Their plan is formally called the Sky Crane, or more informally called the Seven Minutes of Terror.  You must watch this video.

Click for Seven Minutes of Terror

There is also an excellent PhD comics video on Curiosity.  The breakdown below shows the steps involved between flying 80 miles above the surface at 13,200 mph to being (hopefully) gently lowered to the ground on the Sky Crane.

Remember, there have been failures.  Let’s look at a few to see what can go wrong:

• Mars Polar Lander – cause uncertain but crash most likely caused when descent rockets accidentally shut off while still 50 meters above the surface
• Deep Space 2 – fate unknown, designed to tunnel a probe into the surface of Mars but all communications were lost
• Mars Climate Orbiter – a story which I tell in class every year where a crucial piece of software used English units instead of Metric units causing the orbiter to disintegrate in the upper atmosphere

These three failures all happened between 1996 and 1999.  Since then the track record has improved with several successful missions.  Curiosity is the largest and most ambitious rover so far.

On Sunday night, find some friends, make some popcorn, and root for Curiosity.

-Dr. D

Christmas has come early this year, but instead of Santa Claus we have Randall Munroe to thank.  He is a genius, a cartoonist, and interestingly enough, a physics major.  XCKD, his webcomic named by carefully choosing an unpronounceable four-letter name, is subtitled “A webcomic of romance, sarcasm, math, and language.”   The warning at the bottom is also important: “Warning: this comic occasionally contains strong language (which may be unsuitable for children), unusual humor (which may be unsuitable for adults), and advanced mathematics (which may be unsuitable for liberal-arts majors).”  The comics are brilliant, and I’ve probably shown dozens and dozens of these in lectures over the years.  There’s plenty more I’d like to show, but are unsuitable for mixed company and un-tenured professors (the relativity of simultaneity joke comes to mind).  So how do we improve on ultra-geeky-and-funny web humor?  Why, with What If of course.

ANSWERING YOUR HYPOTHETICAL QUESTIONS WITH PHYSICS, EVERY TUESDAY.

He has devoted every Tuesday to answering an interesting question with rock-solid physics.  His first post, Relativistic Baseball, explores a pitch at 90% the speed of light, and ends up with a fascinating result.  Yesterday’s post tackles a subject near to my heart (after just finishing a semester of Pattern Recognition), the Robot Apocalypse.

Have fun exploring!  If thinking about a mole of moles doesn’t get you through the week, then nothing will.

-Dr D