One of the complications of interplanetary research is that the probes you’ve placed on the other planet can’t be reached via radio while the planet they are on passes to the other side of the sun, which happens now and then. In fact, for the days before and after Mars is opposite the sun, communication is risky because it is remotely possible that something could be misunderstood if the signal is messed up by passing near the sun. So, from January 27th through February 11th there will be no talking to the Rovers on Mars (but some listening).
Conveniently, Opportunity Rover has arrived at a rock that happens to be of interest. The mass spec on Opportunity uses a radioactive source to elicit readings from rocks, but that source is rather old (half life of about a year, and it’s been a few years…) so the mass spec has to stare at a rock for a week or so to make sense of it. So, NASA will have Opportunity staring at this one rock for the entire time. Pity, because it might have been interesting to see if Opportunity could tell us what the other side of the sun looks like….
Read the rest of the story here.
, consists of the smallest possible number of words to explain the concept in a useful and entertaining way, and thus lays an important planck in anyone’s physics education.
is part of my own personal enigma. I have shown it to people who don’t know me, who don’t know what I think about, who don’t know much about what I study. Nineteen out of twenty such people react in this matter:
, Ernst Mayr breaks down the body of thought often referred to as “Darwin’s Theory” into five separate and distinct theories, the second of which being “common descent.” Darwin’s second evolutionary theory (second by Mayr’s count, not Darwin’s) is really a hypothesis that could be worded this way:
