Thursday, August 30, 2018

A flagrantly dishonest list

        Maurice Cotterell describes himself, on his primitive web site, as an engineer and scientist—but in reality he's an author who hit upon a genre that turned out to sell rather well. The lead paragraph of his Rational Wikipedia article provides some examples of the anti-science beliefs he holds dear. Click on the label at the foot of this article to see what else this blog has had to say about him.

        Cotterell's ideas are sufficiently bizarre (and inaccurate) to have attracted the attention of the producers of the overnight radio show Coast to Coast AM, who appear to be addicted to inaccuracy.note 1 He's guested on that show no less than 19 times since February 2002, most recently on 5th August this year.

        On that occasion he trotted out a criticism of Isaac Newton's law of gravity that was an illustration of the perils of lèse majesté. If you're going to knock one of the Great Men of Science, you'd better be sure of your ground. On C2C-AM, Cotterell tripped spectacularly. His claim was that, in describing the acceleration of a falling object under gravity, Newton had omitted to take into account the centrifugal force of the Earth's rotation acting contrary to the force of gravity. He's wrong because an object in free fall is not subject to that centrifugal force.note 2

Slamming into Mars
        His intended point was that Newton's mathematical lapse explains why so many spacecraft designed to soft-land on Mars have failed, and his claim was that 10 of 18 such attempts (55%) have failed. I got interested in that statistic since I could not recall as many failures, so I requested his list and he very graciously provided it by e-mail.

        The first thing I noticed was that he listed only 17 missions, not 18, and only 9 failures. The list included some familiar prangs—the early Soviet attempts (although even here he confused Mars 6 with Mars 7) and the ESA's ill-fated Beagle 2. More modern examples include Schiaparelli, also an ESA project.

        But Lookee here—what's this? Phobos 1 and Phobos 2  tallied as failures??? These were Russian scientific space probes of 1988/9, and were indeed (mostly) failures, but they were never intended to land on the planet itself, only on one of its two moons, Phobos. Phobos 1's mission was to orbit Phobos and drop a small landing capsule onto its surface. In one of the most excruciating woopsies of the entire history of spaceflight, a computer technician omitted a hyphen in a line of code and unintentionally sent an "end-of-mission" command to the spacecraft. Phobos 2 returned some excellent images of Phobos but it, too, fell victim to the gremlins of computer software before it could complete its mission.

        So Maurice Cotterell's list of Mars surface landers is inflated by two failed missions that have no business in that list at all. Not only is he wrong about the interaction between gravity and centrifugal force, the entire premise of his argument is, in my opinion, dishonest.

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[1] Witness their current love affair with Joel Wallach, who is billed as a doctor but is in fact no such thing. He's a pill salesman, making a fortune from his monthly spots on the show.

[2] An object actually attached to the surface is influenced by centrifugal force, which is why things weigh 0.34% less at the equator than they do at the poles.


astroguy said...

Why cherry pick on Mars? What about Moon or Venus? There have been many failures there, yet the Moon rotates on its axis once a month, and Venus takes well over 200 days. Centrifugal force clearly is minimal there, yet there have been many, many failures.

expat said...

Good point. There haven't been enough soft-landing attempts at Venus for statistics to be valid. For the Moon, I make it 8 of 27 (30%). My stats for Mars are 5 of 13 (38%).

expat said...

Those are failure rates, not success rates.

expat said...

FYI acceleration due to centrifugal force at Moon's equator = -12.32 x 10^-6 m/sec^2

vonmazur said...

I like his soft accent, (Lancashire??) But his statements are not correct, IIRC, even G Snoory pointed this out to him...As for the pill salesman, I just go to the all night classical music when they start up with the pill sales...Makes me want to hear LMH with her latest misinterpretation of some interview...I pine for the days of Long John Nebel and George Adamsky....At least it was fun to hear..