The Honda Gold Wing motorcycle, both has reverse and absolutely needs it! Old four engined bombers, such as the B-17 (which did not have reverse pitch propellers) could creep backwards on a taxiway up by alternately holding the brake on one wheel (e.g. The right side) while while advancing the throttle on the outboard engine on the same side and then, next, doing the same things on the other side… etc,, causing the aircraft to slowly wiggle backwards. My puny, mini 4 door Nissan Leaf, is the fastest production car in the world… going backwards (97 MPH). While certainly not obvious, computers can be designed to work backwards just as well as forwards (but usually only after going forwards can they then go backwards… too bad for those wanting to factor large integers but handy for those wanting to not necessarily dissipate any energy when computing!) When I was a kid, old gasoline powered model airplane engines ran backwards as well as forwards, sometimes spontaneously switching in flight with disastrous consequences. But the best such things are the most microscopic laws of physics, where absolutely everything that happens forwards, can also happen backwards… that is, CPT backwards. Ed Fredkin From: Bill Gosper <billgosper@gmail.com<mailto:billgosper@gmail.com>> Reply-To: <billgosper@gmail.com<mailto:billgosper@gmail.com>> Date: Mon, 27 Jan 2014 11:20:24 -0800 To: <math-fun@mailman.xmission.com<mailto:math-fun@mailman.xmission.com>> Subject: [math-fun] Microwave ovens "There is no reverse on a motorcycle ..." was supposedly one of Shannon's favorite test sentences. http://languagelog.ldc.upenn.edu/myl/Shannon1950.pdf --rwg From: meekerdb <meekerdb@verizon.net<mailto:meekerdb@verizon.net>> On 1/27/2014 1:22 AM, Joerg Arndt wrote:
Most certainly a kind of motor is used where the initial internal position (and possibly the initial current) determines the direction.
But I've noticed that mine seems to be completely consistent. It reverses every time.
A similar thing used to be (long ago) a problem with tractors when the motor was idling: it could start moving backward when put into move, potentially injuring/killing the people accompanying it (usually walking behind).
A two-stroke engine will also run backwards. Even though the ignition timing is poor for running backward it can get started that way by kicking back when starting. Once at the start of a motorcycle race I saw kid have his bike lurch backwards as everyone else leaped forward. A look of puzzlement came over his face as he tried easing out the clutch again and the bike started to back up. Then he threw down the bike as if it had betrayed him. Brent Meeker
Best, jj
* James Propp <jamespropp@gmail.com<mailto:jamespropp@gmail.com>> [Jan 27. 2014 10:12]:
Why do microwave ovens alternate between rotating the food-carousel clockwise and rotating it counterclockwise (or, as the Brits would say, anticlockwise)?
Jim Propp
OK, so why are μwave ovens so damn noisy? Note to James Randi: Unworthy nonbeliever, if you want to learn the true power of homeopathy, try making Earl Grey tea in a sauerkraut jar. -- You received this message because you are subscribed to the Google Groups "mathfuneavesdroppers" group. To unsubscribe from this group and stop receiving emails from it, send an email to mathfuneavesdroppers+unsubscribe@googlegroups.com<mailto:mathfuneavesdroppers+unsubscribe@googlegroups.com>. For more options, visit https://groups.google.com/groups/opt_out.