[math-fun] Lissajous physob
Alan Adler (gosper.org/alan.JPG . "I'm not an inventor, I'm an engineer, dammit," ) is motorizing my Lissajous illusion for G4G11. Lo res (7MB): gosper.org/MVI_0200.mp4 Hi res (314MB): gosper.org/MVI_0200.MOV You can see it on the worktable in the JPG, upended with a pulley removed. Also note the (unrelated) Euler disc. --rwg Poor Leo: To Google translate trompe l'oeil from French to English, spell it the same but say "Tromp Leo".
Wow. Okay, that is extraordinary. I had not expected the physical object to be that much more impressive than the computer graphic. --Michael On Sat, Mar 8, 2014 at 6:51 AM, Bill Gosper <billgosper@gmail.com> wrote:
Alan Adler (gosper.org/alan.JPG . "I'm not an inventor, I'm an engineer, dammit," ) is motorizing my Lissajous illusion for G4G11. Lo res (7MB): gosper.org/MVI_0200.mp4 Hi res (314MB): gosper.org/MVI_0200.MOV You can see it on the worktable in the JPG, upended with a pulley removed. Also note the (unrelated) Euler disc. --rwg Poor Leo: To Google translate trompe l'oeil from French to English, spell it the same but say "Tromp Leo". _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
-- Forewarned is worth an octopus in the bush.
Agree with Michael -- damn extraordinary, congrats to both of you. And, BTW, œil (and trompe l'œil) have a "ligature"; o and e are glued together. I don't know if this is the same in the English "import" of the word. Best, É. Catapulté de mon aPhone 2.014+
Le 8 mars 2014 à 14:10, "Michael Kleber" <michael.kleber@gmail.com> a écrit :
Wow. Okay, that is extraordinary. I had not expected the physical object to be that much more impressive than the computer graphic.
--Michael
On Sat, Mar 8, 2014 at 6:51 AM, Bill Gosper <billgosper@gmail.com> wrote:
Alan Adler (gosper.org/alan.JPG . "I'm not an inventor, I'm an engineer, dammit," ) is motorizing my Lissajous illusion for G4G11. Lo res (7MB): gosper.org/MVI_0200.mp4 Hi res (314MB): gosper.org/MVI_0200.MOV You can see it on the worktable in the JPG, upended with a pulley removed. Also note the (unrelated) Euler disc. --rwg Poor Leo: To Google translate trompe l'oeil from French to English, spell it the same but say "Tromp Leo". _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
-- Forewarned is worth an octopus in the bush. _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
What are we seeing here? It looks like a rigid object rotating, but what's making it rotate? It looks like the motion is caused by two rollers, either rolling in the same direction or in opposite directions, but either way, how can such a symmetrical set-up impart angular momentum? I can guess that part of the answer is that the object being rotated is itself asymmetrical, so frictional forced work asymmetrically, but I'm still puzzled. Presumably if you reversed the directions of both rollers, the object would start rotating the other way. Are the rollers rolling in the same direction or opposite directions? I've tried peering closely at the video, but I can't tell. Others more mechanical than I can probably work this out with pure reason. What other effects can be achieved with rollers? (It seems like the sort of transmission system Arthur Ganson would have explored.) Jim Propp P.S. I recall seeing a similar effect in the opening scenes of the Superman movie from the 1970s, where the villains from Krypton are penned into an enclosure surrounded by a sine wave. On Saturday, March 8, 2014, Bill Gosper <billgosper@gmail.com> wrote:
Alan Adler (gosper.org/alan.JPG . "I'm not an inventor, I'm an engineer, dammit," ) is motorizing my Lissajous illusion for G4G11. Lo res (7MB): gosper.org/MVI_0200.mp4 Hi res (314MB): gosper.org/MVI_0200.MOV You can see it on the worktable in the JPG, upended with a pulley removed. Also note the (unrelated) Euler disc. --rwg Poor Leo: To Google translate trompe l'oeil from French to English, spell it the same but say "Tromp Leo". _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com <javascript:;> http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
Jim: maybe this picture will make Bill's trickery clear. http://graphics8.nytimes.com/packages/other/crossword/GosperLissajous.gif --Michael On Mar 8, 2014 1:08 PM, "James Propp" <jamespropp@gmail.com> wrote:
What are we seeing here? It looks like a rigid object rotating, but what's making it rotate? It looks like the motion is caused by two rollers, either rolling in the same direction or in opposite directions, but either way, how can such a symmetrical set-up impart angular momentum?
I can guess that part of the answer is that the object being rotated is itself asymmetrical, so frictional forced work asymmetrically, but I'm still puzzled.
Presumably if you reversed the directions of both rollers, the object would start rotating the other way.
Are the rollers rolling in the same direction or opposite directions? I've tried peering closely at the video, but I can't tell. Others more mechanical than I can probably work this out with pure reason.
What other effects can be achieved with rollers? (It seems like the sort of transmission system Arthur Ganson would have explored.)
Jim Propp
P.S. I recall seeing a similar effect in the opening scenes of the Superman movie from the 1970s, where the villains from Krypton are penned into an enclosure surrounded by a sine wave.
On Saturday, March 8, 2014, Bill Gosper <billgosper@gmail.com> wrote:
Alan Adler (gosper.org/alan.JPG . "I'm not an inventor, I'm an engineer, dammit," ) is motorizing my Lissajous illusion for G4G11. Lo res (7MB): gosper.org/MVI_0200.mp4 Hi res (314MB): gosper.org/MVI_0200.MOV You can see it on the worktable in the JPG, upended with a pulley removed. Also note the (unrelated) Euler disc. --rwg Poor Leo: To Google translate trompe l'oeil from French to English, spell it the same but say "Tromp Leo". _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com <javascript:;> http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
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I'd like to see one roll across a table: it will appear to float and twist. On Sat, Mar 8, 2014 at 12:19 PM, Michael Kleber <michael.kleber@gmail.com> wrote:
Jim: maybe this picture will make Bill's trickery clear.
http://graphics8.nytimes.com/packages/other/crossword/GosperLissajous.gif
--Michael On Mar 8, 2014 1:08 PM, "James Propp" <jamespropp@gmail.com> wrote:
What are we seeing here? It looks like a rigid object rotating, but what's making it rotate? It looks like the motion is caused by two rollers, either rolling in the same direction or in opposite directions, but either way, how can such a symmetrical set-up impart angular momentum?
I can guess that part of the answer is that the object being rotated is itself asymmetrical, so frictional forced work asymmetrically, but I'm still puzzled.
Presumably if you reversed the directions of both rollers, the object would start rotating the other way.
Are the rollers rolling in the same direction or opposite directions? I've tried peering closely at the video, but I can't tell. Others more mechanical than I can probably work this out with pure reason.
What other effects can be achieved with rollers? (It seems like the sort of transmission system Arthur Ganson would have explored.)
Jim Propp
P.S. I recall seeing a similar effect in the opening scenes of the Superman movie from the 1970s, where the villains from Krypton are penned into an enclosure surrounded by a sine wave.
On Saturday, March 8, 2014, Bill Gosper <billgosper@gmail.com> wrote:
Alan Adler (gosper.org/alan.JPG . "I'm not an inventor, I'm an engineer, dammit," ) is motorizing my Lissajous illusion for G4G11. Lo res (7MB): gosper.org/MVI_0200.mp4 Hi res (314MB): gosper.org/MVI_0200.MOV You can see it on the worktable in the JPG, upended with a pulley removed. Also note the (unrelated) Euler disc. --rwg Poor Leo: To Google translate trompe l'oeil from French to English, spell it the same but say "Tromp Leo". _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com <javascript:;> http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
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-- Mike Stay - metaweta@gmail.com http://www.cs.auckland.ac.nz/~mike http://reperiendi.wordpress.com
Oh my gosh. *Now* I get it! Jim On Saturday, March 8, 2014, Michael Kleber <michael.kleber@gmail.com> wrote:
Jim: maybe this picture will make Bill's trickery clear.
http://graphics8.nytimes.com/packages/other/crossword/GosperLissajous.gif
--Michael On Mar 8, 2014 1:08 PM, "James Propp" <jamespropp@gmail.com <javascript:;>> wrote:
What are we seeing here? It looks like a rigid object rotating, but what's making it rotate? It looks like the motion is caused by two rollers, either rolling in the same direction or in opposite directions, but either way, how can such a symmetrical set-up impart angular momentum?
I can guess that part of the answer is that the object being rotated is itself asymmetrical, so frictional forced work asymmetrically, but I'm still puzzled.
Presumably if you reversed the directions of both rollers, the object would start rotating the other way.
Are the rollers rolling in the same direction or opposite directions? I've tried peering closely at the video, but I can't tell. Others more mechanical than I can probably work this out with pure reason.
What other effects can be achieved with rollers? (It seems like the sort of transmission system Arthur Ganson would have explored.)
Jim Propp
P.S. I recall seeing a similar effect in the opening scenes of the Superman movie from the 1970s, where the villains from Krypton are penned into an enclosure surrounded by a sine wave.
On Saturday, March 8, 2014, Bill Gosper <billgosper@gmail.com<javascript:;>> wrote:
Alan Adler (gosper.org/alan.JPG . "I'm not an inventor, I'm an engineer, dammit," ) is motorizing my Lissajous illusion for G4G11. Lo res (7MB): gosper.org/MVI_0200.mp4 Hi res (314MB): gosper.org/MVI_0200.MOV You can see it on the worktable in the JPG, upended with a pulley removed. Also note the (unrelated) Euler disc. --rwg Poor Leo: To Google translate trompe l'oeil from French to English, spell it the same but say "Tromp Leo". _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com <javascript:;> <javascript:;> http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com <javascript:;> http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
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The two rollers are rotating in the same direction, which is opposite to the direction in which the object is rotating. The motion is induced by friction (and gravity). Think of them as gears with very fine teeth. Hot dog warmers do the exact same thing: http://ecx.images-amazon.com/images/I/61ZJyTQeuWL._SL1500_.jpg In California we have smog check stations which use a similar pair of rollers for the car wheels, except in that case the motion is generated by the car wheels rather than the rollers. Tom James Propp writes:
What are we seeing here? It looks like a rigid object rotating, but what's making it rotate? It looks like the motion is caused by two rollers, either rolling in the same direction or in opposite directions, but either way, how can such a symmetrical set-up impart angular momentum?
I can guess that part of the answer is that the object being rotated is itself asymmetrical, so frictional forced work asymmetrically, but I'm still puzzled.
Presumably if you reversed the directions of both rollers, the object would start rotating the other way.
Are the rollers rolling in the same direction or opposite directions? I've tried peering closely at the video, but I can't tell. Others more mechanical than I can probably work this out with pure reason.
What other effects can be achieved with rollers? (It seems like the sort of transmission system Arthur Ganson would have explored.)
Jim Propp
P.S. I recall seeing a similar effect in the opening scenes of the Superman movie from the 1970s, where the villains from Krypton are penned into an enclosure surrounded by a sine wave.
On Saturday, March 8, 2014, Bill Gosper <billgosper@gmail.com> wrote:
Alan Adler (gosper.org/alan.JPG . "I'm not an inventor, I'm an engineer, dammit," ) is motorizing my Lissajous illusion for G4G11. Lo res (7MB): gosper.org/MVI_0200.mp4 Hi res (314MB): gosper.org/MVI_0200.MOV You can see it on the worktable in the JPG, upended with a pulley removed. Also note the (unrelated) Euler disc. --rwg Poor Leo: To Google translate trompe l'oeil from French to English, spell it the same but say "Tromp Leo". _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com <javascript:;> http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
On Sat, Mar 8, 2014 at 5:51 AM, Bill Gosper <billgosper@gmail.com> wrote:
Alan Adler (gosper.org/alan.JPG . "I'm not an inventor, I'm an engineer, dammit," )
Is that the same Alan Adler who used to sign off sci.math or sci.math.research posts with "Ignorantly yours" ? [...snip...]
On Sat, Mar 8, 2014 at 6:52 PM, James Buddenhagen <jbuddenh@gmail.com>wrote:
Is that the same Alan Adler who used to sign off sci.math or sci.math.research posts with "Ignorantly yours"
That was Allen Adler. See http://mathforum.org/kb/search!execute.jspa?forumID=13&q=ignorantly&rankBy=1...
Minor point: His actual name is Allan Adler. I don’t know why his name is listed on some of the hits as “Allen”. —Dan On Mar 8, 2014, at 8:00 PM, W. Edwin Clark <wclark@mail.usf.edu> wrote:
On Sat, Mar 8, 2014 at 6:52 PM, James Buddenhagen <jbuddenh@gmail.com>wrote:
Is that the same Alan Adler who used to sign off sci.math or sci.math.research posts with "Ignorantly yours"
That was Allen Adler. See http://mathforum.org/kb/search!execute.jspa?forumID=13&q=ignorantly&rankBy=1... _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
P.S. Of course, I mean the mathematician, not the inventor. —D. On Mar 8, 2014, at 10:33 PM, Dan Asimov <dasimov@earthlink.net> wrote:
Minor point: His actual name is Allan Adler. I don’t know why his name is listed on some of the hits as “Allen”.
—Dan
On Mar 8, 2014, at 8:00 PM, W. Edwin Clark <wclark@mail.usf.edu> wrote:
On Sat, Mar 8, 2014 at 6:52 PM, James Buddenhagen <jbuddenh@gmail.com>wrote:
Is that the same Alan Adler who used to sign off sci.math or sci.math.research posts with "Ignorantly yours"
That was Allen Adler. See http://mathforum.org/kb/search!execute.jspa?forumID=13&q=ignorantly&rankBy=1... _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
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So is this an application for a 3-d printer? [For a non-motorized version: The film of the figure rolling back and forth on the table was really great!] On 2014-03-08 03:51, Bill Gosper wrote:
Alan Adler (gosper.org/alan.JPG . "I'm not an inventor, I'm an engineer, dammit," ) is motorizing my Lissajous illusion for G4G11. Lo res (7MB): gosper.org/MVI_0200.mp4 Hi res (314MB): gosper.org/MVI_0200.MOV You can see it on the worktable in the JPG, upended with a pulley removed. Also note the (unrelated) Euler disc. --rwg Poor Leo: To Google translate trompe l'oeil from French to English, spell it the same but say "Tromp Leo". _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
Thanks! Indeed, Shapeways made the rotors from Neil Bickford's stl, modulo my scaling. --rwg On Sun, Mar 9, 2014 at 2:16 PM, Michael Greenwald <mbgreen@seas.upenn.edu>wrote:
So is this an application for a 3-d printer? [For a non-motorized version: The film of the figure rolling back and forth on the table was really great!]
On 2014-03-08 03:51, Bill Gosper wrote:
Alan Adler (gosper.org/alan.JPG . "I'm not an inventor, I'm an engineer, dammit," ) is motorizing my Lissajous illusion for G4G11. Lo res (7MB): gosper.org/MVI_0200.mp4 Hi res (314MB): gosper.org/MVI_0200.MOV You can see it on the worktable in the JPG, upended with a pulley removed. Also note the (unrelated) Euler disc. --rwg Poor Leo: To Google translate trompe l'oeil from French to English, spell it the same but say "Tromp Leo". _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
participants (10)
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Bill Gosper -
Dan Asimov -
Eric Angelini -
James Buddenhagen -
James Propp -
Michael Greenwald -
Michael Kleber -
Mike Stay -
Tom Karzes -
W. Edwin Clark