Sohereis a Mobiuspantthatmakesthreetwistsokaybyitself.
Youknow, wedon't careabouttheshapetheMobispentbyitselfisreallynodifferentto a mathematicianthantherubberband.
It's just a loop, Okay, we'renotlookingatthecrosssection, andwhetherit's twistedornot, it's justwe'relookingatthecenterlineoffthenotthatdefinestheknot.
ButonceyoutaketheMobispanandhesplititdownthemiddle, itbecomes a notnow.
Westartedoutthis a trefoilknotnow, andsoherehe's roughlytripleknot.
Andthenwesplitthistriflenotdownthemiddlebecauseithappensinthistriflenottobeoff a Mobiusstructure.
Letmebackup a littlebitandshowyoutwodifferentprofiles.
They'retooartistic.
Trefoillots.
I kindofcallthem, like, youknow, trefoilstandingonitsowntwofeetbecausetheywerecarefullydesignedsothat I canactuallysostandingup, they'renotgonnatoppleover.
Canyousee a difference?
Well, I'm claimingoneofthemis a mobilespan, andtheotheroneisnot, Let's figureout, youknow, whetherthisoneistwisted.
So I'm startingonthesideofit's a camerauponthelowpieronthem, runningmyfingersslowlydownhere.
Gettotheundersideofthisfoot.
I'm comingtothefrontier.
I'm gettingaround.
I'm stayinghereontheuppersideofthatfoot.
I'm cominguphereon I'm backwhere I startedit.
Soonthesameside.
Sothisoneisdoublesided.
Okay, I couldpaintthis.
Ireneand I couldpainttheotheronerantandeverythingwouldbefine.
Butnowlet's comparethattotheothermoviespent.
If I'm startinghereagainonyourside, I'm movingdownhere.
Soit's justonelongstring, youknow, essentiallytiedtogetherandvilewhenitwasstillfusedwithoutthegapinthemiddle, itwas a trifle.
Notnow.
It's a muchmorecomplicatednothowmanycrossingsdoesthisthinghave.
Actually, notthateasytosee, but I wasamazed a dayMissSarai.
Itwaslike a sevenyearoldkit, and I showthemthatandwithinsecondshesaid 12thandherealizedwhereverwehad a crossinginourtriflenotWenowhadsplitthatwenowgetfourcrossings.