Naked Science Forum

Non Life Sciences => Technology => Topic started by: Geezer on 21/12/2011 18:41:28

Title: What would a mobius projector do?
Post by: Geezer on 21/12/2011 18:41:28

If you spliced a piece of movie film into a mobius strip, what would you see when you projected it?
 
I suppose it would have to be 9.5, 16 or 35mm film. 8mm would be a non-starter.

Title: Re: What would a mobius projector do?
Post by: RD on 21/12/2011 19:43:34

Chronological and the right way round, then backwards* and laterally-reversed, then return to chronological and the right way round, ... (I think)


[* anti-chronological ]

Title: Re: What would a mobius projector do?
Post by: imatfaal on 22/12/2011 10:23:35

Correct time and direction and orientation for first loop - then from the wrong side and upside down but in correct chronological order for the second , then back to the first ...

Title: Re: What would a mobius projector do?
Post by: Geezer on 22/12/2011 18:16:21

I don't think there would be any downside uppyness. Wouldn't it just alternate between true and mirror image versions of the clip?

Title: Re: What would a mobius projector do?
Post by: RD on 22/12/2011 19:54:37

Quote from: Geezer on 22/12/2011 18:16:21

Wouldn't it just alternate between true and mirror image versions of the clip?

On second thoughts, Yes you're right.

Having constructed a paper version similar to Imatfaal's (https://www.youtube.com/watch?v=hOdn4QSHRRA), (but with the numbers rotated 90 degrees, and only written on one side), I'm retracting the backwards (anti-chronological) bit: it would always project the same sequence in chronological order, and right way up, just flipping from right-way-round to mirror image and back again.   

Or without paper reconstruction: A loop of film without a Mobius  twist would just play the same sequence repeatedly, always the right way up and in chronological order.  The addition of the half-twist causes lateral-reversal every other loop.
 

Title: Re: What would a mobius projector do?
Post by: Geezer on 22/12/2011 20:58:48

Quote from: RD on 22/12/2011 19:54:37

(but with the numbers rotated 90 degrees, and only written on one side),

Yes - I suspect Matt is not entirely au fait with old-fangled cinematography  ;D

Title: Re: What would a mobius projector do?
Post by: imatfaal on 23/12/2011 10:05:19

Quote from: Geezer on 22/12/2011 20:58:48

Quote from: RD on 22/12/2011 19:54:37

(but with the numbers rotated 90 degrees, and only written on one side),

Yes - I suspect Matt is not entirely au fait with old-fangled cinematography  ;D

I am beginning to think that might be the case

Title: Re: What would a mobius projector do?
Post by: Geezer on 23/12/2011 18:23:02

This question turned out to be a lot more trixy that I had imagined!
 
It might actually be quite a good way of understanding how different people solve problems. I tend to be very "visual". I can "see" diagrams and animated models in my brain, so I had no problem visulalising the sequence of this imaginary loop running through an imaginary projector.
 
On the other hand, when I am faced with a blizzard of text, or even worse a barrage of mathematical equations, my initial response is to break out in a cold sweat and try to run away just as fast as I can.
 

Title: Re: What would a mobius projector do?
Post by: imatfaal on 28/12/2011 16:10:39

Quote from: Geezer on 22/12/2011 20:58:48

Quote from: RD on 22/12/2011 19:54:37

(but with the numbers rotated 90 degrees, and only written on one side),

Yes - I suspect Matt is not entirely au fait with old-fangled cinematography  ;D

actually took me a while to work out what this meant - and I didn't, I asked my old man and he explained.

I had even gone to the extent of recording another video - this time with acetate to make sure I wasn't going crazy

But from the above the digits are vertically wrong, not laterally.  Then when realisation dawned and I understood why RD had said "but with the numbers rotated 90 degrees",  I googled film images and all became clear and yes the image is laterally wrong not vertically when talking about film.

Re the problem solving;  I love numbers and equations - but if you start talking about flipping this, mirroring that and spatial movements in the real world I will start thinking with my hands and the make the thing.  The confusion I had with your and RD's correct explanations shows how easy it is to get lost with English (Scots) language even when the maths and the empirical experiment are clear.

ps the makeshift stand for the iphone is the most useful sort ever