# Bent Aluminium Optical Illusion

By on March 22, 2006, with 119 Comments

Try to solve the following enigma. The following piece of aluminium was neither thinned not elongated. And no pieces were added. It was not a sphere or a cylinder. So how can it have this shape now?

119 Responses
1. Ani says:

um.. a possible way of doing this is by creating that sheet of aluminum with four normal arms and then cutting through from the left side of the arms along their thickness…(it really is difficult to explain in mere words..)Just so u get the ill point out that after the work is done, the thickness(not the width, not the length, the THICKNESS) of the overlapping arms will be half the thickness of the rest of the thing.. This is why it is almost impossible to do it with paper(like one of them here pointed out..) because paper alreay it too thin and u cant cut through its thickness (unless its some sort of “two-ply” tissue paper or something..)

• kid says:

NOOOOOOOOOOOOOO

yall are WAY overthinking this

the bottom straight plate is actually two that lay one over the other
thats how they get that “mountain”
the two pieces of metal are as long as the rectangle is wide so they can peak like that

2. Anonymous says:

Ani has got it. It’s a symmetrical object so think about reflection and think laterally about what it might mean to “cut” a sheet of metal. How many ways can you cut a sheet 8mm thick? Horizontally? Vertically? Laterally?!

3. Anonymous says:

To anyone who has said ‘Photoshop’. Do the world a favour and stop breathing. This is an actual physical exhibit. Having seen it myself in Wanaka I think that Chain (no. 42) has offered the only sensible solution in relation to the actual problem, which I have to say isn’t clearly defined on this page.

4. Tobie says:

Following on the idea that Chain(42) gave I think i also have a possible answer: Imagine a flat but elliptical shape of aluminium sheet. Now take the shape in question and “elliptically” apply is to the elliptical sheet of aluminium (i.e. the long sides of the sheet in question was the short sides of the elliptical sheet of aluminium). With a little bit of tapping on the short sides of the elliptical sheet, you can bend them to become straight but ofcourse the inside bars would them overlap, which is exactly what we want! The longer edges of the elliptical sheet was simply cut off straight to form the short sides of the sheet in question!! :)

5. paul says:

ohhhhhkay… we have metal of all kinds, tooled and died into technological marvels like internal combustion engines, spacecraft, automatic weapons, or precision clockwork, and you all are marveling at a piece of aluminum with overlapping bars. arguably not an easy task but hardly worth any disbelief, i should think.

6. Ryan says:

It’s called welding. ^_^

7. idle_knight says:

quite good explanation from Chain(#42) yet one certain factor affects the theory(an aluminum sheet from parallelogram to rectangular shape) w/c is deformation on its corners!if the cutting pattern is done precisely wherein the slant width of the parallelogram is almost vertical then fabricating this cut piece into its final form a rectangular shape will have a negligible deformation!you can check me out if you want the visualisation of the cut out piece.(autocad program)

8. matthew says:

The bent rhombus idea makes the most sense.

9. the David says:

What optical illusion are they talking about.
The lower portion has two overlapping pieces whereas the top portion they didn’t overlap and they just screwed them together.

10. tsk tsk tsk tsk Its NOT VERY Hard Look at the other one thats strapped down…cant you see its overlapped?? Duuuuuh All we have to do is just unscrew those nails holding them down try to bend both of them the oposite dirrection and then when there good enough let go and they slam together creating what you see now

REMEMBER Illusions are simpiliar then you think!

11. Jesse says:

thanks luke and all those who saw it before. the bottom cross section has another piece underneath it. the top was placed like that, might have been tacked but i doubt it.

12. Tracy says:

It’s two pieces of aluminum overlapping each other that have been lifted up to lean against each other. The cross bar shows two pieces overlapping below. Sorry, but this one was really obvious…

13. Austin says:

if you look really closely at the bottom one it looks like theres one piece of metal over the other

14. Zerro says:

It’s bendable….lol look at the bottom it overlapped….they just made the shape like that by bending it and then bolted it…just a theory though

15. liam says:

if you look closely at the collim beneath it and look to the left of it you will see that theirs two layers so they just unscrewed it then bent it up then screwed it back together forming a different shape

16. tristan says:

if you look at the 3rd line (from the top), you can see on its right side that one sheet is nailed (or screwed, or whatever) to the one below it.

17. :P says:

wow

18. bryce says:

you guys/gals r over thinking it way too much. if you view the bottom cross bar(middle steel thingy(the one the flat)) look in the middle of it… do you see how it is symmetrically cut? if your not getting my wind here let me say this! BEND THE tWo SEPERATE Peices of metal up ( the one opposite the tall medal thingy. if you still not understand then either you cant comprehend me or your taking my meanning to high in standerds. hope this clear it up.

19. amanda says:

bryce is right. thats stupid

20. Cory says:

Bryce is right. look to the left of the left rivet. you can clearly see the edge and upper corner of the piece coming from the right

21. sephiroth2308 says:

There are actually two pieces of metal, one on top, one on the bottom, look at the lower one, there is something underneath it.

22. somebody says:

i think there is only 1 piece but the pieces in the middle over lap each other

23. Jack says:

this ones kinda stupid…

24. Ivy says:

I think it might be doable using a brick shape.

Imagine a slab of brick, use the 2 sides of the brick to cut the “E” shapes, and for the top/bottom frame (that is shorter than the middle) cut diagonally into the brick.

25. Andrew says:

Poured into a mold. Start with a wax shape, form it how you want, cover it with clay/plaster/sand, melt the wax out, pour in molten metal, let cool

26. kevin says:

omg i hate this

27. Tabitha says:

Mirror on the left.

28. nelson says:

Its as Andrew has commented, aluminium is a cast metal that can be formed into any mold or shape you desire. Once cast the shape can then be bent into the above configuration.

29. nick says:

its boobs

30. Cyphis says:

Is there a solution to this? I can’t even figure out what the problem is.

31. ryen says:

it is simple look at the lower one.When you cearfully look you will see that there are two :one above other

32. :| says:

It’s one piece, but if you look closely you can see the frame but in the middle, there are 4 pieces sticking out not just to, the to at the bottom are over lapping, but the two at the top were bent

33. Dan says:

So the problem is, if it is one solid piece that is neither thin nor elongated, then it should not be possible that the middle two strips meet and overlap. But they do. How? The answer is that through a clever amount of bending and possibly pounding the edge strips are moved in parallel to each other but making the “box” trapezoid until the middle strips that used to be parallel are now facing each other. The illusion is completed by re-cutting until the trapezoid is again at right angles.

34. don says:

no look at the metal that is normal can’t you see that there are two aluminum strips that are overlapping each other.

35. wynwlkr says:

Well, I guess I’m stupid. What is the answer?

36. astrid says:

um its kindof obvious that they are overlapping! not really amazing….

37. kid says:

yall are WAY overthinking this

the bottom straight plate is actually two that lay one over the other
thats how they get that “mountain”
the two pieces of metal are as long as the rectangle in aid so they can peak like that