First question here; I hope this question fits the rules well :)

So, first please see the two images below:

Image 1

Image 2

As you can find yourself, the eraser appears to float motionless over the register's page, with more than half of its area outside the contact area with the register. This picture has not been modified. The eraser is a normal unmodified brand new cuboid eraser found in stores.

Don't be bewildered :) This is possible; and these pictures are from my own experiment.

Question: How is this possible? Or how have I done this?

Of course, that you have to find! ;)

Please post your answer along with a picture (just as I have) of the eraser floating in air explaining what you did. Remember that the eraser has to float over a register kept over a table.

There is only one definite answer (at least, I believe there is). Happy solving :-)

So, after thinking that I could bewilder you all with my original puzzle, I am bewildered myself. I tried to be as clear as possible. First as I was told that one definite answer should be there, so I edited the question to state that just one definite answer is there to my knowledge. I clearly stated that the eraser is motionless, still I get a comment that a man is floating in air like this eraser. I tell that the eraser is unmodified, still I get answers breaking this rule. I tell that this is a real world situation, still I get an answer that the background image is tilted. People are breaking what I say. Is this my fault? And then I am told that the question is too broad so we are closing it.

I thought that I would explore some new ideas. I tried to be as positive as possible, but I guess I can't handle this much negativity. Too remove all scopes of this question being reopened, I answer the question myself:

The center of gravity is maintained by the compass with a pencil. In the rush of closing this question, none of you thought of this, which I thought would be too easy for the genius people here.

Thank you everyone. and Good bye.

  • 3
    $\begingroup$ Sorry, but "explore the different (creative) ways in which this is possible" isn't what we're looking for in challenge questions. Puzzles here should have a definite answer, not invite a bunch of different answers. $\endgroup$
    – xnor
    Commented Dec 6, 2014 at 11:25
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    $\begingroup$ I want to add that you clearly made an effort to find and follow the rules, and it's our fault for not having guidelines like the one I mentioned written clearly and in one place. We're still trying to figure out what we're about and how to convey that to new users. So, even if this question doesn't work out here, I encourage you to stay around and post more. $\endgroup$
    – xnor
    Commented Dec 6, 2014 at 12:16
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    $\begingroup$ @d'alar'cop Yes. I will do some yoga. I don't get disappointed so easily. I do believe you can expect me to come back and post another puzzle. $\endgroup$ Commented Dec 7, 2014 at 13:14
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    $\begingroup$ Your question is contradictory. You say that the eraser is “floating over” the register, but the photo shows it laying on the register. “Floating” implies that the eraser is not in contact with the book or the table. Your solution does not have the eraser floating. $\endgroup$ Commented Dec 7, 2014 at 15:18
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    $\begingroup$ @GaurangTandon. In the question and one of your comments, you say that the eraser is "unmodified". But the third picture shows that it clearly has been modified (by having a counter-balance stuck in it). This solution seems quite similar to several of the suggested answers, making me wonder whether you're playing an elaborate game of double-bluff. So come on: tell us what the real solution is :-) $\endgroup$
    – ekhumoro
    Commented Dec 7, 2014 at 18:24

4 Answers 4


A few possibilities that spring to mind, some more practical than others:

  1. Eraser is in the process of falling at the moment the photo is taken (shutter speed of 1/250 or faster will 'freeze' motion).

  2. Photo is taken in 0-g or low-g environment e.g. space station, descending aircraft, descending lift.

  3. Surface tension: water, oil, etc.

  4. Static electricity.

  5. Frame of reference is rotating (picture is sideways, camera is spinning with other equipment), Coriolis force is in play. E.g. all equipment is on a wheeled trolley being spun around fast.

  6. Wind: a fan below the frame of the photo is pushing air upwards; a vacuum cleaner above the frame of the photo is pulling air upwards.

  7. Black hole outside frame of photo is causing gravity distortion.

  8. Descriptive text is untrue: picture has been modified, eraser has been modified (e.g. hollowed out at one end to shift centre of gravity, concealed magnet, etc etc).

  9. Rubber has perished, stuck itself to the paper.

  10. Glue.

That's before we even get onto the possibilities of parallel universes....

  • 1
    $\begingroup$ btw, sixth point is mine :) $\endgroup$
    – nicael
    Commented Dec 6, 2014 at 15:53
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    $\begingroup$ I think that the point 7 must be the true! :) $\endgroup$ Commented Dec 6, 2014 at 19:52
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    $\begingroup$ with so many answers you feel equally answer this thing, I'd assume you voted to close as too broad - not that it's any of my business :p $\endgroup$
    – d'alar'cop
    Commented Dec 6, 2014 at 22:21
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    $\begingroup$ @d'alar'cop, youtube.com/watch?v=Oz8RjPAD2Jk $\endgroup$
    – A E
    Commented Dec 6, 2014 at 22:24
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    $\begingroup$ Oh, that's ok if the answer is tongue-in-cheek. ;) $\endgroup$
    – A E
    Commented Dec 7, 2014 at 11:20
  1. glue or anything sticky
  2. a magnet in a hole in the eraser
  3. lead in a hole in the eraser
  4. a hidden paperclip stuck between the pages
  5. a thumbtack

There are too many answers.

This is an unfolded paper clip stuck between the pages.

paperclip solution

OK, a new possibility:

  1. A glass table.
  • $\begingroup$ You can view yourself that nothing of this sort can be seen in the picture I posted. The contact area is too small for these things to happen, and the rubber can fall off easily. Think something creative! The eraser is unmodified. So not points 2, 3 atleast. $\endgroup$ Commented Dec 6, 2014 at 16:37
  • $\begingroup$ OK, "unmodified" removes some. $\endgroup$
    – Florian F
    Commented Dec 6, 2014 at 17:29
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    $\begingroup$ +1 Is that your own "Goedel Escher Bach"? :D $\endgroup$
    – d'alar'cop
    Commented Dec 8, 2014 at 3:47
  • $\begingroup$ The question is rhetorical, right? What you want to tell is: "I know that book!". So yes, it is "Gödel, Escher, Bach" and yes, I own it. $\endgroup$
    – Florian F
    Commented Dec 8, 2014 at 9:17
  • $\begingroup$ No I genuinely wanted to know if you had it :p I love that book. Don't forget to use the @ $\endgroup$
    – d'alar'cop
    Commented Dec 18, 2014 at 17:35

Clearly the eraser is touching the register at more than one points. Rubber often sticks to paper after a long time, like a few days. So, i think, you left the eraser in the register for a day, with more than half of it lying outside. It got stuck then, when you opened the register.

  • $\begingroup$ Good! I didn't think of this. Though this is not the case as in the question; but yes, this could be possible. +1 $\endgroup$ Commented Dec 6, 2014 at 15:48

The notebook is tilted at a steep angle. The eraser balances on the upper edge aided by a little surface friction.

The background is provided by a printed image that has been rotated to make it look like the notebook is being held horizontally.


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