# Why can't my hand go through my desk? (physics question) **URL:** \ **Category:** Factual Questions\ **Created:** [January 26, 2005, 10:54pm UTC](https://boards.straightdope.com/t/why-cant-my-hand-go-through-my-desk-physics-question/286835 "2005-01-26T22:54:55Z")\ **Posts on this page:** 11\ **Page:** 5
**Author:** ![drachillix](https://avatars.discourse-cdn.com/v4/letter/d/48db29/32.png) [@drachillix](https://boards.straightdope.com/u/drachillix)\ **Post date:** [January 26, 2011, 8:12pm UTC](https://boards.straightdope.com/t/why-cant-my-hand-go-through-my-desk-physics-question/286835/81 "2011-01-26T20:12:10Z")
> [@Stranger\_On\_A\_Train](#): > > It’s all “empty space” and all filled by fields. Ah so you are saying my Hovercraft is filled with **feilds** , now I understand. ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [January 26, 2011, 8:38pm UTC](https://boards.straightdope.com/t/why-cant-my-hand-go-through-my-desk-physics-question/286835/82 "2011-01-26T20:38:13Z")
lol! You guys are such nerds! The correct answer to the OPs question is “your hand doesn’t go through the desk because you punch like a little girl”! ---
**Author:** ![Keeve](https://avatars.discourse-cdn.com/v4/letter/k/f07891/32.png) [@Keeve](https://boards.straightdope.com/u/Keeve)\ **Post date:** [January 26, 2011, 9:40pm UTC](https://boards.straightdope.com/t/why-cant-my-hand-go-through-my-desk-physics-question/286835/83 "2011-01-26T21:40:51Z")
> [@Stranger\_On\_A\_Train](#): > > Do you mean predict analytically, or actually measure? Either way, I’m not picky. If it helps, let me rephrase it like this: Suppose a reasonably flat and smooth bar of pure silver is placed on top of a reasonably flat and smooth bar of pure gold. Further suppose that the silver atoms/molecules are more or less Distance A from each other, and that the gold atoms/molecules are more or less Distance B from each other. Now: How close are the closest silver and gold to each other? In other words: Are they so close to each other like they are to themselves? Or is there some distance between them that prevents them from merging into each other? ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [January 26, 2011, 9:51pm UTC](https://boards.straightdope.com/t/why-cant-my-hand-go-through-my-desk-physics-question/286835/84 "2011-01-26T21:51:58Z")
> [@Keeve](#): > > In other words: Are they so close to each other like they are to themselves? Or is there some distance between them that prevents them from merging into each other? The surfaces of most things are pretty jagged at the microscopic level. There are points on the surfaces that _approach_ the closeness of the solids to each other (I’m not sure _how_ close.) But _most_ of the material will be quite far away from the opposing surface, in molecular terms, because of the un-flatness of the two surfaces. In fact, if you were to polish the surfaces to such a fine degree that they _do_ nearly lock up, you can get the materials to adhere to each other! ---
**Author:** ![Hoopy\_Frood](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hoopy_frood/32/8452_2.png) [@Hoopy\_Frood](https://boards.straightdope.com/u/Hoopy_Frood)\ **Post date:** [January 26, 2011, 9:52pm UTC](https://boards.straightdope.com/t/why-cant-my-hand-go-through-my-desk-physics-question/286835/85 "2011-01-26T21:52:24Z")
> [@MOIDALIZE](#): > > Has your hand been stuck in a desk this whole time?! Well, he didn’t state that he needed the answer fast. But since time is relative anyway, maybe this is fast. ---
**Author:** ![Rachellelogram](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rachellelogram/32/8689_2.png) [@Rachellelogram](https://boards.straightdope.com/u/Rachellelogram)\ **Post date:** [January 26, 2011, 10:30pm UTC](https://boards.straightdope.com/t/why-cant-my-hand-go-through-my-desk-physics-question/286835/86 "2011-01-26T22:30:06Z")
It is not impossible for all the atoms of oxygen in a room to cluster in a corner for long enough that you will suffocate. However, it is so improbable that for practical purposes, it will never happen. ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [January 26, 2011, 10:43pm UTC](https://boards.straightdope.com/t/why-cant-my-hand-go-through-my-desk-physics-question/286835/87 "2011-01-26T22:43:47Z")
> [@Ludovic](#): > > In fact, if you were to polish the surfaces to such a fine degree that they _do_ nearly lock up, you can get the materials to adhere to each other! I saw something like this when I was a kid. A friend of mine had these two ceramic (as far as I remember…not sure what they were made out of but seemed like a ceramic) disks that were flat on one side and bulged out into a handle (sort of…just something you could grip) on the other side. Put them together and they were impossible for my young arms to pull apart. Supposedly they were so smooth it caused them to adhere to each other. There was no adhesive and no magnets. I _think_ the explanation I got was air pressure somehow held them together. It has been many moons, more than I care to count, since I saw those and have never seen their like since so I may be remembering wrong but that is my recollection of it. ---
**Author:** ![DesertDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/desertdog/32/11503_2.png) [@DesertDog](https://boards.straightdope.com/u/DesertDog)\ **Post date:** [January 27, 2011, 12:07am UTC](https://boards.straightdope.com/t/why-cant-my-hand-go-through-my-desk-physics-question/286835/88 "2011-01-27T00:07:19Z")
> [@Whack-a-Mole](#): > > I saw something like this when I was a kid. > > A friend of mine had these two ceramic (as far as I remember…not sure what they were made out of but seemed like a ceramic) disks that were flat on one side and bulged out into a handle (sort of…just something you could grip) on the other side. > > Put them together and they were impossible for my young arms to pull apart. Supposedly they were so smooth it caused them to adhere to each other. There was no adhesive and no magnets. I _think_ the explanation I got was air pressure somehow held them together. > > It has been many moons, more than I care to count, since I saw those and have never seen their like since so I may be remembering wrong but that is my recollection of it. [Jo blocks](http://en.wikipedia.org/wiki/Gauge_block) stick together and air pressure is a factor, but the most minor of the three believed responsible. Were the surfaces at all oily? ---
**Author:** ![standingwave](https://avatars.discourse-cdn.com/v4/letter/s/9de0a6/32.png) [@standingwave](https://boards.straightdope.com/u/standingwave)\ **Post date:** [January 27, 2011, 12:27am UTC](https://boards.straightdope.com/t/why-cant-my-hand-go-through-my-desk-physics-question/286835/89 "2011-01-27T00:27:18Z")
> [@Crafter\_Man](#): > > When I slap my hand down on my desk, my hand comes to rest atop the desk. But if each atom in the desk is 99.99% nothingness, and each atom in my hand is 99.99% nothingness, shouldn’t my hand just go through it? This is worth watching. I’ve cued it to the appropriate point but the entire talk is worth viewing: [Richard Dawkins speaking at TED2005](http://www.youtube.com/watch?v=1APOxsp1VFw#t=4m27s). _A proponent of psychic warfare, (Major General) [Stubblebine](http://en.wikipedia.org/wiki/Albert_Stubblebine) was involved in a U.S. military project to create “a breed of ‘super soldier’” who would “have the ability to become invisible at will and to walk through walls”.[3] He features prominently in Jon Ronson’s book The Men Who Stare at Goats,[6] where he is described as firmly believing that he himself can walk through walls.[7]_ ---
**Author:** ![Keeve](https://avatars.discourse-cdn.com/v4/letter/k/f07891/32.png) [@Keeve](https://boards.straightdope.com/u/Keeve)\ **Post date:** [January 27, 2011, 12:57am UTC](https://boards.straightdope.com/t/why-cant-my-hand-go-through-my-desk-physics-question/286835/90 "2011-01-27T00:57:01Z")
> [@Ludovic](#): > > In fact, if you were to polish the surfaces to such a fine degree that they _do_ nearly lock up, you can get the materials to adhere to each other! I always suspected that. Thanks! ---
**Author:** ![Keeve](https://avatars.discourse-cdn.com/v4/letter/k/f07891/32.png) [@Keeve](https://boards.straightdope.com/u/Keeve)\ **Post date:** [January 27, 2011, 12:58am UTC](https://boards.straightdope.com/t/why-cant-my-hand-go-through-my-desk-physics-question/286835/91 "2011-01-27T00:58:07Z")
> [@DesertDog](#): > > [Jo blocks](http://en.wikipedia.org/wiki/Gauge_block) stick together and air pressure is a factor, but the most minor of the three believed responsible. Fascinating! [Previous page](https://boards.straightdope.com/t/why-cant-my-hand-go-through-my-desk-physics-question/286835.md?page=4)