Will two gauge blocks wrung together stay conjoined if put into a vacuum chamber , or is it purely air pressure which holds them together temporarily?
I am aware that covalent bonding will lead to permanent conjunction if the blocks are left wrung together for an extended period of time, but is there any temporary atomic level bonding in the short term ?
It’s my understanding that they stick even tighter in vacuum, because you don’t get any traces of air trapped in between them.
That may well be the case … but if so then what exactly is the force that holds them together ?
And while we are at it, here is an ancillary question … we are all familiar with these neoprene suction cups … they have unbelievable holding power … but if you stuck a suction cup to a piece of glass and then put the assemblage into a vacuum chamber, would the suction cup still stick to the glass ?
According to this article, intermolecular forces hold them together even in a vacuum, but I hadn’t even heard of these things until I read the OP, so I don’t know how accurate it is. They seem pretty fascinating, though…
Gaugeons.
Air pressure actually isn’t a big deal except in a vacuum.
It’s kind of cool to see, actually. If you ever get a chance to play with them, do. Any good machine shop has some.
When I was a kid, they were called Johansson Blocks, named after the inventor, who was still alive then.
According to Mitutoyo,
You be old…
I used to use these every day, wringing them together. To make them stick, I would breath on them a little bit.
It is the same molecular forces that hold the molecules of each individual block together.
If the block surfaces could be made perfectly flat, they would stick together permanently and basically become a single block
some more info : Optical contact bonding - Wikipedia
The same concept in this Asimov short story: Nuclear Shears by Isaac Asimov from Foundation
That’s not a short story; that’s an excerpt from Foundation.