@sonhouse
This is misleading. There is no pressure inside a Proton. At least not in a meaningful sense for humans. Pressure is Force per area. It is quite clear that if your area becomes smal even a very tiny force will lead to very high "pressures". But what exactly is the area on which the pressure is acting? In fact the Proton has no surface. You can define any surface of a particle using different criteria, but it is never like a table-top or something in that vein.
Next Point in the article the Claim is that pressure and Counter pressure are of equal magintude. So the net force is Zero...
And I would want to see an Experiment design to try to measure anything like a a "pressure"... The smallest pressure sensors yet are still several atomic Diameters in size, so afactor of at least 10e4 over the Diameter of a Proton...
@Ponderable
well they admit they can only depend on supercomputer calculations and due to the complexity took two of them a full year to complete.
Shannon might be saying pressure when he means 'force'. He was thinking of a very small person plunged into the center of the proton and feeling the accelerations they would undergo as a result, like if that proton was the size of our solar system and you were flying around in it in a space shuttle or some such.
@sonhouse
In fact I have no Beef with the performed work. The Point is how it is reported in your source. Science journalists try to explain something which is very abstract to a wider audiece. But some simplifivcations will just not make things clearer but give a wrong impression.
@Ponderable
Is it wrong to assume if the proton was in fact the size of the solar system and we were in a space shuttle near it, wouldn't we be flung outwards?