This is very misleading. Most of the discomfort would be from the hard table against the back of your hand, and this would be because of local pressure on specific points.
Good point, but it feels about as uncomfortable if you use a padding over the table that eliminates the stress concentrations at your bones and knuckles. Especially if you double the dumbbell weight and recognize that it’s only a pressure increase of 10%.
Your thought experiment with the dumbbell is an incorrect way of thinking about ambient pressure. Ambient pressure pushes against an object from every direction. It does not work to deform or break, only compress from all sides.
Picture this: You have a hand-sized water balloon on a table. You place the two dumbbells on it; it breaks. You have another water balloon. You take this one, tie it to a dumbbell, and drop it into deep water. Do you expect it to break when descends to 3 feet (i.e. 10% increase in pressure)?
I would not expect it to break at all. When water and other non-gases are put under pressure, the bonds and repulsive forces within push back.
Don’t quote me on this part, but I would guess that to break a bone with just ambient pressure, you’d have to raise the pressure to about the compressive strength of the bone, around 100 megapascals. For reference, standard atmospheric pressure is around 100 kilopascals.
edit: changed 3 meters to 3 feet, per prase’s comment.
Good point, but it feels about as uncomfortable if you use a padding over the table that eliminates the stress concentrations at your bones and knuckles. Especially if you double the dumbbell weight and recognize that it’s only a pressure increase of 10%.
I don’t agree with this.
Your thought experiment with the dumbbell is an incorrect way of thinking about ambient pressure. Ambient pressure pushes against an object from every direction. It does not work to deform or break, only compress from all sides.
Picture this: You have a hand-sized water balloon on a table. You place the two dumbbells on it; it breaks. You have another water balloon. You take this one, tie it to a dumbbell, and drop it into deep water. Do you expect it to break when descends to 3 feet (i.e. 10% increase in pressure)?
I would not expect it to break at all. When water and other non-gases are put under pressure, the bonds and repulsive forces within push back.
Don’t quote me on this part, but I would guess that to break a bone with just ambient pressure, you’d have to raise the pressure to about the compressive strength of the bone, around 100 megapascals. For reference, standard atmospheric pressure is around 100 kilopascals.
edit: changed 3 meters to 3 feet, per prase’s comment.
3 meters underwater is about 30% of atmospheric pressure added, not mere 10%.
Sorry, I forgot feet != meters. Ha.