isn`t that the reason they only part fill these high altitude weather balloons with helium, and when they get high enough they achieve the spherical shape, but at ground level look more like a baseball in the bottom of a condom.

The matter is the balloon: the pressure difference between the vacuum and the inside of the balloon would not last. The pressures would attempt to equalize, eventually ending in the popping of the balloon.

 

Obviously you would need sufficiently rugged material to withstand an atmosphere of pressure difference. It was more a gedanken experiment than practical suggestion, though.

I asked this question in an oral exam once. The other examiner called me cruel afterwards.

I asked this question in an oral exam once. The other examiner called me cruel afterwards.

 

It's a great oral question, though, IMO. And better suited to oral rather than written exams.

Since nobody has specified the pressure in the helium ballon it is perfectly possible to have a helium balloon in a vacuum. You just need to be sure not to put much helium in it.

BTW, I don't play baseball so I'm no expert but re. "at ground level look more like a baseball in the bottom of a condom". Wouldn't that be the wrong way up?

BTW, I don't play baseball so I'm no expert but re. "at ground level look more like a baseball in the bottom of a condom". Wouldn't that be the wrong way up?

 

You've got a baseball in a condom, and the problem the mental image poses to you is the orientation?

 

It reminds me of the joke about cold-war propaganda: the Russians asked the US to please send them condoms 12" long x 3" in diameter. LBJ gave the OK, as long as they were marked "medium."

It's a great oral question, though, IMO. And better suited to oral rather than written exams.

 

 

Apparently the "fastest 1/4 mile" question is even better. It has yet to be solved....

 

Cheers