Fictional Vacuum Globe Rises?

  • Thread starter rabbitandcrow
  • Start date
  • Tags
In summary, the conversation discusses the concept of a globe with a vacuum inside and the effects of increasing its size. It is concluded that the globe will eventually rise into the atmosphere due to the Archimedes force exceeding its gravity. The pressure inside the globe is not a factor in this scenario. The conversation ends with the acknowledgement that understanding the concept is similar to understanding buoyancy and can be aided by researching the term "Archimedes".
  • #1
I've done my own head in - all because I didn't study basic gas physics hard enough. So...

Assume I have an indestructible, impermeable, rigid globe (of a fictional metal, say) containing a complete vacuum, and I am able to change the size of the sphere at will. My globe and I are standing at sea level. If I keep increasing the size - and so, volume - of the globe, will the globe eventually rise upwards into the atmosphere?

It will, right?

I guess the fact that the pressure inside the globe is always zero is kind of throwing me, for some reason.
Physics news on
  • #2
Yes it will.
If your assumptions hold, when you increase the size of the globe, it will finally rise upwards into the sky. Because the total weight of the globe is unchanged, and the Archimedes increases when the volume of the globe increases, so you will get to the point that the archimedes force exceeds the gravity of the globe. Pressure inside the globe has nothing to do in this case.
  • #3
Right. Good. Thank you very much.

It's a buoyancy thang! I completely understand now. Sometimes all you need to solve a problem is the right word to put in the wikipedia search. In this case, "Archimedes".

Again, thanks.

What is a "Fictional Vacuum Globe Rises"?

A "Fictional Vacuum Globe Rises" is a concept in science fiction where a large, spherical object appears out of nowhere and rises into the sky. It is often depicted as being filled with a vacuum or void, and is usually unexplainable by current scientific understanding.

How does the "Fictional Vacuum Globe Rises" work?

The mechanics of how a "Fictional Vacuum Globe Rises" is typically left up to the imagination of the author or creator. However, it is often attributed to advanced technology or supernatural forces.

Could a "Fictional Vacuum Globe Rises" happen in real life?

Currently, there is no scientific evidence or understanding that would support the possibility of a "Fictional Vacuum Globe Rises" occurring in real life. It remains purely a fictional concept.

What are the potential dangers of a "Fictional Vacuum Globe Rises"?

In fictional depictions, a "Fictional Vacuum Globe Rises" can pose a variety of dangers, such as causing destruction or displacement of objects and people in its path. It can also lead to chaos and panic among the general public.

What are some examples of "Fictional Vacuum Globe Rises" in popular culture?

Some popular examples of "Fictional Vacuum Globe Rises" in pop culture include the mysterious black monolith in the film 2001: A Space Odyssey and the Upside Down in the TV series Stranger Things. These depictions often serve as plot devices to drive the story forward.

Suggested for: Fictional Vacuum Globe Rises?