I’m not a physicist, but I’ll try to answer your question:
Gravity, pressure (atmospheric), and a vacuum are not the same; nor are they mutually exclusive.
The Earth’s mass and centrifugal forces are said to exert a total of 1 gravity (1g). While the influence of gravity is scientifically never-ending, there is a distance or limit, known as the Hill Sphere where the effects of a celestial body’s’ gravity dissipates enough that its influence is scientifically negligible. For the planet Earth, the Hill Sphere is about 1.5 billion km or 0.01 astronomical units (AU).
Shortly after the Earth formed, there was no atmosphere and different types of gasses like Nitrogen, etc were being expelled by tons of volcanic activity; much like Venus. Due to the Earth’s gravitational force, these gasses didn’t just dissipate into space; over approximately 3 billion years, these gasses built up and interacted with other gasses / processes that an atmosphere formed. Earth’s atmosphere today is made up of 78% Nitrogen, 21% Oxygen, 0.9% Argon, and 0.1% others. This mixture of gasses, compacted by the Earth’s gravitational force, exerts 360 degrees of 6.9 Kpa at sea-level. At 498.9 km above sea-level, the atmospheric pressure becomes zero
A vacuum is technically space devoid of matter; therefore, there are varying levels of vacuum. Space is said to be 99.999% vacuum because the amount of matter in Space is infinitesimal compared to the size of the Universe.
A hard vacuum (99.999%) on Earth can be constructed by pumping / sucking out the matter from a container, but while the internal contents of the vacuum would now have zero atmospheric pressure, the vacuum and contents or lack of still exists on Earth and is still experiencing 1 gravity. If you puncture the vacuum at sea-level, the 360 degree atmospheric pressure of 6.9 Kpa would force air into the vacuum.
In other words, a hard vacuum doesn’t negate gravity; if it did, gravity in Space wouldn’t be possible and NASA wouldn’t need the vomit comet to simulate micro-gravity. Therefore, when they say they can produce enough thrust in a hard vacuum to overcome 1 gravity, they quite literally are saying that within the vacuum on Earth, they can make an object weightless / move.
Note: Someone else already posted essentially what I did in a much more concise manner… but I already typed all that… so… gonna leave it up for now
If I remember right that is the slang term for a device used to simulated high force situations astronauts are expected to experience. So named for the frequent effect
It’s so much more interesting than the parent comment makes it out to be, though. In case you didn’t already read anything about it, it’s an ordinary (on the outside) jet that flies in parabolic arcs which at a certain point lets the passengers experience microgravity and float around the modified cabin for a minute or so at a time. Anyone can go for a ride last I checked… if you have several thousand dollars laying around, anyway.
I’m not a physicist, but I’ll try to answer your question:
Gravity, pressure (atmospheric), and a vacuum are not the same; nor are they mutually exclusive.
The Earth’s mass and centrifugal forces are said to exert a total of 1 gravity (1g). While the influence of gravity is scientifically never-ending, there is a distance or limit, known as the Hill Sphere where the effects of a celestial body’s’ gravity dissipates enough that its influence is scientifically negligible. For the planet Earth, the Hill Sphere is about 1.5 billion km or 0.01 astronomical units (AU).
Shortly after the Earth formed, there was no atmosphere and different types of gasses like Nitrogen, etc were being expelled by tons of volcanic activity; much like Venus. Due to the Earth’s gravitational force, these gasses didn’t just dissipate into space; over approximately 3 billion years, these gasses built up and interacted with other gasses / processes that an atmosphere formed. Earth’s atmosphere today is made up of 78% Nitrogen, 21% Oxygen, 0.9% Argon, and 0.1% others. This mixture of gasses, compacted by the Earth’s gravitational force, exerts 360 degrees of 6.9 Kpa at sea-level. At 498.9 km above sea-level, the atmospheric pressure becomes zero
A vacuum is technically space devoid of matter; therefore, there are varying levels of vacuum. Space is said to be 99.999% vacuum because the amount of matter in Space is infinitesimal compared to the size of the Universe.
A hard vacuum (99.999%) on Earth can be constructed by pumping / sucking out the matter from a container, but while the internal contents of the vacuum would now have zero atmospheric pressure, the vacuum and contents or lack of still exists on Earth and is still experiencing 1 gravity. If you puncture the vacuum at sea-level, the 360 degree atmospheric pressure of 6.9 Kpa would force air into the vacuum.
In other words, a hard vacuum doesn’t negate gravity; if it did, gravity in Space wouldn’t be possible and NASA wouldn’t need the vomit comet to simulate micro-gravity. Therefore, when they say they can produce enough thrust in a hard vacuum to overcome 1 gravity, they quite literally are saying that within the vacuum on Earth, they can make an object weightless / move.
Note: Someone else already posted essentially what I did in a much more concise manner… but I already typed all that… so… gonna leave it up for now
The… vomit comet?
https://www.livescience.com/29182-what-is-the-vomit-comet.html
If I remember right that is the slang term for a device used to simulated high force situations astronauts are expected to experience. So named for the frequent effect
Oh, interesting! Thanks for explaining.
It’s so much more interesting than the parent comment makes it out to be, though. In case you didn’t already read anything about it, it’s an ordinary (on the outside) jet that flies in parabolic arcs which at a certain point lets the passengers experience microgravity and float around the modified cabin for a minute or so at a time. Anyone can go for a ride last I checked… if you have several thousand dollars laying around, anyway.
So in theory if you built a vacuum tube from the earths surface to “space” and sealed it at both ends you could have a frictionless elevator
I mean… sure. But you could do the same from the surface of Earth to the height of the Eiffel tower. Or my uncle Bob’s third floor apartment.