How and when did humans discover there was no air in space?


How and when did humans discover there was no air in space?

In: 1574

Scientists noticed long ago that air pressure decreases as you climb mountains. It was Blaise Pascal (who the unit of pressure Pascals is named after) who conducted this experiment which led other scientists to believe that at a certain altitude, you would get a near-perfect vacuum.

1643 Torricelli ~~indebted~~ (typo!) invented the barometer (to measure air pressure)

1648 Perier (prompted by his brother in law, Pascal) climbed Mount Puy de Dome with a barometer. Noticed that atmospheric pressure decreased with altitude

1659 von Guericke experimented with the vacuum pump. He concluded that the atmosphere was around the earth in a shell, getting less dense with altitude, and so it must reach a vacuum at some point

1687 Newton put forward his theory of Universal Gravitation

As you go up mountains, the air becomes “thinner”. This is clear from human experience at higher elevations. Mountain climbers face difficulty breathing, and they also observed instruments to measure pressure (the barometer) in the mountains in the 1600s.

From this it’s fairly easy to extrapolate that as you keep going higher, the air will keep reducing, till you reach some point where there’s no air, or almost no air.

Now the first real objects to reach space came in the 1940s (German v2 rockets), and definition of the boundary between earth and space (Karman line) were first proposed in the late 1950s. Sputnik and Laika also happened in the late 1950s.

So in a sense, no air in space was confirmed in the 1950s, but it was expected given what we (as humanity) knew from the 1600s.





one guy went up, took his helmet off, and went “Nope”, then quickly suffocated. that guys name? – Richard Simmons. …and thats why we dont hear anything from him anymore.

Interestingly, while people are talking about 17th century discussions of pressure and the like, as far back as the ancient Greeks agreed that what was out in space wasn’t “air.” They called it “aether,” and decided that that was why planets orbited the way that they did.

So “you can’t breathe in space” is actually an idea that goes back thousands of years.

[I believe they captured the moment in this documentary I saw.](

Funny bit of trivia: some self-styled scientists (who may have degrees to lend credence to their claims) still believe that interstellar space is formed out of aether and isn’t actually a vacuum.

For the longest time, scientists believed in aether because they couldn’t explain why light travels through space if there’s no medium to propagate it with.

Now we know that light is an electromagnetic wave and is self-propagating – it needs no medium. Einstein’s work in this area helped dispel that notion entirely, for most respectable scientists.

So… I don’t know the exact date, but it wasn’t until the early 1900s where prevailing scientific thought changed from “aether” to “vacuum” for the space between stars.

We suspected it long before we were able to fly. We would have known from having to breath harder after traveling up mountains that there was less breathable air at altitude. What we didn’t know was how high the atmosphere actually extended.

One of the earliest flight experiments came shortly after the development of the hot air balloon in the late 1700s. Before the earliest aeronauts took to the skies, they sent a duck (a flying bird, known to be able to survive at altitude), a chicken (a flightless bird, but with an anatomy similar to a duck) and a sheep (a mammal, with physiology similar to that of a human). When all three survived their balloon flight, we knew that our atmosphere was thicker than we previously suspected.


There’s an Air in Space Museum?