until gas is ejected and pushed on

I haven't watched the video but I assume that you are watching a space ship launch off from the ground right

Regardless, the vacuum is an inequivalent comparison to space

you can see the rocket move the second the jet stream appears @Rigg5

You're not comparing apples to apples

?

I mean

And yes, to an extent

Nope

if it needed a medium to move

it would have the atmosphere to push off of so

it’s not a perfect vacuum

Space is 10 to -17 tor value

smoke isn't necessary

space isn't a perfect vacuum

extreme pressure differential

no large area in the universe is

no but there's not a huge difference in pressure

simply put

if you go up to 100km

which is around where space is agreed to begin

but still has a thin atmosphere

it's not like

the air is pressurized at one atmosphere

and then immediately switches to a near perfect vacuum

^

There is stuff

Then there is less stuff

gravitational attraction pulls gases toward the earth, and the compression forces from the gasses on top

Then there is no stuff

provide higher pressure at sea level

That’s how our atmosphere works

and with less gas on top the higher up you go, the lower the pressure

in fact, the earth's atmosphere may extend, at an indescribably small thinness, hundreds of thousands of kilometers away from sea level

But you get to a point in deep space

where the amount of matter in a given space

is so miniscule, that the degradation it causes in movement and orbits is negligible over any reasonable amount of time

in fact, the ISS has to perform periodical boosts to keep its orbit high enough every couple months

as it loses 2-4 m/s in that time frame from orbital degradation

as they are only I think 450 km or so above the surface, so there's still a little bit of atmosphere to be slowed down

The propellant is an oxidizer and creates its own chemical reaction to produce thrust.