would be cool if inertia wasn’t a thing
People have a terrible understanding of orbital mechanics and apparent weightlessness. It’s not like gravity just stops affecting you after you get out of the atmosphere. Getting out of the atmosphere is the easy part of getting to orbit. Going sideways fast enough is the hard part.
I feel like everyone should play KSP, just to get a taste of it
I used to baby sit a friend’s kid when he was a wee lad, frankly we spent most time playing KSP. Used to give him challenges like if he could build a ship using x amount of parts and make orbit would let him order out pizza instead of food his mom prepared for us. He rarely succeeded at first but apparently kept at it long after I stopped mentoring him and apparently is now going to school to be an aerospace engineer. And before all that his mom could never get him to do his math homework as a tyke.
Pizza has a strange powers over humans. Good job friend.
The real friends is the pizza we make along the way.
Definitely not all those kerbals stranded on Duna. He never did figure out how to properly make it there and back
Nothing got me working on math quite like trying to figure out my ship’s ∆v back in 2014 before I installed Kerbal Engineer
What a great origin story
what? are you telling me I couldn’t reach the other side of the planet by jumping for 12h ?
Anon’s airship has inertial dampeners. Checkmate, atheists.
That’s easy, instead of accelerating towards your destination you just have to brake and stop moving to let the earth move under you, checkmate physics
Also, wind.
Doesn’t inertia fuel our magnetosphere?
I hope troll logic makes a comeback
I hope so too, given how many people are taking this seriously.
ikr they forgor to say “Problem?”
This is just playing into the hands of big basket.
Missed opportunity there: get more seats installed or attach the balloon to a bus or something, I don’t know - and whenever the earth below rotates to where your destination is, just yeet yourself out Felix Baumgartner style.
More people means more profit and fewer busloon trips needed, meaning the eco footprint is smaller and you’ll get a Christmas card off a random polar bear/penguin thanking you your service.
The only minor inconvenience I can think of is that your parachute effectively takes up your carry-on luggage allowance so you’ll have to pay to check anything that doesn’t fit in your pockets, but other than that I think you’re good to go
Don’t forget to thank the busdriver
I think in a balloon bus, it’s a balldriver
attach the balloon to a bus
Yo boys we’re going on the battle bus (sorry for my terrible joke, it just reminded me that I’m fucking old because this was popular like 6 years ago)
just yeet yourself out Felix Baumgartner style.
this would be so awesome. i’d spend the whole time trying to come up with something clever to say, right before the yeeting.
I’m not a rocket surgeon, but I think the amount of energy required to reach orbit is higher than what a jet would use.
Nah, weather balloons can get really really high. The problem here is, the atmosphere doesn’t “end” it just gets thinner and thinner. You would still spin with the earth, just a bit slower.
Okay so then like, 14 hours.
I think it would probably be more like several days.
And also in the opposite direction to what OP is thinking.
The problem is the atmosphere more or less spins with the planet.
Ignore winds for a second, and just imagine the hot air balloon going up. The balloon goes up because the density of the balloon is lower than the air it’s displacing. At some height that will no longer be true, and the density of the balloon will be the same as the atmosphere, at that point the balloon can’t go any higher. Because of that, the balloon will always be in a fairly dense part of the atmosphere.
So, if it weren’t for the winds, the balloon would just rotate with the planet. But, the balloon will be caught in the wind. If it takes off from North America or Western Europe, it’s most likely going to end up in a westerly trade wind. If it’s going up from South America or Africa the main trade winds would be headed east. Some of these would be hurricane force winds at the surface, but they’re still much slower than a jet. So, a balloon could go around the globe, but it would take 3-4x as long as a jet to go the same distance.
These trade winds are how the Chinese spy balloon was launched from China but was able to float over the USA. If a balloon can go up and down in the atmosphere, it can often be directed pretty well towards some specific spot because there’s often a wind at some height going the direction needed.
Also, to address the “inventor’s” idea that a balloon in the stratosphere would “stay in one place”, even if you could completely leave the atmosphere you wouldn’t stay in one place. Anything going up from the surface would have a certain amount of angular momentum due to the rotation of the earth. At the surface this is 460 meters per second at the equator, or approx 1000 miles per hour. So, if you wanted to not rotate with the earth, you’d have to accelerate to 1000 miles per hour relative to the surface just to be stationary with respect to something outside the planet, like say the sun. You can do this in a jet. In fact, if you take a jet going west, sometimes you end up going more or less the same rotational speed of the planet, just the opposite direction. This can be fun when you take off at 9am, fly for hours, then land at 9am. It gives you pretty brutal jet lag though.
Orbit doesn’t really come into it. They’re talking about a balloon in the stratosphere. But, if you wanted to go into orbit, to be in orbit you have to accelerate sideways. Whether you’re going east to west, west to east or north to south orbit has nothing to do with the rotation of the earth, only its mass. To reach low earth orbit you’d have to get to about 8 km / second, or about 20x as fast as the rotation of the earth. This is what most of the rocket fuel is used for when a rocket puts something into orbit.
In fact, the scenario describes is one where you could never be in orbit. If you’re in a fixed place with the earth rotating under you, your orbital velocity is zero, and there’s no orbit where that’s possible.
The problem here has almost nothing to do with the atmosphere and nearly everything to do with the massive amount of energy required to cancel out the inertia of already moving at about 1000MPH radially relative to the center of the earth, assuming anon launches his magic balloon from the equator. The kind of energy that takes, oh IDK, a fucking rocket.
In other words, if you could actually float above the atmosphere somehow, you wouldn’t just stop relative to the surface of the planet because it’s not the air current that carries you along, but the fact that you started off moving along with the earth’s rotation and did nothing to slow down.
Well that’s why they’re going really high up, so the earth rotates beneath them
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Conservation of momentum.
You don’t suddenly stop moving with the Earth just because you’re no longer standing on terra firma. Like, if you throw a ball it doesn’t just suddenly fall straight to the ground once it leaves your hand.
Plus, in a hot air balloon you’re still in the atmosphere… Which is also moving. But even if you were in the total vacuum of space, the above applies and you still wouldn’t remain stationary without actively countering the momentum you already have. And then you’d just be pulled in by gravity, unless you actively counter that too. And all that countering of forces is way more costly with fuel than simply accounting for the fact you’re already moving at super high speeds along with the rotation of the planet.
Conservation of momentum doesn’t really come into it for this scenario. A balloon is a huge, low-density object so it’s basically always going to go at the same speed of the wind at whatever height it’s at.
The only way conservation of momentum could matter is if the balloon could get out of the atmosphere so it wasn’t being pushed around by the wind. But, of course, the way a balloon works is that it goes up as long as its density is lower than the density of the atmosphere it’s in. That means it’s always going to be stuck in fairly thick atmosphere, and always subject to the winds.
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Randall Munroe answered that in detail - https://what-if.xkcd.com/58/
That does not answer the question. The balloon is not going to orbit, high atmospheric balloons exist and do not require propulsion.
The reason it won’t work is because the atmosphere is coupled to the ground and rotates with the ground.
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This is dumb as shit. Hot air balloons only go so high, less than 70k feet according to records. They only stay aloft if the heat is continually applied, if not, air cools and they sink. They move with the air, and the air moves with the planet.
This doesn’t work for the same reason jumping in an airplane doesn’t slam you into the back wall.
I don’t think it was posted because it was brilliant…
Balloons using hydrogen can reach 33 miles. But even then the atmosphere still moves with the ground.
Yeah, but anon smart, u dumb. Checkmate.
Ok but they’re going really really high up
If you go much higher the balloon will leak heat through black body radiation faster than you’ll be able to heat it. And even if you insulated the balloon in a way that didn’t add too much weight you’d eventually get to the top of the atmosphere and hot air balloons won’t go into space because they don’t have any propulsion systems.
If you fill it with helium, it will go into space, and then it will immediately explode.
70k ft: 21,336m
Sig figs!!
70k ft = 21 km
Going from the US to Japan or China by hot air balloon would mean going the long way over Europe due to the jet stream, this would take more than 12h.
Your move, globe heads.
