Startups building balloons to hoist tourists
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If this needs to be said, i think its not clear to everyone... being "in space" is not what causes weightlessness. "Falling" towards your local gravitational source does it. This includes orbiting.
Until they start decelerating, which is immediately. They’ll also feel it fairly rapidly, I think.
https://en.wikipedia.org/wiki/Reduced-gravity_aircraft#Opera... (emphasis added):
“The sensation of weightlessness is achieved by reducing thrust and lowering the nose to maintain a neutral, or "zero lift", configuration such that the aircraft follows a ballistic trajectory, with engine thrust exactly compensating for drag”
If you crush something in a hydraulic press, it might have balanced forces and zero acceleration.
For that matter, Im not accelerating when I lay on the surface of the earth, but I hardly feel weightless.
Weightlessness only feels weird because we rarely feel it.
If you were suddenly in empty space (e.g. in an area with zero intrinsic acceleration), you would feel like you are falling.
Because the feeling of falling is actually the feeling of NOT having the constant gravity (i.e. acceleration) you're used to.
If you were born in weightlessness, gravity would be the strange feeling (cue Bane saying, "you only adopted weightlessness, I was born in it").
https://en.wikipedia.org/wiki/Drop_tube -- https://en.wikipedia.org/wiki/Reduced-gravity_aircraft -- https://en.wikipedia.org/wiki/Free_fall
The opposite of falling is accelerating, and you feel acceleration. A rocket rocketing in an empty universe would feel the same as a rocket rocketing in orbit would feel the same as a rocket just sitting around on Earth. Wait, that last one's different...
We happen to live most of lives in a somewhat exceptional case of constant acceleration (with respect to falling). The ground below our feet has gotten us pretty used to acceleration. But, if you jump, you'll feel like falling too!
Our brain is used to gravity. That is why weightlessness feels weird.
But falling and weightlessness are indistinguishable to your brain. They are exactly the same thing.
So, if all the gravity around you suddenly disappeared, your brain would initially tell you that you are falling.
Only after some time would you convince yourself that, "No, I'm not falling... Gravity just disappeared. I'm just weightless."
Considering the same question for geostationary orbits had me confused for a moment and then I realised we are not in a fixed location relative to the Earth, thanks to the Earth's spin. I wonder what extra percentage weight we would feel if it weren't spinning.
So the answer is, if you could hold the ISS stationary without falling, people in it would feel almost as much gravity. You would have to go much higher than the ISS to feel weightless without orbiting/falling.
Assuming people feel weightless at 1m/s2 or less, you can solve for that! And the answer is 13,600 km.
As for the centrifugal force from the Earth's rotation, Wikipedia puts it at about 0.3% (which, added to the effect of the Earth's bulge, means you feel a total of 0.5% less weight at the equator than at the poles).
https://www.quora.com/What-is-the-acceleration-due-to-gravit...
At the ISS, the extra distance from the center of the earth is minimal compared to the radius of the earth itself. Therefore, there wouldn't be a great difference.
The centripetal force question is a little more challenging, but still in the realm of algebra. The complicated part is setting up the problem and understanding where the forces are coming from and if/how they cancel each other.
You have to get pretty far away to experience true "weightlessness".
The convention was to never use the term "zero gravity," since using that term would perpetuate a common misunderstanding. Instead, we've used the term "microgravity" in its place—which makes sense, as there are still small gravitational forces acting on every object in space.
NASA also published a webpage with a good explanation of what microgravity is, with a nice diagram of how it works (including a visual of the parabolic flight): https://www.nasa.gov/learning-resources/for-kids-and-student...
Indoor skydiving lets you ‘fall’ for hours, but you don’t accelerate so you don’t feel weightless.
That said this seems… dangerous. Giving me OceanGate vibes.
It's clearer at 100k feet, but if you're intent on not seeing it then you still won't see it.
I have doubts that even orbit would change their minds. They've already gone through contortions about why it's night in some places when it's day in others. I am quite certain they're up to the task of explaining why they're over America now and then Africa, previously out of sight, a few minutes later.
It's just not worth arguing with those on intent on being stupid. They can simply say "no" and no power of evidence or logic can force them to do otherwise.
I also remember reading (but cannot find a reference) that it is easier to design a container for overpressure than to design it for underpressure.
In this case, I think providing a safety valve that fails before the container implodes violently may be a a good option (https://en.wikipedia.org/wiki/Pressure_vessel#Safety_feature...)
My concern would be that the team would cut safety corners until the probability of success just barely rises above some threshold, rather than engineering everything to have as low a risk as is feasible. Is 0-1atm easier than 1-infinity atm? Yes, but that just means you can cut more corners.
It's like the cheaper knock off (poorly funded) version (not in a space ship) of going to space vs the well funded rocket based company.
It would be an interesting new way to travel.
The U2 was famous for this issue, the pilots were flying on a knife edge because a stall (a less aggressive situation that deploying from a static balloon) would mean the plane starts accelerating well beyond it's structural limit before you can do anything about it.
I'm glad there are multiple players in this space so they can compete and drive the cost down over time.
Answer: exclusivity.
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Or to explain the topic in economic terms: with their offering, these companies offer a given supply for balloon rides into the stratosphere. On the other hand, for a given price for such a ride, a demand to buy it for this price. What a company wants to optimize is
(number of sales for a given price) * price.
Since the supply is currently rather limited, the price can be set to a very high value to optimize this function.
They need to make back the cost of R&D. IE, based on how much it costs to design and certify the balloon, the first flight might operate at a loss. They will need to perform X successful flights before they break even on the cost of R&D.
IE, it might cost $10,000 to pay the staff on the balloon ride, but the vessel itself might cost 10 million to design. It might use $200,000 worth of parts, but the factory cost $20 million to build. Those costs need to be amortized by paying passengers.
I'm sure the cost will come down, just like everything else. See https://en.wikipedia.org/wiki/Economies_of_scale
Simultaneously, from all sides sellers are now constantly testing the elasticity of consumer budgets to maximize profit until they exclude the bottom x%, it's a huge financial strain for the poorest among us.
That’s kind of the whole point of the capitalist / consumerist model: first movers take high risks with investment and can reap outsized returns if successful, while success breeds competition from new entrants who have a proven market and a product to copy. The expansion of the market means more price competition, driving prices and returns down.
I’m not saying it always works like that, just that it generally does.
This suddenly makes paying for a 0g flight a steal.
This CEO of a balloon company doesn’t seem to understand how balloons work.
https://www.cnn.com/americas/live-news/titanic-missing-sub-o...