/sci/ - Science & Math

>>3133603
>air ship

oops, I know it's just one word :|

over 9000 ft

>Since the density of the air decreases with higher altitude, does this mean the rate of climb decreases with higher altitude as well?
No, you can totally fly into space and keep going.

>>3133636
he asked for rate of climb, not that you can fly into outer space

>>3133657
Oh, sorry then.

No, the rate of climb stays constant until you clonk into the wall that separates us from outer space.

>>3133603
A lot of things might change with altitude.

Thrust, air resistance => airspeed
airspeed, air density => lift

the positive buoyancy will stop when the air density is equal to the density inside the airship, and yes, the rate of climb will decreases as the airship goes higher

how high airship can theoretically go? when the positive buoyancy stops

no, it actually slows down as the density of the surrounding air becomes equal to that of the airship


u retord

>>3133710
>no, it actually slows down as the density of the surrounding air becomes equal to that of the airship

positive buoyancy will stop at that time, not that it will slow down after that

u retard

>>3133710
>>3133725
You are both wrong. This has already been answered: >>3133680

>>3133730

not-sure-if-serious.jpg

>>3133741
I have ridden in an airship.

We all felt the clonk. There can be no doubt.

If you don't believe me, you try riding an airship.

>>3133710

do you even know how buoyancy work?

>create vacuum inside of airshit.
>maximum low density.
>???
>SPACE!

Fuck rockets, we should be sending our shit into space with balloons.

>>3133755
If you can create a lighter-than-space craft, you can not only float into space, you can go faster than light with your warp drive.

>>3133755
>>create vacuum inside of airshit.

not possible, or even if it can, the container to have that vacuum will cancel any benefit from doing that

best options are hydrogen/helium

airship

how do they work

???

profit

>>3133765
Not once you're in THE DIAMOND AGE

>>3133897

wat

>>3133897

DIAMONDOID VACUUM BAGS LARGE ENOUGH TO TRANSPORT NORTH DAKOTA TO NORTH KOREA IN A DAY

And it doesn't really matter where you're going when you can just rally a large enough numerical force to hijack it to America. That's all that really matters in China.

>Create hot hydrogen balloon
>SPAAAAAAACE

Where's my prize for inventing easy, economical space travel?

what is this, I don't even

Space blimps are best hypothetical launch vehicle. Safer and faster than a space elevator, more mobile than a railgun, more economical than a rocket.

However, once you've gotten to a high altitude you need some other vehicle if you want the thrust to set up an orbit of any kind; that's what rockets are good for.

>make airship with solar sail material
>vacuum inside, supported by radiation pressure
>sail on the top of the atmosphere

What matters is velocity, the earths gravitational pull is pretty much the same on the edge of the atmosphere as it is on the ground.

>>3135549

air resistance will be far less, good for rocket launching at that time - if that was safely possible

what is this, I don't even

>>3135519

Use hydrogen as coolant!

what is this, I don't even

nigger!!!!

>>3133755
brb inventing vacuum field drive

what is this, I don't even

>>3137673

Well I, for one, even.

>>3135549
even so, you've still climbed a bit of the gravity well for free

potential energy etc, even with no velocity

what is this, I don't even

>>3138923
This is the thread where the sky goes "Clonk!"

>>3138929

does that really exist? wtf

Engines don't operate as well at extremely high altitudes, usually because of air temperature and density.

The density of helium is 0.1786 kg per cubic meter. The density of dry air at the surface of the Earth is 1.2754 kg per cubic meter, and decreases with altitude by the coefficient described on the chart. When the density of helium matches the density of the Air it will be neutrally buoyant. Airships have a lot to weigh the helium down, so they will become neutrally buoyant at a much lower altitude than raw helium.

>>3139463
Forgot the pic.

>>3139463
>>3139474
thought so

>>3139407
rockets should work just as well it does at sea level, right?

The rate of ascent should decrease, but by how much would depend on how much the membrane can stretch... i.e. The membrane carrying the lighter gas will expand as the pressure decreases with increased altitude and will displace a larger volume.
>>3140753
Rockets work waaay better at higher altitudes (less gravity). In addition, the rocket has consumed most of it's weight at higher altitudes and is also significantly lighter.

>>3140801
>The membrane carrying the lighter gas will expand as the pressure decreases with increased altitude and will displace a larger volume.

^ THIS

and temperature varies with altitude, so the 'balloon' should be able to accommodate the expansion of the gas

>>3140753

Yep. Rockets outperform air-breathing engines at high altitudes (if a worthwhile comparison could be drawn since they're very different mechanisms).

They carry all their own fuel, so they're not effected by the external environment. And as the other guy stated, the lighter they are, the better they perform. And at high altitudes, they've become lighter.