The Last Post Game!!!!

[Swatopluk]

Ich bin Graf Zahl und zähle auf ihre Stimme.

Last Post

[Sibling Zono (anon1mat0)]

Last _{Graf Von Zeppelin?} Post

[Swatopluk]

Unlike his American incarnation Count von Count the German has no 'von'

And I actually like the German version of the bone song better
https://www.youtube.com/watch?v=GyP1cyQXwX4

Last Post

[Aphos]

Last _{or maybe Led Zeppelin} Post

[Swatopluk]

Lead is not a good cosntruction material for lighter than air crafts

Last _{also too soft} Post

[Sibling Zono (anon1mat0)]

But possible as demonstrated by the MythBusters.

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[Swatopluk]

I theory one could also built an armored balloon that could resist heavy artillery and be 'filled' with vacuum.
The problem is that it would have a diameter of several miles.

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[Sibling Zono (anon1mat0)]

That would justify a rigid structure.

Last _{you can use kevlar+carbon fiber to tolerate the material stress at a lower weight} Post

[Swatopluk]

That is not much use against explosive shells, esp. not those with impact fuses.
To be 'vacuum resistant' it would have to be rigid in the first place.

Btw, it would be nice entrance exam question how large a hydrogen/helium/vacuum balloon would have to be that had an outer shell of iron one metre thick.
The math is easy but it would require the examinee to think a bit outside the normal.

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[Sibling Zono (anon1mat0)]

That would have planetary dimensions.

Last _{better build a dyson sphere} Post

[Swatopluk]

A 1 atm of atmospheric pressure at 25°C the diameter of the 'vacuum filled' iron balloon (hull thickness 1 m) would have to be 40 km to begin to float.

On Earth that would be problematic since the atmosphere does not extend far enough out. The drop of pressure with height would require a greater diameter and so forth.

One would have to try it on Venus or Jupiter.

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[Sibling Zono (anon1mat0)]

It would never work with a sphere, at less than 9Km you have 1/3 pressure.

Last _{a disc OTOH...} Post

[Swatopluk]

The more one deviates from the spherical shape, the larger the relative surface gets.
As I said, Earth is not a place where it could get tested.

Last _{I also doubt the structural stability} post

[pieces o nine]

Btw, it would be nice entrance exam question how large a hydrogen/helium/vacuum balloon would have to be that had an outer shell of iron one metre thick.
The math is easy but it would require the examinee to think a bit outside the normal.

Last     _{Lindorm, are you paying attention to these exam question suggestions?}     Post

[Swatopluk]

I see only limited connection to railways

Last _{armored trains went out of fashion with fascism} Post