For Questions That Don't Merit Their Own Thread

[Superluminal Gremlin]

 

What is the big white ball?

Is it water? Fuel?

Does anyone know?

[razark]

There are two of them. One is oxygen, the other is hydrogen.  From what I see, the one pictured is the hydrogen tank.

 

So yes, it's fuel.  And also water (some assembly required).

Edited August 26, 2022 by razark

[kerbiloid]

(Looks at the trailer with green letters at the down-right corner).

They put round gases into spherical tanks, and long gases into cylindric ones.

P.S.
The maroon captions look shocking.

"Liquified Hydrogen.
Flammable Gas."

If it's liquified, it's not a gas, it's a flammable liquid.

No "No smoking" like on the oxygen tank. Ok, it's "flammable", but oxygen is inflaming, too.

So, "Don't smoke near the oxygen tank. Go to the hydrogen one."

Edited August 26, 2022 by kerbiloid

[TheSaint]

15 minutes ago, kerbiloid said:

So, "Don't smoke near the oxygen tank. Go to the hydrogen one."

LOL. I was just thinking the same thing. I'm broken that way.

Edited August 26, 2022 by TheSaint

[DDE]

Can an average human literally punch through the pressure hull of a spacecraft?

[TheSaint]

4 hours ago, DDE said:

Can an average human literally punch through the pressure hull of a spacecraft?

Depends on the spacecraft. I remember a quote from one of the Apollo astronauts where they said that the pressure hull of the Lunar Module was so thin at certain points that you could just put your hand through it. Which makes sense, since it was only designed to hold 5 psi of pressure. But, I wouldn't try that with, say, the Space Shuttle, where the hull is designed to withstand reentry, atmospheric flight, etc. That's probably a little more sturdy.

[magnemoe]

4 hours ago, TheSaint said:

Depends on the spacecraft. I remember a quote from one of the Apollo astronauts where they said that the pressure hull of the Lunar Module was so thin at certain points that you could just put your hand through it. Which makes sense, since it was only designed to hold 5 psi of pressure. But, I wouldn't try that with, say, the Space Shuttle, where the hull is designed to withstand reentry, atmospheric flight, etc. That's probably a little more sturdy.

Yes, the lunar landing module was very flimsy as it had to be as light as possible and only handle 5 psi and lunar gravity. Now I kind of doubt you could punch a hole, but it would be easy to penetrate with an screwdriver or similar. 

Other crafts, no they are probably build stronger than aircraft as they face stronger forces. 

[kerbiloid]

It's even thicker than a beer can.

[DDE]

7 hours ago, TheSaint said:

I remember a quote from one of the Apollo astronauts where they said that the pressure hull of the Lunar Module was so thin at certain points that you could just put your hand through it.

The question was insoired by something to that effect said in Apollo 13 as well as Mark Watney's stress-induced rover-punching in The Martian.

[kerbiloid]

http://www.collectspace.com/ubb/Forum14/HTML/001072.html#:~:text=Due to the weight saving,three layers of kitchen foil.

Quote

Crew Compartment
The crew compartment was cylindrical in section in a welded and riveted construction, 92 inches in diameter and 42 inches deep, giving a habitable volume of 160 cubic feet, just sufficient for the two crewmembers to stand side by side. Due to the weight saving programs the compartment skin was reduced to a thickness of 0.012 inches, the equivalent of approximately three layers of kitchen foil.

 

(LEM)

[SunlitZelkova]

What is the longest length of a time for a vehicle (ship, car, tank, plane, spacecraft) to spend from development approval to first flight?

Space Shuttle was approved in 1972 and flew in 1981.

SLS was approved in 2010 and hasn’t flown.

[DDE]

5 hours ago, SunlitZelkova said:

What is the longest length of a time for a vehicle (ship, car, tank, plane, spacecraft) to spend from development approval to first flight?

Space Shuttle was approved in 1972 and flew in 1981.

SLS was approved in 2010 and hasn’t flown.

Angara, 1992 - 2014. There are many similar examples, but the first flight of a developmental prototype fudges up the math.

[kerbiloid]

https://en.wikipedia.org/wiki/Leonardo's_aerial_screw

Quote

The Italian polymath Leonardo da Vinci drew his design for an "aerial screw" in the late 1480s, while he was employed as a military engineer by Ludovico Sforza, Duke of Milan from 1494 to 1499. The original drawing is part of a manuscript dated to 1487 to 1490 and appears on folio 83-verso of Paris Manuscript B [it; pl], part of the papers removed from the Biblioteca Ambrosiana in 1795 by Napoleon and still held by the Institut de France in Paris.

In 2022 a drone based on Leonardo's design flew.^[2]

528 years

https://www.cnet.com/science/this-drone-flies-using-da-vincis-530-year-old-helicopter-design/

[magnemoe]

7 hours ago, kerbiloid said:

https://en.wikipedia.org/wiki/Leonardo's_aerial_screw

528 years

https://www.cnet.com/science/this-drone-flies-using-da-vincis-530-year-old-helicopter-design/

Not sure if that counts as in drone, people has made flying lawn mowers, no not operational ones as I know but model planes who looks like yes that is an flying  lawn mower. 

[DDE]

44 minutes ago, magnemoe said:

Not sure if that counts as in drone

Quote

Drones are not new.

- New York Times, 1946

The requirements for 'guidance' are pretty vague. There's an old canard about Michail Lomonosov sketching a twin-rotor spring-loaded drone to loft a lightning conductor after he saw an experimenter use a kite and get zapped to death. That's Russia's claim to the invention of both helicopters and drones.

Spoiler

 

Edited September 4, 2022 by DDE

[JoeSchmuckatelli]

What is "Io's Footprint"? 

[magnemoe]

On 9/4/2022 at 11:34 PM, DDE said:

The requirements for 'guidance' are pretty vague. There's an old canard about Michail Lomonosov sketching a twin-rotor spring-loaded drone to loft a lightning conductor after he saw an experimenter use a kite and get zapped to death. That's Russia's claim to the invention of both helicopters and drones.

  Hide contents

 

Would that thing even lift of on Titan? these cogs looks very heavy so do the structure. 
And yes the US developed propeller driven version of the V1 bomb during WW 1, never used in combat as accuracy was poor and it was an expensive system over dropping bombs. 
I say the V1 and V2 was pretty pointless systems anyway. Now you can say the same about strategic bombing until end of 1944 there you could drop kilotons on targets. 

[kerbiloid]

(Io)
The Love, Death & Robots s03e03 The Very Pulse of the Machine has revealed the true nature of Io, so I'm not surprised.

9 hours ago, magnemoe said:

And yes the US developed propeller driven version of the V1 bomb during WW 1

WWII.

And yes, why make simple when you can complicate. A tin pipe of the pulse engine vs propeller mechanics.

[razark]

7 hours ago, kerbiloid said:

WWII.

No, WWI.

https://en.wikipedia.org/wiki/Hewitt-Sperry_Automatic_Airplane

https://en.wikipedia.org/wiki/Kettering_Bug

[darthgently]

On 8/25/2022 at 10:38 PM, TKMK said:

What is the big white ball?

When I read this then glanced at the pic the first thing I saw was the Moon.  So the 3rd big white ball is the Moon, in case that is in question

[steve9728]

Weird question: if someone wants to demolish some buildings and build a new one on the same site, how to deal with the foundations of the old one?

[JoeSchmuckatelli]

5 hours ago, steve9728 said:

Weird question: if someone wants to demolish some buildings and build a new one on the same site, how to deal with the foundations of the old one?

Depending on the structure (and the jurisdiction) you may need an licensed architectural engineer to advise you or create a plan. 

Simple single story house foundations can be removed via jackhammer attachments on excavators and the debris hauled away - with the new foundation dug and poured on site.   That's in most places in the United States. 

 

If you are looking at a multistory building - you'd want to be sure that the original wasn't gooned up.  If it was you may have a major remediation issue. You do not want to try to use a foundation intended for a different building.  Hard stop.   Because the foundation is a critical component of the overall structure - it is not something that you should 'wing'. 

Edited September 17, 2022 by JoeSchmuckatelli

[kerbiloid]

Spoiler

150 kt underground nuclear demolition system.

 

[steve9728]

15 hours ago, steve9728 said:

Weird question: if someone wants to demolish some buildings and build a new one on the same site, how to deal with the foundations of the old one?

The reason why I have such a question: I finally back home and my mother said that have you seen someone can cut the rocks like cutting the tofu? Me: ?

"Ok, fine..."

Here used to be a community consisting of some Chinese version of the "Khrushchev House" and is for the employees of a state-owned company.

Spoiler

Here used to be:

And what they are planning is going to build three 44 to 46-storey flats to compensate the residents who originally owned properties here. An apartment building, an office building and hotel of about the same height, and five commercial buildings that should also be about the same height.

Sincere thanks to the soundproof windows. Shenzhen is a city founded in the 1970s and 1980s, and now I know how to answer the question "What is your city's specialty": does site noise count?

Edited September 18, 2022 by steve9728

[magnemoe]

2 hours ago, steve9728 said:

The reason why I have such a question: I finally back home and my mother said that have you seen someone can cut the rocks like cutting the tofu? Me: ?

"Ok, fine..."

Here used to be a community consisting of some Chinese version of the "Khrushchev House" and is for the employees of a state-owned company.

  Hide contents

Here used to be:

And what they are planning is going to build three 44 to 46-storey flats to compensate the residents who originally owned properties here. An apartment building, an office building and hotel of about the same height, and five commercial buildings that should also be about the same height.

Sincere thanks to the soundproof windows. Shenzhen is a city founded in the 1970s and 1980s, and now I know how to answer the question "What is your city's specialty": does site noise count?

I have seen images of stuff like that used in quarries. including something who looked like an giant chain saw who cut rock and using long wires  you move to cut rock. 
Bu that is because you want stones of an regular size for building or decorations. For making holes explosives or an jackhammer on an excavator to break up stone. 
Here they are not taking out stone blocks but as its close to other buildings you can not do large blasts and the jackhammers are slow. 

But the reason why you dig down into rock is usually to get basements levels and that looks a lot like an parking garage.