For Questions That Don't Merit Their Own Thread

[SunlitZelkova]

3 hours ago, kerbiloid said:

1948 article

https://forums.spacebattles.com/threads/invasion-base-on-the-moon.331069/

The Lunar Race real beginning and aim.

https://warspot-ru.translate.goog/15171-zavoevanie-luny?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=ru

Apparently there is a hoax with somewhat widespread dissemination among ufologists and conspiracy theorists in Russia, in which it is claimed that during the Potsdam Conference, Stalin proposed splitting the Moon among the four victorious powers (USSR, US, UK, and France).

If it was real though the costly race could have been avoided lol.

[kerbiloid]

23 minutes ago, SunlitZelkova said:

Apparently there is a hoax with somewhat widespread dissemination among ufologists and conspiracy theorists in Russia, in which it is claimed that during the Potsdam Conference, Stalin proposed splitting the Moon among the four victorious powers (USSR, US, UK, and France).

If it was real though the costly race could have been avoided lol.

This was thought out by Roman Arbitman in his pseudohistorical fiction novel, while the projects listed in the article were real, and were funded with real money by real governments.

[Hyperspace Industries]

9 hours ago, K^2 said:

A lot of linear accelerators are built as banks of cavities with applied RF field providing electrostatic potential to drive charged particles through it. Not all thrusters are going to use the same principle, but there is going to be some sort of equivalent where more power gives you more thrust.

No. You don't want batteries in your ion drive engine. They are too heavy for the amount of energy they can hold. You are better off just burning kerosene at this point and using exhaust directly. The whole point of an ion drive is that you have something with enormous energy density that you can use to generate high I_SP by accelerating propellant directly. For example, you might use solar panels which can't give you a lot of power, but they can give you an huge amount of energy over the life time of the panel. Currently, the only attainable power sources that give you both the high power and high energy density are nuclear.

So if you're designing an ion drive engine, you're always going to be either building for a low thrust application with solar panels or nuclear RTG, or a high power system that's powered by a full nuclear reactor. No other existing power sources are remotely adequate.

Well, it's closer to a weird arcjet engine than an ion engine, here's a description of my idea, just so I can be sure it won't work, because it is not even close to an ion engine design. Sorry for wasting everyone's time with these posts:

The fuel tank mass would be at least 50% regular hydrogen, to account for inefficiency in breaking up the hydrogen, the rest would be solar panels to provide power.

The hydrogen would be pumped into a "combustion chamber" where one or more 300 volt 50 amp arcs would turn some of it into atomic hydrogen, which would then (as in the welding) recombine into diatomic hydrogen, creating heat and releasing energy which would propel it at high speeds out of the nozzle, producing thrust. Oxygen could also be added for combustion.

Sorry for pestering you with my dumb ideas, but I really want to know why this design won't work, and it's not like an ion engine.

[DDE]

26 minutes ago, Hyperspace Industries said:

The hydrogen would be pumped into a "combustion chamber" where one or more 300 volt 50 amp arcs would turn some of it into atomic hydrogen, which would then (as in the welding) recombine into diatomic hydrogen, creating heat and releasing energy which would propel it at high speeds out of the nozzle, producing thrust.

This sounds dangerously like a perpetual motion engine. Are you sure you don't want a VASIMR or something more mundane?

[SunlitZelkova]

50 minutes ago, kerbiloid said:

This was thought out by Roman Arbitman in his pseudohistorical fiction novel, while the projects listed in the article were real, and were funded with real money by real governments.

Yes. It was a joke in relation to military use of the Moon.

[K^2]

17 minutes ago, Hyperspace Industries said:

Sorry for pestering you with my dumb ideas, but I really want to know why this design won't work, and it's not like an ion engine.

It's not that it won't work. It's that it's less efficient than a bunch of other, simpler options. There is nothing wrong with the concept on the fundamental level.

Ultimately, what you're trying to do is making propellant depart your ship as rapidly as possible. You have two principal ways of achieving this. You can either make propellant really hot and let thermodynamics do its thing or you can apply electromagnetic forces to accelerate propellant.

If you are going with any kind of thermal engine, the limiting factors are temperature of the chamber and how light the particles of propellant are. The lighter the particles, the more velocity they'll have at the same temperature. With water exhaust, a LH2+LOX engine is already really, really close to the limit before your combustion chamber starts to melt. There are some clever ideas for afterburners, but they're more about augmenting thrust than I_SP. So the only way to get better efficiency is to have exhaust that's lighter than water. Realistically, that's helium or hydrogen. And there are few reasons not to go hydrogen at this point. At this point, you'll have to start adding heat from external source. How you do this is kind of irrelevant. An electric arc is fine, but you can also just use a nuclear reactor. That's all that NTR is. You pipe hydrogen through core of a reactor and use the heat to drive the rocket. And the thing is, the I_SP of an NTR is also just limited by temperature at which components start to melt. And you can't go much past that. Even if you decided to recombine atomic hydrogen into molecular, you are still temperature-limited, so you aren't getting a better I_SP.

There are two ways to circumvent it. First, you go even lighter. Don't recombine hydrogen and use atomic hydrogen for propulsion. This can let you get more I_SP at the same temperature. This is where I thought you were going with all of this. It is, however, very energy-inefficient. Your other option is to have other means of confinement. Basically, instead of working with a gas, you start working with plasma. VASIMR rockets do precisely that. They are essentially thermal rockets with a plasma bottle for a chamber. Here, instead of wasting energy on splitting hydrogen, just increase the energy you put into plasma and get more thrust. There is just no reason to deal with atomic hydrogen once you are working with plasma until you get into absolutely absurd energy ranges, but then the question becomes what your power plant is?

So in the end, there just isn't a niche for atomic hydrogen in anything remotely like modern rockets.

[ARS]

Just like how deforestation affect the change on Earth's climate, could (over)-reforestation (I don't know the term, but essentially too much trees on the planet) push the Oxygen level on Earth's atmosphere to a deadly concentration?

[K^2]

1 hour ago, ARS said:

Just like how deforestation affect the change on Earth's climate, could (over)-reforestation (I don't know the term, but essentially too much trees on the planet) push the Oxygen level on Earth's atmosphere to a deadly concentration?

Seems unlikely. The more oxygen you get in atmosphere, the more flammable everything gets. Historically, the highest that the partial pressure of O2 got to was about 0.35 bar. Oxygen toxicity to humans starts at about 0.5. But there are a lot of other life forms that can be far more sensitive. Also, excess oxygen allows for a lot of life that isn't possible now, like giant flying insects which will simply suffocate in flight in modern atmosphere. So the consequences to climate, flora, and fauna can be very dramatic. But I don't think it will be directly poisonous to humans.

[JoeSchmuckatelli]

2 hours ago, ARS said:

Just like how deforestation affect the change on Earth's climate, could (over)-reforestation (I don't know the term, but essentially too much trees on the planet) push the Oxygen level on Earth's atmosphere to a deadly concentration?

Slightly related to your question: https://www.google.com/amp/s/news.mongabay.com/2021/05/is-planting-trees-as-good-for-the-earth-as-everyone-says/amp/

O2 isn't the risk, ham-handed and ill informed people with the best of intentions, lots of money and popular support can cause more harm than good. 

[magnemoe]

4 hours ago, K^2 said:

Seems unlikely. The more oxygen you get in atmosphere, the more flammable everything gets. Historically, the highest that the partial pressure of O2 got to was about 0.35 bar. Oxygen toxicity to humans starts at about 0.5. But there are a lot of other life forms that can be far more sensitive. Also, excess oxygen allows for a lot of life that isn't possible now, like giant flying insects which will simply suffocate in flight in modern atmosphere. So the consequences to climate, flora, and fauna can be very dramatic. But I don't think it will be directly poisonous to humans.

That was back during the Carboniferous time, you got trees fungus was unable to break down who would reduce co2 levels but don't explain the high oxygen level. 
And I guess this was pretty damp times else forest fires would be very common, guess it was in dryer areas. 

[K^2]

8 minutes ago, magnemoe said:

That was back during the Carboniferous time, you got trees fungus was unable to break down who would reduce co2 levels but don't explain the high oxygen level. 

Yeah, apparently virtually all of the world's coal deposits are from that time, when trees were already a thing, but fungus that can break down cellulose wasn't, and trunks of dead trees would just accumulate. Which is both amazing and terrifying, seeing how we're releasing that carbon back into atmosphere for the first time in hundreds of millions of years.

 

That does lead me down a thought path, though. What if we were to engineer a cellulose alternative that would be just as viable as building material for the plants, but that existing enzymes are useless against, and just started planting forests upon forests of these instead of regular trees. Could we use that to lock up enough carbon to make a difference? It's ok if these engineered trees aren't as competitive biologically, as when you plant a grove, whatever you planted has a significant advantage of being there first. Bonus points if it's actually a viable construction material too, giving us a wood alternative that doesn't rot and is just as or more environmentally friendly. Might be a good angle to get funding for it based on this as well.

From perspective of genetics, ecology, and energy use, this seems viable. But my organics and biochem-fu is weak, so I have no idea how hard it'd be to even come up with a structure that is still essentially sugar based, is strong, and is resistant to the array of enzymes other organisms use to break down cellulose and other polysaccharides already.

[magnemoe]

16 minutes ago, K^2 said:

Yeah, apparently virtually all of the world's coal deposits are from that time, when trees were already a thing, but fungus that can break down cellulose wasn't, and trunks of dead trees would just accumulate. Which is both amazing and terrifying, seeing how we're releasing that carbon back into atmosphere for the first time in hundreds of millions of years.

That does lead me down a thought path, though. What if we were to engineer a cellulose alternative that would be just as viable as building material for the plants, but that existing enzymes are useless against, and just started planting forests upon forests of these instead of regular trees. Could we use that to lock up enough carbon to make a difference? It's ok if these engineered trees aren't as competitive biologically, as when you plant a grove, whatever you planted has a significant advantage of being there first. Bonus points if it's actually a viable construction material too, giving us a wood alternative that doesn't rot and is just as or more environmentally friendly. Might be a good angle to get funding for it based on this as well.

From perspective of genetics, ecology, and energy use, this seems viable. But my organics and biochem-fu is weak, so I have no idea how hard it'd be to even come up with a structure that is still essentially sugar based, is strong, and is resistant to the array of enzymes other organisms use to break down cellulose and other polysaccharides already.

CO2 levels was 8 times higher than now so we are kind of trying to recreate the Carboniferous although we need the high oxygen level for the giant bugs  

Making trees who don't break down on the other hand sounds like an very bad idea seeing how much problem we have with plastic. Just scale it up an high order of magnitudes. 
Normal trees would work well enough, as long as the co2 problem is pretty short lives who I assume. 

[kerbiloid]

7 hours ago, ARS said:

Just like how deforestation affect the change on Earth's climate, could (over)-reforestation (I don't know the term, but essentially too much trees on the planet) push the Oxygen level on Earth's atmosphere to a deadly concentration?

The deforestation is running mostly in equatorial zone, where the fallen trees rot in a couple of weeks, releasing all accumulated carbon back into the air.

So, the tropic forests have zero carbon (and thus, oxygen) balance.
They mean almost nothing in sense of the atmosphere, and their presence/absence is a problem of the locals, (As everything there which is not a bog covered with trees anymore, becomes a desert).

The real carbon/oxygen balance is provided by the cold bogs of subarctic zone (see them white), where fallen trees sink and get buried long before they can rot, and by the ocean with its enormous carbon dioxide capacity.

[Gargamel]

On 12/7/2021 at 2:02 PM, Hyperspace Industries said:

Also, shouldn't my question have been answered before you posted yours? Those are the rules, aren't they?

No, there’s no rules to this thread.   There’s often multiple conversations going on.  

[K^2]

5 hours ago, magnemoe said:

Making trees who don't break down on the other hand sounds like an very bad idea seeing how much problem we have with plastic. Just scale it up an high order of magnitudes. 

Plastic presents problems because it does degrade into microplastics that tend to get everywhere. Plus, the way we manage landfills. If it was another polysaccharide instead, something that mostly stays put, and the parts of it that don't revert back to some simple sugars, we could let it just accumulate in the jungles and make them heavily carbon-negative.

[JoeSchmuckatelli]

3 hours ago, K^2 said:

Plastic presents problems because it does degrade into microplastics that tend to get everywhere. Plus, the way we manage landfills. If it was another polysaccharide instead, something that mostly stays put, and the parts of it that don't revert back to some simple sugars, we could let it just accumulate in the jungles and make them heavily carbon-negative.

These neat 'find ways to sequester the carbon' ideas are likely solvable... But I question the prudence.  Beyond unforseen consequences - it is a method of excusing industry and consumers taking no action on emissions reduction. 

The kid in LA still has to breathe the smog as they wait for the fake trees or rock producing factory to suck the CO2 out of the atmosphere.  And you need different tech for the methane, heavy particulates, Sulphur, etc. The recapture tech shifts the financial burden away from the polluter. 

I'd rather see capture at the source required. 

Edited December 9, 2021 by JoeSchmuckatelli

[kerbiloid]

The geneticists should develop infusoria who gather the plastic particles and build homes from it, sticking them together. It will simplify its further utilization.

If these infusoria also sinkable, it will cover the oceanic bottom with a thick layer of plastic, but it's anyway what noone needs.

[JoeSchmuckatelli]

@SunlitZelkova - this may be of interest:

https://arstechnica.com/science/2021/12/revisiting-the-tsar-bomba-nuclear-test/

Newly declassified info about the American response and other interesting stuffs 

[K^2]

9 hours ago, JoeSchmuckatelli said:

These neat 'find ways to sequester the carbon' ideas are likely solvable... But I question the prudence.  Beyond unforseen consequences - it is a method of excusing industry and consumers taking no action on emissions reduction. 

The kid in LA still has to breathe the smog as they wait for the fake trees or rock producing factory to suck the CO2 out of the atmosphere.  And you need different tech for the methane, heavy particulates, Sulphur, etc. The recapture tech shifts the financial burden away from the polluter. 

I'd rather see capture at the source required. 

Yes, but capture inherently can only give us net zero. We're so far behind the curve that we have to be developing net negative approaches as well that can be deployed worldwide. We basically have to do all of the above. Replace emitting processes with non-emitting, especially in energy production, have mandatory capture anywhere greenhouse gasses are produced, and develop methods for carbon capture that can be used elsewhere.

Part of the problem is that global average temperature increase leads to all kinds of additional outgassing, mostly from melting glaciers, but also from reduction in permafrost, heating up of old bogs, etc. This means that even if we reduce our CO2 production, we still have more net CO2 released in atmosphere than can be naturally absorbed, meaning, the CO2 will continue climbing, and we don't know for sure whether the process is a complete runaway or will simply lead to an equilibrium at higher temperature. Either one's bad for us, though. We have to start taking CO2 out of the atmosphere in addition to cutting production to as close to zero as we can manage.

[SunlitZelkova]

11 hours ago, JoeSchmuckatelli said:

@SunlitZelkova - this may be of interest:

https://arstechnica.com/science/2021/12/revisiting-the-tsar-bomba-nuclear-test/

Newly declassified info about the American response and other interesting stuffs 

So the article states building a 1000 megaton or 10000 megaton bomb was proposed by Edward Teller as a response to Tsar Bomba.

Interestingly, the author of the article the article is about and the man interviewed (Alex Wellerstein) states the weapon would be impractical because "it would weigh the same as the Space Shuttle". Assuming this means just the Orbiter though, looking at the numbers (53,590 lb for the Orbiter), a Saturn V derived ICBM should have been capable of lifting it.

What is the weight-to-yield ratio for thermonuclear weapons? Am I correct?

What about a 1000 megaton bomb? What sort of LV would be capable of lifting it? (Asking these questions for anyone to reply)

[JoeSchmuckatelli]

49 minutes ago, SunlitZelkova said:

So the article states building a 1000 megaton or 10000 megaton bomb was proposed by Edward Teller as a response to Tsar Bomba.

Interestingly, the author of the article the article is about and the man interviewed (Alex Wellerstein) states the weapon would be impractical because "it would weigh the same as the Space Shuttle". Assuming this means just the Orbiter though, looking at the numbers (53,590 lb for the Orbiter), a Saturn V derived ICBM should have been capable of lifting it.

What is the weight-to-yield ratio for thermonuclear weapons? Am I correct?

What about a 1000 megaton bomb? What sort of LV would be capable of lifting it? (Asking these questions for anyone to reply)

Glad you're asking the math guys!

Did you ever look at the report I linked?  Had some old 'guesses' about the post war economy given different scenarios that I thought you would be interested in.

Edited December 10, 2021 by JoeSchmuckatelli

[sevenperforce]

41 minutes ago, SunlitZelkova said:

What is the weight-to-yield ratio for thermonuclear weapons? Am I correct?

What about a 1000 megaton bomb? What sort of LV would be capable of lifting it? (Asking these questions for anyone to reply)

When it comes to yield-to-weight, bigger is better. Of course you get into absurdities fairly quickly. The flight crew that dropped Tsar Bomba was not entirely expected to survive. A 1000-megaton bomb would probably have a mass 5-7 times greater than the Tsar Bomba, around 160 tonnes. The explosion would be the equivalent of a direct impact from a rocky asteroid 260 meters in diameter at 17 km/s. The zone of total destruction would be 200 miles across.

It's just not realistic.

And I don't know of any good way to drop 160+ tonnes on someone.

[SunlitZelkova]

1 hour ago, JoeSchmuckatelli said:

Glad you're asking the math guys!

Did you ever look at the report I linked?  Had some old 'guesses' about the post war economy given different scenarios that I thought you would be interested in.

Err… which report? I apologize. There have been so many discussions (I have either just observed or actually participated in), some involving wars, some involving economies, that I am not sure which exact report you are referring to.

If you are referring to the 1970-something Congressional report on nuclear war, no, I did not, as my main focus at the time was how nuclear war might affect climate change, which I assumed the report would not have anything on, as it was before climate change was widely accepted.

I do happen to be in the process of writing a nuclear war scenario for a different video game, and the only part left is the aftermath, so I will be sure to check it out. It will be a good resource, as my previous plan revolved around pure assumptions.

I completely forgot about it, so thanks for the unintentional reminder!

[JoeSchmuckatelli]

27 minutes ago, SunlitZelkova said:

I do happen to be in the process of writing

That's what I remembered: writing something - and the resource is something I found interesting when I first read it probably 25 years ago.  I think there are some parts on climate, but, again going from memory, there was a strong presumption of nuclear winter back then - although I don't remember whether its specifically in there.  There are also (I think) parts about differing city construction techniques vs survival and fallout, etc.

Edited December 10, 2021 by JoeSchmuckatelli

[ARS]

Considering the operational parameters, design and operating principle, does V2 considered as a missile or a rocket?