For Questions That Don't Merit Their Own Thread

[kerbiloid]

It's at 660 m depth in a desert. No.

"Standard" 1 Mt crater is ~90 m deep (visible) and ~200 m deep (actual, but filled with ejecta). The rocks will crack down to ~500 m deep.

Edited March 29, 2021 by kerbiloid

[DDE]

3 hours ago, SunlitZelkova said:

Would a 1 megaton ground burst at the Waste Isolation Pilot Plant cause enough extra fallout to be worth targeting an ICBM at? Assuming the winds are coincidentally optimal enough to blow towards the direction of the Great Plains/farming states.

I apologize if this doesn't count as a science related question.

What @kerbiloid said, although going with the general principle, Russian military literature on de-escalation nuclear strikes makes a point that you should only nuke non-nuclear powerplants to signal resolve.

[JoeSchmuckatelli]

10 hours ago, SunlitZelkova said:

Would a 1 megaton ground burst at the Waste Isolation Pilot Plant cause enough extra fallout to be worth targeting an ICBM at? Assuming the winds are coincidentally optimal enough to blow towards the direction of the Great Plains/farming states.

I apologize if this doesn't count as a science related question.

Let me point out another issue - the 'why' of targeting any radiation deposits.  As in, it is not going to accomplish what you might want to achieve through armed conflict. 

Absent the initial effects of the blast, the radiation fallout is operationally a terror/fear weapon and functionally an area denial weapon (that works both ways). Except that in the area denial role it turns out to be largely ineffective. 

Think about the Bikini Atols, Chernobyl, Hiroshima and Nagasaki and Fukushima.  They're not the blighted lifeless wastelands people fear will happen following intentional or accidental release of radioactive material.  Certain kinds of radiation that linger seem to be as dangerous as smoking - as in, yeah it can kill you - but not very fast.  There are, of course, hot spots that will cook you if you are close enough - hence area denial still works... But that stuff, that concentration is necessarily going to be close to the source and not scattered broadly.  (if you scattered broadly - you don't get enough radiation to kill quickly, etc) 

So - if you think about nuclear weapons as just big bombs, you can start to plan how to use them.  In other words - ignore the radiation in your planning - aside from calculating how soon after you can safely move in. *

 

 

 

*(and you are only calculating radiation levels that will kill in hours or days - anything past that can be ignored for military purposes) 

[DDE]

5 hours ago, JoeSchmuckatelli said:

Let me point out another issue - the 'why' of targeting any radiation deposits.  As in, it is not going to accomplish what you might want to achieve through armed conflict. 

Absent the initial effects of the blast, the radiation fallout is operationally a terror/fear weapon and functionally an area denial weapon (that works both ways). Except that in the area denial role it turns out to be largely ineffective. 

Think about the Bikini Atols, Chernobyl, Hiroshima and Nagasaki and Fukushima.  They're not the blighted lifeless wastelands people fear will happen following intentional or accidental release of radioactive material.  Certain kinds of radiation that linger seem to be as dangerous as smoking - as in, yeah it can kill you - but not very fast.  There are, of course, hot spots that will cook you if you are close enough - hence area denial still works... But that stuff, that concentration is necessarily going to be close to the source and not scattered broadly.  (if you scattered broadly - you don't get enough radiation to kill quickly, etc) 

So - if you think about nuclear weapons as just big bombs, you can start to plan how to use them.  In other words - ignore the radiation in your planning - aside from calculating how soon after you can safely move in.

*(and you are only calculating radiation levels that will kill in hours or days - anything past that can be ignored for military purposes) 

Relevant light reading:

 

[magnemoe]

7 hours ago, JoeSchmuckatelli said:

Let me point out another issue - the 'why' of targeting any radiation deposits.  As in, it is not going to accomplish what you might want to achieve through armed conflict. 

Absent the initial effects of the blast, the radiation fallout is operationally a terror/fear weapon and functionally an area denial weapon (that works both ways). Except that in the area denial role it turns out to be largely ineffective. 

Think about the Bikini Atols, Chernobyl, Hiroshima and Nagasaki and Fukushima.  They're not the blighted lifeless wastelands people fear will happen following intentional or accidental release of radioactive material.  Certain kinds of radiation that linger seem to be as dangerous as smoking - as in, yeah it can kill you - but not very fast.  There are, of course, hot spots that will cook you if you are close enough - hence area denial still works... But that stuff, that concentration is necessarily going to be close to the source and not scattered broadly.  (if you scattered broadly - you don't get enough radiation to kill quickly, etc) 

So - if you think about nuclear weapons as just big bombs, you can start to plan how to use them.  In other words - ignore the radiation in your planning - aside from calculating how soon after you can safely move in. *

*(and you are only calculating radiation levels that will kill in hours or days - anything past that can be ignored for military purposes) 

Yes, Chernobyl has lots of wildlife its an unofficial natural park. We don't want to live there its radiation for obvious reasons. But an moose its most likely death is killed by human hunters. 
Except its not legal to hunt in the Chernobyl zone. Yes you could hunt for sport but they know some people will sell the meat. So the moose live longer. 
 

[SunlitZelkova]

Thanks for all of the answers. I asked as in another game I am playing the US and China are going to war, and I was trying to figure out if there is a "creative" way to increase the damage with China's relatively small number of missiles capable of hitting the US.

One other thing- although the fallout/radioactive contamination may not cross continents, would "crater killing" or directly hitting nuclear reactors at power plants be worthwhile?

[JoeSchmuckatelli]

5 hours ago, SunlitZelkova said:

Thanks for all of the answers. I asked as in another game I am playing the US and China are going to war, and I was trying to figure out if there is a "creative" way to increase the damage with China's relatively small number of missiles capable of hitting the US.

One other thing- although the fallout/radioactive contamination may not cross continents, would "crater killing" or directly hitting nuclear reactors at power plants be worthwhile?

Again... Why? 

 

You are falling into the trap of thinking the unique thing about a nuclear bomb is its 'best' attribute.  Just because radiation is unique to nuclear weapons does not make it the true horror of the device. 

 

It is a single bomb that is a city killer. 

 

Radiation is a side show.  It is the thing no one understands and so is scared of - but you need to look at the fire bombings of ww2 and really try to appreciate the horror - and then look at what a nuke does.  If you end up thinking that radiation is a desired effect... I can't help you. 

 

Now - back way back away from the effects of the weapons - and ask yourself what purpose you hope to accomplish?  Ambrose Bierce described war as the untying of a political knot with the teeth that would not yield to the tongue. 

 

So - in employment of nuclear weapons - whether in a game or in life... What do you hope to achieve through use of the weapon? 

 

FYI - the Chinese nuking San Onofre is only going to liquid us off. 

[SunlitZelkova]

1 hour ago, JoeSchmuckatelli said:

Again... Why? 

In the event of a nuclear war between Russia and the United States, Russia would target US missile siloes. Destroying the siloes (according to American analysts, I am mentioning this only because I don't know what the Soviets/Russians actually planned to do) would require ground detonations, which would create much more fallout that due to the location of US ICBM fields, would significantly effect domestic food production in America *in a negative way*, to put it without being dramatic.

China apparently has a countervalue nuclear strategy, so no missiles would be targeted at the siloes- only cities. In the game I am playing, the nuclear war is full scale, and given the amount of destruction the US is intent on destroying the PRC completely in retaliation. Within the game, the Chinese know this. They also know that due to the relatively small number of missiles they have that can hit the US, the damage will all in all be rather minimal compared to a US-Russia scenario. As you said, in time, even if an American city is hit with a 5 megaton weapon, it will eventually be "clean" and rebuilt, just as Nagasaki and Hiroshima were. America would survive. MAD would not be mutual.

So I was trying to find a way to maximize damage with a small number of weapons, specifically achieving that "silo strike" effect. To use an analogy with a fictional example, I was thinking of something kind of a nuclear version of blowing up a dam with a small number of conventional bombs to flood an entire valley and cause destruction, but on a continental scale.

Unfortunately for my virtual Chinese army, it seems there is no way.

[kerbiloid]

A 100 MW reactor or a radioactive waste pool hit by 1 Mt cause
up to 200 000 km² of uninhabitable territory first six months after
up to 90 000 km² 5 years later
up to 1 000..3 000 km² 100 years later

Both reactor and pool destruction never achieve same radiation levels as 1 Mt even close (~1% of it) but contain long-living isotopes causing long-term low-level contamination.

The silos unlikely could cause very high levels, as it's underground and protected and the hit would hit not the silo itself, but ground in one-two hundred meters away.

The nuke power plants are usually built in industrial regions, not on plowland.
So, most of contaminated areas will be cleaned and rebuilt, while most of plowlands are lying far from them.

(Also, one can presume who would be the told guest volunteer in the process of cleaning after hitting the cities).

9 hours ago, SunlitZelkova said:

significantly effect domestic food production

There are non-domestic food productors outside the contaminated countries which can become told domestic.

9 hours ago, SunlitZelkova said:

So I was trying to find a way to maximize damage with a small number of weapons

Easily. Self-hit "your" own factories to make the sneakers cost twice, and

9 hours ago, SunlitZelkova said:

MAD would not be mutual.

Also, somebody has a great dam cascade and agriculture totally based on irrigation from of almost spent rivers...
So the countervalue strategy is also so-so. It would mostly solve for the opponent the problem of his poor class.
The opponent's core would be just scratched, but the revenge devastating.

Edited March 30, 2021 by kerbiloid

[JoeSchmuckatelli]

8 hours ago, SunlitZelkova said:

In the event of a nuclear war between Russia and the United States, Russia would target US missile siloes. Destroying the siloes (according to American analysts, I am mentioning this only because I don't know what the Soviets/Russians actually planned to do) would require ground detonations, which would create much more fallout that due to the location of US ICBM fields, would significantly effect domestic food production in America *in a negative way*, to put it without being dramatic

 

So - yeah, when you target a silo you necessarily need to have a ground or sub surface burst.  Given that the Chinese and Russians have gotten space ships to other planets, we can assume that they can hit whatever they target.  But you target a silo only to prevent it from launching its missile at you. 

... 

 

So - let me explicate a bit: if I order an air strike on a building being used as a C&C / FO platform... My purpose is to destroy the enemy's capabilities and deny his ability to harm me. If afterwards, the rubble of the building pops the tires of his technicals and sprains the ankles of his infantry - I'm happy with the result. 

Yet I don't take out buildings in hopes that the secondary effects will assist my efforts. 

[SOXBLOX]

Hypersonics are here!

Looks like the ARRW booster will be tested off of the California coast. Only a mockup glide vehicle; this is an engine test.

One of the U.S. Army's ships will monitor the test. Yes, Army. Don't ask me why.

Edited March 30, 2021 by SOXBLOX

[kerbiloid]

42 minutes ago, SOXBLOX said:

One of the U.S. Army's ships will monitor the test. Yes, Army. Don't ask me why.

A subterrene?!...

[DDE]

54 minutes ago, SOXBLOX said:

One of the U.S. Army's ships will monitor the test. Yes, Army. Don't ask me why.

*laughs in Imperial Japanese Army submarines*

[DDE]

10 hours ago, SunlitZelkova said:

MAD would not be mutual.

To elaborate on Joe's argument, you operate from a very broad definition of survival and thus resilience.

Chinese nuclear nuclear doctrine and thus force composition is based on causing unacceptable damage as a means of achieving deterrence. Countervalue is the only option for it, not just because of size or indeed the technological sophistication needed for silo-sniping, but because PLA still adheres to a no-first-strike pledge, abandoned by the 1998 Russian doctrine and never made by the US. The other parties forsee varied uses for nuclear weapons as part of various escalation and de-escalation schemes.

Counterforce in the age of ICBMs, meanwhile, only really works if you strike first - even if the adversary staggers their salvoes for whatever reason, even the opening round is going to cause unacceptable damage. It's a toss-up, of course, but in the age of New START, the US having a significant lobby calling for the abandonment of ICBMs, and missile defense anxiety, I doubt Russia's RVSN bothers with counterforce.

[K^2]

6 hours ago, DDE said:

*laughs in Imperial Japanese Army submarines*

"The Japanese sank both our tank and Ferris wheel, sir."

[SOXBLOX]

4 hours ago, K^2 said:

"The Japanese sank both our tank and Ferris wheel, sir."

Reminds me of Operation Petticoat, when the torpedo runs ashore and Cary Grant says, "We sunk a truck!"

[K^2]

2 hours ago, SOXBLOX said:

Reminds me of Operation Petticoat, when the torpedo runs ashore and Cary Grant says, "We sunk a truck!"

Huh. I barely remember that movie. The quote above is from 1941 where a tank is sunk by Japanese sub under similar circumstance. Maybe, Spielberg stole the idea from Operation Petticoat.

[ARS]

Frequently, in space sci-fi, we can see ships (whether small or large) that's asymmetrical in shape (that is, the port and starboard side are drastically different in shape, which in turn makes one side heavier than other), mostly this is a mobile space station or space colonies, with more thrusters placed at the smaller side to compensate the thrust from engines placed on the other side. From engineering perspective, especially in spaceflight, should the spaceship being better designed as symmetrical or should the asymmetrical design be avoided as possible? I know that the aerodynamic doesn't matter in space and you can build spacecraft in any shape that you want, but I think the symmetrical design are usually much easier to design, especially for engine layout, and in case of engine failure, the stability of the ship isn't affected as much since the center of thrust is more or less focused at a single point at the rear (in case of multiple engine design that necessitates the placement of some engines off the main center of thrust, just turn off the other engine on the other side). That being said, should this mean that in a large-scale space battle, if the enemy bring an asymmetrical capital ship, theoretically, we can just focus on attacking only one engine (preferably the smaller one) so that one it's disabled, the ship can only helplessly spin in place since no thrusters to compensate the asymmetrical center of thrust from the engine on the other side

What do you guys think?

[kerbiloid]

The mass distribution decides.
The ship can be geometrically asymmetrical but have a lot of room on the bulky side and dense equipment on the compact side, so its inertia is distributed symmetrically.

Of course, no powerful engines or single-barrel cannons should have a significant offset from an axis passing through the CoM, to prevent rotation on throttling or shooting.

https://en.wikipedia.org/wiki/Blohm_%26_Voss_BV_141

[DDE]

2 hours ago, ARS said:

(in case of multiple engine design that necessitates the placement of some engines off the main center of thrust, just turn off the other engine on the other side)

Depends on how many engines you have to spare. TBH on a warship some sort of thrust vectoring is desireable anyway.

Which is why you miss the important bit: any one engine can be used to propel an asymmetric craft so long as it points through the CoM. Less so with pronouncedly asymmetric craft, of course, since you'd beed mad gimbal angles.

[kerbiloid]

Also there was a dedicated thread on this topic.

And of course
 

Spoiler

 

Edited April 2, 2021 by kerbiloid

[tater]

 

The guy they interview, Luke Talley (IBM, worked on the Saturn V fight computer) is incredible, I could listen to him all day.

[munlander1]

After some quick reading, It’s my understanding that the precursor of vitamin d in the human body is only converted to vitamin d after being exposed to  UVB radiation.

Does this happen in a dedicated cell or organelle? How comparable is the process photosynthesis?

Obviously a human cannot sustain themselves with UVB radiation and water.

Edited April 3, 2021 by munlander1

[kerbiloid]

Vitamin D is a common name of a group of chemical compounds. 

Mostly (and D₂ - exclusively) it's consumed with food, but human body can produce some of the group members itself (not all of them).

It also appears in UV-irradiated food, so it's a set of photochemical reactions.

So, the food is primary source, the solar bath is auxilliary.

[ARS]

Bullets have effective range (the longest range it has enough kinetic energy and still reliably do damage) and max range (the longest range it travels). We're assuming that this value is based on shooting level horizontally, and the values might change depending on the angle of the gun fired. In any case, air resistance will eventually slow down the bullet and gravity will pull it downward, decreasing it's kinetic energy the longer it travels. But what about this? Let's assume that a gun has effective range of 200m and max range of 300m (at level firing), but what if we fire it straight downward? For instance, firing it from 1000 m high elevation, so the gravity isn't a factor of it's max range. Assuming that there's no wind (but there's still air resistance), could the air resistance from traveling 1000m downward enough render the bullet not effective at all (no kinetic energy left to reliably do damage) or it's still lethal all the way down?