More space news!

[L. Marcus]

Gamma rays are absorbed quite handily by the atmosphere, so you'd get the biggest boom just at the emitter. No great range. Rather then to just lob an AM grenade at the target.

[BlueCloud2k2]

I don't see the military building AM grenades in the near future.

 

AM RPGs? Sure.

 

AM Mortar Rounds? Sound kickass.

 

AM Cruise Missiles? Why not?

 

Grenades? Not so much.

 

Though I though the Gama-pulse from a nuke was what did most of the irradiating and caused most of the fallout?

[Zeropoint]

Well, gamma radiation doesn't make things radioactive, so the gamma pulse doesn't contribute to fallout. The majority of the gamma ray energy from a nuke detonated in air goes to heating the air for the blast and thermal effects. While nukes DO deliver a potentially fatal radiation pulse, in general anyone close enough to get lethal radiation poisoning will be killed immediately by the explosion.

[BlueCloud2k2]

Gotcha. Always did find that confusing.

 

Which must be why scientists working on Fusion Reactors aren't worried about leaky gamma radiation.

 

Though IIRC don't fission reactors put out a bunch of gamma that gradually degrades the reactor housing?

[L. Marcus]

In some brief research, the only lighter fusion process I could find that produces gamma rays are ²H + ¹H --> ³He, and that's not the one being produced in proposed fusion reactors.

[tkdguy]

http://www.thedailybeast.com/articles/2014/05/11/the-hypervelocity-star-that-s-being-booted-from-the-galaxy.html

[Cancer]

Gotcha. Always did find that confusing.

 

Which must be why scientists working on Fusion Reactors aren't worried about leaky gamma radiation.

 

Though IIRC don't fission reactors put out a bunch of gamma that gradually degrades the reactor housing?

The thing that chews up reactor housings (and makes for the nasty pollution from nuclear spills) is neutrons. Neutrons get absorbed by nuclei and sometimes convert those nuclei into something radioactive with a long half-life. Only thing you can do about that is wait. That transmutation chews up local chemistry (when the atom changes elements, the compound you had ... isn't anymore), and the recoil of absorbing or even merely scattering neutrons tends to knock the atom clean out of whatever solid matrix they were in, degrading the solid's mechanical strength. Gamma rays tend to do ionization damage ... nasty on chemistry and biology but not usually a nuclear change.

 

Fission reactors explicitly need neutrons to work. In principle fusion reactors don't, but to fuse proton-rich species takes higher temperatures and so is harder technologically.

[BlueCloud2k2]

And this concludes our class on Intro to Nuclear Physics for Dummies. The Final is due last week. Have a good summer break.

[Spence]

I don't see the military building AM grenades in the near future.

 

AM RPGs? Sure.

 

AM Mortar Rounds? Sound kickass.

 

AM Cruise Missiles? Why not?

 

Grenades? Not so much.

 

Though I though the Gama-pulse from a nuke was what did most of the irradiating and caused most of the fallout?

 

Well they did develop a nuclear artillery shell in the late 50's.    If someone thought that was a good idea then someone could latch onto a grenade and think it is a good idea too

[L. Marcus]

Just look at GURPS Ultra-Tech.

[Cancer]

Right now CERN is stockpiling antihydrogen so they can perform spectroscopic measurements on it and see if it has the same spectrum as normal hydrogen. Theory says it should, but the experiment has never been done, and it's worth doing.

 

The amount of antihydrogen accumulated is tiny ... let it annihilate, and the energy yield won't even be enough towarm a cup oftea.

[L. Marcus]

That would be the awesomest way to make tea, ever.

[Cancer]

There's a niche market: Cancer's Antimatter-Powered Coffee House!

[Lawnmower Boy]

Well they did develop a nuclear artillery shell in the late 50's.    If someone thought that was a good idea then someone could latch onto a grenade and think it is a good idea too

 

Technically, they developed an artillery weapon capable of delivering the smallest feasible atomic weapon, with the idea that it would make a good tactical area denial weapon. Godless commie hordes like to rush about without bridging columns to slow them down, so you shoot a big explosive into a defile like the Fulda Gap, and, boom, there you, go, big crater, how much good are all those T-54s doing you now, you insensate Bolsheviks? Now you just need a means of shooting the darn things. so first you get the Davy Crockett recoilless rifle, which can be carried around on a jeep at the expense of being one of those danger-zones-is-greater-than-weapon-range things. Then you get a 280mm siege mortar, running into the objection that railway artillery isn't usually deemed tactical. (Although who knows? Maybe American Cold War-era railway troops laid track really fast.) Then you get the W48, which can be fired out of a standard 155mm (although probably not to any great range), using twice as much plutonium (which is super expensive) as in a regular "tactical" nuclear bomb to produce a 72 ton explosive, which is just dumb for anything other than, as I say, crater-making. Finally, you get the W33, which could be fired from the regular 203mm gun-howitzer and  may have been a deliverable micro-hydrogen bomb. 

 

You will notice that we know a lot about everything prior to the W33. That's because the US Army was basically building for the greater good of nerd humour at that point. ("Hey? What if, in the distant future, Jon Stewart runs out of things to make fun of?" And then the guys at the Livermore labs say, "Don't worry, we've got it." And then people look at them funny, and the Lab guys realise they probably shouldn't let it out that they have a time machine that gets Internet from 2010.)

 

Anyway, with the W33 you finally get a weapon that really can tear a useful hole in the Fulda Gap with a single shot. So they deployed it, let it be known that it was deployed, and forced the mindless revolutionary myrmidons to bring lots of bridging parts along with them in their rush to the Rhine. And since, as we know, atheists are only allowed to play with little "Giorgy" dolls and never get their hands on capitalistic Lego or Mechano sets, they never learn how to assemble Bailey Bridges.

 

And that, kids, is how Freedom was saved.  

[tkdguy]

It's not often the Pope makes space news, but even Martians can be baptized.

[Cancer]

That sentiment has been expressed before, though not by a pope. It comes with a proviso that the Martian really has to want to be baptized ... no mass baptisms or forced ones.

[Lawnmower Boy]

That sentiment has been expressed before, though not by a pope. It comes with a proviso that the Martian really has to want to be baptized ... no mass baptisms or forced ones.

Charlemagne don't play that game.

[L. Marcus]

'cus he's dead.

[tkdguy]

Russia's response to Ukraine sanctions

[LordGhee]

http://news.yahoo.com/alien-planet-camera-most-sensitive-exoplanet-imager-yet-185628276.html

 

 

More planets

[Greywind]

http://www.iflscience.com/space/bizarre-gas-planet-takes-80000-years-orbit-its-star

[tkdguy]

Rising sea level threatens NASA's launch pads

[BlueCloud2k2]

Interesting the way they are predicting a 5-foot increase in sea level over an 120 year period.

 

Let us hope they are pessimistic in those numbers.

[Steve]

According to the article, since 1945 the water levels have risen nine inches (23 centimeters) and they are predicting another 30 centimeter rise by 2100.

 

I know I live in a country which doesn't use metric, but 30 cm is not equal to five feet.

[Steve]

Some of the commenters make some interesting points, one of which is about land subsidence. If the land is sinking due to tectonic changes or the over-reliance on groundwater, that's a totally different thing than the seas actually rising.