Mesons and the ground combat picture

[Ulsyus]

What sort of damage would they do at that point? Would it be sufficient to cause damage control parties to have to respond, or would it be just a case of "that nuke was a bit too close for comfort Captain. We need to train more countermeasures on the next salvo incoming from that BB!" ?

 

[JimMarn]

Uhm folks, 21 centimeters is less than a meter. It takes 100 centimeters to equal 1 meter.

So 21 cm is 0.21 meters, less than 25 percent of a meter.

 

[HG_B]

What sort of damage would they do at that point? Would it be sufficient to cause damage control parties to have to respond, or would it be just a case of "that nuke was a bit too close for comfort Captain. We need to train more countermeasures on the next salvo incoming from that BB!" ?

I imagine mostly ionizing rad damage. A "neutron bomb" would be a better nuc for outer space I think.

 

[Nathan Brazil]

Uhm folks, 21 centimeters is less than a meter. It takes 100 centimeters to equal 1 meter.

So 21 cm is 0.21 meters, less than 25 percent of a meter.

The reference is to the scale of the Striker miniatures game vs. real life scale
1cm game board = 10m within universe
a 1:1000 ratio

 

[Ulsyus]

I imagine mostly ionizing rad damage. A "neutron bomb" would be a better nuc for outer space I think.

If radiation uptake is based on the intensity of the dose, time of exposure, and shielding that exists, then a vessel moving at "fiar" interplanetary speeds that had rad shielding (thinking of T5 armour here) would need a pretty fair sized warhead to go off to have much effect on it, wouldn't it?

 

[HG_B]

If radiation uptake is based on the intensity of the dose, time of exposure, and shielding that exists, then a vessel moving at "fiar" interplanetary speeds that had rad shielding (thinking of T5 armour here) would need a pretty fair sized warhead to go off to have much effect on it, wouldn't it?

Speed (at least that achieved via M-drive) isn't a factor. A nuc bomb in space blasts EM for a mere small fraction of a second. I don't know much about T5 rad shielding.

 

[JimMarn]

The reference is to the scale of the Striker miniatures game vs. real life scale
1cm game board = 10m within universe
a 1:1000 ratio

Okay, it was very confusing to me otherwise.

 

[Ulsyus]

Speed (at least that achieved via M-drive) isn't a factor. A nuc bomb in space blasts EM for a mere small fraction of a second. I don't know much about T5 rad shielding.

Looking at the nuke damage tables on p229, it seems that when comparing them with the AVs on p407, it'd take a pretty big vessel with several layers of armour, some with specific RAD protection, to survive a direct hit from a tac-nuke sized missile. Given they may be difficult to achieve, a smaller vessel with even one layer of anti-Rad plating is likely to be able to withstand a near miss (approx 150 to 500m from target).

 

[aramis]

Speed (at least that achieved via M-drive) isn't a factor. A nuc bomb in space blasts EM for a mere small fraction of a second. I don't know much about T5 rad shielding.

At far interplanetary speeds, the interplanetary media becomes low energy alpha and beta radiation for all practical purposes.

A week at 1G is about 5,900. km/s, and alpha 16 about 16,000 km/s. so, roughly, 1/9 the energy from any old Helium nucleus you happen to hit. It takes a few nm of lead, or a couple mm of lesser metals, to stop the alpha and most of it's cascade effect.. But the alpha wear can induce considerable effect... 1E6 atoms per cm^3 in the interstellar medium...10000 cm per square meter, so 1E10 per square meter per cm. 1E12 particles per meter. 5.9e6 m/s is 5.9e18 particles per second, at 1/9 the standard alpha energy...

http://www.oasisllc.com/abgx/radioactivity.htm

 

[Ulsyus]

A week at 1G is about 5,900. km/s, and alpha 16 about 16,000 km/s. so, roughly, 1/9 the energy from any old Helium nucleus you happen to hit. It takes a few nm of lead, or a couple mm of lesser metals, to stop the alpha and most of it's cascade effect.. But the alpha wear can induce considerable effect... 1E6 atoms per cm^3 in the interstellar medium...10000 cm per square meter, so 1E10 per square meter per cm. 1E12 particles per meter. 5.9e6 m/s is 5.9e18 particles per second, at 1/9 the standard alpha energy...

Translated for those of us whose majors were history and politics...?

 

[Travellerspud]

alpha particles travelling very fast (relative to your ship at least) hit stuff on your hull's surface and eventually knock stuff off the atoms of your ship's hull, turning them over time into other stuff (which probably is not as good as a hull material as one would hope for)

 

[aramis]

alpha particles travelling very fast (relative to your ship at least) hit stuff on your hull's surface and eventually knock stuff off the atoms of your ship's hull, turning them over time into other stuff (which probably is not as good as a hull material as one would hope for)

And the free electrons (beta) accrue a charge on your ship and erode the surface as well. Plus, the alpha triggers beta on impact.

Once you get to a week at 1G, you're talking earth-saturn or further, mind, you're going fast enough that the basic equations no longer suffice, and dilation has to start being accounted for. 1 week at 3G, and you're getting standard energy alpha in significant doses.

It makes the metal brittle.

Plus, at those speeds, the miligram grain of dust at 5,900,000m/s, is dumping 1.7e10 joules... a 20mm APDS round carries 1.23e5 J... so about 1.5e5 * the energy... that grain of silica has enough oomph to go in one side and out the other of a wwII era battleship... sufficiently high energy to not even deform the armor a lot; the armor does not have time to bend. a 1 milligram chunk of rock is half a millimeter, by the way. A tiny spec of dust will hit with as much energy a 20mm cannon... but a small enough area that it penetrates 50m+...

That much energy density, you get near instant liberation of molecular bonds.

 

[HG_B]

At far interplanetary speeds, the interplanetary media becomes low energy alpha and beta radiation for all practical purposes.

I was referring to a ship's speed NOT saving it from exposure to a nuc going off next to it. Along the lines of what you are talking about, there was an interesting article about what would happen to a FTL ship vis-a-vis this. Amazing.

 

[Ulsyus]

So vessels in the OTU would need some sort of shielding to simply even travel at interplanetary speeds without being bent the wrong way through a series of different means.

Something in the M-drive? Gravitic field protecting the hull?

 

[HG_B]

So vessels in the OTU would need some sort of shielding to simply even travel at interplanetary speeds without being bent the wrong way through a series of different means.

Something in the M-drive? Gravitic field protecting the hull?

MgT is set in the OTU. The hulls are just stated to be VERY strong. Hence the ineffectiveness of non-space ship scale weaponry on them. The OTU is irrelevant in that context. We have cell phones now that are also powerful computers. You just auto retcon tech as it appears. The game as written in '77 is no longer relevant. (Marc wrote it with very little science or tech knowledge.) New versions come out every few years.

Lex parsimoniae is the best approach. that's what Matt & Co. did.

 

[mike wightman]

According to the CT boxed module the manoeuvre drive generates a field that protects a ship from intense radiation and micro meteorite impact:

Ships under power are not affected - part of the M-drive generates a low-power screen against radiation and meteorite impact -

 

[aramis]

So vessels in the OTU would need some sort of shielding to simply even travel at interplanetary speeds without being bent the wrong way through a series of different means.

Something in the M-drive? Gravitic field protecting the hull?

You need a couple meters of steel to safely go 60*60*24*7*9.8 m/s... that's 5.927040 Mm/s, or 5927.04 km/s. Note that the fastest ships in the OTU probably only go a little over 12x that... (and get hit with particulate radiation effects 144x as strong.)

Note that, except in Stellar Size I and II systems, almost nothing is more than a week away at TL9+. The Jump Drive makes N-Space travel longer than about 7 days time-ineffective. It also makes the economics suffer badly before two weeks, even for slow non-time critical cargo.

 

[Ulsyus]

It also makes the economics suffer badly before two weeks, even for slow non-time critical cargo.

How so?

 

[HG_B]

According to the CT boxed module the manoeuvre drive generates a field that protects a ship from intense radiation and micro meteorite impact:

According to MT & MgT it is advanced hull materials that do it. So, in CT you have ships with low tech, weak hulls and in MT & MgT you have advanced, high tech hulls that are super tough.

Pick your smaller can o' worms. For MTU there are no deflector shields a la Star Trek. (at least < TL 17)

 

[mike wightman]

Not quite

In CT you have the super tough material hulls too; armour materials were originally defined in CT's Striker, and used the same TL breaks as HG2