Target: Earth!

[Agemegos]

G'day

 

I was just reading the striking section on page 197 of Star Hero in which Steve calculates that Earth would be cracked open by a nuclear weapon test, when I came across this remarkable sentence:

 

"So, the odds of hitting it, even from 1,000 miles away, are much better than average; from 20 miles (roughly equivalent to geosynchronous orbit), you'll only miss if you roll an 18."

 

Geosynchronous orbit has a radius of 22,000 miles, and therefore an altitude of 18,000 miles, not an altitude of 20 miles.

 

Seen from geosynchronous orbit (22,000 miles), Earth's 8,000-mile diameter subtends 20 degrees. It should be about as hard to hit as a hex three hexes away. Seen from 20 miles it would just about fill your field of view.

 

I think in this case the HERO rules have been pushed so far they have well and truly broken.

 

Regards,

 

 

Brett

[Michael Hopcroft]

Re: Target: Earth!

 

G'day

 

I was just reading the striking section on page 197 of Star Hero in which Steve calculates that Earth would be cracked open by a nuclear weapon test, when I came across this remarkable sentence:

 

"So, the odds of hitting it, even from 1,000 miles away, are much better than average; from 20 miles (roughly equivalent to geosynchronous orbit), you'll only miss if you roll an 18."

 

Geosynchronous orbit has a radius of 22,000 miles, and therefore an altitude of 18,000 miles, not an altitude of 20 miles.

 

Seen from geosynchronous orbit (22,000 miles), Earth's 8,000-mile diameter subtends 20 degrees. It should be about as hard to hit as a hex three hexes away. Seen from 20 miles it would just about fill your field of view.

 

I think in this case the HERO rules have been pushed so far they have well and truly broken.

 

 

20 miles was probably either a typographical error or Steve getting his sums wrong. I had my copy of Star HERO stolen (I'm ordering a replacement), but there are times when system math in any game system, even one as dependent upon it as HERO, must give way to basic logic. The math may say that a single nuclear test would rack open the Earth's crust -- yet hundreds of nucelar tests have been conducted and the planet hasn't cracked upon once. In this case, the math is wrong. If you want to shatter the planet like an egg, you need a bigger hammer. A 10-mile asteroid moving at relatvisitic speeds migth not even be enough to do it (although I never took physics so don't ask me to do the math).

 

Makes me wonder how George Lucas, who was never one to jutoify his msuings with anything as mundane as science, could imagine an energy beam powerful enough to cause entire planets to explode. Sure it looks great on film, but really -- planets don't have explosive material at the core. what exactly could the beam have been detonating?

 

You can boil away a planet's atmosphere, crisp its surface, and possibly cause its oceans to evaporate into space -- but how do you BLOW IT UP?

 

This could be an improtant consideration because eventually players will want to blow up the enemy planet in certain types of camapgins, and all the methods above of wiping a planet clean of all ability to supprot life are far less satisfiyng than an Earth-shattering KABOOM!

[Captain Obvious]

Re: Target: Earth!

 

Plot device.

 

These sorts of weapons are incredibly uncommon in sci-fi. Most doomed planets remain as a lifeless hunk of rock, not a new asteroid belt. If you want players to be able to blow up a planet, then let them do it under some incredibly limited circumstances. Maybe the alien artifact can do it, but afterwards, some components crumble under the stress, rendering it useless. Otherwise, you'll get players blowing up planets simply because some customs agent at the downport confiscated their plasma rifles.

[Rapier]

Re: Target: Earth!

 

Otherwise' date=' you'll get players blowing up planets simply because some customs agent at the downport confiscated their plasma rifles.[/quote']

What's wrong with that? Sheesh, you are acting likes it's totally unreasonable.

[Dr. Anomaly]

Re: Target: Earth!

 

You can boil away a planet's atmosphere' date=' crisp its surface, and possibly cause its oceans to evaporate into space -- but how do you BLOW IT UP?[/quote']

Well, if the beam was powerful enough, it could punch right through the crust and mantel to the core. Should it vaporize the solid inner core of the planet, the planet would detonate, the way a well-shaken soda bottle can...from pressure, not from some "explosive material".

[Blue Jogger]

Re: Target: Earth!

 

Actually, a beam composed of pure anti-gravitons where the transverse and longitudinal waves were set to the exact harmonic frequency of the planet, it would explode quite nicely. In actuality, the gravity glue would rapidly evaporate and then the excess anti-gravity would "push" the matter out in all directions.

 

Of course, that's assuming that gravitons even exist.

[Zeropoint]

Re: Target: Earth!

 

If an energy beam of sufficient magnitude hits ANYTHING, it will explode. As the energy is absorbed by the target, the material of the target will heat up. That will, at high enough energy levels, lead to chemical breakdown, melting, and vaporization. If more energy is supplied than needed to vaporize the material, you get super-heated high-pressure vapor. With enough energy, you get VERY super-heated, VERY high pressure gas: plasma.

 

Anyway, that expanding vapor cloud will impinge on the rest of the target. In a Death Star-level event, the pressure will act fast enough that there won't be time for normal heat transfer. Instead, a powerful shock wave will travel through the planet. This shock wave will deliver enough energy that the planet material near the beam impact site will also be vaporized. The effects will spread through the planet very quickly, producing large volumes of plasma and vapor, and immense shock waves will shatter whatever doesn't get vaporized.

 

The high-pressure cloud of vapor will then propel the liquid and solid fragments outward.

 

 

 

Short version: a substance can explode with its own energy, or with energy from an outside source.

 

Zeropoint

[KA.]

Re: Target: Earth!

 

I was sort of thinking of what happens when you put an egg in the microwave.

If you could heat the core enough, quickly enough, that all that expanding stuff was being held back by the crust for a brief time . . . KABOOM!

This would require a weapon that selectively heated the core instead of just melting holes in the crust, but I could at least allow it as a sci-fi possibility.

 

KA.

[jackalope]

Re: Target: Earth!

 

Microwaves definetely sound like the culprit to me. A giant microwave beam that converts all of the magma at the core into superheated plasma, and the resulting expansion tears the planet into pieces.