Inverse Square Law Calc

[ByAsura]

Say a character fires an attack 10 kilometres above the ground and it shakes an underground facility, what would the yield and method of calculating the power behind the original attack?

 

[ByAsura]

Bump.

 

[Agnaa]

I don't think we have a reliable method for calculating shaking small areas.

 

[Spinosaurus75DinosaurFan]

There's that earthquake speed chart.

 

[Agnaa]

Earthquake charts only work for earthquakes, due to the distance away that earthquakes are.

 

[Spinosaurus75DinosaurFan]

I was referring to this.

 

[Agnaa]

I still hold my position that that chart wouldn't work for an attack 10km above ground that shakes an underground facility.

 

[Spinosaurus75DinosaurFan]

That chart can be used for the shaking of the facility, and then Inverse Square Law to get the attack.

 

[Spinosaurus75DinosaurFan]

Of course if you can actually calculate the speed of the shaking facility it's even better.

 

[Agnaa]

Yes, but that chart gets you the power of an earthquake causing that shaking, which isn't applicable, as I said earlier:

Earthquake charts only work for earthquakes, due to the distance away that earthquakes are.

We've been treating earthquake calcs like this for months now. Ever since 8-B Barney.

 

[Spinosaurus75DinosaurFan]

According to DontTalkDT for localised shaking we can use that chart if we know the mass of the stuff that's shaking.

For example if a localised area shaking seems to resemble a magnitude 3 earthquake we use the speed value for magnitude 3.

 

[Agnaa]

We can technically use that, but I remember it giving absurdly low results. I think it was used for Barney's feat and gave 10-C results or something similarly ludicrous.

EDIT: oh yeah, you did that calc lmao. ByAsura said that because of those absurdly low results it shouldn't be used as a method, I guess it's something that calc group might need to talk about.

 

[Spinosaurus75DinosaurFan]

I mean getting low-end results doesn't mean it's necessarily incorrect, burning a character with tens of thousands of degrees (which authors tend to think is impressive) is just 9-B via conduction as well.

 

[Spinosaurus75DinosaurFan]

Also funnily enough the chart gives higher results for large sized celestial bodies.

 

[Agnaa]

Huh, okay then.

It also does make sense that it gives higher results for celestial bodies. Earthquake equations are designed for a conventional earthquake volume.

 

[Spinosaurus75DinosaurFan]

Of course again if we can actually find the shaking speed in the feat that would be the best option.

 

[Agnaa]

I guess so, but I feel like just using KE of the maximum speed that it gets at one movement left or right is severely lowballing it.

Not that lowballing is necessarily a bad thing, but I can't help the feeling that there is a more correct calculation we could derive.

 

[Spinosaurus75DinosaurFan]

Well I can't really think of a method to calculate shaking something other than KE.

 

[Agnaa]

It would be some sort of multiplier on KE. Because the current method is only getting the energy of one movement from left to right, rather than the entire series of shakes generated.

Maybe it'd need to be some integral of a varying KE over the time? idk

 

[Spinosaurus75DinosaurFan]

Well to make things simple maybe the KE in one second?

 

[Agnaa]

That might work. We'd need to know/assume how many shakes back and forth occur in a second, and multiply the KE by that.

 

[Spinosaurus75DinosaurFan]

bump

 

[Antvasima]

What are the summarised conclusions here?

If you need input, you can ask other calc group members.

 

[KLOL506]

How do we even figure out the total distance shook?

 

[Agnaa]

We're trying to find a better method for shaking a small area (small enough to where we can't use the earthquake formula).

The current method is just KE of the mass, but if you visualize it, that's just the energy of a single shake (one movement from left to right), not the energy of the entire process.

The idea Spino and I had would involve calculating the KE in one second of the shaking.

We need more input from calc group members on how best to estimate that.

 

[KLOL506]

Yeah, I get that, but how will you figure out the distance to get your speed?

 

[Spinosaurus75DinosaurFan]

I linked a chart above for different magnitudes of earthquake.

 

[KLOL506]

The magnitude I get, but once you get how many times it shook, how would you get your energy value from it then?

As in, do you multiply the number of times shaken with any other value after that?

 

[Spinosaurus75DinosaurFan]

dW/dt I guess, so it'll be how many shakes in a second. Assuming the shaking lasts for at least 1 seconds ofc.

 

[Agnaa]

@KLOL I was responding to Ant, didn't see your post.

We won't be using distance for speed. Probably just assume a number of shakes for a second (or calculate one in accordance with an earthquake chart), and multiply the KE result by the number of shakes in one second.

 

[Spinosaurus75DinosaurFan]

Of course if you can somehow find the KE of a shake that would be better.

 

[Antvasima]

@Agnaa

Thank you for the explanation.

 

[Spinosaurus75DinosaurFan]

But what if it's just a statement saying "shaking"?

 

[Spinosaurus75DinosaurFan]

Apparently a 10 storey building has a frequency of 1 hertz/cycle per second.