A quick question about GBE

[ArbitraryNumbers]

Do we use meters for the radius in the GBE formula, or kilometers?

Either way I think this should be specified to prevent any further confusion.

 

[CNBA3]

I agree with that, we need units of measurement and an accurate equation

 

[DontTalkDT]

In general everything is SI. (unless otherwsie stated)

If you don't use SI, you will still get a result, just in a different unit (If you write the units into the calculation, like physics teachers in school usually suggest for that very reason, there are no problems with units, I think)

 

[Antoniofer]

Formula use the units: meters for distance, m/s^2 for acceleration, kg for mass and kg/m^3 for density (depending of the ecuation).

 

[CNBA3]

from what I could tell, the http://www.stardestroyer.net/Empire/Tech/Beam/Calculator.html has the must accurate equation, but it won't allow me to change any other factor besides gravity, diameter and height of observer.

 

[Antoniofer]

What's the "height of the observer"? you only need the gravity/radius/mass/density (two of them) to calculate GBE. Unless we discuss what we do with stars (forget the name of the variable n).

 

[DontTalkDT]

What's the "height of the observer"? you only need the gravity/radius/mass/density (two of them) to calculate GBE.

You can also use gravitational acceleration on the surface and radius, which is what the calculator is doing . It is just another way to write down the same formula, though. It isn't any better than the other ones.

(It basically calculates the mass of the planet from the gravity and then uses the mass, radius formula)

Height of observer is only for the distance to horizon, not for the GBE, I think.

 

[CNBA3]

What's the "height of the observer"? you only need the gravity/radius/mass/density (two of them) to calculate GBE. Unless we discuss what we do with stars (forget the name of the variable n).

It was on that website that I linked to you, but other than that, the formula required for it radius of 38 km, gravity of 1g, mass of 16e+17kg and density of 2000 kg/cm3, basically units for nessus where gravity is the same as earth's. I can't change the info for the two out of four which auto changes them for some reason.

 

[Antoniofer]

Guess that the height is for additional results unrelated to GBE. Anyway, that calculator doesn't seems any special, it has the same result that I can calculate with any of our equations.

 

[CNBA3]

here is the equation for the earth GBE:

3/5 Gravity (6.674e+-11)Nm2kg-2 Mass(5.97219e+24^2) kg ^2 Radius(6.371e+6) meter

but it doesn't seem to give that number for the Earth Joules

 

[CNBA3]

actually, I found the most accurate of GBE websites for other facts such as mass and radius

https://www.fxsolver.com/browse/for...ng+Energy+-+spherical+mass+of+uniform+density

maybe we should add that to the GBE page?

 

[Antoniofer]

That is still the same equation that we use. using the values of the Earth you're going to obtain 2.24*10^32 J, however, since the density of Earth isn't uniform, several other sources have a value of ~2.48*10^32 J; what formula did they use? not sure, most likely some kind of integration of said formula.

 

[CNBA3]

Nevermind, with the link above, I believe we have the best equation to find GBE for other celestial bodies, just the one draw back is the gravity constant to that of Earth.

 

[Antoniofer]

No need of gravity when you have either mass or density. I known a more simple method instead of calculate that all over again, but is difficult to explain (for me).

 

[CNBA3]

thats fine, thank you