Universe Sandbox

Universe Sandbox => Universe Sandbox | Support & Bugs => Topic started by: Spartan117jmc on January 08, 2015, 11:56:48 AM

Title: Rocky Gas Giant with a temperature at: "Positive infinity"????
Post by: Spartan117jmc on January 08, 2015, 11:56:48 AM
Umm.. ok i played with the Canis Majoris and i tried to set the mass to 1000 times that of the sun and the radius identical to the sun to see what would happen and wow was i surprised. mass was successfully altered but... then i set the radius and POOF it turned super-hot AKA "Positive infinity" and it also seems to be rocky :O WHAT...the HECK??
Title: Re: Rocky Gas Giant with a temperature at: "Positive infinity"????
Post by: Gordon Freeman on January 08, 2015, 12:11:59 PM
I've had the temperature calculator go nuts too by setting the atmospheric mass to "+1000 Milky Way masses".

The planet froze over and the temperature shot up to "Negative Not a Number"
Title: Re: Rocky Gas Giant with a temperature at: "Positive infinity"????
Post by: Spartan117jmc on January 08, 2015, 12:30:08 PM
Try replicating what i did. see it for yourselves (In Paused mode) It works every time:Use Canis Majoris and set Mass to 1000X Sun + Radius to 1X Sun Respectively While Paused = Crazy Temperature
Title: Re: Rocky Gas Giant with a temperature at: "Positive infinity"????
Post by: C7 on January 11, 2015, 04:40:10 PM
TLDR : Math breaks when you enter stuff that doesn't make sense. Report with exact steps if you find these in the future.

At a certain point the equations used can fall apart when invalid data is entered.

This is a very simple example, but if there's something to the effect of c = a / ( b - 10000);  And you enter in b = 10000 then the equation resolves to  c = a / 0; Which will give you an invalid result. Depending on the placement of the negation, you will get either Not a Number, or an Infinity case.

This in unfortunately quite possible with equations that simulate real effects, as the values you enter are "impossible" in the real world. We need to track down all these cases and add error handling for them. It's a bit tricky though, since in a lot of these cases, there is no sound answer we can provide.

If you find cases like this, it's really useful if we can have exact steps and values entered to test with, so we can reproduce them here.

Thanks!