Fun with applets!

[longstreet]

I love this guys physics applets, and I just found one that can be used to get a visual on what's happening in a fusor. It simply shows particles reacting to an undescript vector field; so no charge, collision, etc... This is NOT a fusor simulator, but it is interesting.

Here is the link to the applet page: http://www.falstad.com/vector3d/

An applet should come up automatically, and it has a default with particles falling into point. First, change the "display" drop-down to force setting: "Display: Particles (Force)", rather than "Display: Particles (Vel.)". Now you can play with different field types. Basically anything that doesn't have the word "single" or "rotational" will give you fusor type stuff, except the complicated stuff at the bottom of the list.

I prefer the "1/r^2 sphere" field. Try changing sphere size and field strength!

have fun!
Carter

[Captain_Proton]

This is excellent! What a great find...

[Q]

yes, very interesting! especially when you expiriment with the "field strength" and "sphere size". the different modes of operation that it demonstrates has given me a few ideas...
Q

[longstreet]

It seems that 1/r^2 is the potential, which is wronge for a point source. Potential is 1/r. So, it's not exactly like a fusor's field.

Carter

[Starfire]

Great one Carter - should put in ' Links'

Have you tried some of the others?
http://www.falstad.com/mathphysics.html

[Richard Hull]

Very nice!

Did anyone look at it max'd out on field and on particles and on both. Is the formation of a crude star seen real, or imagined by optical illusion within the cube??

Looking at the thing crosseyed will help or with averted vision.

Richard Hull

[longstreet]

Yes John. He has many great wave applets.

Richard, I think that "star" forms because the box is not spherical. There are simple more particles along those axis so it looks like a star. The diaginal is sqrt(3) times longer than from face to face. I don't think it's the same as "star mode" in a fusor.

[longstreet]

Try this... Set the size of sphere to max size, set particle number to max, and set force to zero and reset so everything is still. Then *slowly* increase the force to the max. Nice little oscillation there.

edit: also try the above with force at zero. Then just tap the up arrow so force is at lowest non-zero value. Wait till a nice ball forms in the middle and then set the force to max.

Carter

[Q]

yeah, the 1/r^2 field would be more accurate for a gravitational field, but the visualization does help a few gears to turn in the ol' noggin.

Q