MythBusters Water Heater Rocket

MSimon · Post by **MSimon** » Mon Dec 07, 2009 8:23 am

Why hasn't Polywell been fully funded by venture capitalists?

Because Bussard/Nebel got a better offer from the US Navy.

I can tell you personally that it is not from lack of money. Money on the order of what Nebel is getting this year from the Navy.

Josh Cryer · Post by **Josh Cryer** » Mon Dec 07, 2009 12:38 pm

Betruger · Post by **Betruger** » Mon Dec 07, 2009 6:29 pm

I wonder what that little flash 2/3s of the way up the heater's side is, just before liftoff.

Aero · Post by **Aero** » Mon Dec 07, 2009 7:30 pm

@Josh -
How does one embed this youtube video?
http://www.youtube.com/watch?v=457DSAxu ... r_embedded

It shows how these things should work, although from the sound of it, the rocket may have failed at altitude.

Josh Cryer · Post by **Josh Cryer** » Mon Dec 07, 2009 11:06 pm

Betruger, I believe it is the electronics component part of the tank. Could have slightly ruptured there but since the bottom is designed to blow before the top, all of the pressure got released downward. But yeah, while making the .gif it stood out to me, too.

Aero, afraid this site doesn't allow embedding videos, phpBB2 is really nasty, to add a button is such a pain, it requires hand editing source code. It's so much easier on phpBB3.

(Hint hint.)

I believe they got up to 500 feet with it.

Betruger · Post by **Betruger** » Tue Dec 08, 2009 12:43 am

Thanks Josh.

krenshala · Post by **krenshala** » Tue Dec 08, 2009 4:15 am

Josh Cryer wrote:Betruger, I believe it is the electronics component part of the tank. Could have slightly ruptured there but since the bottom is designed to blow before the top, all of the pressure got released downward. But yeah, while making the .gif it stood out to me, too.

To me it looked like the water pipe hookup to "feed" (or fuel) the water heater broke off, expelling some steam, a fraction of a second before the bottom broke. It could definitely have been the electronics, however.

Aero · Post by **Aero** » Tue Dec 08, 2009 6:09 am

I stepped through your gif one frame at a time at 300%. I think the flash is a change in stage lighting reflection off the tank, maybe due to deformation just prior to failure. I don't think its steam because there is no residual haze in the air between the flash and the bottom blowing out. The flash comes and goes, steam would come and get worse. Just my opinion.

Josh Cryer · Post by **Josh Cryer** » Tue Dec 08, 2009 11:54 am

Actually, I should say that the top of the tank is designed to withstand pressure, not that the bottom is designed to blow. The top has pressure valves designed specifically to release any pressure up there. This would never happen unless those valves failed (or in this case, were locked down tight by the MythBusters).

I think you got it Areo, btw. A water tank is two layered (took 'em apart as a kid so I am intimately familiar with the things). It's probable that the tank deforms ever so slightly producing a rather unique, if scary, reflection / explosion illusion. The light seems to fade out as it rises, not something you'd expect from a small explosion.

Betruger · Post by **Betruger** » Tue Dec 08, 2009 10:00 pm

Simplest solution is to watch a better source. DVD or BR or something.

Josh Cryer · Post by **Josh Cryer** » Wed Dec 09, 2009 2:11 am

The source was HDTV 720p, but I don't have it anymore. Should've looked at it closer, but edited it resized.

jnaujok · Post by **jnaujok** » Wed Dec 09, 2009 5:54 pm

Josh Cryer wrote:The source was HDTV 720p, but I don't have it anymore. Should've looked at it closer, but edited it resized.

In the original broadcast, on a 47" TV, it was quite easy to see it was an electrical arc as the electronics disconnected itself (or broke in some way.) The familiar blue/purple flash of the electrical arc was very clear in some of the shots, and careful watching shows that Jamie had hooked it up using alligator clips, that likely would have pulled away as soon as it started moving, drawing the electrical arc.