something so cool it must be illegal

[ilbob]

http://www.metacafe.com/watch/833648/huge_solar_balloon_easy/

[RocketMan]

That makes me have all kinds of mischievous thoughts...

[Joe Demko]

I've done these in science classes. It does work and work well on a bright sunny day.  If you live down south, you should have excellent results.   I kept mine tethered on a piece of monofilament.  Letting them go is nothing but long-distance littering.

[Manedwolf]

That site is a bit dangerous. One of their other videos is "how to make a firework launcher that works remotely via a cellphone".

http://www.metacafe.com/watch/692380/make_a_firework_launcher/

Yeah, or an IED detonator. Lovely. Completely, how to do it. How to take apart the phone, and which circuit to use so you can call the phone from another phone and blow something up. :/

And yes, I already gave the link to the FBI's report thingie. Let them see what they think of it. The last thing we need is easy instructions for the durka-jihad nuts acting on their own here, how to use two prepaid cellphones to blow up something.

[grislyatoms]

I am going to try the balloon with kiddo. Looks rather fun!

P.S. I wonder if clear plastic would work better than black? "Greenhouse effect" type of thing or whether the black would absorb more energy.

We might have to try both.

[Joe Demko]

I'll save you the effort.  Black works best followed by dark green.  Other colors and transparent do work, but they take longer to heat up and start floating.

Please tether your balloons.  You are littering, at best, if you release them.  Unless you live close to an airport where planes are taking off and landing, I guess there isn't too much risk of them drifting into aircraft travel lanes...but even so, I advise tethering them and disposing of them properly when the fun is done.  I don't know too much about jet aircraft but even if it won't stop an engine, sucking one of these things in probably wouldn't do one any good either.

[grislyatoms]

I'll save you the effort.  Black works best followed by dark green.  Other colors and transparent do work, but they take longer to heat up and start floating.

Thanks for the info. We may try both anyway, so I can ask kiddo a few questions about what she thinks will happen.

Please tether your balloons.  You are littering, at best, if you release them.

Will do. (Though I would not have done otherwise )

[Jamisjockey]

I am going to try the balloon with kiddo. Looks rather fun!

P.S. I wonder if clear plastic would work better than black? "Greenhouse effect" type of thing or whether the black would absorb more energy.

We might have to try both.

Please only do it if you tether the ballon.
Loose ballons are a hazard to aviation.  I've seen 2 serious incidents due to ballons.  One F18 ingested ballons on short final, one AV8 on departure.  Both times cost the taxpayers alot of cash.

[Perd Hapley]

grisly, I think you should tether your balloons.   

[grislyatoms]

Nahh, I think I'll tether them instead.

[S. Williamson]

Please have your balloons tethered.

 

[Joe Demko]

Another hint, these work best if you carefully time when to do it.  You want to do it before things really begin to heat up where you live.  In my classes, they worked best if we filled them with the relatively cool air right around 7:30 AM.  The greater the temperature difference between the ambient air and the air inside the bags, the more spectactular your results will be.

[grislyatoms]

I live in the high desert. 55 degrees at night/early morning right now and 85-90 degrees during the day.