[Onlyinterestednotdevoted (OP)]

My girl and I are curious...how big would a helium balloon have to be to lift 35 lbs. I have no idea, but I assume it would have to be pretty big, because it would have to displace at least 35 lbs. of air. So if you could give me an idea in general terms (as my name suggests I am not a big scientist.)

[RD]

Lawrence Richard Walters, nicknamed "Lawnchair Larry" or the "Lawn Chair Pilot", (April 19, 1949 – October 6, 1993) was an American former truckdriver who took flight on July 2, 1982 in a homemade aircraft. The device, dubbed Inspiration I, was fashioned out of a patio chair and 45 helium-filled weather balloons. He rose to an altitude of 16,000 feet (3 miles or 4,900 meters) and floated from his point of origin in San Pedro, California into controlled airspace near Long Beach airport.

http://en.wikipedia.org/wiki/Larry_Walters


Larry survived, Father de Carli did not...

Father de Carli has not been seen since he took off from the town of Parana on Sunday in a contraption made of 1,000 helium balloons and a chair.

Rescuers have since found a cluster of multi-coloured balloons floating off the coast of Southern Brazil prompting fears that the priest died out at sea.

http://www.telegraph.co.uk/news/1901407/Brazils-ballooning-priest-may-be-latest-self-inflicted-tragedy.html

[Don_1]

Some people get some real daft ideas in their heads don't they

[RD]

What is Onlyinterestednotdevoted's 35lb payload ? : a dog ?, a young sibling ?   [:0]

[Onlyinterestednotdevoted (OP)]

It is her youngest son.

[Bored chemist]

Does that count towards a darwin award?
http://en.wikipedia.org/wiki/Darwin_Awards

[Onlyinterestednotdevoted (OP)]

Does that count towards a darwin award?
http://en.wikipedia.org/wiki/Darwin_Awards [nofollow]

NO. I don't think I'm worthy of the Darwin Award. But thank you for the nomination. But let me ask a more personal question. I weigh about 205 lbs. How big would the balloon have to be to lift me about 15 feet off the ground?

[RD]

Does that count towards a darwin award?
http://en.wikipedia.org/wiki/Darwin_Awards

NO. I don't think I'm worthy of the Darwin Award. But thank you for the nomination. But let me ask a more personal question. I weigh about 205 lbs.
 How big would the balloon have to be to lift me about 15 feet off the ground?

A balloon which could lift you 15 feet could also lift you 15,000 feet and more. You would keep on rising until the balloon burst in the thinner atmosphere at high altitude, you would then plummet to the ground where you would become eligible for a Darwin award.  [xx(]

Lawnchair Larry survived by having 45 balloons, he burst a few with a pellet gun to allow a survivable descent.

[Onlyinterestednotdevoted (OP)]

Well how much air would I have to displace to allow me to lift?

[lyner]

Well how much air would I have to displace to allow me to lift?

Your own weight plus a little bit.

[Bored chemist]

Roughly 1 cubic metre will lift about 1 Kg.
Helium is not a renewable resource but fools are. If anyone plans to do this experiment please use hydrogen.

[Onlyinterestednotdevoted (OP)]

but isnt hydrogen much more explosive than helium?

[Chemistry4me]

If your struck by lightning or something similar of that nature, hydrogen can be used. I don't think anyone will do this experiment in wild weather though.

[Bored chemist]

If your struck by lightning or something similar of that nature, hydrogen can be used.

Thanks for that.