@BillRM,
Quote: Now are you going to back down now or not?
No because I didnt do the calc so in order for me to back down I need to mentally refute what I heard on NPR. OK so if the guy on NPR is correct and you are wrong
(1). I hadda find out the lift in terms of cubic feet of helium, (not in grams per fortnight or clevis's per hectare). SO I looked up your numbers and came up with other numbers (under STP and US dimensions)
(2) a cubic foot of Helium will lift 28.2 grams (ok just so we start out on an equal footing)
(3) A gram is 1/448 of a pound or 0.0022 (pounds per gramm) . SO, if we multiply (28.2) X (0.0022) we have (0.063 pounds per cubic foot). THis says that a cubic foot of helium will lift 0.06 pounds
(4) I can simplify all this by just multilying the volume of helium weve got by 0.063 to find out its ideal lift potential
(5) THE GUY ON THE RADIO SAID THAT THE BALLOON HAD A VOLUME (filled with helum) OF 2400 CUBIC FEET
(6) (2400) X(0.062) = 148.8 pounds.This says that a 2400 cubic foot balloon can lift 148.8 pounds
SO, according to NPR's volume the balloon was capable of lifting about 150 pounds.
SO if the kid weighed 80 pounds and the balloon and that little "cabin" weighed only , say 50 pounds, the kid would be liftabel NO? . NOW I didnt do any corrections for temp or density so if I knock off another 20 lb for that, the entire balloon and "CAbin needed to weigh 30 pounds.
I dont know, is that doable ? Id say yes cause I could design a Ti cabin less than 20 pounds that could carry (4), 20 lb turkeys, so I assume we can achieve liftoff with 4 turkey carcasses. ANYWAY even if Im off, Im close enough to NOT make it implausable.
You are correct Billy that the guy is a fraud , but for totally wrong reasons, because your calcs didnt fully disclose the truth.
I think your problem is that you were thinking CGS and didnt really convert over to pounds and cubic feet. Its a mistake that beginning students do all the time.