Comments on: A hot air balloon is almost entirely hot air https://www.isegoria.net/2020/06/a-hot-air-balloon-is-almost-entirely-hot-air/ From the ancient Greek for equality in freedom of speech; an eclectic mix of thoughts, large and small Thu, 28 May 2026 23:08:55 +0000 hourly 1 http://wordpress.org/?v=3.6.1 By: Steve Johnson https://www.isegoria.net/2020/06/a-hot-air-balloon-is-almost-entirely-hot-air/comment-page-1/#comment-3200979 Steve Johnson Wed, 10 Jun 2020 01:10:27 +0000 https://www.isegoria.net/?p=46729#comment-3200979 So you’re saying it’s a good name.

]]> By: Dave https://www.isegoria.net/2020/06/a-hot-air-balloon-is-almost-entirely-hot-air/comment-page-1/#comment-3200928 Dave Tue, 09 Jun 2020 22:13:42 +0000 https://www.isegoria.net/?p=46729#comment-3200928 Well, yeah. The difference between the mass of heated air and the mass of the same volume of unheated air has to equal or surpass the combined mass of everything else.

E.g. air at 450 Kelvin (350 Fahrenheit) is 2/3 as dense as the same air at 300 Kelvin (80 Fahrenheit), and so able to lift half its own mass, if the envelope doesn’t melt or catch fire.

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