Errors in Death from the Skies

[Gillianren]

If you think people are being rude, report it.

[dirty_g]

same for you. The point it its not rude enough to report is it. Being sarcastic or snarky you can get away with. Being outright nasty you cannot.

[hhEb09'1]

The paperback edition is out.

[Spoons]

hhEb09'1 - Did Phil ever end up getting on to Colbert? If so I must have missed it. If not, we must petition for this! 2 stars on one show - a binary episode.

[Ze_Kraggash]

Page 205, DFTS; describes the red giant Sun swollen to 100 times its present radius. It mentions that the gravity at the surface will be less than 1 percent of Earth gravity.The square inches are measured at the current radius, I guess, before and after. By the time it gets to the surface of the red giant, the radiation per square inch will be 1/10,000 of that, right? But, wouldn't luminosity be related to the surface?

If the Sun is 100 times bigger, it area will be 100 x 100 = 10,000 times bigger than today. However, on page 204 it says the luminosity will be 2,400 times as great. That means each square inch will be (2,400)/(10,000) or roughly 1/4 as luminous as today.

[grapes]

If the Sun is 100 times bigger, it area will be 100 x 100 = 10,000 times bigger than today. However, on page 204 it says the luminosity will be 2,400 times as great. That means each square inch will be (2,400)/(10,000) or roughly 1/4 as luminous as today.

Yes, I think that was the point I was trying to make. I'll have to go back to the book to remember the context...

[Tobin Dax]

Remember that Luminosity per square inch varies with temperature to the fourth power, following the Stefan-Boltzmann law. The red giant sun will have a cooler surface temperature than its current temperature, and so the luminosity per square inch will be less then than it is now.