tag:blogger.com,1999:blog-13727952.post1897596098917460561..comments2024-03-28T05:50:51.675-04:00Comments on Doux Reviews: The Expanse: Gaugamela Billie Douxhttp://www.blogger.com/profile/17141769005175631213noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-13727952.post-53872122341099552272021-01-09T11:58:52.577-05:002021-01-09T11:58:52.577-05:00I love The Expanse, but the writers really botched...I love The Expanse, but the writers really botched the numbers at the beginning of this episode. Twice.<br /><br />First, the physicist that Avasarala is asking for advice estimates an impact energy of 1 - 4 megatons of TNT given an asteroid diameter at 10-30 metres and assumes a nickel-iron core (which seems unlikely given the way it broke up around Venus, but let's go with it). Assume a diameter of 20m, or a radius of 10m. Density of iron is about 7g/cm^3, and the densities of Pallas and Vesta are around 4.3, so let's assume 5g/cm^3, or 5,000Kg/m^3. He then mutters something about the velocity at impact of either 3,000 or 30,000 kilometres per hour — I can't quite tell, and 'kilometres per hour' is not a unit a physicist would use, but, again, let's go with it. Minimum entry velocity at Earth is actually 11 kilometres per second, which is 39,600Kph, so let's assume that.<br /><br />Volume (V) = (4/3)pi*r^3 = 4,188m^3<br />Density (d) = 5,000Kg/m^3<br />Mass (m) = d*V = 2.094x10^7Kg<br />Velocity (v) = 11,000m/s<br />Kinetic energy at atmospheric entry (Ke) = (1/2)mv^2 = 1.26687x10^15J<br /><br />That translates to an explosive yield at impact (assuming an impact angle of 90° and negligible loss of velocity) of about 300KT of TNT, which isn't that much — okay, it's about 10 Hiroshimas, but that's peanuts (it's basically the yield of a single Minuteman III ICBM warhead). It's nowhere near 3-4 megatons, a yield 10 times larger. In comparison, the Tsar Bomba device detonated by the USSR — the largest nuclear detonation in history — had a yield of 50 megatons.<br /><br />Secondly, the visual that Alex and Bobbie are watching aboard the Screaming Firehawk shows a blast expanding out of the atmosphere and a shock wave spreading across a vast region of Earth's surface, and the announcer states that the estimated yield is 300 to 400 kilotons. That image is no 300 kiloton blast, nor are those of any of the other impacts shown during the episode.<br /><br />300KT is puny by even today's standards. The warheads thrown around by Earth and Mars on The Expanse are enormously more powerful, and Marco Inaros is going to have to lob far bigger rocks if he's going to teach the Inners a lesson.NomadUKnoreply@blogger.comtag:blogger.com,1999:blog-13727952.post-25164931635200301662021-01-03T23:51:42.366-05:002021-01-03T23:51:42.366-05:00Enjoyed your review, Mark, of an amazing episode.
...Enjoyed your review, Mark, of an amazing episode.<br /><br />-- Not Fred! Nooooo! It seems like an episode that really needed the unexpected death of a long running character, but I liked Fred, dammit.<br /><br />-- I absolutely loved Avasarala getting word to Gao because she knew the chef. But these days, I like every scene with Avasarala. <br /><br />-- It sounded like the second rock hit exactly where I'm currently living, which is a hop, skip and a jump from Philadelphia. :)<br />Billie Douxhttps://www.blogger.com/profile/17141769005175631213noreply@blogger.com