Timeline for What kind of missile flew with such speed in 1st century BCE?
Current License: CC BY-SA 4.0
11 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Feb 8, 2021 at 0:57 | comment | added | Mark Olson | @Alex's point is valid. One kg of lead travelling at 100 mph has about 1 kilojoule of kinetic energy. That's all the energy available for heating, and it doesn't matter if it's heated by air friction or deformation on impact. The maximum heating for a 100 mph lead projectile is10 degrees K. The real heating will be less as some of the energy will be lost as sound or in moving other objects. Lucretius was mistaken if he thought there would be significant heating: There isn't. | |
| Feb 7, 2021 at 4:43 | comment | added | jamesqf | @Alex: I think the point here is that Lucretius was mistaken about the source of the heat. It wasn't from the friction of flying through the air, but from deforming on impact. | |
| Sep 9, 2020 at 22:32 | comment | added | Alex | When I drive my car at 100mph its extrerior surface is not appreciably heated, not even mentioning the melting point of lead:-) | |
| Sep 8, 2020 at 20:33 | comment | added | releseabe | If you bend a piece of metal back and forth heat is generated very fast and obviously so lead deforming upon impact will almost certainly be warm to the touch but air friction at 100 mph would not cause noticeable increase in temperature. But an amazing idea so long ago that there was a relationship between heat and motion which was not really understood until 200 years ago -- one smart guy to come even close so long ago. | |
| Sep 8, 2020 at 16:48 | comment | added | MCW♦ | @DarioQuint - please add that comment to the answer - and if you can cite the Trimontium Trust paper, that will help (I tried, but there are multiple papers to which that could refer). | |
| Sep 8, 2020 at 16:33 | review | Low quality posts | |||
| Sep 8, 2020 at 17:03 | |||||
| Sep 8, 2020 at 16:31 | comment | added | Dario Quint | I can swing a hammer at far below 100mph, and yet cause a piece of lead about the same size as roman shot to heat up. Stating "my guess" was directed at his actual meaning, which barring Lucretius rising from the dead can't be known with 100% accuracy. My math/physics admission was likewise an admission that, while I can't run the specific numbers for you, similar energy transference indicates it would be heated to some extent. | |
| Sep 8, 2020 at 16:25 | history | notice added | MCW♦ | Needs citation | |
| Sep 8, 2020 at 16:20 | comment | added | Pieter Geerkens | Guesswork is not really what we look for on this site. Hitting something with a hammer is not at all similar to the friction of flying through the air - and I fully expect the ancients understood that. | |
| Sep 8, 2020 at 16:18 | review | First posts | |||
| Sep 8, 2020 at 17:23 | |||||
| Sep 8, 2020 at 16:15 | history | answered | Dario Quint | CC BY-SA 4.0 |