Editing Talk:2011: Newton's Trajectories
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:Except (as far as we know) Newton never considered parabolic trajectories. Whether he did or didn't, the original diagram didn't show anything beyond a circular orbit. [[User:Mr. I|Mr. I]] ([[User talk:Mr. I|talk]]) 12:36, 25 June 2018 (UTC) | :Except (as far as we know) Newton never considered parabolic trajectories. Whether he did or didn't, the original diagram didn't show anything beyond a circular orbit. [[User:Mr. I|Mr. I]] ([[User talk:Mr. I|talk]]) 12:36, 25 June 2018 (UTC) | ||
:Maybe because the hard part is attaining a stable orbit. Once you do that, it's relatively trivial to escape it. Indeed even the orbit itself, while being determined by Earth, can be considered an escape since you will never again come back to Earth as long as that orbit is maintained. So Randall may have considered that close enough to talk about escaping the bonds of earth (which the stable orbit accomplished) and traveling to the stars (which is the logical next step; or at least to moons and planets so far in our case). [[User:N0lqu|-boB]] ([[User talk:N0lqu|talk]]) 15:03, 25 June 2018 (UTC) | :Maybe because the hard part is attaining a stable orbit. Once you do that, it's relatively trivial to escape it. Indeed even the orbit itself, while being determined by Earth, can be considered an escape since you will never again come back to Earth as long as that orbit is maintained. So Randall may have considered that close enough to talk about escaping the bonds of earth (which the stable orbit accomplished) and traveling to the stars (which is the logical next step; or at least to moons and planets so far in our case). [[User:N0lqu|-boB]] ([[User talk:N0lqu|talk]]) 15:03, 25 June 2018 (UTC) | ||
| + | ::See this What If? question: https://what-if.xkcd.com/58/ [[Special:Contributions/172.68.46.191|172.68.46.191]] 00:18, 28 June 2018 (UTC) | ||
When Jane's Defence discusses strategic (read: nuclear) weapons systems, they do not distinguish between satellite delivery vehicles and ICBM launch vehicles. The only differences are the trajectory and the payload. This comic is definitely about satellites and ICBMs. I'm new here, sorry if I'm not signing this properly --OtherBarry-- | When Jane's Defence discusses strategic (read: nuclear) weapons systems, they do not distinguish between satellite delivery vehicles and ICBM launch vehicles. The only differences are the trajectory and the payload. This comic is definitely about satellites and ICBMs. I'm new here, sorry if I'm not signing this properly --OtherBarry-- | ||
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Fiery death is also mankinds's future if we remain passive and refrain from destroying ourselves, since the sun will eventually grow to engulf the earth. ([https://en.wikipedia.org/wiki/Future_of_Earth#Solar_evolution Solar Evolution]) So the comic is not necessarily as pessimistic as some may think. However, he leaves out the possibility of civilization ending in a non-fiery way before this event. [[Special:Contributions/198.41.230.10|198.41.230.10]] 16:48, 25 June 2018 (UTC) | Fiery death is also mankinds's future if we remain passive and refrain from destroying ourselves, since the sun will eventually grow to engulf the earth. ([https://en.wikipedia.org/wiki/Future_of_Earth#Solar_evolution Solar Evolution]) So the comic is not necessarily as pessimistic as some may think. However, he leaves out the possibility of civilization ending in a non-fiery way before this event. [[Special:Contributions/198.41.230.10|198.41.230.10]] 16:48, 25 June 2018 (UTC) | ||
| β | Note that for this comic the launch angle is near vertical and for all cases the object launched is steered in flight to the final trajectory. For Newton's canonball the ball was launched horizontal to the local Earth surface from a high mountain. A canonball launched vertically appears to be acted on by "forces" when seen from the Earth frame of reference. These "forces" depend on the launch site, altitude and velocity of the object - they are due to the rotating frame of reference. Baring atmospheric resistance, the only true forces on the ball after launch is gravity. But it is certainly true a ball fired vertically from anywhere but the poles does not land back at the site of launch due to the rotation of the Earth. For canon available in Newtons day corrections to aim were not necessary but by the late 1800's big guns were firing projectiles far and high enough that corrections for Coriolis forces were required. Corrections were pre-calculated for range and firing direction for whatever theater of war the gun was being used. | + | Note that for this comic the launch angle is near vertical and for all cases the object launched is steered in flight to the final trajectory. For Newton's canonball the ball was launched horizontal to the local Earth surface from a high mountain. A canonball launched vertically appears to be acted on by "forces" when seen from the Earth frame of reference. These "forces" depend on the launch site, altitude and velocity of the object - they are due to the rotating frame of reference. Baring atmospheric resistance, the only true forces on the ball after launch is gravity. But it is certainly true a ball fired vertically from anywhere but the poles does not land back at the site of launch due to the rotation of the Earth. For canon available in Newtons day corrections to aim were not necessary but by the late 1800's big guns were firing projectiles far and high enough that corrections for Coriolis forces were required. Corrections were pre-calculated for range and firing direction for whatever theater of war the gun was being used. |
