Timeline for The Lost Fleet's descriptions of trajectories as 'curves' at 20% of light speed
Current License: CC BY-SA 4.0
22 events
| when toggle format | what | by | license | comment | |
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| May 23, 2023 at 9:38 | comment | added | Ahmed Tawfik | It's funny how the answers to this question scifi.stackexchange.com/questions/275721/… agree with my points. | |
| May 20, 2023 at 23:34 | comment | added | Ahmed Tawfik | I think I'm just going to ask this question on physics or space stackexchange, appropriately edited... | |
| May 19, 2023 at 17:02 | answer | added | Xantec | timeline score: 1 | |
| May 19, 2023 at 12:14 | comment | added | AcePL | @AhmedTawfik. Please see my wdited answer. | |
| May 19, 2023 at 9:46 | history | edited | Ahmed Tawfik | CC BY-SA 4.0 |
more examples and clearer explanation of each
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| May 19, 2023 at 9:32 | comment | added | Ahmed Tawfik | @AcePL If you recall, some fleet formations cover more volume than planets and their moons together. So paths wouldn't even notice planets. Additionally, there are many examples where the fleet is mentioned to be curving. One latest example is in chapter 1 in Resolute (Outlands). I'll edit my post. | |
| May 19, 2023 at 0:49 | comment | added | Mark Olson | @AcePL Walking speed is definitely relativistic, but the effect is too small to notice. The gamma factor (1/sqrt(1-v^2/c^2) for 0.2c is 1.026 so that relativistic effects are about 3%. Nothing you'd notice casually. OTOH, gravitation of stars and planets can only change the velocity by about the escape velocity at whatever radius you are at. So a grazing pass to the Sun would change a body's velocity by no more than 100 miles/sec (and any other body far less) which is far less than 0.2c -- at those speeds gravitational effects are tiny. Those ships would basically fly in straight lines. | |
| May 19, 2023 at 0:30 | comment | added | AcePL | @MarkOlson. 0.2c is definitely relativistic, and with effect being noticeable. IIRC relativistic effect can be measured at 0.02c? Fleet in question is not under acceleration and for several reasons it first went deep in-system, closing with the system's bodies for salvage. So it's obvious it has to plot a course around sun and those astronomical bodies to the point it can exit the system, which means it must take gravitational pull from them all into account... | |
| May 18, 2023 at 23:36 | comment | added | Hypnosifl | @MarkOlson - in passages from the Lost Fleet where the author mentions curved paths, is there context that could tell us whether the ships are accelerating or in free fall in those scenes? | |
| May 18, 2023 at 23:02 | comment | added | Mithoron | I think you should maybe check some harder SF ;) Maybe it's a plot-hole or overstatement, dunno, I didn't read the books. In principle you could use whatever "magical" drive they had to bend the trajectory, but dunno why... | |
| May 18, 2023 at 21:34 | comment | added | Mark Olson | @Jiminy Cricket True that even at relativistic speeds, geodesics will be followed by freely falling bodies but only by freely falling bodies. Ships under acceleration are not freely falling bodies and do not follow geodesics. Additionally, when you're moving at 0.2c, geodesics look very, very straight. (At those not-really-relativistic speeds, good old Sir Isaac's theory describes motion pretty well.) | |
| May 18, 2023 at 20:06 | answer | added | Kristian H | timeline score: 3 | |
| May 18, 2023 at 18:44 | comment | added | Hypnosifl | @Spencer I think it was probably meant as a question of whether there was any in-universe explanation for something that seems unrealistic in real-world terms, sort of like asking if there is an in-universe explanation for why Star Wars ships make sound in space or bank when turning. | |
| May 18, 2023 at 18:14 | comment | added | Spencer | @Hypnosifl Do you think this is a real-world science question? | |
| May 18, 2023 at 17:35 | comment | added | Hypnosifl | @Spencer - The comment clarifies that Ahmed Tawfik didn't really mean 100% unaffected by gravity, just not enough of a curve "to be significantly visible at solar system scale" (OP should be edited to reflect that). If you look at photons, even if they get close enough to the sun to graze the surface, the bending of their path due to gravity is only about 1.75 arcseconds, where 1 arcsecond is 1/3600 of a degree, not visible to human eyes if you use a typical type of coordinate system for planetary motions. Assuming 0.2c would be similar, did author get physics wrong or some other explanation? | |
| May 18, 2023 at 15:32 | comment | added | Spencer | Why would you expect "any movement to be a straight line and unaffected by gravity"? Is this about real-world physics? | |
| May 18, 2023 at 12:00 | answer | added | AcePL | timeline score: -1 | |
| May 18, 2023 at 9:36 | comment | added | Jiminy Cricket. | Well, sure, but shallow curves are still curves. They'd want to plot these things accurately over long distances to avoid having to expend fuel on course-correction on the way. | |
| May 18, 2023 at 9:29 | comment | added | Ahmed Tawfik | Any curve from an object travelling at 0.2 light would have to get really close to a planetary body/star to curve enough to be significantly visible at solar system scale, I think. Just like how gravity lensing with light works. | |
| May 18, 2023 at 9:25 | comment | added | Jiminy Cricket. | That speed wouldn't make them immune to having to follow geodesics, even light itself does that. There's an interesting (if not strictly relevant to the question) extra-galactic map of gravity that the milky-way is gliding through in anything but a straight line. | |
| S May 18, 2023 at 9:17 | review | First questions | |||
| May 18, 2023 at 9:18 | |||||
| S May 18, 2023 at 9:17 | history | asked | Ahmed Tawfik | CC BY-SA 4.0 |