Activity for Tristan Klassenâ€
Type | On... | Excerpt | Status | Date |
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Are there *plausible* planetary conditions where jet aircraft just don't have much advantage over propeller-driven aircraft? I've seen Which is easier to develop: a piston prop engine or a jet engine? and my own Effects of 10atm pressure on engine design neither of which answers this. Would different atmospheric density, composition, etc. ever be able to achieve this? Are there conditions under which no practical aircraft... (more) |
— | over 4 years ago |
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Sprawling climbers: how will they develop tools and civilization? Say we have an intelligent species whose body plan is inspired by walking insects (ants, beetles, etc.) and reptiles (particularly lizards). More specifically, let's say they have four legs (I think they'd have things a bit easier with six, so I'll ask the four-leg case, because if it's solvable, s... (more) |
— | over 5 years ago |
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What can I see on the flyers' world? Planetary conditions: 0.5x Earth gravity (guess: 0.9x Earth density, 0.777x Earth radius, so about 0.42 Earth masses... but that's probably not important). Atmosphere broadly similar to Earth but 10x surface density and pressure. Because of half gravity, scale height is 2x Earth, 17km, so column mass... (more) |
— | over 5 years ago |
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Effects of ~10atm pressure on engine design Take a planet with an atmosphere similar to Earth's but, say, 9-10x as dense. What is this going to mean for the performance and design of the heat engines that are so familiar to us? Higher oxygen partial pressure... easier to burn? But higher air density means more heat conducted away... easier eng... (more) |
— | over 5 years ago |
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Can a planet have a day that's always longer than night? This question has been rewritten to incorporate all clarifications. On Earth, half the planet is illuminated at any time (let's ignore eclipses). Axial tilt lets day lengths vary, but over the course of a year, every location is illuminated half the time. It's easy to make a planet where, over a ye... (more) |
— | almost 6 years ago |
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Is a planetary 'temperature inversion' plausible? It was disputed in the 1940s-50s whether Venus had a hot surface and cool cloud layer or a cool surface and hot cloud layer. As I recall, both were considered at the limits of plausibility at the time. We know that Venus turned out to be case 1. But is case 2 still a plausible type of planet,... (more) |
— | almost 6 years ago |
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I'm stranded on an alien planet. How do I measure an earth year without a clock? I just got shoved through a stargate onto a planet I don't know. I was told the gate would open again in exactly one Earth year. I wasn't carrying anything; I don't even have my watch. How do I know what day I can return home? I can count days, but first, I need to determine the absolute length of... (more) |
— | over 9 years ago |
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Acceleration insulation: I can build the Moon cannon, now what? This is steampunk, so assume a non-relativistic, non-quantum world (but more on that shortly). I want a material that insulates against acceleration but not gravity. Full explanation: This is the material one would use to line the walls of a cannon-launched spacecraft. Let's assume that the insu... (more) |
— | almost 10 years ago |
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Is it possible to make a logically consistent set of laws that produces physics similar to that in superhero comics? I'm not talking about stuff like radiation and mutations. I'm talking about mechanics (for now). Necessary effects: With superstrength, you can... lift objects weighing many tons without your feet sinking into the ground lift heavy objects at arm's length without overbalancing lift structures ot... (more) |
— | almost 10 years ago |
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Is it possible to have a logically consistent world where F=mv instead of F=ma? And could it look anything like the universe we know? Don't get hung up on the terminology. In general, you seem to see through it easily, so I don't want any more answers mentioning that. I'll say it's a translation error: My "F" is the quantity that, in the equations of motion discovered by physic... (more) |
— | about 10 years ago |