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Everything posted by KSK

  1. Just for comparison purposes, according to Wikipedia, the world Maglev speed record is 603 km/h, achieved on an 18.4 km track. That's from rest to full speed and back to rest. A little bit of back-of-the-envelope maths gives me an acceleration of approximately 0.15g and a time to reach maximum speed of 110s or just under 2 minutes. Put a Maglev in a vacuum tube so that it can keep accelerating and you very quickly get to some pretty ridiculous speeds even at .15g. Again, for comparison, commercial passenger jets travel at about 600 mph (from a quick online search) or 965 km/h. The above Maglev in a vacuum tube would hit passenger jet speed in about 3 minutes and about 14 km into its journey, assuming my arithmetic checks out. In that context, accelerating at 1 or 2g looks a bit like overkill. Edit: This is a very rough calculation of course - for one it ignores air resistance completely and, for two, it assumes a constant acceleration to the half way point and then constant braking to rest. But I think it gets the main points across - it should only take a relatively modest constant acceleration for a vacuum tube train to comfortably beat out commercial air travel for raw speed, and those kinds of acceleration are quite achievable with current technology. Whether a vacuum tube train can be made as reliable and safe as commercial air travel is another matter.
  2. Good to see this one back! Glad college life is going well too!
  3. I, for one, find it mighty suspicious that they cut the audio feed when the dolphin turned up. I bet it was whistling the Star Spangled Banner.
  4. This. So very, very much this. Arnie in his prime, special effects that were there when they needed to be rather than gratuitous 'LOOK - A SPECIAL EFFECT' shots, and probably one of my all time favorite sci-fi movie scenes of all time. And best yet, my godson is almost old enough for it and old enough to appreciate it. On a completely different note, I recall Short Circuit 2 being as good as, if not better, than the original. Unsure if either movie will have stood the test of time though.
  5. Depends how that person is flying. If they’re relying purely on wing flapping for propulsion then probably very slowly. On the other hand it might be possible to let gravity do the work, depending how the antigrav pack works. If it’s capable of letting a person rise against gravity and can also be adjusted to provide various amounts of lift then it might be possible to go vertically upwards under antigravity power, turn the pack off (or ‘throttle’ it way back) and dive to gain speed, set the pack to neutral to avoid lithobraking and glide as far as you can until air resistance slows you down. Repeat as necessary.
  6. Elephants are the obvious example of ‘tentacle manipulators’ and, thinking about it, an excellent counter example to my previous post where I thought that tentacled critters using tentacles as both ‘arms’ and ‘legs’ would be more plausible than something that mixed up articulated limbs with tentacles. So - scratch that comment. I was curious about octopuses as another possible example of ‘tentacle manipulators’ though and found this paper: https://www.cell.com/current-biology/fulltext/S0960-9822(09)01914-9?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0960982209019149%3Fshowall%3Dtrue It describes an interesting - for this discussion - ‘stilt walking’ behaviour which a certain octopus species will use when carrying coconut shells around. ”To carry one or more shells, this octopus manipulates and arranges the shells so that the concave surfaces are uppermost, then extends its arms around the outside and walks using the arms as rigid limbs.” (emphasis added) Admittedly ‘stilt walking’ is pretty cumbersome but I thought the rigid limb thing was relevant to this discussion, as an example of a soft bodied critter being able to rigidify(sp?) itself if required. On that basis I could imagine a soft bodied tentacular alien being able to rigidify itself if it needs to brace for tool manipulation.
  7. The one drawback I can think of for hands is that they're relatively fragile with a lot of moving parts and so there's quite a few ways they can go wrong or be impaired. A tentacle might be more robust (so 'better' in one sense) but wouldn't be quite as versatile as a hand for manipulating tools. However a tentacle would be a much more flexible and versatile carrier for that tool manipulator than an arm is for a hand. A tentacle with some kind of receptacle in the end (think of an elephant's trunk) would be reasonably capable as a manipulator whilst being considerably more flexible and versatile than an arm. It could grasp a handle with ease (an octopus would have no problem holding a hammer), the receptacle at the tentacle tip would allow for holding smaller tools or manipulating 'poking' tools like bradawls or punches (or daggers). About the only thing I can think of where it would seriously struggle would be with scissors and related tools where having multiple digits to operate multiple parts of the tool simultaneously is an advantage. One could operate a pair of scissors two-handed but it would be clumsy. Perhaps a bifurcated tentacle then, with each tentaclet(?) having a receptacle at its tip? Something else to think about when considering alternatives to hands is that you're also likely to be considering alternatives to feet. In general nature seems to be quite good at coming up with symmetrical body plans or body plans where similar structures can be pressed into service for different roles. Arms and hands vs legs and feet for example. I would find an alien creature with tentacle manipulators which walked on another set of tentacles to be much more believable than some half-and-half critter with humanoid articulated legs and tentacular arms. Of course - as you've mentioned before - 'aliens' could be the product of human biological engineering, in which case all bets are off. From a worldbuilding perspective, I'd find it interesting to write about a fictional race of tentacle critters. How would that reduced dexterity (compared to hands) affect their approach to every day matters. Take clothing for example - I imagine that manipulating buttons or zips with tentacles could be a real pain, so they might favour clothing with as few closures as possible, and perhaps rely on toggles or overgrown cufflink style closures (longer, easier to grip with a tentacle) than buttons. Hook and loop fasteners would be significantly easier to use, so perhaps all their clothes would rely on alien Velcro. Likewise for spacecraft controls - they might depend more on buttons and biggish levers rather than fiddly small switches, assuming that their spacecraft are still flown with manual controls. Or, what would arts and crafts look like for these critters? I doubt they're going to be much good at needlework, so anything hand-stitched might be the mark of a true crafts-critter. So much so that human crafts like embroidery or tapestry work would completely knock their socks ( or other tentacle-tip protective garments ) off! Maybe that turns out to be the basis for their peaceful artistic and cultural exchange with humanity? It's those kind of small details that I think would make this fictional race feel really alien rather than humans-by-another-name.
  8. For those about to sleep. We salute you.
  9. Nah - Elastic Failure are prog rock. They probably have a theramin player who can also knock out a kicking kazoo solo if the mood takes her. Now CatastrophicFailure on the other hand or, more probably CataströphicFailure? That's your thrash metal band right there.
  10. I, for one, look forward to our oddly shaped, Dayglo music storage media. Although warp drive would be pretty neat too.
  11. A couple of other thoughts. Firstly - I was being kind of prescriptive in that last post, for which I apologize. If you (and that's generic you rather than addressing this to Spacescifi) want to delve into the minutia of a fictional technology, trying to figure out a plausible way to make it work and keeping everything tight and consistent within the story setting, then go for it! I'd be the first to tip my hat to you if it works, and concede that you're a far better worldbuilder than me, with a damn sight more patience. Secondly - and this is directed to Spacescifi - you might get more informative answers to a straight question rather than dressing it up in a particular sci-fi setting. If you're looking for a design for a reusable orbit-to-dirt rocket powered shuttle, I'm sure there are folks on here who would help crunch the numbers and give you some idea of how fictional, or otherwise, the thing would need to be.
  12. Ahh - I think you either misunderstood me or I wasn't very clear. When I'm thinking near future, I'm thinking non-FTL ships powered by something that's recognizably a rocket engine. It may be chemical, it may be some variety of nuclear thermal, it might be fusion at a pinch (pun not intended). Either way, I'll be scouring the depths of Project Rho, looking for engine designs that have at least been worked out to some extent and come with actual values for thrust and specific impulse - although I'll probably assume that my fictional engines are operating at the upper end of any performance ranges described. I probably won't be going into the details of how - for example - a solid core nuclear thermal rocket works and I'll almost certainly never give actual numbers for engine performance but I will have them to hand. So, if the story calls for a journey to Planet X, I'll plan it out in broad strokes: pick a likely sounding total delta-V for the journey and from that, work backwards to figure out how much fuel I need. In turn, that gives me a rough idea of what the spacecraft looks like and what sort of capabilities it might have. Is this basically a flying fuel tank on a one way journey? Does it need to be capable of aerobraking? Are the engines efficient enough that I have spare cargo capacity for a orbit-to-surface shuttle? Can I go for a bigger design with a built in centrifuge, or are my crew just going to have to deal with zero-g for the journey? That sort of thing. More fictional spaceships are actually fairly easy to make capable without being overpowered. The problems tend to come in if you insist on using acceleration to create artificial gravity. If you're okay with assuming some kind of artificial gravity generator (which, to my mind is no more outlandish than your SCI drive), then the need for a constant 1g acceleration drive disappears. Alternatively, if you're okay with a hyperdrive, then you can effectively do point to point interstellar travel with almost arbitrarily short journey times. Healthwise, it doesn't much matter if your crew are in zero-g for a few hours, or even a couple of days. Heck - you could go for a biological solution and assume that your crew is genetically engineered to overcome the effects of living in zero-g. Or just accept that the effects of zero-g can't be fully mitigated and have a setting where some planets are simply off-limits to certain space-faring characters because their gravity is too strong. There's a reason that some technologies (like artificial gravity) have become sci-fi tropes. They solve a particular problem without going too far down the rabbit hole of unintended consequences. If you want the story to involve a futuristic technology (rather than the technology just being Trek-like background stuff that makes things happen), then a good way of doing it - in my opinion at least - is pick some limitations and follow the consequences of those limitations, rather than tying yourself in epicycles trying to solve every last problem. And don't explain the technology - any 'explanation' is likely to be technobabble at best, and leave you open to those pesky unintended consequences at worst. For example, in The Mote in God's Eye, spacecraft have a shield (I forget what it's called but it's named after an in-universe character). If I remember rightly it's basically a perfect energy absorber - right up to the point where it overloads and releases all the stored up energy in one go. Which tends to be bad news for whatever it's shielding. So you can fly through the upper atmosphere of a star and be absolutely fine - but you'd better make sure not to stay in there too long, and you probably want to plan for a few days downtime afterwards whilst your shield radiates all the stored up energy away. The physics of how this shield works are never explained (for good reason) but its basic operational principles are clear and come with meaningful consequences.
  13. Give the guy a break - he's probably talking to his mouse again. And yeah, I'm with Roddenberry on that one. Can't quite picture the Enterprise flipped saucer low. Sort of agree, depending on the fiction. I'm right with you on not spelling out the details because your characters most likely won't know or care about them and I'm not a great fan of Star Trek Technical Manual style explanations based on piling technobabble atop technobabble. If I was writing a near-future space travel tale though, I would probably want to figure out roughly what a given engine was capable of for the sake of keeping things consistent behind the scenes, even if I just called it a 'fusion thruster' or something in-story. Plus, it's helpful to know how roughly how much of a fictional spaceship needs to be devoted to propellant tanks, when it comes to describing them.
  14. Objectively, these are far from the best but if you're looking for TV that I loved as a kid: Automan (because Cursor.) Manimal (because who wouldn't want to turn into a black panther at will.) The Tripods. (Let's hear it for pre-CGI BBC budget special effects!) And y'all can get off my lawn now.
  15. Today's dinner was an experiment in fusion cuisine (because that sounds better than 'throwing together whatever I had left in the fridge'). Leftover chicken, vegetable and oyster sauce stir fry, bulked out a bit with black pudding, and served over rice. As the song goes: "This was a triumph."
  16. Star Trek vessels do go into orbit but the technical details are handwaved away or deliberately ignored for dramatic effect. From Memory Alpha: According to the Star Trek Encyclopedia (2nd ed., p. 460): The term "standard orbit" was used as an ingenious means of allowing the captain to give a technical-sounding command when the ship entered orbit, without having to bore the viewer with tedious details of orbital inclination, apogee, perigee, and orbital period. It was at one point thought that standard orbit would be synchronous, allowing the ship to remain stationary over a single point on a planet's surface, but a visual-effects shot of the ship, motionless over the planet, would not have been dynamic, thereby lacking dramatic value. Moving the ship was, therefore, a conscious decision by the show's producers. Even when the ship was required to "hover," some slight movement was shown so that the image wouldn't be static. The Star Trek Encyclopedia – A Reference Guide to the Future is the "definitive" Star Trek reference book, compiled by the production staff and officially licensed and endorsed by Paramount Pictures/CBS Consumer Products. So the Star Trek Encyclopedia is about as canon as it gets.
  17. Crew Dragon takes about 40 minutes to return to Earth from starting its deorbit burn. https://blogs.nasa.gov/spacestation/2020/08/02/the-spacex-crew-dragon-is-go-for-deorbit-burn/ Twelve minutes of that is taken up with the actual burn because it’s carried out using small maneuvering thrusters. The Shuttle (which is probably a better comparison vehicle here) took about an hour from starting the deorbit burn to landing. Six hours was the total time including closing the payload bay doors, getting the crew suited up and other checks and procedures.
  18. I think part of the fascination is that it’s one of those ideas that sounds just too crazy to work - but as far as the General Atomics team could figure out - it would work. Then there’s the part where it scales up really well (because big yield nukes are easier to design than small yield), so you end up with a launch vehicle that can put really crazy amounts of payload into orbit compared to even Nova/Saturn V/Starship sized chemical boosters. It’s also very old-school ‘Jeb the Thrillseeker’ KSP for anyone who’s been around the forum long enough. It’s just a really big geeky, space nerd’s dream (raises hand as a paid up member of the geeky space nerds) - it’s just a shame about the practicalities.
  19. Agreed! Although, according to Wikipedia at least, the Soviets landed a couple too. Admittedly, that would still count as 'pretty tough' in my book.
  20. Does measuring the Earth-Moon distance down to the nearest millimetre count as precise? Lunar Laser Ranging experiment - Wikipedia
  21. Godspeed B1051.13 ‘Billybobfry’
  22. Tillage + seed + irrigation + time = food. Depending on your field of course.
  23. And maybe one day, Starship/Superheavy will be iconic enough that all new rockets are compared to it, rather than the Saturn V. This isn’t meant as a snark - I think it’s a tribute to the Saturn V engineers and how far out of time they were that their work is still the benchmark for cutting edge rocketry over 50 years later.
  24. Yeah, those power transmission lines are going to stand up well to a nuke as well. I suppose they could go underground but they won’t be for the same reason that combustion plants aren’t going to be made seriously nuke-proof. Too expensive. And frankly, if the nukes start flying hard enough that a nuclear winter happens - well good news. There’s not going to be much left for those windmills/solar panels/combustion plants to power anyway. I’ll stick with my green powah fantasies thanks. Because ‘will not survive a nuclear war’ is a critical flaw in pretty much damn near everything. Unless you were just trying to troll me. In which case, job well done, have an internet cookie.
  25. Tiberium heralds the dawn of a new age... I have no reason to dispute the conclusions of the video but the presentation was a little too much like an old Command and Conquer cutscene for my liking.
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