Of course spaceships aren't boats. They're called spaceSHIPS. On a more serious note: there's nothing wrong with writing about spaceships like they were seafaring vessels. Try not to get too worked about this if it annoys you, it's not getting you anywhere. Actually, from the perspective of a writer, I love when other writers make "mistakes" like this, because it means I have an easy job writing stuff that is far better than they did.
About spaceships moving like boats: Why not? Perhaps the tech that allows the ship to accelerate to high speeds without a bunch of nasty side-effects, has the unintended consequence of making ships behave like, well, boats? We know quiet a bit, but we still don't know everything! Yeah you're right, I was ignoring it, and while trying to come up with a new name for the genre I only thought of another oxymoron. "Speculative Reality", but that would assert itself as a more philosophical genre than a 'scientific' one. But then again, science has it's basis in philosophy. There probably isn't a much better alternative than sci-fi. If we ignore the naming, there is still some confusion in the whole genre. This confusion leads to threads like this and complaints of FTL, ships moving like boats, etc. That's probably because books and other works aren't given their stamp as "Soft/Social" or "Hard" sci-fi. In soft, pretty much anything with a 'science' sounding explanation goes. But, it's still separated from fantasy, in that it actually has some form of explanation/basis in reality. Spoiler: Asimov He seems to be a pretty great writer and thinker, I would consider it terrible wrong to put a fantasy tag on one of his works. The issue is probably that many hard sci-fi writers/readers, like op, don't like the fact that they're getting mixed up with soft sci-fi writers/readers? Should the genre be divided into two? Or is that just futile and unnecessary? It also depends on the story, one set in a very advanced/futuristic universe would have little to do with science and more to do with philosophy, since there is no telling what kind of technologies might be present. We humans are prone to bypass the impossible. Does anyone know which category of sci-fi is most popular? Soft or Hard? Books only.
I'm guessing soft because that's what most science fiction authors write. However, this depends on your definition of hard and soft. I know people who think The Time Machine is hard science fiction. I disagree.
It is possible that high speed interstellar spacecraft will need to be aerodynamically sound. Although the density of the interstellar medium is very low (about one atom per cubic centimeter, I believe I read somewhere) a craft moving through it at a significant fraction of the speed of light would apparently experience non-trivial aerodynamic drag. This also means that thrust would have to be applied continuously to maintain the craft's speed, just as with, for example, airplanes.
Yeah. Unless (and even still when) the ship is operating as a bussard ramjet and it depends on the matter it runs through as its medium of propulsion, there comes a point where the ship's speed does make the interstellar medium an "atmosphere" through which it is moving. It may not need to take into account things like lift (wings), but some thought is going to have to go into the design of what faces the oncoming medium and what doesn't. A ship like the Enterprise from Star Trek present a really, really big "face" as she travels through space and the struts holding the nacelle tubes away from the ship present as dead flat surfaces against the superluminal onslaught.
I'm sorry I didn't see this thread earlier. My own thought is that, in most of the sci fi with which I am familiar, the notion of space vehicles as "ships" has much more to do with our conception of the human aspects of exploration and long voyages than a desire to see the technologies themselves as similar. Star Trek has been mentioned a few times. Even in my pre-teen years (when it was first airing), I knew that the idea of stars floating past the ship was silly. Anything far enough away to be a speck of light wouldn't appear to move, and anything close enough to appear to move would be massive. But we accept it because there needs to be a visual cue that the ship is actually moving, just as a vessel at sea is clearly moving because it throws spray and creates a wake.
For me the main point is feasability. Any tech in a sci-fi story has to have enough feasibility to suspend disbelief. The finite details are there to give something for the super-fans to argue about. As a sci-fi writer I have to "develop" believable tech to a point that answers basic questions. Go to far into the explanation and I'll start losing the reader's interest, not enough and I'll lose them entirely. Sci-fi in film and television does this faster than books I think, mainly because the reader has to conjure up the image from their own imaginiation which they are more likely to believe. A film or TV story shows you and image then begs "believe me!" In my imagination the lizard man doesn't have a visible seam arond his neck, the Millennium Falcon has an inexplicable propulsion system that doesn't require extrnal fuel tanks twenty time the size of the craft, and the areo dynamics of a tilt-rotor, in-wing, venturi fan work just great, espcially in the low gravity of Pandora.
The moving stars are okay in principle. Even the stars in the Earth's sky move like that, more or less, only very slowly so we don't notice it without using sensitive instruments. The problem Star Trek has is the stars fly by far too quickly to be consistent with the story line. It does look cool, though. I once did some calculations about this to support a story I was writing. My star ship was going 500 light years in about six months or about 1000x faster than light. The FTL drive in my world accelerated instantaneously with no inertial effects inside the craft and I wanted to understand what the view through the viewport would look like... assuming no distortions due to the FTL drive. If the trip starts above a planet, that planet would vanish almost instantly by receding into the distance more quickly than the eye could follow. The star, say the sun, would shrink to a blazing dot quickly as well but you could follow that; it would take a couple of minutes before it appeared to just be a super bright star. It would then fade to normal stellar brightness over the course of an hour or so. You'd probably be able to see it fading while you watched, at least at first. The other stars would move but you'd have to keep your eye on one to see the effect. They would appear to crawl across the sky. If the ship passed closely to a star, say a light year or so, it would brighten, pass by the ship, and fade into the distance behind over a period of several hours... perhaps a couple of days. Based on the look of the stars in Star Trek, they would have to be moving extremely fast, perhaps millions of times faster than light. That kind of speed doesn't work at all with the rest of the Star Trek universe, but the reality would not be nearly as cool looking.
Warp speed is the concept that space itself is bent as they travel through it. The streaks of light aren't from simply moving fast through space. However, artistic liberty differs from science based speculation. Warp Speed: What Hyperspace Would Really Look Like
That's how I felt about the ship in Prometheus. If the engines can do this, then those can't be bussard ramjets. Where's all the fuel for the intergalactic flight they mention, one galaxy to another galaxy?
I actually wasn't referring to the streaks of light that the Star Trek (as well as Star Wars) films depict, I was referring to the slow movement of bits of light drifting by as the spacecraft moves forward, as depicted in the old TV show.
Interesting perspectives summarising considerations I have mulled for a fair while and have avoided, to the best of my ability. Thankfully, my main characters are ignorant observers which is handy since it means you haven't got to explain the how, but rather that it simply...does! This process has served me fine although I freely admit that I had always ensured I was considerate of physics principals. The problem I have hit upon is that at some point, even the most simple minded individuals ask 'how'. I have tried to provide some kind of explanation, one that panders to the character asking the question and subsequently the reader, whilst ensuring it is vague enough that I am protected from over analysis and subsequent criticism by the reader, and allows for interpretation- after all, isn't part of the enjoyment found in reading sci-fi/fantasy leaving something to the imagination? The thing is that while we can sit here and regurgitate theoretical physics, it is very much that; theoretical*. Faster than light travel is as implausible as artificial gravity, according to what we currently understand. But I'm certainly not saying one is more plausible than the other or that they are possible or impossible, I'm simply saying that if you're going to write something that suggests faster than light travel is possible, there is no use getting up in arms about artificial gravity which certain individuals have suggested in earlier comments. If you're going to bend the laws of physics to suit your story, you may as well be consistent! Explosions in space, though, are just stupid I think the point is that whilst there are many things that are impossible, there is no hard and fast rule for what is possible either, which, thankfully, gives a writer a certain level of poetic licence. For instance, I have everyone with jet packs, zipping around like the Jetsons, which is hella cool** In short; no, Spaceships are not boats, they're anything you want them to be!*** *theoretical, but usually mathematically sound. Usually - see the FTL particles in Italy. ** none of my characters have jetpacks. That's retarded. ***a pot of petunias, for example.
Yeah, I think if the author explains and explains, it starts to look like s/he's just showing off, cramming in information for information's sake ("Look! Look! I did my research! Am I not clevah?"). But if the author (about) knows how stuff works, the setting tends to read more cohesive, creating at least an impression of plausibility, even if the things weren't entirely explainable (like faster than light -travel).
I'm not sure what to make of that article. They are doing calculations about a phenomenon that may not have any physical reality to describe what it would really look like. Am I the only one who finds that logically contradictory?
Cueing in on the ...and other bad habits bit: In another thread we were shredding Sci-Fi horror films, which of course gave me an urge to watch one of them, and I noticed that at the opening of the epically appalling Event Horizon, it notes that the occurrences of the film take place in 2047. 2047 will not be the amazingly different science fiction future. It will not be this: 2047 is going to look a whole heck of a lot like today. This happens all the time in bad Sci-Fi. I get bent when they put the spectacularly different and awesome future only 3 or 4 decades away. Nope.
It depends on how solid the mathematical theory is behind the predictions: Astrophysics uses a lot of models and the models are based on observable evidence carried to wherever the mathematical models take them. How the doppler shift would affect the observed EM wavelength is a pretty solid basis.
I suppose. I'm not a physicist but I understand our current physics forbids objects from moving through space faster than light. As one approaches the speed of light length contraction and time dilation effects "go to infinity." It seems to me the doppler shift would probably do the same (I admit that my relativity isn't good enough to be sure), and so talking about the doppler shift seen by objects moving faster than light just... doesn't make sense. It seems like the students must be making some assumption that directly violates known physical principles to obtain an answer of any kind. Well they are... they're assuming FTL speeds are possible! *shrug* I dunno. I do agree that if FTL speeds are possible somehow the view out the window would probably be weird.
The idea of a warp drive doesn't violate the principles of physics. Just because we can't yet, or maybe never will have the technology to accomplish such a feat, the concept is to travel though space that is bunched up or bent, akin to but not exactly like traveling through a worm hole. What would violate the laws of physics (not that I know what the hell I'm talking about), would be to travel FTL through regular space time. It's like traveling backward in time doesn't violate any laws of physics that we know of, but we also don't know why the arrow of time only goes in one direction. We can't do it, but the equations work forward and backward.
There's an interesting article on Wikipedia about the Alcubierre drive. If you believe what it says there, apparently the technology to create one would also allow us to create a backwards going time machine. Alcubierre himself speculates that any technology that allows FTL travel would also allow time travel into the past. Many physicists believe that is impossible because of the paradoxes that it entails. So while general relativity does allow backwards time travel, the "chronology protection conjecture" says those solutions will be ruled out... along with wrap drive most likely... once we have a full accounting of quantum gravity.
This is exactly why stories about crappy cars that go back and forth in time on the power of a lightning strike are so cool!
And today was the day I realised I have no idea what over half the words on this thread even mean. Well, maybe not that many.
Your guess is right. As velocity approaches the speed of light, the redshift becomes infinite. Therefore, it doesn't seem logical to talk about redshift and blueshift for speeds greater than the speed of light.
