erturs

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• Commented on A fistful of tropes
  End of discussion, since your instant assumption is that I'm a Dilbert Musker, rather than someone who thinks the solar system isn't enough. Whoa, easy there... who said anything about the Muskrat? I assume that you (and other regular posters...
• Commented on A fistful of tropes
  Fine. Go back to living in caves here on Earth, in luxury cave condos. I WANT OFF THIS PLANET. I want to me real aliens, so we can actually get another view of reality, among other things. What, so...
• Commented on A fistful of tropes
  Charlie's right, this isn't the place to discuss physics in any kind of detail. May I suggest Stackexchange or Physics Forums as good places to ask about closed timelike curves, which are a standard topic in relativity....
• Commented on A fistful of tropes
  And second, if you are serious about protecting human civilization from asteroids, you should be building vaults and shelters here on Earth, not on Mars. If a K-T impactor hit tomorrow, Earth would still be far more hospitable than...
• Commented on A fistful of tropes
  Here's a simple argument that the principle of relativity requires that to avoid temporal paradoxes there must be a maximum speed of message exchanges; a more sophisticated argument is required to show that this maximum is c, but it's not...
• Commented on A fistful of tropes
  Sigh. That was precisely one of the cases I analysed, and I found that it didn't breach causality. Yes, Bob saw it 'before' it happened, but there was no way that it could create a causal loop. What was?...
• Commented on A fistful of tropes
  As I posted before, the sorts of constraint needed are things like the FTL speed is no more than c^2/v, where v is the relative speed. And how do you propose to enforce such a constraint in a world...
• Commented on A fistful of tropes
  The central problem with the arguments against FTL are that they assume infinite resolution for observation. Alice can see Bob light years away. Not at all -- the central problem is that Alice can send Bob an FTL message,...
• Commented on A fistful of tropes
  @ 588: "If Bob and Alice are moving apart at 0.866c, Bob "observes" (that is, calculates after correcting for finite propagation speed of light) Alice's clock as ticking half as fast as his, and vice-versa." Two people both being...
• Commented on A fistful of tropes
  A Merchant Princes origin story would be really interesting. Of course, any more fiction set in the Merchant Princes universe would be really interesting. As would more Laundry Files, New Management, or Saturn's Children books. Or, you know, completely new...
• Commented on A fistful of tropes
  Try this out: give me something (a link, whatever) to something that shows that a "closed timelike loop" does not return to the same point in ->TIME<- that it started? Why should it return prior to leaving, rather than...
• Commented on A fistful of tropes
  OK, "unconstrained" FTL is forbidden by speical relativity. The thing is, though, that either the constraints are themselves a violation of the principle of relativity (the FTL drives work differently in some frames of reference), or you have to create...
• Commented on A fistful of tropes
  Yeah, in the real world castaways tend not to do very well, and Robinson Crusoe in space is even less likely. OTOH that's a trope ripe for deconstructing (a raft of the Méduse situation could get very interesting if the...
• Commented on A fistful of tropes
  2. I have FTL, and it does not involve time travel (for example, see the Alcubierre drive). Sorry, no. Alcubierre himself says that warp drives can be used for time travel. See for example his paper Warp Drive Basics);...
• Commented on A fistful of tropes
  Trope I haven't seen in OGH's fiction (although perhaps I missed it): castaways marooned in a dangerous place (in SF typically they've crashed on a distant world). A bit like "brave settlers conquering the hostile planet" (which made a brief...
• Commented on Make Up a Guy
  I get confused when people ask me what the names of my pets are, because it's usually effectively the first time the idea has occurred to me at all. To say I don't see the point would not really be...
• Commented on Make Up a Guy
  It might look a lot like our current world! only with sarcastic talking cats giving our heads of state their marching orders (and no reduction in carbon emissions because the Owners like it hot). And it just takes some tweaks...
• Commented on Make Up a Guy
  Let's try that one again - why would you wind up in the spacial location that you began, just because you wind up in the temporal location you began? A closed timelike curve is a closed path (loop) in spacetime....
• Commented on Make Up a Guy
  What kind of society would superintelligent cats form? Governance would be a difficult. I can't see a strong central government forming. Democracy might be an option, but requires compromise, and cats aren't particularly inclined to compromise. Perhaps some sort of...
• Commented on Make Up a Guy
  Why would a closed timelike path take you to your past? Why would it not end right where it began? It does end right where and when it began, that's why it's a loop. So at some point in the...
• Commented on Make Up a Guy
  How do I know I've traveled through time? What happens to me that's different than what happens if FTL doesn't contradict relativity? FTL doesn't have to involve time travel; your example is a case where it probably wouldn't. But if...
• Commented on Make Up a Guy
  You've misunderstood my point, which is that education doesn't necessarily have to be "useful". As for quantum mechanics, yes there are many problems in quantum field theory which are computationally intractable. But that's true even of classical mechanics (e.g. fluid...
• Commented on Make Up a Guy
  I don't think you read the original paper, or else misunderstood what a "closed timelike curve" is. It's a path that if followed literally takes you to your own past. You don't need a powerful telescope to observe the potential...
• Commented on Make Up a Guy
  There is essentially damn-all reason to teach any 20th century mathematics or physics (except for statistics and just possibly special relativity) before university. Quantum mechanics is particularly irrelevant. I have to disagree, although I suppose it depends on what you...
• Commented on Make Up a Guy
  Well, alcubierre warp drives aren't time machines. They warp space, rather than accelerating the ship. Like a wormhole, a warp radically decreases the distance the ship moves across space, in this case by warping the distance the ship moves through...
• Commented on Make Up a Guy
  No idea where you're located, but here (Canada) there is no time/money for teachers to stay current in their fields. This might not make a difference when the subject is Shakespeare, but for the sciences it means that senior teachers...
• Commented on Make Up a Guy
  Actually, I have a short I'm trying to sell, set in my future universe, where they invent the FTL drive, and my handwaving is a lot less vague. Unless you've got an explanation for why your FTL drive doesn't double...
• Commented on Make Up a Guy
  Well, no. Fiction is presented as fiction. Lies are presented as fact with intent to deceive. Fair enough; I was being too glib with the "I tell lies for a living" tagline many authors use. I think my main...
• Commented on Make Up a Guy
  On the subject of chatGPT (and potential strossGPT, heinleinGPT, etc.): if the purpose of a system is what it produces, consider that chatGPT produces "plausible sounding" text without regard for whether it is actually true or not. In other words,...
• Commented on Empire Games (and Merchant Princes): the inevitable spoiler thread!
  I will try again, once. With what I am talking about, the cause DOES precede the effect, in all frames involved in the causal chain. Inertial frames of reference are coordinate systems. Only events can be "involved in a causal...