Bill Phil

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About Bill Phil

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    Some Engineer Guy

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  • Location The Planet Gunsmoke
  1. Chain reactions of nuclear weapons are essentially impossible. The cores aren't capable of exploding on their own. They're very near to a critical/supercritical reaction, but the one bomb going off isn't going to compress the cores, it'll vaporize them. Or scatter them. Either way the Orion is toast... but since these aren't conventional bombs you're talking about a sub-kiloton explosion where a large portion of the energy is in a plasma cone. I'd be more worried about where that's heading.
  2. It's very hard to be invisible with a big enough civ. Waste heat gives you away.
  3. Red dwarf stars have very low likelihood for gas giants. This star has an unusally high metallicity, so rocky planets could be fairly likely.
  4. I truly wish I could say..... Nitpicking? it is under your name...
  5. BO did land a booster and reuse it before SpaceX. That's simply a fact. But that doesn't diminish SpaceX's accomplishments, rather it's a sign of the differing approaches the two businesses use. BO is much more gradual in their pursuit, starting with landing and reusability while SpaceX started with orbital launch and then moved to landing and reusability. BO is also using a lot less money. But they're also trying to fly passengers on sub-orbital hops using New Shepard, which SpaceX isn't attempting. The business models are different, albeit BO does wish to develop a heavy lifter. SpaceX is farther ahead in terms of putting stuff into orbit and then landing the first stage, but BO beat them to a successful demonstration of a rocket going into space and landing under its engine's power. We're generally referring to propulsive landings in the atmosphere after having gone to space.
  6. Pretty much, yeah... Propulsive landings were done in the 90s, but not into space. Then BO did it from space first (even reused a rocket before SpaceX). And now SpaceX has done it. But it's likely that they would both be nowhere near where they are without DC-X.
  7. Considering that many students are required to memorize quite a few different things of various lengths, it's very possible for the majority to memorize a large number of... well, almost anything. They memorize thousands of words due to simply knowing how to speak/write/read English. The reason those kids are outliers is because students are only required to learn a few digits of Pi by the curriculum. But many students have to memorize many other things, otherwise they simply wouldn't pass their finals. Everything from vocab words to grammar rules to formulas to what happened in 1066 and much more. Heck, history finals have a boat load of names, people, places, battles, and dates. Yet many kids are able to pass those tests. They're outliers in the sense that they have chosen to memorize those digits. Not so much in their capability (unless they memorize hundreds...) to memorize them.
  8. Starting from orbit, the Oberth effect would be almost negligible. It's very useful if you're going to the Moon in a single launch, but not quite as useful if you're starting from orbit (in fact, the relative energies of the orbits would be slightly less, so *shrug*). They weren't aware of the van Allen belt, which also extends down into the ISS's orbit. It's called the South Atlantic Anomaly.
  9. "Oh carp! Don't you know that having the answer and the question in the same universe means that said universe will colla-" Then the universe ended. It just so happened that an inter-universal highway was being built through it. Needless to say, the construction workers were quite glad that the universe which was in the way no longer exists. If only they could tell their supervisors exactly why it was no longer present, their lives might go on fine. On-topic The problem with having a seed of the universe is that we need to know the algorithm that said seed goes through to generate the result. We don't know that.
  10. It might not be a scam, and if it isn't the people who tried to set it up were probably disappointed... I don't see why they aren't making a space lottery where you buy a ticket for the possibility of, say, a trip on SpaceShipTwo (once it flies). And then build up to orbital flights.
  11. Jury's still out, and that isn't evidence for there being aliens. But looking at the logic of it, the jury is simply out. We're looking mostly on the radio part of the spectrum, at a tiny part of the sky for a tiny amount of time. Why should we expect to find anything? The only interesting thing we've found is the Wow! signal. But there's no reason to assume that's from aliens... And there isn't any evidence against, and there's none for. It's basically Russell's Teapot. You can't prove it's there or not, and it doesn't even matter, at least for now. Who knows, maybe we're the Universe's Elder Things? We could be the ancient species that seeds life in the Universe.
  12. I have no idea who that's from. I don't know if that's paraphrasing from someone or not, but it popped into my head a little while ago.
  13. Under the same logic the definition of asteroid is too broad, considering it has everything from bodies in hydrostatic equilibrium hundreds of kilometers across to bodies the size of a fist... Is "asteroid" meaningless? Why should "planet" be any different? Heck, "moon" is just as meaningless as "asteroid", why should "planet" be special? Of course, that's not an argument for changing the definition, but saying that it would be too broad as to be meaningless isn't a good argument against it, as a planet could be defined as a body in hydrostatic equilibrium (perhaps disregarding its status as orbiting another planet, as double planets are a possibility), which would have more meaning than "asteroid" and "moon," as it would distinguish a planet from other objects to a larger degree than both of those terms. So, we can either make Ceres not an asteroid, and change the definition of "asteroid" and "moon" to be more meaningful while adding special categories for moons and asteroids in hydrostatic equilibrium, or we just leave the mess where it is. "Body in hydrostatic equilibrium but is not fusing elements at its core" is a mouthful, so we could just shorten it to planet... or come up with something new entirely that includes planets and dwarf planets. On to the topic at hand: Considering there are kids who memorize dozens, or even more, digits of Pi, I don't think it's all that hard to just memorize them, if the kid wanted to. But it probably wouldn't be that big of a deal in science class at all. We don't memorize the names of all of the moons of Jupiter or Saturn, so...?
  14. The real kicker isn't so much power, which will determine the cost of the laser system, but the energy required, and its associated cost, which is quite low. The general rule of thumb is about a megawatt per kilogram of payload into LEO, so we'd need gigawatts to get tonnes into orbit. But it's gigawatts applied for a matter of minutes, and the power output of conventional rocket engines is comparable. The advantage provided by laser launch is separating the power from the rocket, increasing thrust to weight. 20 tonnes is 20 thousand kilograms, which, according to the rule of thumb, would need 20 gigawatts. Let's say that our time to orbit is 8 minutes, or 480 seconds. 20 gigawatts * 480 seconds == 9.6 terajoules Divide by 3.6 million joules per kilowatt-hour, and you get roughly 2.67 million kilowatt-hours. Assuming average price per kilowatt-hour is 12 cents, then it costs roughly 320,000 USD for electricity alone. This is going to be the smallest cost. The real problem will be the cost of the lasers, which will need to be spread out over a large number of launches. Maintenance will be an issue, but it shouldn't be a big one. Another problem is that if we use LH2, the tank will be huge. As in, huge. But pulsed laser propulsion looks promising, as it can use the atmosphere for propellant initially, and almost anything else afterwards, since the temperatures involved are so freaking huge. It's almost like an Orion sans nukes...
  15. Sure. That all applies to the ocean and the sky, but not so for space. Why, you ask? Because space is so huge, and satellites so small, that collisions are extremely unlikely. Have they happened? Yes. Will they happen? Yes. Will it be a problem? No. Space is fundamentally different, in that it's so much bigger. But even so, you're model is too simple. Aircraft collisions are excruciatingly unlikely, but they happen. Why is this, you ask? Is it because people were wrong about Big Sky? No, it's due to a few things: 1. More planes in the air increases likelihood of collision 2. Most planes have to land eventually, and thus there are high traffic regions of the sky. Here is where most collisions occur. In space, we have very few vehicles and no ports to speak of. Until a far future scenario plays out, this issue will not exist.