p1t1o

Its not just our species, its pretty much every complex animal! And even after millions of years of extreme evolutionary pressure we all still need it! Any creature which could discard sleep would have a huge advantage!

Or full body camoflage.

On the subject of membrane thickness, and scaling it up to contain large forces. I was reading about battleship guns the other day, 16 inchers, that sort of lark. Turns out the barrels of these things are constructed in a more complex way than one would imagine. Referred to as "built up guns" a rough description is that they have a 1-piece "liner" that is the innermost metal layer that would actually be in contact with the shell. Around this they forge "sleeves" or "hoops" which compress the liner under great pressure, I forget the exact mechanism they use to achieve this but its around on the internet somewhere. It involves hydraulics of immense power IIRC. The strength of the barrel dictates the maximum power of the propellant charge and thus the capabilities of the weapon, so stronger is better. Anyway, you'd think that you could just keep increasing the thickness of the layers (oh yeah, there can be multiple layers, the barrel of the 16 inchers on Iowa-class ships consisted of 12 components) to get greater resistance to the pressures of firing and thus allow greater propellant charges. But you cant. When you fire a gun like this, the barrel expands from its under-pressure state, through the neutral state, towards the point of elastic failure. This is the limit that sets the max pressure. Making the barrel stronger/thicker helps, to a certain point. With a very, very thick barrel of large excess, as you increase the pressure what happens is the barrel expands, and is constrained by the outer layers, those layers expand slightly too, but the lateral expansion is not as much due to the decreasing radius as you travel inwards from the surface, so there is actually no thickness that can prevent the inner surface expanding to the point of cracking at a certain pressure, and once cracks are formed, even a very very thick breech will shatter after multiple firings. Hence, there will be a limit to the pressures that you can contain even with very, very thick rubber, and I doubt those pressures are going to be that high, in this context.

Hohoho! I see what you did there

Eek! Power is not a quantity of energy! Pedantry aside, much relevant data here: https://qntm.org/destroy

oops

I guess my dreams are generally quite normal, but here are some notables: 1) I occasionally have dreams in which nothing in particular happens but the whole thing is infused with deep dread and fear. Of what i have no idea, just arbitrary, source-less dread. 2) I occasionally have dreams which play out as a normal day, ie: I get out of bed, get dressed and go to work. Thanks brain, I really need that break from reality. 3) I had a dream in which I definitely died, and I *didn't* die in real life! All those movies are lying to us! In the dream I was next to a nuke when it went off, I didnt wake up instantly, first everything went white.

Now I can actually see the picture and understand that other comment I can appreciate the semi-practical nature for sure. My favorite (jokey) tattoo suggestion is from my mate, who suggested getting a 1:1 scale portrait of his own face, tattood (tattooed? tattoo'd?) onto his face.

Well that is collapsing an EM doppler shift into an audio signal, and then trying to detect it with the human ear, yes I doubt that is possible! I was just resisting the idea that "frequencies never, ever change"

I think your explanation of voices in helium is correct, but you can absolutely change the frequency of sound or light, eg: the Doppler Effect, and you dont have to invoke any timey-wimey stuff [for EM radiation] either as the observer, emitter and the photons are all in the same frame of reference.

Definitely not a serious job offer, whether it is a "scam" requires more input. Could just be an overly aggressive marketing campaign that a recruiter is doing, or more likely they are just fishing for active telephone numbers that they will then sell on to another company that will call you to ask about that car accident you had 6 months ago and if you have sought any compensation. The fact that its a text is the first and only red flag you need.

I cant see the picture, but that is ok, because my point would be - if its a tattoo, get something that you *dont* need to ask people "Should I get this tattoo?" Get what you want, by all means, but since its permanent, get the one *you* like having displayed, not the one you think everyone will like. Is "hilarious" a good enough reason? Is it "several decades" hilarious? If so, deffo go for it. If you ask people about it, it doesnt matter what it is, there will be someone who is like "meh" so why ask?

You're all wrong. They moonwalk it in.

Yup.

For mining? Really? Rocks? Transported by air? Rocks? With Helium? *Rocks*? Never happening!

Well the first thing I thought when I saw it was that it was a Skylon - an engineering idea that is only partially thought through, to generate some pretty pictures with just enough detail to look legit. Its not a deception, its an advanced type of advert, in the form of a sort of "mock" engineering proposal - not necessarily inaccurate, but not 100% fleshed out, only a shell of a project - accompanied with some glossy literature about a hypothetical mission and what that might look like. Perhaps further supported by some public statements as if it were a real thing. I fully expect that whatever fully-thought-out Mars project Musk brings about, to resemble this only superficially, if at all, and be a heck of a lot more complicated. This isn't a criticism of SpaceX/the ITS or Reaction Engines/Skylon, its quite common in the aerospace industries it seems: (Wow actually there were like loads of examples)

Well it makes a lot more sense if you parse "Plans unveiled for...." as "Artist unveils...." ..."Plans"... sheesh

Geostationary would only work in an equatorial orbit, otherwise it is going to be swooshing through the air at a fair rate of knots and will come down quite rapidly. Even in a geostationary, equatorial orbit it will be susceptible to winds, which would eventually perturb it enough to drag it down. Unless you anchored it to the ground, and then you've got a standard space elevator, with all the usual caveats of that. I've got to imagine that with the geosynchronous version, there is significant drag as it dips in and out of the atmosphere each day as well. And I dont wanna be the engineer that has to come up with a method of re-boosting the danged thing.

Awww. I was hoping for a youtube clip of someone having a full-blown tantrum in zero-G. Would love to see that

I say they just concrete over a 10km x 10km square and just tell pilots to "fit on it". The terminal, hangars and gates would be underground, and to depart, planes would be elevated on a lift into the centre of the square. "Just take off somehow". Cuts down on air traffic control costs + complexity, you get all the benefits of no crosswind/optimum headwind, no problems with weird camber or steering on takeoff/landing runs. There are literally no downsides as long as pilots keep their head on a swivel, which they do already. Might be useful to fit planes with horns. The beep-beep kind, not the stab-stab kind. Although...

Scary movies I can handle, scary games freak me out.

Here in the UK we have the highest concentration of tornados per unit area in the world, believe it or not.

I've never liked this concept, just an excuse for people to say "Oh god you guys I like totally have a special fear of clowns you guys, like more than most people I have like a *special* fear of them." It rubs me the wrong way in the same way as people who say "Oh god you guys, you know I HATE needles!" Nobody likes being stuck with a needle, genius. Now that I'd watch.

Ok, but will it have an air-dock for my flying submarine?

From the wiki: "The idea of rocket propulsion by combustion of explosive substance was first proposed by Russian explosives expert Nikolai Kibalchich in 1881, and in 1891 similar ideas were developed independently by German engineer Hermann Ganswindt. General proposals of nuclear propulsion were first made by Stanislaw Ulam in 1946, and preliminary calculations were made by F. Reines and Ulam in a Los Alamos memorandum dated 1947.[1] The actual project, initiated in 1958, was led by Ted Taylor at General Atomics and physicist Freeman Dyson, who at Taylor's request took a year away from the Institute for Advanced Study in Princeton to work on the project." Ref: http://www.webcitation.org/5uzTHJfF7