# Tag Info

150

They could brace themselves against the world behind them. Basically, they would subconsciously learn to simultaneously exert an equal and opposite force spread out over a much larger area behind them or anywhere else that isn't the car they're throwing. A sign of an amateur telekinetic could be being thrown back by their 'throws' because they haven't ...

129

This turned out unexpectedly fun... and for once the answer to a question involving 99.99% of the speed of light isn't "everybody dies" Where is this sphere being fired from? If it's from outside the solar system then hitting the earth as a sphere is.... a problem... The volume of 1000 kg of tungsten = 51.9 L Radius = 0.23 m That's 5439.5 moles of ...

87

They would be round, because that's the best format for storing gas. They would also probably be drifters with little flight control. So...

70

I am not sure where the energy would come from for this It would come from the scanner itself. In order to make extremely-high-precision scans, the scanner itself has to direct considerable energy at the target of the scan. The more precision you want, the more energy you need to pump into it. Much of that energy is absorbed by the target, which is what ...

66

Assuming the Required Secondary Powers, certainly. The superhero in question is capable of running at 100 times the speed of a bullet. For simplicity's sake, we assume that the bullet is a standard 5.56x45mmNATO round travelling at approx. 1000m/s. Since most depictions of heroes with superspeed show them doing everything like normal humans, except faster,...

65

You won't be able to have this in a universe that uses our physics. The degree to which space itself expands or contracts is related to the cosmological constant and the density matter within that space. A universe full of water is going to have an insane matter density. Which can be balanced by a large cosmological constant. The problem arises in that ...

64

What you're looking for is largely the opposite of what we saw for the 1mm tall robots. Surface tension of water is a noticeable thing, there's a clear bulge that would seem smaller than memory suggests it should on any given surface. Of course we're not looking at such a pronounced effect in this case, but it would be significantly reduced. Gravity would ...

63

Easy Peasy. Fusion reactors. The primary challenge involved with fusion power is maintaining containment, which is a big challenge given the pressures and temperatures involved. Not only will the neutrons deposit energy in the blanket material, but their impact will convert atoms in the wall and blanket into radioactive forms. Materials will be ...

62

TMM;DR (Too Much Math, Didn't Read): For anyone who doesn't want to go through the derivations and calculations below, here are the important points from my answer: We're not working with the same space as normal, friendly, Euclidean space. This means that while we can still integrate and differentiate scalar functions defined on this space, we need to ...

60

Collision penetration by velocity. As a starting note, we cannot talk about a graphics fps, and only a physics fps. Graphics fps only exists to the outside observer, we can only experience our universe through physics. This is a classic problem in video-games. If physics is checked by frames and if objects are overlapping, then if something travels fast ...

58

Yes There are several devices in existence that work based on similar principles as yours (with one or two adjustments). While they're used for plasma research, rather than weapons, they could presumably be adapted for your purposes. If you were to make a plasma cannon from scratch, you should probably model it at least in part after one of them. The major ...

56

In physics mirror symmetry is called parity, so the question is whether any of the fundamental interactions depend on the parity. It turns out that the electromagnetic and strong interactions do not depend on the parity, but the weak force does. In fact parity is maximally violated by the weak interaction - only left handed particles and right handed ...

54

This "weapon" has already been built. It's called the European X-Ray Free Electron Laser (XFEL), and it's used for super-accurate imaging of molecules. Point is, whenever the XFEL hits a target molecule, all the electrons are simply blasted away from the molecule, and the more inert rest of atomic nuclei dissolves in a Coulomb-explosion. The scattered X-...

53

Just because the heavens don't tick doesn't mean Earthly stuff won't tick as well. People are going to count their heart beats, breaths and bowel movements. Humanity may have used the sky as its sole time piece for millenia, but once we started to pay people by the hour we got creative. The sundial was the last time piece to depend on astronomy. The ...

51

Improved efficiency! Lifted from https://physics.stackexchange.com/questions/46788/how-efficient-is-the-human-body The MET (Metabolic Equivalent Task) readout on your gym equipment is your body doing 1Kcal/kg/h = 4184 J/kg/h and can be reasonably accurately measured by how much oxygen a test victim uses. Sitting still is roughly 1 met and ...

50

Gravity - Time of fall. Assuming they live in the same gravitational field as the non-giants then simply drop something and see how long it takes to hit the ground. A normal human is about $2m$ tall. It takes an object roughly $0.6$ seconds to fall $2m$ in our approximately $10\, ms^{-1}$ A $10m$ fall would take about $1.4$ seconds. The relevant formula ...

50

Let us consider the humble FET Here's a rudimentary description of a Field Effect Transistor (FET): Imagine water moving through a pipe. When the gate value is all the way open, water flows through the pipe freely. As you close the gate valve, the water through the pipe is restricted until the valve is finally closed and no water can flow. The magic? ...

49

The Fast and the Furiously Crazy Since you've eliminated the sensible solution (bypasses or double tracks), let's go with an insane one! All your trains have rail tracks running on top of them and extra wagons with ramps at the front and back. When a priority train approaches, they lower the ramps onto the rails and the priority train drives straight over ...

47

No. The mass of a proton is about $1.67\times10^{-27}$ kg. Therefore the total maximum energy released by its annihilation with an antiproton is $2mc^2= 2\times1.67\times10^{-27}\times9\times10^{16} = 3\times10^{-10}$ Joule. This is not much. Even if all this energy would be deposited inside the victims brain, it is a very small amount. But it would not. As ...

46

You might be surprised to learn that even the full power version of this gun could be fired by an experienced shooter without physical augmentation. It's all about gun design. First, there's porting. This is a pair or symmetrical set of openings in the top of the barrel, near the muzzle (typically to either side of the front sight). Propellant gas, still ...

44

According to WolphramAlpha, the relativistic kinetic energy of such a bullet would be $6.265 \cdot 10^{21} \ \mathrm J$, or 1.5 million megatons. The gravitational binding energy of Earth is $2 \cdot 10^{32} \ \mathrm J$, therefore we can stay assured that the planet won't be completely wiped out. Quoting from this useful page, the impact energy would be ...

43

If you were fast enough to have coordinated movements, yes you could catch a bullet. Simply grab it and slowly push against it until it slows down and it is stationary in your hand. Your approach would be kind of like how a trampoline catches a falling object, by gradually slowing it down. You would not simply stand still and let it pass through your hand ...

42

"I'll be back before you can walk to the lake." If not an exact sense or measurement for time, maybe they'd have an approximate one based on distance. Just as we say "an hours' drive" or used to say "about a weeks' journey," though obviously people drive, cart, and walk at different speeds, a civilization may generally agree on a common-sense "average." ...

41

Two trains become one. On the track there is a train heading in one direction at 100 km/h and a second train heading towards it at 200 km/h. You do not specify the distance between them. If there is some distance there is time for this maneuver. Slow train slows down, stops, goes into reverse. Previously slow train accelerates, in reverse, until it is ...

40

If the light coming out of the amulet is well collimated (i.e. it can form a narrow beam that does not disperse - like a laser) and the light is emitted continuously rather than in pulses, then what it does will depending on the aperture (i.e. the cross sectional area) of the amulet. Assuming a diameter of 2-3 cm (wristwatch or locket sized), an intensity ...

39

The depth isn't the problem, it's the shape that matters. A perfectly frictionless curved surface can be treated like a swing or a half-pipe. Increasing the slide distance up to the point of exceeding the top edge just by control of weight and position. It'll take a bit of time to get used to the movement but an agile person should be able to escape a bowl ...

39

Short: No Long Why? (heat) The sun uses its gigantic mass to fuse hydrogen. If the sun was light enough to orbit the Earth it would not generate enough pressure to start the nuclear fusion. Can't it burn normally? No because: You don't have oxygen in/on the sun Burning would only work for a couple of months maybe years. Why (light/energy) When the ...

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EDIT: In retrospect, I think it's possible there is some confusion about what you're asking for. If you're asking us to help fit your story requirements to real science, that's what I've tried to do below. It's a loose fit, to be sure. But, if you don't actually care what the purported mechanism is, and you're just asking us to help invent diegetic ...

36

Actually, the world as described by the standard model of particle physics cannot account for time intervals lower than the Planck time, which is approximately $5.4\times 10^{-44}s$. But the current smallest time interval uncertainty in direct measurements is approximatevely $1\times 10^{-20}s$. Litteraly any experiment (such as those described in other ...

33

Frame Challenge: My Invisible Friend Joe You’re looking at this the wrong way. If I tell my friend Joe to go pick up a rock and throw it, and he does, I will never experience the associated ‘equal and opposite reaction’ because I’m not the one doing the throwing. You’re imagining telekinesis as reaching out an invisible arm from yourself, and assuming ...

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