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Is gravity a wave then, like light? I thought the jury was still out on that.
by sosuke 13y ago
Is gravity a wave then, like light? I thought the jury was still out on that.
- maaku 13y agoGravity is the structure of space-time, and that structure supports waves. The proper analogy would be that gravity is like electromagnetic fields, and the equations of electro magnetism support wave-like events, and we call this light.
- omegant 13y agoSo mastering the energy Of gravity could be the ultimate advanced civilization objective. A warp drive is just the first practical (or at least the most obvious) aplication of such technology. <_end Startrek like voice>
- maxerickson 13y agoA reactionless drive (that just pushes on spacetime instead of trying to alter it) is probably even more practical.
- jp555 13y agovacuum propeller. Imagine if a submarine had to carry all the water it's propeller pushes on? That's rockets today. If we could make a vacuum propeller, that acts directly upon space-time, it would radically transform the prospect of space travel.
- deletes 13y agoThey are doing research in this direction. http://en.wikipedia.org/wiki/Quantum_vacuum_plasma_thruster http://en.wikipedia.org/wiki/Quantum_vacuum_plasma_thruster
- mladenkovacevic 13y agoYour comment just put a big goofy grin on my face.
- hackinthebochs 13y agoWarp drive would at the very least require an equivalent finding for momentum.
- jerf 13y agoMastering THE ENERGY OF GRAVITY! is trivial. Pick something up right now. Now, lift it over your head. You've given it GRAVITATIONAL ENERGY! Now, drop it. It has now expressed its GRAVITATIONAL ENERGY! Do not confuse science fiction with science fact. Exactly, exactly how gravity works is a mystery, yes, but interacting with the gravitational field is very, very settled science. If you want to harness the mighty power of gravity, build more tidal harnesses.
- saalweachter 13y agoNot to mention that gravity is kind of puny even at that scale. The rate of energy loss from the Earth's rotation due to the tides is about 3.3 TW. In 2007, the US consumed about 3.1 TW.
- wcoenen 13y agoAnother way to look at this is that human civilization consumes a scary amount of power. Our global energy consumption in 2008 was estimated to be 474 exajoules. The total energy received by the earth from the sun during a year is about 5 million exajoules, a fraction of which reaches the surface. So we are only a factor 10,000 away from that. At a seemingly modest 2% yearly growth rate, we could increase our energy consumption a hundredfold in two centuries, and waste heat will start to become an issue.
- saalweachter 13y agoYep, even today waste heat is equal to something like 5%[1] of the global heat gain. Still the lesser problem today, but once we bring a petawatt of clean fusion online... [1] it's been awhile since I looked up this number. Could easily be an order of magnitude lower, which is still fairly impressive.
- maxerickson 13y agoWhat is 'the global heat gain'?
- hackinthebochs 13y agoIf the propagation of gravitational effects is analogous to electromagnetic waves, then maybe this is an avenue for a "gravity cloaking device" which would have interesting implications (hoverboard anyone?)
- wcoenen 13y agoCloaking yourself from waves would not negate the effects of a constant field.
- deleted 13y ago[deleted]
- allochthon 13y agoKeeping in mind that gravity is only one of four interactions, and not even the only one working at long distances, I would have figured that it is an important component of the structure of spacetime. Have I overemphasized the other interactions in thinking this?
- AnimalMuppet 13y agoWell, the other interactions (electromagnetic) propagate through spacetime. Gravity waves are ripples in spacetime itself. So they aren't quite the same.
- miralabs 13y agoLight is both a particle and a wave
- privong 13y agoThe carrier for gravity may also have wave-particle duality, via the graviton[0]. 0 - https://en.wikipedia.org/wiki/Graviton https://en.wikipedia.org/wiki/Graviton
- mcguire 13y agoWhile light's behavior as both particle and wave can easily be observed, the particle carrier for gravity, the graviton, hasn't been observed in the wild. As a result, gravity is currently only a wave, in relativistic spacetime.
- gnaritas 13y agoOr, light is neither a particle nor a wave, but a distinct thing that seems to behave like both under various circumstances.
- lnanek2 13y agoThere are some cases in quantum mechanics where you just have to accept that a value can be two different things at once, not that is was really one thing. Like it or not, superposition is a real thing, so it is inarguable that assuming something has to have one value at any one time is wrong. Wave-particle duality is a lot like that as well, where it is tough to come up with some distinct thing that could possibly act like a particle, but still diffract like a wave.
- Double_Cast 13y ago> where it is tough to come up with some distinct thing that could possibly act like a particle, but still diffract like a wave. Armchairing here. But as I understood, objects in quantum-land are known as "amplitudes in the complex plane". They behave like this all the time and under all circumstances, and should be understood on their own terms. E.g. squaring the height of pond ripples doesn't return a probability distribution. The "sometimes it's a wave, but other times it's a particle" idea is a historical artifact, like how humanity uses a base ten number system.
- sethrin 13y agoThat gravity propagates as a wave is a consequence of Relativity. To date we have no direct detections of gravitational waves, but we have detected energy loss in a binary system which is consistent with theory. http://en.wikipedia.org/wiki/PSR_B1913%2B16 http://en.wikipedia.org/wiki/PSR_B1913%2B16
- Wintamute 13y agoAs far as I understand it gravitational waves are "ripples" in the fabric of spacetime caused by the motion of high velocity, high mass bodies. That's why they're called "gravitational waves" not "gravity waves", i.e. they're not waves of gravity, rather waves caused by gravitational bodies.
- deleted 13y ago[deleted]