11 KiB
Society acquires the power/technology to raise or lower the speed of light in localized areas. What happens?
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Author: u/OrzBrain Fingers to dance, hands to catch, arms to pull*
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URL: https://www.reddit.com/r/rational/comments/5lwiu2/society_acquires_the_powertechnology_to_raise_or/
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Score: 3
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Created: 2017-01-04T02:53:32
Post:
[removed]
Comments:
u/eaglejarl [+10] (53 minutes later)
I asked this on /r/AskPhysics back when I was writing Induction. The answers I got varied from "physics doesn't work like that" to "don't be ridiculous." The most useful response -- which still wasn't that useful -- was "physics is an interdependent edifice. You can't change one part without throwing everything out of whack."
Whatever the answer, weird things are going to happen at the interface. Also, you can send signals "faster than light" by sending them through / around the affected zone (depending on whether the zone is sped up or slowed down). You could use that to get limited FTL communication, which means sending messages back in time within one of the zones.
u/Menolith [+3] Unworthy Opponent (8 hours later)
One way to explain why the universe has so uniform temperature is that billions of years ago, c was substantially higher. As far as I understand it's not a terribly popular (i.e. well-supported) theory, but it does exist nonetheless so varying c doesn't necessarily break literally everything.
There is an SCP entry which outlines some of the stranger possible outcomes of locally altered c.
u/pixelz [+7] (an hour later)
I'll just note that we routinely change the speed of light in localized areas - see https://en.wikipedia.org/wiki/Refractive_index - but I understand that you're thinking of it from a "change the constant c in the laws of physics" superpower perspective.
u/Zeikos [+3] Communist Transhumanism (a day later)
Nope, c is the same, photons simply have to travel more space because they bounce between the materials atoms.
They still travel at c.
u/Charlie___ [+1] (a day later)
https://en.wikipedia.org/wiki/Refractive_index#Microscopic_explanation
u/MereInterest [+6] (20 hours later)
Avoiding the question: We already can, at least in one direction. Glass has a higher index of refraction than vacuum. The speed of light in a medium is
c/n, wherenis the index of refraction. Therefore, the speed of light in glass is slower. Tada! I'm guessing that this isn't what you meant, and will assume that you mean changing the speed of light in a vacuum.Short answer: Either everything breaks, or you live like gods.
Long answer: Light is an electromagnetic wave. This was first shown by noticing that the speed of light can be calculated from the strength of the electric and magnetic forces.
c = 1/sqrt(epsilon_0 * mu_0)The bigger the value of epsilon_0, the weaker the electric force. The bigger the value of mu_0, the stronger the magnetic force. In order to change the speed of light, you need to change one of these values.So, what happens if you change the electric force? Well, electrons around a nucleus are primarily held together by electric attraction. Change the strength of that attraction, and chemistry breaks down. Carbon now bonds much more strongly to itself, or much less strongly. Your body is mostly carbon. This is deadly.
Let's change the magnetic force instead. This ends up being even worse. Nuclei are held together by the strong nuclear force, with an additional spin-orbit magnetic coupling. This magnetic coupling helps to determine which nuclei are stable, and which are not. By changing it, ordinary nuclei might become radioactive.
So far, it would be extremely dangerous to make one of these fields, but safe so long as nothing ever goes into it. However, it gets even worse.
Much of modern physics is based on symmetries. Noether's theorem is a really cool application of this. Any time you have a symmetry, it makes there be some conservation law associated with it. The universe is translationally symmetric, which causes conservation of momentum. The universe is rotationally symmetric, which causes conservation of angular momentum. The universe is time-invariant, which causes conservation of energy.
Since the speed-of-light bubbles can be created and destroyed, there is no time-symmetry, and so conservation of energy is gone. Since the speed-of-light bubbles exist in only a limited region, conservation of momentum is gone. This breakage can be exploited to freely create and destroy energy and momentum, as desired. Imagine cars that require no fuel. Imagine spaceships that fly forever, continually accelerating by exploiting the bubbles to gain momentum.
Note that I have yet to say anything about special relativity, which is where the speed of light plays the biggest role. That is because I'm not sure how to keep special relativity at all without these symmetries. Special relativity assumes that the speed of light is the only constant, and works from there.
If special relativity does still exist in some form, then causality is completely broken. Temporarily changing the speed of light, travelling through that region, then turning the speed of light down, is equivalent to faster-than-light travel. Any form of FTL is equivalent to time travel. This stack exchange post gives a bit of the math behind it, along with an example.
So, in short, such a change would fundamentally alter our role in the universe. Either we would change the universe so much that we would no longer be able to survive in it, or we would exploit it in order to live like gods, with truly unlimited energy and time travel.
u/OrzBrain [+2] Fingers to dance, hands to catch, arms to pull (a day later)
So, in short, such a change would fundamentally alter our role in the universe. Either we would change the universe so much that we would no longer be able to survive in it, or we would exploit it in order to live like gods, with truly unlimited energy and time travel.
I'm pretty sure you win best answer. I see that due to the interconnections of the laws of physics, being able to change the value of c in a defined area would be similar to being able to change the value of pi in a defined area. All hail the many angled ones!
Some time it would be cool to see a story with superpowers in it, but the theme of the story not so much about the powers as about the fact that every single one of those powers, if present in a world actually similar to the "real" world, would represent a flaw or change in the laws of physics which could be exploited by humanity to relatively easily munchkin our technology to godlike power.
u/MereInterest [+2] (a day later)
Thank you. It was a fun question to answer, and I'm glad that you enjoyed it.
u/Trudar [+5] (10 hours later)
I think we would get the most potent explosive in the universe. The area with changed c would have different energies for subatomic particles, which would probably force an array of exotic decays, freeing tons of energy. Also we would get that energy (photons) in wavelengths normally not achievable. As /u/eaglejarl wrote, that would trigger cascades of new reactions at the border of the zone.
In most of bigger atoms, electron configuration is shaped by relativistic effects, so most of our chemistry would fall apart.
I doubt we would get time signalling, tho, that space would most probably behave like compressed space, distorting the light cone, but not stepping out of it, so yeah, as long as you could get any coherent signal trough the violently exploding zone, it would be FTL signalling.
u/xamueljones [+3] My arch-enemy is entropy (58 minutes later)
The game, A Slower Speed of Light, may be relevant.
u/PenultimatePresence [+2] I shall make a promisement to not perform malice (2 hours later)
Just using heuristics I have developed from my exposure to relativity: areas with slower speeds for light would change/evolve slower relative to areas with faster speeds of light, massless particles (such as photons) would travel at the local speed of light for all observers, areas with a constant speed of light would behave normally but areas where c is changing with respect to space (or time) would be... confusing, you would still get c=1 (or whatever it is in the units you are using) if you tried to measure it no matter the relative difference between c 'here' and 'there', if a massive (having mass) particle went into an area with a different speed of light it would slow down / speed up so that it is now traveling at the same fraction of c as it was before but would not feel any acceleration, the value of c would be dependent on some object/particle/process and would move/change with the position/state of the thing that is changing/causing the value of c, causality might get weird. Example: you have built a tube of altered c between two galaxies with a higher value of c than usual space. There is a physical thing that is causing the change in c that either projects the change where you want it to be or just causes the change around itself and you have a line of it going between the destinations. Each end has an entrance/exit where the change in c over space is as gradual as possible so you minimize the strangeness for anything you want to travel through the tube. Say you're in a ship that is going to enter the tube, the ship mundanely accelerates to lets say .5c in normal space then begins to enter the tube, as you go deeper into it you notice that everything outside the tube seems to be happening slower, orbits of planets, turbulence of plasma in stars, other ships. Once fully inside, nothing seems any different inside the tube, but if you look outside the tube there would be distortions in the images reaching you due to the tube of altered c. From outside the tube it looks like you are traveling much faster, possibly faster than local c, also with distortions. You eventually reach your destination and come out of the tube of altered c sooner than light could travel between the two spots, so you are able not only to look back and watch your ship when it first entered the tube, but as you look at the tube nearer to you, you can see your ship which appears to be traveling backwards through the tunnel as the light nearer you reaches you first. The point at which these two images meet would be the point at which you began moving at local, unaltered c, and the time you would observe this would be the time it takes local light to get from that point to where you are now.
u/MatterBeam [+1] (a day later)
I think the affected area would immediately decompose into a rain of high-energy particles that trigger an atomic explosion a nanosecond later.
u/PeridexisErrant [+1] put aside fear for courage, and death for life (a day later)
Per the rules in our sidebar, this is not a place for 'what if' scenarios.