INFINITE LIGHTSPEED YOOOOOOOOOOOOOOOOOOO

[Maria Sirona]

Wild question i've been wondering for some time now: what if the speed of light suddenly became infinite? The thing that would be noticed first would be that the (night (only?)) sky would be completely white as the light from all stars that currently exist would come to us on the literal same moment as it leaves. Color shift (red shift and blue shift) would also be eliminated, and we wouldn't have to worry about time delays with spacecraft, making, say, driving a rover with a joystick possible. But i wonder what would change beyond that?

[MKI]

I'm curious about the idea of having an "infinite" speed limit for light, does that mean it moves at infinite speeds instantly? Or that it could move that fast but moves... slower? I'm not sure if "infinite" speed is practical in the real world, or at least if we have any idea how it would work. 

AFAIK light particles need to be moving at some speed, as there isn't such thing as moving "infinitely fast" at least in our universe. Not only that but if you get anything moving that fast, let alone "infinitely fast" wouldn't that just destroy everything? Sure photons are small and light, but if your going stupidly fast, I'd assume bad things would happen once they run into something. 

 

The other aspect would be how relativity would be affected in a universe where the speed of light changes. My understanding of general relativity makes me think that having an infinite speed of light would mean you have essentially no time at all, as all things would be occurring simultaneously.  Or more practically if the speed of light became higher/faster, that would mean light travels faster/further in the same amount of relative time, and thus I would assume this means the universe moves at a different relative speed. I can't wrap my head around it to know how that would affect us, but it would to a degree. I'll let someone with a better idea of general relativity respond haha.

Simply put a universe with an infinite speed of light would probably not be anything like what we understand as our universe, but its an interesting thought experiment for sure!

 

side-note

The concept of a variable speed of light reminds me of a certain book I recently read ;D

Edited March 8, 2022 by MKI

[Admiral Fluffy]

The lightyear would become irrelevant.

[cubinator]

The sun would explode as nuclear energy overpowers gravity infinitely.

[HebaruSan]

Light cones would be flattened. All Lorentz factors (1/sqrt(1-v²/c²)) would be 1, so most of special relativity would go out the window. E=mc² would give infinite energy. Cosmic microwave background radiation would all reach its destination and disappear forever.

[Admiral Fluffy]

20 minutes ago, HebaruSan said:

Light cones would be flattened. All Lorentz factors (1/sqrt(1-v²/c²)) would be 1, so most of special relativity would go out the window. E=mc² would give infinite energy. Cosmic microwave background radiation would all reach its destination and disappear forever.

So....

Edited March 8, 2022 by Admiral Fluffy
This image is great. I've used it two times today.

[TheSaint]

22 minutes ago, HebaruSan said:

Light cones would be flattened. All Lorentz factors (1/sqrt(1-v²/c²)) would be 1, so most of special relativity would go out the window. E=mc² would give infinite energy. Cosmic microwave background radiation would all reach its destination and disappear forever.

[magnemoe]

59 minutes ago, cubinator said:

The sun would explode as nuclear energy overpowers gravity infinitely.

Yes either the sun would go out or go supernova. Do not at any time fiddle with the fine tuned constants. Yes pi=3 is more convenient but not if earth turn into an black hole, on the bright side you don't have to do more trigonometry  

[Codraroll]

1 hour ago, HebaruSan said:

E=mc² would give infinite energy.

Infinite energy from every atomic reaction, that is. Depending on whether the "infinite" value of c is to be taken literally or just that it's really, really high, your cell metabolism would burn you to a crisp or even totally destroy the planet. That is, the planet would probably be destroyed by any number of other chemical reactions anyway, so total barbecue would be on the agenda regardless.

[Zacspace]

The speed of light isn't really the speed of light so much as it's the speed of causality. You wouldn't be just raising the speed limit of one thing, but of almost all things to infinity. This basically breaks everything. I don't think current models are complete enough to describe how broken everything would be.

[MKI]

1 hour ago, Zacspace said:

The speed of light isn't really the speed of light so much as it's the speed of causality. You wouldn't be just raising the speed limit of one thing, but of almost all things to infinity. This basically breaks everything. I don't think current models are complete enough to describe how broken everything would be.

Wait... if that's the case wouldn't that mean everything, everywhere, for anything is happening instantly?

 

multiverse confirmed!

[Spacescifi]

5 hours ago, Maria Sirona said:

Wild question i've been wondering for some time now: what if the speed of light suddenly became infinite? The thing that would be noticed first would be that the (night (only?)) sky would be completely white as the light from all stars that currently exist would come to us on the literal same moment as it leaves. Color shift (red shift and blue shift) would also be eliminated, and we wouldn't have to worry about time delays with spacecraft, making, say, driving a rover with a joystick possible. But i wonder what would change beyond that?

 

Awww.... I answered this once.

Everything dies everywhere.

Infinite light speed means light from the sun won't have time to diffuse before it hits earth, same goes for all the stars.

Imagine everything everywhere being lased with lasers as hot as the surface of stars.... EVERYWHERE!

[HvP]

Relativity speaking, from the perspective of the photon light is always moving at infinite speed and its entire journey and all its interactions happen instantly. This is because the relativity equation for time dilation is bounded by the speed of light itself, causing time to slow down as speed approaches c.

I guess what you mean to ask is what if the speed of light from our perspective was measured to be infinite.

It seems to me that everything in the universe would instantly reach thermal equilibrium everywhere. Because even if there would have been giant explosions, massive heating, burning and death - all of that would instantaneously skip right to the end point of entropy anyway because every point in the universe could instantaneously transmit its energy to every other point in the universe. Leaving an expansively dilute, featureless, uniform energy distribution.

Edited March 8, 2022 by HvP

[NFUN]

1 hour ago, Spacescifi said:

 

Awww.... I answered this once.

Everything dies everywhere.

Infinite light speed means light from the sun won't have time to diffuse before it hits earth, same goes for all the stars.

Imagine everything everywhere being lased with lasers as hot as the surface of stars.... EVERYWHERE!

too bad you didn't answer it correctly

[Zacspace]

1 hour ago, MKI said:

Wait... if that's the case wouldn't that mean everything, everywhere, for anything is happening instantly?

 

multiverse confirmed!

Only if infinite speed = instant happening. It's either that or near-instantly, but that might be a huge difference, especially given that, as mentioned in another comment, this flattens the light cone making the entire universe the observable universe. We might have particles that have to travel an infinite distance to have whatever thing happen to them if the universe truly is infinite in size.

I think this might actually break a fair number of theories that support a multiverse too (any that involve black holes at a minimum since I don't think they would be able to form). OP is possibly the greatest supervillain of this or any reality.

[HebaruSan]

4 hours ago, Codraroll said:

your cell metabolism would burn you to a crisp or even totally destroy the planet

Doesn't the energy in cell metabolism relate to changing chemical bonds, i.e. atoms sharing electrons? What role do you see the speed of light playing in that?

2 hours ago, Spacescifi said:

Infinite light speed means light from the sun won't have time to diffuse before it hits earth, same goes for all the stars.

No, that's not how that works. Sunlight diffuses because it's spreading out into more and more space the further it travels, and it has to do that regardless of how much time passes.

2 hours ago, HvP said:

It seems to me that everything in the universe would instantly reach thermal equilibrium everywhere.

Really? Obviously infrared radiation would travel instantly from object to object. But would the emission be sped up as well?

Think about a hot object and a cold object in a small vacuum chamber in the normal universe. The distances are small enough that the light speed delay for the infrared radiation is negligible. Yet it still takes time for the objects to reach thermal equilibrium, since the hot object still has to emit all that radiation, and it doesn't do that all at once.

[cubinator]

5 hours ago, Zacspace said:

The speed of light isn't really the speed of light so much as it's the speed of causality. You wouldn't be just raising the speed limit of one thing, but of almost all things to infinity. This basically breaks everything. I don't think current models are complete enough to describe how broken everything would be.

Well, to elaborate on my sun comment:

Every nuclear reaction would produce infinite energy, and thus be rightly able to accelerate every atom in the sun to infinite speed instantly. Since the atoms are now traveling at infinite speed, a bunch of them ram right into the Earth after literally no time at all, destroying it and scattering all its atoms in similar fashion. Now because the speed of light is infinite, and all atoms in the Sun are now traveling at infinite speed, they reach all other places in the universe in an instant, carrying the energy to break apart anything in their path. This would occur to every star in the universe, so you would be lucky to be missed by a single atom. Then, like some others have said, things would settle down in another instant and things would get pretty stable at some low temperature.

[HvP]

31 minutes ago, HebaruSan said:

But would the emission be sped up as well?

You're certainly right that the potential and kinetic energy of particles would have to dissipate into heat over a finite time. I overlooked that.

I'm a little fuzzy on how connected electromagnetism might be to mass and inertia (not very as I understand higgs-field research.) But I do know that photons of the right wavelength can impart its entire momentum as energy to an atom, and that the actual moment of absorption is instantaneous but also time reversible. Photons can pass all of their energy into an atom, but the re-emission of photons is a slower process than light speed.

Which raises a fundamental question in my mind. What actually slows down this process, and is it dependent on the speed of light but at some fraction? Also, how does the atom actually get the energy out of a photon? E=mc². Which means that the energy of the system in this scenario would be infinite since the speed of light (c) is now infinite. Which breaks the whole system because now that atom has an infinite amount of energy which it can radiate to every other atom in the universe instantly, which then...

[HebaruSan]

2 hours ago, HvP said:

I'm a little fuzzy on how connected electromagnetism might be

Oof, thanks the reminder that the speed of light can be derived from Maxwell's equations. If the electric constant is ε₀ and the magnetic constant is μ₀, then:

So infinite c is going to do something weird to E&M. Possibly the strength of both fields might be 0? In which case, no more atoms or chemistry at all.

[Spacescifi]

1 hour ago, HebaruSan said:

Oof, thanks the reminder that the speed of light can be derived from Maxwell's equations. If the electric constant is ε₀ and the magnetic constant is μ₀, then:

So infinite c is going to do something weird to E&M. Possibly the strength of both fields might be 0? In which case, no more atoms or chemistry at all.

 

I figured everything dies more or less somehow.

Natural physical systems are often the way they are because other ways would be a disaster or would not work.

Edited March 9, 2022 by Spacescifi

[KSK]

14 hours ago, Admiral Fluffy said:

The lightyear would become irrelevant.

Buzz will never be irrelevant! Even at infinity if not beyond.

[RCgothic]

Also, in an infinite universe, technically every single point of the sky is occupied by a star. It's just that some points of the universe are further away than the age of the universe in light-years, so the light hasn't reached us. And since most of the universe is expanding away from us faster than the speed of light it never will.

If the cosmic speed limit is eliminated, now the sky will be completely full of star. Being completely surrounded by star is thermodynamically equivalent to being within a star. The entire universe will be at the temperature of stars.

Which as has already been mentioned, will all be going supernova with infinite energy. So infinitely hot stars.

And because c is infinite, the mass of matter will not increase with speed. Which means that it can also be accelerated to infinite speed. Which means all the matter in the universe will gain infinite energy, be accelerated to infinite speed, and then blasted through every point in the universe simultaneously.

So yeah, this is a very very big bang scenario.

Edited March 9, 2022 by RCgothic

[Kerwood Floyd]

So, to sum up:

Q: what if the speed of light suddenly became infinite?

A: nothing good

 

[KSK]

Because somebody has already quoted from Ghostbusters, @RCgothic’s last post put me in mind of this:

”I want you to imagine all life as you know it coming to a end and every atom in your body exploding at the speed of light.”

”Okay that’s bad. Important safety tip - thanks, Egon.”

[darthgently]

22 hours ago, Maria Sirona said:

Wild question i've been wondering for some time now: what if the speed of light suddenly became infinite? The thing that would be noticed first would be that the (night (only?)) sky would be completely white as the light from all stars that currently exist would come to us on the literal same moment as it leaves. Color shift (red shift and blue shift) would also be eliminated, and we wouldn't have to worry about time delays with spacecraft, making, say, driving a rover with a joystick possible. But i wonder what would change beyond that?

If it were infinite from the beginning I don't think anything we currently know about our universe would apply at all.  The first thing that comes to mind is that if it were infinite, then I'm not sure time would even exist