Simulations/matrix and the speed of light

[bilby]

c is not just the maximum speed of information transfer in our universe; It's also a fundamental constant that underlies physical phenomena that are otherwise apparently unrelated to stuff moving around. And it crops up a lot. It's far more than a mere speed limit, such as you might expect due to the limitations of a simulation. Describing c in such narrow terms just comes across as insufficiently well informed about reality as to have a useful opinion on it.

 

[excreationist]

c is not just the maximum speed of information transfer in our universe; It's also a fundamental constant that underlies physical phenomena that are otherwise apparently unrelated to stuff moving around. And it crops up a lot. It's far more than a mere speed limit, such as you might expect due to the limitations of a simulation. Describing c in such narrow terms just comes across as insufficiently well informed about reality as to have a useful opinion on it.

My focus is only on the most significant aspects of physics that are very relevant to the simulation idea. As far as me having a "useful opinion" goes, you could help by clarifying things...

From post 48

Then there would be absolute time - every clock would move at the same rate, regardless of how they accelerated.
This is how people (including Newton, who was no dunce) intuitively think the universe is. But that's not how it is. The idea of simultaneity is meaningless as soon as you consider acceleration

Are you saying that Newton's idea of simultaneity is a contradiction? Or just that there isn't simultaneity in our universe?

In short, the answer to your question is that without a cosmic speed limit, time as we know it, and causality, would be impossible. A limit is (at least according to Einstein, and I am happy to concede that he's both smarter and more knowledgeable than I in this area) a prerequisite for causes always preceding their effects, rather than effects preceding their causes.

I don't understand what you mean... a simulation would prefer a world where causes preceded effects but I am interested in why this wouldn't be the case if there was no cosmic speed limit...

 

[excreationist]

From "The Simulation Hypothesis" Documentary 11:08
https://www.youtube.com/watch?v=pznWo8f020I&feature=youtu.be&t=670

Consider the fact of a maximum speed in nature - the speed of light. In 2011 scientists reported neutrinos traveling faster than the speed of light but those findings were retracted when it was discovered that equipment used in the experiment was faulty. Nothing has ever been seen to travel faster than the speed of light. Nature has a maximum speed and events in a virtual world would also be a maximum speed since they would be limited by a finite processor. There's also the curving of space by massive objects and time dilation at very high speeds. Both phenomena correlate to virtual processing load effects. High matter concentrations in our universe may constitute a high processing demand such that massive objects would slow down the information processing of space-time similar to the way that high data demands in a computer will slow down the processing speed.

 

[bilby]

My focus is only on the most significant aspects of physics that are very relevant to the simulation idea. As far as me having a "useful opinion" goes, you could help by clarifying things...

From post 48


Are you saying that Newton's idea of simultaneity is a contradiction? Or just that there isn't simultaneity in our universe?

In short, the answer to your question is that without a cosmic speed limit, time as we know it, and causality, would be impossible. A limit is (at least according to Einstein, and I am happy to concede that he's both smarter and more knowledgeable than I in this area) a prerequisite for causes always preceding their effects, rather than effects preceding their causes.

I don't understand what you mean... a simulation would prefer a world where causes preceded effects but I am interested in why this wouldn't be the case if there was no cosmic speed limit...

There's no simultaneity, because there are no preferred reference frames, and observers in different frames don't agree on the rate at which time passes.

Newton didn't know this, but we know it because observation of situations where Newton and Einstein predict different results show that Einstein's predictions are right, and Newton's are not.

In the absence of c, literally nothing in our modern physics remains true, so literally everything and anything is possible, and speculation about it becomes futile.

If everything was different, nothing would be the same, so we have literally nothing to talk about with regards to that hypothetical.

 

[excreationist]

There's no simultaneity, because there are no preferred reference frames, and observers in different frames don't agree on the rate at which time passes.

Newton didn't know this, but we know it because observation of situations where Newton and Einstein predict different results show that Einstein's predictions are right, and Newton's are not.

I'm talking about simultaneity in a theoretical universe where there is no speed limit... not about this one.

In the absence of c, literally nothing in our modern physics remains true,

That's ok with me

so literally everything and anything is possible, and speculation about it becomes futile.

Apparently in string theory (10^500 universes?) and MWI just about anything is possible too. I'm just speculating about some basic ideas - not a complete theory of everything.

If everything was different, nothing would be the same, so we have literally nothing to talk about with regards to that hypothetical.

Well we could start off with Newton's ideas about the universe... then see if anything is self-contradictory (and our own universe is irrelevant). Simulations would normally be related to Newton's ideas rather than Einstein's, etc.

 

[Jimmy Higgins]

But if there is no speed limit that implies work can be performed without expending energy.

 

[excreationist]

But if there is no speed limit that implies work can be performed without expending energy.

Accelerating to a given speed would require energy or gravity, etc. How else could you get to a speed?

 

[Jimmy Higgins]

But if there is no speed limit that implies work can be performed without expending energy.

Accelerating to a given speed would require energy or gravity, etc. How else could you get to a speed?

Light? How fast is it going and why?

 

[excreationist]

Light? How fast is it going and why?

In this thought experiment let's say we can see light from stars instantly... As far as "why" goes, it is because it would seem self-evident to early scientists. They also didn't believe in light particles. In computer simulations light is reflected off of surfaces instantly... I think it is conceivable that a universe could work like that... Or is it self-contradictory?

 

[bilby]

Light? How fast is it going and why?

In this thought experiment let's say we can see light from stars instantly... As far as "why" goes, it is because it would seem self-evident to early scientists. They also didn't believe in light particles. In computer simulations light is reflected off of surfaces instantly... I think it is conceivable that a universe could work like that... Or is it self-contradictory?

You're back to "What would things be like if none of our physics were correct?", and the answer can only be "completely different". Without physics, we have no framework to even begin to imagine what the universe might look like, or how it might behave.

If everything were different, nothing would be the same. That's it; That's a complete and exhaustive statement of exactly how it would be if c = infinity. Further speculation on that topic is pure futility.

 

[excreationist]

....If everything were different, nothing would be the same. That's it; That's a complete and exhaustive statement of exactly how it would be if c = infinity. Further speculation on that topic is pure futility.

Well it seems like even many/most of the Greek philosophers thought light had a limited speed... (I wasn't aware of that - sorry) I wonder why Einstein believed that nothing could go faster than the speed of light? Maybe I'll never understand his reasoning. (edit: well I'll try and watch a lot of tutorials on YouTube about relativity)
Well for now I suspect that a simulation would be more CPU intensive if the speed of light was faster. Though maybe it doesn't make much difference.

 

[excreationist]

https://phys.org/news/2019-06-ai-universe-sim-fast-accurateand.html

For the first time, astrophysicists have used artificial intelligence techniques to generate complex 3-D simulations of the universe. The results are so fast, accurate and robust that even the creators aren't sure how it all works.

"We can run these simulations in a few milliseconds, while other 'fast' simulations take a couple of minutes," says study co-author Shirley Ho, a group leader at the Flatiron Institute's Center for Computational Astrophysics in New York City and an adjunct professor at Carnegie Mellon University. "Not only that, but we're much more accurate."

Machine learning is also involved in Flight Simulator 2020....

 

[bilby]

....If everything were different, nothing would be the same. That's it; That's a complete and exhaustive statement of exactly how it would be if c = infinity. Further speculation on that topic is pure futility.

Well it seems like even many/most of the Greek philosophers thought light had a limited speed... (I wasn't aware of that - sorry) I wonder why Einstein believed that nothing could go faster than the speed of light? Maybe I'll never understand his reasoning. (edit: well I'll try and watch a lot of tutorials on YouTube about relativity)
Well for now I suspect that a simulation would be more CPU intensive if the speed of light was faster. Though maybe it doesn't make much difference.

YouTube is a shit source for learning anything. Indeed, video is a shit source for learning anything. Read a book. Ask a physicist. Read a book written by a physicist.

Einstein showed that energy, mass, and c have a fixed relationship, as described by his most famous equation.

He realised that this implies that any object with a non-zero mass when stationary, would require an infinite amount of energy to accelerate it to c. It also (less obviously) implies that objects with a rest-mass of zero cannot travel at any speed other than c in a vacuum; and that implies that all reference frames must see zero rest mass particles (eg photons) travel at c, regardless of the different reference frames (ie different observers) moving relative to one another.

So if you have a spaceship moving past a planet at 0.5c, and the pilot shines a light in front of him, the pilot will see the light depart at c away from his ship; But an astronomer on the planet will also see the light moving at c, and therefore only going 0.5c faster than the spaceship.

This discrepancy is resolved by the fact that the two observers disagree about how fast time is passing.

According to Newton, space and time are universal, and speed is the relationship between them. But this is observably not true (though it's extremely close to true for slow moving objects, so it's an understandable mistake to make).

According to Einstein, the speed of light is universal, and time varies to allow different observers to report an identical value for c, relative to themselves, despite their different motions.

Photons do not experience time; And so do not experience distance. To a photon emitted by a quasar on the edge of the visible universe, the detector in the Hubble Space Telescope is zero seconds, and therefore zero metres, journey from emission to absorbtion. But from the reference frame of the HST, the time taken from emission to absorbtion was ~90 billion years. Moving clocks run slow; Clocks moving at c don't run at all.

 

[excreationist]

YouTube is a shit source for learning anything. Indeed, video is a shit source for learning anything.

I think channels like "PBS Space Time", Vsauce and "Two Minute Papers" are very good at teaching me things... (and sometimes TED talks) there are videos aimed at different audiences, such as children... it might be true about learning "anything" for you, but not for me....

Read a book. Ask a physicist. Read a book written by a physicist.

I'm a slow reader, I have no visual imagination, books are expensive, etc.... I can play videos at double speed... as far as "Two Minute Papers" goes there wouldn't be books available about many of the latest papers... and video demonstrates things like "deep fakes" better than a book can.

Einstein showed that energy, mass, and c have a fixed relationship, as described by his most famous equation.

He realised that this implies that any object with a non-zero mass when stationary, would require an infinite amount of energy to accelerate it to c. It also (less obviously) implies that objects with a rest-mass of zero cannot travel at any speed other than c in a vacuum; and that implies that all reference frames must see zero rest mass particles (eg photons) travel at c, regardless of the different reference frames (ie different observers) moving relative to one another.

So if you have a spaceship moving past a planet at 0.5c, and the pilot shines a light in front of him, the pilot will see the light depart at c away from his ship; But an astronomer on the planet will also see the light moving at c, and therefore only going 0.5c faster than the spaceship.

This discrepancy is resolved by the fact that the two observers disagree about how fast time is passing.

According to Newton, space and time are universal, and speed is the relationship between them. But this is observably not true (though it's extremely close to true for slow moving objects, so it's an understandable mistake to make).

According to Einstein, the speed of light is universal, and time varies to allow different observers to report an identical value for c, relative to themselves, despite their different motions.

Well I still don't understand how he came up with his assumptions. But I plan on watching many videos about it.

 

[Jimmy Higgins]

You are talking about Einstein and light and haven’t read about the train thought experiment?

Also Maxwell owns the speed of light, not Einstein.

 

[Jimmy Higgins]

....If everything were different, nothing would be the same. That's it; That's a complete and exhaustive statement of exactly how it would be if c = infinity. Further speculation on that topic is pure futility.

Well it seems like even many/most of the Greek philosophers thought light had a limited speed... (I wasn't aware of that - sorry) I wonder why Einstein believed that nothing could go faster than the speed of light? Maybe I'll never understand his reasoning. (edit: well I'll try and watch a lot of tutorials on YouTube about relativity)
Well for now I suspect that a simulation would be more CPU intensive if the speed of light was faster. Though maybe it doesn't make much difference.

YouTube is a shit source for learning anything. Indeed, video is a shit source for learning anything.

Actually, it can be a great source if you look well and avoid anything that is exploitative, especially around science. MIT has some courses online there on Quantum Mechanics.

Sadly, the exploitative junk is certainly much more common.

 

[excreationist]

You are talking about Einstein and light and haven’t read about the train thought experiment?

Also Maxwell owns the speed of light, not Einstein.

I've heard of it but I don't yet understand why reality must follow his thought experiment.

 

[Jimmy Higgins]

You are talking about Einstein and light and haven’t read about the train thought experiment?

Also Maxwell owns the speed of light, not Einstein.

I've heard of it but I don't yet understand why reality must follow his thought experiment.

Because it has been vindicated at all scales except quantum. The train thought experiment just helps explain it to people who can’t get down with the math.

 

[excreationist]

Because it has been vindicated at all scales except quantum. The train thought experiment just helps explain it to people who can’t get down with the math.

Yes it has been proven in reality.... but I'd like to understand how Einstein knew that that was the case. On the other hand apparently Einstein didn't believe in spooky action at a distance so sometimes his thought experiments aren't necessarily true...

 

[Jimmy Higgins]

Because it has been vindicated at all scales except quantum. The train thought experiment just helps explain it to people who can’t get down with the math.

Yes it has been proven in reality.... but I'd like to understand how Einstein knew that that was the case. On the other hand apparently Einstein didn't believe in spooky action at a distance so sometimes his thought experiments aren't necessarily true...

That wasn’t a thought experiment, it was the math.