Why is light basically infinite in a universe that is basically finite?

[mikehelland]

This isn't a scientific argument, so I thought Metaphysics and Philosophy was a good spot for this.

Light has an infinite range.

Why? The universe has a finite past, and future that involves heat death. Seems like it's over-engineered for no reason.

I talk about that in this short video:

https://www.youtube.com/watch?v=A2hf6k0SytU

[RedshiftDrift]

1- The concept of light as a race car is incompatible with quantum mechanics and special relativity. When the race car leaves A nobody knows if it will make it to the finish line. However, light is an interaction between A and B. The photon connects A and B in a causal manner: once the photon has left A, nothing can stop it from reaching B. In special relativity the distance bridged by light is neither time-like, nor space-like, nor infinite, but actually null.

'c' is for the Latin celeritas (= 'celerity'). Even if it has units of [distance/time], it's not a speed but a fundamental property of energetic interactions between material particles distributed in space-time $\displaystyle c = \sqrt{\frac{E}{m}}$.

2- Better cosmologies don't have a time boundary nor a space boundary.

With a better cosmology, a quantum description, and special relativity, the concerns expressed in the video simply don't exist.

[Pierre314159]

@mikehelland No, we don't "all agree". As I wrote in an other thread, I don't think the "standard model" of cosmology "needs a replacement". I think it needs to be thrown away, ditched, annihilated, forgotten... The very idea of a "standard model" should be abandoned. It is not science.

So, take me out of "all".

[RedshiftDrift]

@HanDeBruijn your example is a classical demonstration, which of course propagates at $c$. I'm talking about the quantum properties of light that are much faster. As far as we can see experimentally, the interaction is instantaneous.
See https://blogs.scientificamerican.com/news-blog/quantum-weirdnes-wins-again-entangl-2008-08-13/ and a more recent measurement
https://www.nature.com/articles/nature11472

[RedshiftDrift]

@mikehelland To continue on the philosophical aspect, there is no inside of the universe since the universe has no bounds. When you write inside it implies an outside. By definition there is nothing outside the universe because the universe is everything.

[HanDeBruijn]

@RedshiftDrift .

According to some cosmological models, there is an observable universe, which is finite and inside the "whole" universe, while the rest of the universe is outside that observable universe of ours and it is infinite.

[mikehelland]

@RedshiftDrift

Fair point. I was thinking of "the universe" as more of an abstract container for time, space, matter, etc, than a specific physical volume.

[budrap00]

You are both correct. Louis is describing the behavior of light from the 4-dimensional perspective of light and Han from the perspective of a 3-dimensional observer.