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[Tschumi]

Here's one I've always wondered about.

Light is not always an uninterrupted straight line. Things can deflect it. Scatter it. Prisms, lenses, water, the atmosphere, moons, planets, celestial bodies, black holes, quasars, dark matter, nebulae, galaxies, galactic filaments, who knows what else.

If you are looking at a droplet of water suspended in midair, the world you see through that drop can be hugely distorted. Flipped, stretched, warped.

What makes us so sure that the stars look anything like we think they do? How many of our constellations are the celestial equivalent an angled watch face blinding a passing motorist? How many of the uncountable gazillions of galaxies whizzing around are swarms of ghost images?

Can we say for sure that absolutely everything up there is a 1:1 representation of reality? I'm not certain we can.

To borrow a phrase from Air: How does that make you feel?

Just wanted to throw that thought out there, in honour of other recent science threads.

 

[Fbh]

Well for starters a lot of what we see is light coming from thousands, millions or billions of lightyears away so it's already an illusion in the sense that we are never really looking at the current reality of any of these stars.
But from my understanding the universe is basically 99% empty space, so there shouldn't be too many things distorting the light.

 

[T8SC]

What if dark energy distorts the light ...

 

[TrueLegend]

We don't see things. There is a reason we don't use the telephoto lens and all images on the internet say concept art. We observe the universe. All direct photos like those from Hubble are doctored and put into proper context. Let me tell you even rotation and revolution of earth is so complex all simulations you may have seen are fake.

 

[German Hops]

The inherent issue discussing the observable universe, is that it can't be done without a little philosophical angle as well as scientific. Within our most widely accepted theory of cosmology, space-time basically overlaps in on itself , forming a large "bubble". The problem here is describing how to define

(or more) dimensions, and it's been done by many, far more intelligent than me.
I'd recommend reading anything or watching anything from a prominent astrophysicist or theoretical astrophysicist. Brian Cox, for one, is pretty good for describing things at a level most people can grasp, as well as going into the fine details.

The main thing to remember is that observable is the key word.

What happens to light at the edge of the observable universe, is quite simply, that it doesn't happen. The universe is expanding and light is following right along with it, as well as everything else. There is no "border" or "edge" that anything is bouncing off of, per se. All of existence, light included, is expanding. And that is, for all intents and purposes, the universe.

 

[StargazerXL]

Actually you are correct. Gravity distorts the path of the light causing it to shift in direction. This effect, called gravitational lensing, is seen all the time in deep astronomical imaging. In the strong case, multiple images of the same background galaxy can be seen around a foreground galaxy. In the weak case, the cumulative distortions made to the light path by haloes around intervening galaxies produces an effect that actually can be used to trace dark matter in those haloes. The effect is not seen towards stars in our Galaxy though because the gravitational fields of intervening stars are not as large.

 

[Coolwhhip]

 

[bender]

 

[InverseAgonist]

What if dark energy distorts the light ...

Then we would be able to easily detect dark energy! Which we can not.

 

[IDKFA]

I remember the first time I smoked weed.

 

[Airola]

Here's one I've always wondered about.

Light is not always an uninterrupted straight line. Things can deflect it. Scatter it. Prisms, lenses, water, the atmosphere, moons, planets, celestial bodies, black holes, quasars, dark matter, nebulae, galaxies, galactic filaments, who knows what else.

If you are looking at a droplet of water suspended in midair, the world you see through that drop can be hugely distorted. Flipped, stretched, warped.

What makes us so sure that the stars look anything like we think they do? How many of our constellations are the celestial equivalent an angled watch face blinding a passing motorist? How many of the uncountable gazillions of galaxies whizzing around are swarms of ghost images?

Can we say for sure that absolutely everything up there is a 1:1 representation of reality? I'm not certain we can.

To borrow a phrase from Air: How does that make you feel?

Just wanted to throw that thought out there, in honour of other recent science threads.

I'm waiting for the reveal of Earth being both flat and round at the same time. Like the universe, it is physically relatively flat and doesn't have boundaries but loops on itself even though at the same time it's flat. We can see the loop as round shape when we observe it from a distance, but it's actually flat the whole time yet loops on itself, kinda like the world maps in 2D RPGs. Our cells and atoms are flat too but from a distance seem to have a certain shape. When quantum physics show atoms being connected the whole time no matter what their distance from each other is, it is because existence is flat but at the same time existence loops on itself in infinite different ways. The atom that is five miles away has a flat line to its counterpart, but as the reality within them also loops at the same time despite there being a flat line between them, they actually are continuously at the same position due to the looping mechanism.

 

[McCheese]

What if we're in an Alien zoo and they can look in but we can't look out

 

[Kadve]

Well, obviously Weird Al could have been right about "everything you know is wrong" since our understanding of reality is ultimately based on perception and nothing else. But that's more philosophy than science (facts vs truth, to also reference Indiana Jones).

What happens to light at the edge of the observable universe, is quite simply, that it doesn't happen. The universe is expanding and light is following right along with it, as well as everything else. There is no "border" or "edge" that anything is bouncing off of, per se. All of existence, light included, is expanding. And that is, for all intents and purposes, the universe.

Kinda sorta. What you are describing is known as the cosmic event horizon, which represents the distance of which light can travel from our perspective in relation to the inflation (around 16 billion light years and constantly shrinking due to the acceleration).

Besides that though is also the Particle horizon. Which instead represents the maximum distance light could have traveled from the universe conception (around 13.77 billion years ago based on our current understanding), which is around 46.5 billion light-years and constantly increasing due to the arrow of time.

You can summarize them by saying that the particle horizon is the distance that we can observe the universe as it was in the past, while the cosmic event horizon is the distance of which someone would be able to observe you as you are right now.