Wait, Whut? (Stupid Vanity)

Curiousity | 03/03/2025 | By Laz A. Mataz

[Lazamataz]

Ok, so, I have a serious question.

Light is not infinitely fast, and it is the universe's speed limit.

Things that have mass cannot travel at the speed of light.

There are galaxies and objects over 93 billion light years away.

But the age of the universe is 13.8 billion years.

Even if Star A was travelling at the opposite direction of Star B, and even if it was traveling at the impossibly-fast speed of light, it could only be that the two stars are 26.6 billion light years apart.

But we see objects 93 billion light years away.

Please try to reconcile these two facts.

🤔

[Openurmind]

I get that too. Like floating upstream on a river...

[nitzy]

yes

[sergeantdave]

The expansion of the universe can be explained by hamburgers, specifically, the universal Michael Moore hamburger law - the more hamburgers you eat, the faster you expand.

We can’t say for certain that the expansion of the universe is due to eating hamburgers, it might be pizza.

You’re welcome.

[Responsibility2nd]

I know you probably don’t care what Grok says; But here we go....

_________________________________________________________________________

Light is not infinitely fast, and it is the universe’s speed limit.

Things that have mass cannot travel at the speed of light.

There are galaxies and objects over 93 billion light years away.

But the age of the universe is 13.8 billion years.

Even if Star A was travelling at the opposite direction of Star B, and even if it was traveling at the impossibly-fast speed of light, it could only be that the two stars are 26.6 billion light years apart.

But we see objects 93 billion light years away.

Please try to reconcile these two facts.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

You’ve raised a fascinating point about the nature of the universe, and it’s one that often trips people up because it involves the interplay between the speed of light, the expansion of space, and the way we measure cosmic distances. Let’s break it down step by step to reconcile the apparent paradox.

First, you’re absolutely correct: the speed of light (about 299,792 kilometers per second) is the ultimate speed limit in the universe, according to Einstein’s theory of relativity. Nothing with mass can reach or exceed it, and even massless particles like photons travel at this finite speed. If the universe were static and 13.8 billion years old, light from the farthest objects could only have traveled 13.8 billion light-years to reach us. Even if two objects were moving apart at the speed of light in opposite directions from a common starting point, the maximum distance between them after 13.8 billion years would be 2 × 13.8 = 27.6 billion light-years (close to your 26.6 billion figure, assuming a slight rounding difference).

Yet, we observe objects that are currently 93 billion light-years away. This number comes from the comoving distance to the edge of the observable universe, which is about 46.5 billion light-years in any direction, making the total diameter roughly 93 billion light-years. How can this be, given the universe’s age?

The key lies in the expansion of space itself. The universe isn’t static—it’s been expanding since the Big Bang. When we say an object is 46.5 billion light-years away today, we’re talking about its current distance, accounting for how much space has stretched over time. The light we see from those distant objects was emitted billions of years ago, when they were much closer to us. As that light traveled toward us, the space it was traveling through expanded, stretching the distance between us and the source.

Here’s how it works:

Light’s Journey and Expansion: Imagine a galaxy that emitted light 13 billion years ago, when it was, say, 10 billion light-years away from our position (these numbers are illustrative). As that light traveled toward us, the universe doubled in size (or more, depending on the expansion rate at different epochs). By the time the light reaches us 13 billion years later, the galaxy’s distance has stretched to 20 billion light-years or more due to cosmic expansion. The farther back in time the light was emitted, the more expansion has occurred since then.
The Observable Universe: The farthest light we see today left its source about 13.8 billion years ago, near the Big Bang. At that moment, those objects were much closer—within a few million light-years of our position. But over 13.8 billion years, the expansion of space has pushed them out to their current comoving distance of 46.5 billion light-years. This distance isn’t about how far the light traveled; it’s how far the objects are now, after space has expanded.
Speed of Separation: When you mentioned Star A and Star B moving apart at the speed of light, relativity limits their relative velocity to c in a static space. But in an expanding universe, the separation isn’t due to their motion through space—it’s due to space itself stretching. Objects can recede from each other faster than the speed of light because it’s not their velocity but the expansion rate of the universe that governs this. Beyond a certain distance (about 14 billion light-years today), galaxies recede faster than c, which is why we’ll eventually lose sight of them as their light can no longer overcome the expansion.
The 93 Billion Light-Year Figure: The 93 billion light-year diameter is the span of the observable universe today—twice the comoving distance to its edge. The light we see from those edges was emitted 13.8 billion years ago, but the sources have since been carried farther away by expansion. The light didn’t travel 46.5 billion light-years; it traveled a much shorter distance in the early universe, and space stretched behind it.
So, to reconcile your facts: the universe’s age (13.8 billion years) tells us how long light has been traveling, while the 93 billion light-year size reflects the current distance to objects whose light we’re seeing, stretched by cosmic expansion. The speed of light remains finite and unbroken—it’s just that space itself is growing, carrying those distant galaxies along with it.

Does that clarify the puzzle for you? If you’d like, I can dig deeper into the math or the Hubble constant’s role in all this!

[Phlyer]

For me, for now, God will suffice.

I can give you lots of topics where, for me, God is the only logical, rational answer. And I fully believe He created the universe. It's just that I believe he set in motion 'laws' of physics and let them do most of the work.

One of my little analogies is this: Suppose you are a cow and you see a car drive by. Small manipulations of the wheel and gas pedal make the car go exactly where the driver wants it to go, but to a cow there is no visible control. It just goes.

We are created in God's image, and since we use mechanisms (rather than brute force, like animals) to accomplish what we want, it seems logical and rational to me that God would set mechanisms in place to accomplish His will. And - like the cow - we may not be able to perceive the manipulations that cause His will to be done, but they're still there.

[Political Junkie Too]

What if the edge of the universe is warped, too? What if the universe is one giant bowl in every direction instead of one giant sphere around a common center?

What if light is simply climbing up the side of a bowl?

-PJ

[zeestephen]

The central concept in regard to space distance is that space itself is "expanding" at a high rate of speed.

The further we are located from the Big Bang, the faster and faster space is expanding.

That is not intuitively obvious to humans because our community of local galaxies is bound together by the natural force of gravity.

At some point in the future, hundreds of millions of years from now, humans will only be able to observe our closest galaxy neighbors.

The shape of the universe is something I have never completely understood.

Apparently, it is "flat," and resembles the largest end of a "megaphone," like a cheer leader would use to amplify his/her voice.

However, the "thickness" of the flat universe is never explained.

The smallest end of the megaphone is where the Big Bang took place, and time began.

The flat universe is expanding, at a high rate of speed, towards the large end of an ever-expanding megaphone.

Does the universe fill up the entire megaphone?

Or - does the universe occupy just a thin, flat slice of the largest end of the megaphone?

I do not understand that part.

In any event, expansion of the universe is ALWAYS taking place at the extreme perimeter of the constantly expanding megaphone.

[telescope115]

I agree somewhat. There are things that God doesn’t control: mainly bad things happening to good people. We bear responsibility for actions we take that cause injury to others. Sometimes they’re accidents, but at times evil takes hold of people and bad things happen. That’s where the Devil exerts his influence.

[Olog-hai]

But you take it for granted that the universe is 13.8 billion years old, a number assumed by “scientists”.

[Right_Wing_Madman]

What is the difference between "the universe" and "all of space?"

As the universe expands, gravity holds the galaxies and galaxy clusters together, but all the space between the galaxy clusters is expanding and galaxy clusters are becoming more far apart from each other.

[Right_Wing_Madman]

Whatever is expanding has to have something to expand into. What is that something?

This question is not possible to answer for two reasons:

1. We can only observe the observable universe, not the total universe, and not what's outside the total universe.

2. We don't know the geometric shape of the universe. It's either closed (like a globe), open (saddle-shaped), or flat (like a piece of paper).



If the universe is closed, it is finite. This means a spaceship could theoretically fly in one direction and eventually arrive at its starting point from the other side it departed.

If the universe is open or flat, it is infinite, meaning the spaceship would fly forever in one direction.

So far, all observations and measurements suggest a flat universe, which means the universe is infinite and it is expanding into infinity.

[odawg]

“This means a spaceship could theoretically fly in one direction and eventually arrive at its starting point from the other side it departed.”

Or, as one scientist said, if you had a powerful enough telescope, you would see the back of your head.

[Right_Wing_Madman]

Or, as one scientist said, if you had a powerful enough telescope, you would see the back of your head.

If the universe is finite or infinite, both possibilities are disconcerting to me.

If the universe if finite, then it is expanding into some sort of "super space" and perhaps there are multiple universes in this super space, like bubbles in a beer.

And if the universe is infinite, it's tough for the human brain to grasp that concept.

[The Duke]

I think it's the 'big oscillation', and if we get really luck the day will come when we can wave at everyone else as they pass by.

But ya gotta be quick! (Ooops! Too slow!)

[Don W]

If time is expanding, why are the years going by more quickly?

That one's easy: Each day, or portion thereof you live becomes a smaller and smaller percentage of the time you have been alive.

As a 2 year old child, a day is 1/730th of your entire existence.

As a 40 year old adult, that same day is 1/14610 of your time on earth, a MUCH smaller proportion, even though the actual time itself has stretched with the expansion of the space-time continuum.

Indeed, one HOUR as a 2 year old is slightly smaller a proportion of your life than a full DAY to your 40 year old self.

[P.O.E.]

Here’s my question:

If there was a big bang there’d have to be a center of the universe (point of origin), but according to modern astronomy, there is no center.

[Phlyer]

. . .mainly bad things happening to good people.

I think it's interesting that while the Creator God (I AM, Yahweh, Jehovah)) is sometimes referred to as the Father in the old testament (usually as an analogy more than as a label), Jesus referred to Him almost exclusively as "The Father."

So I think about what a perfect Father might be like, and it seems to me that it is necessary for a father to let his children make mistakes in order for them to grow in wisdom - to learn that His way is the best way.

The example I use here is looking both ways when you cross a street. As a child, you do it because your parent insists, but as you grow - perhaps after being scared a time or two, or seeing/hearing about others who were hurt - you learn that it's the best way. And so you look both ways even if your parents are not watching.

So, in my mental model, God has set up a world where we are free to make choices - even bad choices - so that we learn that God's way is better and can be happy in Heaven where all choices are in accordance with God's will.

However, in the meantime, the Devil is whispering in our ears about bad choices. God allows that - even though it grieves him - because in his long-term view it is better for us.

But that's just part of my attempt to put a logical, rational structure in the world.

[telescope115]

Yeah, I have my mental model, too. I guess we work out what works for us, mentally to try to make sense of everything, good and bad.

I only know one thing for sure- this ain’t the world we grew up in. I’m 70, and I do remember better times.

[Phlyer]

I’m 70, and I do remember better times.

There is an old saying, and I don't remember the exact wording, but it goes something like this:

From totalitarianism comes revolution, from revolution comes freedom, from freedom comes prosperity, from prosperity comes complacency, from complacency comes dependency, and from dependency comes totalitarianism.

We're somewhere in the complacency/dependency region, and we see the sorts of polarization between those who want even more nanny-state coddling and those who still want to be personally free. And I absolutely agree, I too can remember a time when the US was firmly in prosperity and freedom - including the freedom to fail, and to try again.

I think the cycle is just about inevitable, but it may be that Trump (and perhaps someone like Vance after him) can stave off the next totalitarian cycle until after we're dead. It's a sad thing, but that's about the best I can hope for.

PS Why did you choose telescope 115 for your screen name?

[telescope115]

I’ve seen that saying, that progression of our human nature, attributed to a couple different people, one was G.K. Chesterton, and I forget the other. Whoever first realized it and put it to paper certainly described it accurately.

I agree with you on where we are in that cycle. Thank God Trump came along when he did. He’s not perfect, but he’s what we need right now.

I’m an amateur astronomer, have been for almost 50 years, and my telescope is a refracting telescope with 3 lenses that are 115 millimeters in diameter. For lack of more creativity choosing a screen name, It just popped into my head to use that.