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While it is true that the speed of light is a constant, it is not the case that the universe is expanding faster than the speed of light. Rather, it is the space between galaxies that is expanding, and this expansion is occurring at a rate that is slower than the speed of light.

It is possible that the universe is much older than 13.8 billion years, and that it has been expanding for a longer period of time. However, the age of the universe is not determined by the speed of light or the expansion rate of the universe, but rather by the observed properties of the cosmic microwave background radiation and the rate of cosmic expansion. These observations are consistent with a universe that is around 13.8 billion years old, and this is currently the best estimate for the age of the universe.

Microwave radiation is still light though. At some point, the CMB radiation would not be visible due to the distance being to far for the light to ever reach us.

The CMB could be extending beyond what we could observe due to the speed of light.

Once you figure out that the Universe is expanding, (Hubble did this when he figured out the "red shift" on stars via the Doppler effect) all you need to do is measure the expansion rate today and use the laws of physics to determine how the expansion rate must have changed over time (looking at the oldest stars we can see...) Then you just extrapolate all the way back until you achieve the conditions of the hot Big Bang itself.

https://wmap.gsfc.nasa.gov/universe/uni_age.html

Sure, but you're confusing the relationship. The age of the universe is determined by the observed properties of the CMB radiation and the expansion rate of the universe, rather than the size of the observable universe or the distance to the CMB radiation.

Hey there!

One thing before anything else is to determine how you’re viewing the “edge and origin” of the universe. So far as we understand, there is not some “cosmic waterfall edge” we could just plummet off of. That is not what is meant by expansion. It’s more like a balloon with dots representing galaxies and the balloon is being expanded so that the “rubber” space between each dot gets larger over time. The actual “edge” of the universe is the present moment happening in real time around and throughout you. Space and time are correlated with each other in such a way that you cannot simply think of a spatial boundary. What this edge “is” is the arrow of entropy from moment to moment. It’s not a cosmic rainbow wall that is spatially impassable (so far as we know…)

We use the Hubble constant and extrapolation from expansion (the balloon filling up over time) to arrive at the approximate age. We also can look at how our laws of physics currently work and how they would’ve had to work far enough back with the conditions that matter and energy would’ve had to be in.. in order to give us the way they currently work. There is the CMB that is an immense help to this extrapolation.

The first place to start is with the expanding Universe itself and the one parameter we’ve strived to measure longer than any other: the Hubble constant. On the largest scales, the galaxies we find in the Universe obey a very simple relation between the two observable quantities of distance and redshift, where the farther away an object is from us, the greater its measured redshift will be.

The value of the Hubble constant today isn’t simply the inverse of the value of the age of the Universe, even though the units work out to give you a measure of time. Instead, the expansion rate that you measure — the Hubble constant today — must balance the sum total of every form of energy that contributes to the Universe’s composition, including:

normal matter, dark matter, neutrinos, radiation, dark energy, spatial curvature, etc

There is a lot more to how they do this, but just remember that one of the most fundamental conundrums in cosmology is the small variance in the results of each method to determine the actual age of the universe. You should look into the Friedmann Equation: (I’m sure there are better links, but alas, here you go. I hope it helps!)

https://www.forbes.com/sites/startswithabang/2018/04/17/the-most-important-equation-in-the-universe/?sh=2aa411460da5

If only we knew the laws of physics. Sadly, we still only have an estimate that works pretty well, but has a lot of holes in it. We don't know the Hubble "constant". Is it 73 or 67 km/s/Mpc? Depends how you determine it.

Is Dark Matter real? Maybe. Maybe not.

We can't explain the constants of physics.

There's a lot of unknowns. The age of the universe being one of them. It's all theoretical right now.

If you believe that the universe is expanding from a much denser state (makes no sense, but whatever) and the rate is give by the Hubble "constant" (its not constant), and then calculate backwards (assuming a lot of stuff), then you get 13.8 billion years or so.

Its all based on the assumptions you want to pin your creation mythos on.

Yeah, scientists just guess, since they're not sure. /s

There are margins of error that are taken into account when values aren't known exactly. That doesn't mean we just have no darn idea. "It's all theoretical" is wildly inaccurate. The margin of error on the age of the universe is like 1% - so that's a lot, but it's not, like, "could just be anything, we have no idea."

I mean, they're estimating to the nearest 100 million years. Being off by an order of magnitude or more is one thing, but it's not like they're pinpointing the exact year the universe banged into existence.

This is a challenging and subtle thing, right?

Let's look at it through analogy.

If we have a special kind of dough. One that that continues to grow after we bake it.

And we make a cake. The second that cake comes out of the oven, we put a layer of frosting across the top.

As time goes by, our special kind of dough grows. It makes the cake larger. But it never adds to the amount of icing we put on it. The icing is just stretched in ways so that it remains in the correct proportions.

We can measure that icing, and how it's stretched to determine how much time has passed since we applied it.

That's all this is.

It is not "just theoretical"

Hubble constant, despite what its name suggests, has been shown to not be a constant already, we know it's increasing. Dark matter is 99.9% a certainty, we observe it's consequences and interactions. We only need to experience it first hand to say it's real, that's called being prudent. We can actually explain lots of constants in physics.

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This is why I asked the question here. 🙂

Absolutely not. It’s just the most educated guess at this time.

This was a fascinating read, thank you and OP. Great question.

thats it, science is what we know at the time

I am 43, I remember kids books talking about the universe being 7 billion years old

I wonder after 20 years what people will think of us

The question “is the universe expanding faster than the speed of light?” is not really a valid one anyway - the speed that two points in space appear to be moving away from each other depend on how far apart they are at the time of measurement.

a large piece of space is being dragged one way

"Calculating the age of the universe is accurate only if the assumptions built into the models being used to estimate it are also accurate. " - Wikipedia

So yeah assuming the model is accurate. But that's an assumption. Not a known.

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i wonder how old the universe was that imploded, causing our big bang

Yep very interesting indeed. There is a hypothesis that this is a dipole effect with a repulsion point a little further “behind” us.

> So the speed of light is constant,

Maybe not

https://www.vice.com/amp/en/article/8q87gk/light-speed-slowed

For clarity there is a lot we know and a lot we don't. We have theories that fit all the observations. When an observation does not fit the current theories other theories are created to fill the gaps. Kind of like your car swerving with no reason you know of so you theorize a gust of wind caught you.

The fallacy is in the question… linear time is not real , it’s a man made construct … so in actuality , only our hubris confirms our bias .. the scientific community will only claim 4 % of the known universe at this part .. fearing consciousness discussion and acting as if dark energy and dark matter are the unknown mysterious things … but who TF makes a 4 on a test and stands up and starts making declarations ? It’s just human nature , we have to kind of find a starting point , cling to it , but it’s hardly possible , as for 103-104 years now we have known time is merely a perspective .

No, and besides times relevance dissipates as you get close to the big bang, so your measuring stick will become jumbled

That's interesting. 🙂

That would definitely shake up physics.

Answers like this are why I posted here. 🙂

This is all wrong.

Galaxies are absolutely separating at rates faster than the speed of light. Or more specifically, space between galaxies is expanding faster than the speed of light, Altho the galaxies themselves are still moving at sublight speed. Light moves through this space at the speed of light however, and the furthest things we can see are approximately 13 billion light years away. We see them as they were 13 billion years ago however, “shortly” after the universe stopped being opaque. Those galaxies now however are actually more than 40 billion light years away now, but we haven’t had time to see them yet, for obvious reasons (the universe isn’t that old). The oldest thing we can “see” is the cosmic microwave background radiation - the last signal of the opaque universe which actually makes up a good chunk of radio static you can hear, and emanates from around the 400,000 year old point in the history of the universe.

All of this can be calculated using Einstein GR equations, and others sorted out in the subsequent 50 years.

Without getting into diffEQ, the math works out that all of space time was compressed into the same point (the big bang singularity) approximately 13.8 billion years ago, the total diameter of the universe that we can see now is actually closer to 80bly, but that’s just the part we can see now, the universe could be infinite and we wouldn’t know.

It’s a lot to take in, but you need to remember what we can “see” today is what existed when the light was emitted, not as it is “today”, and the farther away it is, the older that light would be, so the farther back in time you’re looking.

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I know the balloon thing.

My question is, what about inside the balloon. Is there nothing new arising from the middle of the balloon center, or is there, or is there something dormant waiting to start creating again.

Are we really on a layer that is spreading apart, so we live on kind of a flat ish plane that only goes so far up and down? What is outside of the "balloon" compared to inside the "balloon" one is space that is yet to exist the other is space that exists but has very little in it.

I'm in the latrine and that's all the time I have

I am glad I was able to help in some way. I’m sure a more robust cosmologist can dig into the weeds of it all with you, but I wanted to give you at least some breadcrumbs to follow. Just keep in mind that, with Cosmology especially, our models are being adjusted and improved almost monthly these days. It’s always important to remember that a model is just exactly that - a model. They may be very accurate, but there will always be a distinction from our most accurate models and the mechanics of nature itself.

In short: Keep digging into it. No one knows what great ideas might cross your mind.

Probably easier to use your imagination for that one

There's no direct evidence that the cause of the big bang was an imploding universe. Insofar as we can tell, it was the start of both space and time with nothing necessarily preceding it or causing it. Asking what preceded it is kind of like asking what is south of the South Pole. Nonsensical in our space/time geometry.

I think we should all be careful when we're talking about right and wrong. Perspective is important.

You are correct that the space between galaxies is expanding at a rate that is faster than the speed of light. However, it is important to note that this expansion is not a violation of the laws of physics, as it does not involve the movement of matter or energy through space.

The expansion of the universe is a phenomenon that is associated with the expansion of space itself, rather than the movement of matter or energy through space. The expansion of the universe causes the distance between galaxies to increase over time, and this expansion can occur at a rate that is faster than the speed of light. This is because the expansion of the universe is not limited by the speed of light, but rather by the properties of space itself.

I've actually thought about this for a while, and after years of research, I have concluded that the universe is x years old. We just need to find x

First off, I'm not very knowledgeable on the topic but always have trouble understanding how we can confirm things like age of the universe etc.. so forgive me if I'm asking stupid questions.

Your analogy is the first time I've been able to somewhat understand so thanks for that but to follow up, how can we know how much of this "icing" was there to start with in order to accurately tell the age? (Is the icing the cosmic radiation?)

Follow up question. Why do we confrm and deny things based on our limited knowledge? Who's to say that things don't work differently out there in the distant universe? I have trouble thinking that the far universe and even other planets work according to the same laws as we know.

In a nutshell by someone who really understands very little about how scientists figure all this stuff out...

Remember that projections about the age of the universe are still just a theory. Backed up by evidence we can see/detect. Basically, from what we are able to see, scientists have been able to theorize the age of the universe based on evidence we are able to see. Is it possible there is more beyond what we can currently see? Yes, and I like to believe so. But current data doesn't support that theory.

And here is where the balloon analogy of vector dimensionality breaks down for a 3D intelligent lifeform bound by time.

If you are asking:

What is outside the “balloon”?

From OUR perspective, it hasn’t happened yet, so nothing….maybe…..(your guess is as good as anyone else’s.)

What is inside the “balloon”?

Previous stages of the universe’s development. The closer to the “center” of the balloon you get, the further back in time you go, from our perspective.

As for the geometries:

“Flat”, as in the rubber substrate of the balloon to us, encompasses ALL of spacetime. So the “rubber layer” you can consider all of three dimensional space. So, yes, we are on a “layer” in which all three spatial vectors are spreading due to an ever increasing “metric”.

I don’t think I made any statements implying it was breaking any laws of physics?

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So the observable universe only?

There are many different properties of the CMB. Temperature, intensity, spectrum. As time progresses these will all change. From there it's a matter of rewinding the clock back to its original, highest energy state.

We don't know. And the truth is, we can never know with absolute certainty. Science isn't a study of Truth, not really. It's a study of observable phenomena that we use to make models to help us accurately understand our reality.

From that stance, they've been very successful as it gives us technology. Regardless of any Truth statement.

We approach infinity, We approach Truth. Never is either reached.

What we “know” is what best fits what we observe. As observations improve then we we know becomes more refined. It appears that the sun revolves around the earth but as instruments and observations progressed we gained a different understanding. It takes time.

Some observations: the masses of celestial objects are all moving away from each other, as if expanding. If they are moving away from each other, it's a pretty good assumption that, if we were to rewind that, at one point, they were all together.

Measuring the velocity with which they are moving is easy enough. So, coming up with a model for rewinding that (and how long that would take) is actually not the most complicated thing in the world. If we were to "rewind" it, it would take ~14 billion years. Of course, there may be some variables that effect that age, but most of the biggest ones (gravity, expansion, etc) are fairly easily observed and accounted for. So it is unlikely based off current observations that we are trillions of years off. Millions perhaps, but that's fairly small.

Look up physics girl on YouTube. She’s got a video on that.

I think hypotheses is a better fit than theory in some places. A theory is based on observations.

We know that space itself is expanding, so even the meter is not a constant over time. There is no reason to expect the speed of light to be a constant over time, either. These things only appear to be constants when viewed within the context of the instantaneous observations of man during his extremely short existence.

In other words, we have no idea what the age of the universe is. We probably never will know, and the answer would be meaningless to mankind anyway.

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Something/someone of higher power that started it all, maybe? We all know the “cause and effect” of things, how far back beyond the “cause” of things can we go?

The amount of the frosting isn’t relevant. It the way it’s cracked. Specifically we can see how much the CMB light is “stretched” and figure out how old is is from that. The amount of CMB does not factor into that.

We can aim a lot of sensors towards a rock in North America, including our eyes and sense of touch, but also laser spectrographs and electron microscopes. We can aim the same sensors at a rock in India, get the same results, and conclude the rocks are made of the same stuff.

We can aim fewer (but an increasing number!) of sensors at a rock on Mars, for those we get the same results as some rocks on Earth, so we conclude, with slightly less confidence, that the rock on Mars is composed of the same stuff as the rock on Earth.

We can aim even fewer sensors at a rock (well, a glowing dust cloud, rocks are too small and dark to see) in another galaxy. Those sensor readings (spectroscopy in particular) match readings taken from stuff here on Earth, we conclude that the dust cloud in that galaxy is probably made up of the same stuff as we have here. Maybe not, but if it looks like hydrogen, and behaves like hydrogen when heated, it’s probably hydrogen right?

As for your second question, confirming and denying things based on our knowledge is what science is. If we find new workable theories and/or facts that go against our current process, well...we change our process to fit the newly found evidence.

We work with our knowledge because it's all that we have. We don't have access to anything else besides how we as humans think and retain.

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I understand what you're saying.

I just wish I could be alive when we can explore further into the unkown. Any knowledge on this topic fascinates me so much. Thank you again for that icing on the cake analogy. May you have a wonderful day.

> The universe is not expanding faster than c. In the very early universe, this was true,

What’s that supposed to mean? Expansion is a rate, not a velocity. Relative velocity is only locally well-defined.

How did the early universe expand at more than c in any way that doesn’t just as well apply now, over enough distance?

You are alive for that! Look around. So much is being discovered today that nobody can keep up with it all. That's mind blowing to me.

Even as a child in the 80s, I might go months without having some major discovery made, maybe years.

Today I can't get through a single news cycle.

Never fear that we'll run out of discovery. That's not possible. Novel information is created faster than it's absorbed, at least by any given individual.

We're delving into reality in ways today that are mind blowing on many different scales.

The real fear, is running out of time to explore.

We're on the same page about outside the balloon, it's non-existent.

So you would say, there is no traveling outside the "rubber layer.". What is under the rubber layer, the "inside" would be... The past. But that's a little simple to say isn't it? Is that to say yes you can travel there but there will be nothing there when you get there; we are for sure no new matter is being created anywhere.

And if we're on a balloon, we are only seeing a tiny tiny spec of the part of the surface we are on, we aren't assuming we can see through to the other side of the balloon, right? Like I can't see China from where I am even if earth was invisible. But we know that area exists and there should be stuff there?

I have trouble thinking our observable universe is it's own balloon, I believe we would have to be a part of a much bigger balloon.

That's the definition of a hypotheses.

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The previous configurations of matter, energy and spacetime are “under” the rubber layer, because it’s where the rubber layer used to be in terms of entropy. You can’t take a ship and just fly to it. It would have to be a space-time machine capable of reversing entropic systems either globally or locally. Yes, the balloon analogy is simple to say, that’s the trade off. I am not going to be able to describe to you the capabilities and perception of any trans dimensional perspective, because I do not and cannot have that vantage point. The rubber layer is all you will ever be able to physically “travel” within as a being bound by length, width, height and time. So “under” the rubber layer… IF you could reverse entropy, you would simply arrive at the universe in what entropic state the universe happens to be in at the time you “stop reversing time”.

Seeing “through the rubber layer” would be akin to saying you have the power to see matter in superposition at scale. It would appear as nonsense multiple output for few input. Nonlinearity, etc… The more finely we tend to look at the universe on a small scale, the more “elephant in the room” this conversation becomes. Imagine watching a movie and seeing every single frame transposed onto one another at once… whatever that would even mean or look like. It’s important to point out here that the movie would lose all narrative meaning in this configuration. Which should prompt you to ponder what narrative in the abstract even is and if it’s somehow transcendental. It is information we might would actually lose by GAINING transdimensionality. Total conjecture but worth thinking about. Usually it’s the other way around; We gain information going up that ladder. Going down usually forces us to give up a little bit of “true” information about the higher rung.

As for saying it would “just” be the past is a little insufficient, depending on your definition of the “past”. You have to remember to account for the spatial distortion as well. So it’s not like the Langoleirs from Stephen King, where you go back to the past and all the structures and inanimate matter just is “left behind”. All of that matter is subject to entropy as well. On that note, I have a serious hunch that quantum computing and the recent work with local realness and entanglement will drastically redefine our capabilities regarding this issue. I could absolutely be completely wrong as well.

Another note on your question of whether or not there is anything happening at the “center” of the balloon still:

From OUR perspective. No, it was the Big Bang. From outside the perspective of time, who knows? Extrapolating (which is NOT necessarily the correct answer!) from an unconstrainment of the time vector, it could be a permanent ON switch eternally happening. This is nearly alllllll conjecture at this point, but in the words of Richard Feynman, it’s fun to imagine.

To use an even less understood phenomenon and an even poorer analogy:

You would be a particle within that rubber layer. It would take more energy than we can currently generate and use to rip you out of it. And it would absolutely require you to not be constrained by any time vector, which isn’t the case. What would that look and feel like? I have no idea, and I doubt anyone else has a fully proven idea of what that is like. Much like the ink cannot just float off the page of your paper, what use is that ink without paper? Will it even keep its spatial configuration so you can read it? Would your brain even be able to function without an entropic “inertia”? Etc? Now you will have to borrow more and more from philosophy to arrive at a conclusion that you and every other human might never be able to prove… but it’s important that we keep trying.

There is no higher power. We only have the most brilliant minds of our time to figure things out.

To invoke a higher power is to stop asking questions, and that would make life boring.

The universe could be trillions upon trillions of years old, such that we can never see the bulk of it because it is beyond our visual horizon.

However, if that was the case, then there would be nothing at the observable edge of the universe. It would just be darkness. But that's not what we see. When we look to the observable edge of the universe, we see a glow coming from every direction. That glow, despite being very dim and very redshifted, is our glimpse of the Last Scattering event when the plasma that birthed the universe finally broke apart into separate atoms and began to emit photons.

Since stars emit specific wavelength signatures, we can see how much those signatures have shifted to determine the amount of cosmic expansion that has happened between us and any given source. We see that objects farther away are more redshifted. The Last Scattering surface appears to be 40 billion lightyears away, and using the redshift we measure, we find that the light from Last Scattering must have been emitted 13.8 billion years ago.

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>While it is true that the speed of light is a constant

Here is the problem. That is not even true. We're basing everything on things that we ~suppose~ true. We don't even know for sure if the speed of light is not dependent on direction or on anything else that we can't grasp as limited beings.

Now that's just one foundation on what we're measuring the age of the universe. Now imagine that every single other principle is also keen to a complete misunderstanding.

Saying the Universe is such and such old implies a mind standing outside of the universe and measuring its duration. Science likes to pretend it can do this but it’s actually a silly conceit. Anthropocentric thinkings at its most hubristic.

The universe is basically a time-space continuum. There is no way to measure the age of time.

I'm sure there are many fundamental aspects of reality we get wrong, or could be more precise with, or could understand better.

I'm not sure the speed of light in a vacuum is one, but I do agree with the premise you're presenting.

But it's important to understand this isn't about Truth. It's about approaching it. It's not about defining reality. It's about creating models of it that help us to interact with it.

There can be no denying that we have increased our understanding, it's directly reflected in the fact that technology increases and works.

That's the benefit. Not the truth of any given statement. But how these models can advance our understandings.

You see a car driving right at you. It looks like it's going to hit you in five seconds. Who's to say it's not going to hit you in five days? Seems like a fair analogy.

Completely agreed but OP's question was about questioning our measure of the universe's age.

Considering what we just said, I think that the range park that we got has close to no chance to be right. Our entire theory is based on the observable universe and our very vicinity, be it in time or space.

All things considered, we're pretty much toddlers trying to find the Earth's radius.

Perhaps, and we're all offered the same opportunity to observe our reality and put forth theories regarding it.

If the theories we propose do a better job of explaining the observed data and do not introduce any new problems. Those theories are typically accepted to represent a piece of the model.

Explore and plunge and theorize. Because maybe you're the next person that helps us to understand better.

Science doesn't claim to be correct. It's just a framework that is in place to judge the accuracy of predictions, and when it works properly the best predictions are kept, and the ones that are less successful are discarded.

It's certainly not a perfect system. Humans control it. But it's a good system in that it's iteratively accepting of new facts, while discarding any that have been shown to be incorrect.

Idk, maybe the Universe has been here forever

Why do I see experts saying the universe wasn’t actually a singularity at the time of the Big Bang?

Well, if you want to be pedantic, velocity is a rate too, is it not? Distance over time.

Anyway, there are countless articles / studies about this that can explain it far better than anyone on this thread. Suffice it to say, the size of the universe expanded from the planck length to a factor on the order of 10^28 in an extremely short amount of time

Existing radiation would simply be stretched and omnipresent given this massive change. That is why we have the CMB.

>the space between galaxies is expanding at a rate that is faster than the speed of light. However, it is important to note that this expansion is not a violation of the laws of physics, as it does not involve the movement of matter or energy through space.

Oh god, this breaks my brain. The amount of space between galaxies is expanding, but the galaxies themselves aren't moving as a result of the expanded space between them? I'm not saying you're wrong, but god dang I can't wrap my head around how that's actually possible.

The only vaguely coherent thing I can think of is like... a piece of taffy, where the two galaxies are sitting on the edges and you stretch the middle downwards. So the amount of space the taffy occupies increases, but the galaxies don't actually move. But I don't think that's accurate, because if space between us and a distant galaxy is expanding, then the distance increases which it doesn't in the taffy explanation... And I'm back where I started.

In perspective does it matter? Inflationary theory says inflation wasn’t infinite but may go on forever AND so the number of pocket universes might also be infinite. Difficult thought to comprehend — may be impossible to comprehend for our minds — but it had a beginning. Therefore our universe had a beginning. All of which brings to question the idea of “before”. Whatever that might be. And whether time existed before or was emergent.

If you read the earlier analogy with the cake.

We can pretend, because its just an analogy. That space in the analogy is air in the cake.

The molecules of the cake aren't growing or moving. It's only that the air in between them continues to grow.

It will ensure that the cake molecules end up with greater distance between other cake molecules.

But it's not because the cake molecules moved. It's because the air in between them grew.

Now this is just pretend, because air is not space. Air is molecules too. So I don't want to confuse that.

But it does fit the analogy.

Well strictly speaking a singularity is just a breakdown in the known laws of physics. something has to be down their, we just don’t know really what, or how it behaves.

Why did expansion start? Where did it all come from? What came “before”, to the extent that statement even has any meaning? These questions are at the very bleeding edge of theoretical physics and aren’t really testable yet.

If we know where the source of all energy came from (my guess is dark energy/matter) and understand how it came to be, we may be able to know if a universe like this is possible more than once. To have multiple cycles of a 3D universe, there could be energy dissipation and new energy is introduced, or energy is recycled by the joining of what’s left over in a hundred trillion years. Will SMBHs, neutron, pulsar, white/black dwarf stars combine and through kinetic or mass potential reach a higher state again? Will it be enough for another “bang”? Was it that each “universe” is less and less as some galaxies drift outside the range of even the largest SMBH?

Find the source and its source and we’ll know if this is a one way trip to dissipation island.

What Universe? It's on my list of dirty words not to use. Cosmos is better. Avoid fictional singularities.

I wonder whether they ever will be. Our ability to peer back in time relies entirely on what we can see and the radiation we can capture and analyze. Looking back far enough, it all becomes opaque because "first light" hadn't happened yet. Perhaps some new tech will throw the doors open some day, but if we cannot see past a certain point, and that point happened after the "bang," then we will never know what came before the opaqueness.

For that reason, I don't know for sure that the singularity has any merit. If we run the clock backwards we get a singularity, but since we can't see past a certain point, we don't actually know whether singularity is a real concept.

It’s not just about looking “out there”, a lot of the early-universe physics are probed in high energy particle colliders. It’s mostly about understanding quantum effects at that point.

Yeah, I sort of get that, I think at the core of it all I'm just having trouble wrapping my head around the concept of increasing the amount of space between two objects without moving them. Using the cake analogy, I'm finding it difficult to understand how the air molecules move in such a way to take up more space without pushing the things that already occupy that space out of the way. I can accept that they are based on the studies and testimony by people far smarter than I am, but my brain is pitching a fit because I'm struggling to grasp the 'how.'

It probably depends on what you mean by “truly know”, but taking that as literally as possible, no, we’ll never “truly know”

That's okay. I mean these are Big topics. It's taken our species millions of years of slowly building up to this point right now that we have the understandings we do of them.

It's not easy. For anyone. Not for you, Not for me. Not for Einstein.

We're not born innately knowing this, we're educated about it. If they are concepts that we find interesting, perhaps we consider them. It's only through this education and consideration, not just the education itself, that we come to understanding.

Not everyone has the time or inclination to consider these topics, and that's okay.

But for those that do, understanding will grow in some type of correlation between the interactions of the education and your consideration of.

Ask for analogies, they're great tools of abstraction. It takes these difficult concepts out of the realms of mathematics, and puts them squarely into terms we can better understand, everyday language. Math is important, but if it's not a language spoken by us, it's not helpful.

Einstein's brilliance was never that he was a great mathematician. It was his ability to break down very complex thoughts into stories he could understand.

I honestly think there are other pressing matters. Knowing age of the universe is not really important even for the next 500 years. Instead why not channel the resources used into finding things like "age of the universe " to trying to cure cancer? I feel like as of 2022 we have suddenly made momentous developments in curing this curse of a disease and as if we are standing on the edge of a pivotal discovery that will change everything we know about treating this disease. I feel like if properly researched we will be able to see even stage 4 patients being given curative treatment instead of palliative, being cured and going back to living life like it was before the disease; in our lifetimes.

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> Well, if you want to be pedantic, velocity is a rate too, is it not?

Yes, but expansion is velocity over distance, so it’s not units of velocity and thus isn’t c or below or above c.

> Suffice it to say, the size of the universe expanded from the planck length to a factor on the order of 1028 in an extremely short amount of time

The observable universe. Maybe, yes, but that doesn’t make it expand at a certain velocity unless you measure over a certain distance. And at this distance, relative velocity wouldn’t be well defined due to the curvature of spacetime, and wouldn’t be constrained to c anyway.

See first answer to this: https://physics.stackexchange.com/questions/400457/what-does-general-relativity-say-about-the-relative-velocities-of-objects-that-a

I wanted to add another reply here.

What If I wanted a really cool expandable cake like we talked about and asked you to make it for me.

But I've got a very special request.

After you bake the cake and add the frosting. I'd like to add a special flavoring. So that anyone can make this cake taste the way they'd like.

See if you can figure this out. Can I do this? What do the actual interactions look like? If I dropped the flavoring into one part of the cake, how would it distribute?

Would it be evenly? Could it ever fill the entire cake, assuming the cake never stopped growing? How would it travel from one cake molecule to the next?

This will help you to understand concepts like speed of light, and why we can't pass information faster than it.

It'll help you to understand localized events and how they interact with portions of the universe, but never the entirety of it.

Think about the relative movement. Without the flavoring now. The space between two cake molecules will always be a different relationship depending on the location of where they exist in relation to one another.

Two cake molecules side by side will always experience the same relative separation. But two molecules separated by the entire cake will always experience greater total separation because all the spaces of molecules growing in between them are cumulative.

We can pass flavor between two cake molecules, indefinitely. But assuming the cake never stops growing, what you'll find is the ability to spread the flavor becomes a function of the overall growth rate of the cake as a whole, meaning it can never keep up and that the total amount of the cake that is flavored in respect to the total cake, will always decrease.

That's odd. Because we're still getting more cake that is flavored. It's just that the amount we get will always represent a smaller percentage of the whole.

edit: We've taken our analogy in a very specific direction. One of infinite inflation of a mostly spherical object. Our universe doesn't need to meet those criteria. This is just one way to consider things. If the universe has different parameters, the interactions would inherently be different. What if our cake was really a doughnut? What if it were just a 2d plane of 3d information?

Keep these things in mind, as there are clear limitations to locking our thoughts into the ability of analogies to represent ideas.

Well…due to time dilation created by gravity some areas of the universe are older than others. The Earth’s core is 2.5 years younger than the surface. Time is relative and it’s passage is subjective.

I assume you left out the rest of the paragraph because you don't know what Bayesian and Strong Priors means.

The inaccuracy is quantifiable if you do.

> Science doesn't claim to be correct.

That's what the vast majority don't get.

Thanks for the encouragement but as an analogy I'm more a watch it from the couch kind of guy. I guess also a coach since I'm tutoring students (Maths and Physics), so maybe one of them will make a breakthrough :)

I assume, based on the arrogance and presumptuousness of your comment that you have a GUT all figured out and have reconciled the disparities in Hubble values.

That's called "a straw man" argument, with a bonus false dichotomy.

Pretending that we don't know anything because we don't know everything is a glaring indicator of ignorance - not only of the topic at hand, but more generally of a weak grasp of epistemology and argumentation.

Most of us will never provide to the frameworks of science. Not directly. We could, but it requires an understanding of formalized language that most do not possess, including myself.

But we can contribute towards the concepts and ideas and goals. We can encourage one another to have considerations towards the basic principles. Be fair. Be honest. Be critical minded. Try to minimize bias.

And we don't know how that ripples through reality, but I'd like to believe it's a positive influence overall.

I appreciate your time in educating the youth. It's a very important job, and I'm glad that it's being done by someone that does consider these things.

>I appreciate your time in educating the youth. It's a very important job, and I'm glad that it's being done by someone that does consider these things.

Thanks for that. Be assured that I do it with passion.. and I'm quite lucky that they give me back the positivity.

Thank you very much for your detailed response. I was blown away that you referenced the langoliers, that's my favorite Stephen King movie.

You've closed the book as far as I'm concerned, I have no more questions at this point and I'm very satisfied with what you've said. I only wish I did have a question because you would be the man to ask it.

I'll see if I can't muster up an award for ya, just not this moment.

I have an out-there theory, if you're up for hearing it. I promise a good award.

I believe each galaxy has it's own cycle, we know they have their own black holes (maybe not all of them?) But I believe that black holes condense matter to a point that it is torn apart right down to the muons and quarks and eject those bits back into the universe alone, so there are free quarks or maybe smaller floating around in the space of a galaxy, these free floating quarks or smaller eventually find themselves partners and become matter again, or it doesn't, I don't have anything to say it can or does, but I presume it either does or doesn't but ultimately it doesn't create enough matter to keep the universe from it's ultimate death, but the universe does fill up with these quarks without homes so to speak. The cycle continues as the black hole will repeatedly take these in and eject then again but it doesn't have any gain, the cycle isn't fast enough.

I'm sorry for the way I communicate, it's very hard to get what's in my mind on paper without more effort than most. I can continue on and flesh it out more but I need to be on my computer and a keyboard to start lol

I have been proposing this since 1992. I keep getting "keep working on it" as a response and little else.

Absolutely anytime. There are far more qualified people than me that can really get into specifics and special cases with you, but I think we had a good start at opening further roads. I am glad to see that I was able to help you in some small way!

Have you looked into the recent “reverse sieve black hole theory? Similar to your idea. Also, have you checked out Calabi-Yau manifolds? Conjecture at this point, but you might get some original ideas when reading about them:

https://en.m.wikipedia.org/wiki/Calabi%E2%80%93Yau_manifold

Seriously, keep thinking about this. Also it would be good to read about virtual particles and quantum vacuum fluctuation if you haven’t already.

Thanks!

I'm going to take a look at everything I can, I will look at your suggestions post haste!

The manifold is interesting - I'm definitely going to look at that carefully. I think it can help describe this general leftover of mass/matter I want to have, it seems immeasurable now but that hasn't stopped our pursuits before or yet.

The reverse time idea is interesting for sure as well... very interesting. I hadn't considered it but I'm going to look at the details, see if there's anything I can use. edit: I've seen similar stuff to this extent, I think usually involving niel degrasse tyson. It's all very interesting. I need to look at the actual works because through NDT's eyes it sounds like comic book stuff.

Thank you again!