APOD: Time Spiral (2024 Jul 01)

Post a reply


This question is a means of preventing automated form submissions by spambots.
Smilies
:D :) :ssmile: :( :o :shock: :? 8-) :lol2: :x :P :oops: :cry: :evil: :roll: :wink: :!: :?: :idea: :arrow: :| :mrgreen:
View more smilies

BBCode is ON
[img] is ON
[url] is ON
Smilies are ON

Topic review
   

Expand view Topic review: APOD: Time Spiral (2024 Jul 01)

Re: APOD: Time Spiral (2024 Jul 01)

by Chris Peterson » Fri Jul 05, 2024 2:55 pm

Christian G. wrote: Fri Jul 05, 2024 1:38 pm
Chris Peterson wrote: Wed Jul 03, 2024 3:55 am
Avalon wrote: Wed Jul 03, 2024 2:40 am What kind of explanation is "before" not having any meaning in the context of the universe? The entire illustration is a timeline of the universe.
That doesn't mean there's a "before". That word is pretty hard to define when time doesn't exist.
I'm reminded of the "What did God do before creating the Universe? He was preparing Hell for those who would ask!"
We can’t ask what was going on during the time when time did not exist - obviously. My question is: How do you ask the question? What is the correct choice of words?
Before, there was no before, fair enough. But that doesn’t mean it was nothingness.... Did the Big Bang result from a quantic fluctuation, was it a violent transition between two different states of the universe or whatever other speculation misguided or not, whatever the unknowable answer, - how do you merely formulate the question of the "upstream"of the Big Bang?
"Nothingness" is just as difficult to define when "something" doesn't exist. There's no requirement that the Big Bang emerged from anything. There really is no correct choice of words. Words will likely always inform an analogy at best. If these questions are answerable, they will be in the form of mathematical expressions.

Re: APOD: Time Spiral (2024 Jul 01)

by Christian G. » Fri Jul 05, 2024 1:38 pm

Chris Peterson wrote: Wed Jul 03, 2024 3:55 am
Avalon wrote: Wed Jul 03, 2024 2:40 am What kind of explanation is "before" not having any meaning in the context of the universe? The entire illustration is a timeline of the universe.
That doesn't mean there's a "before". That word is pretty hard to define when time doesn't exist.
I'm reminded of the "What did God do before creating the Universe? He was preparing Hell for those who would ask!"
We can’t ask what was going on during the time when time did not exist - obviously. My question is: How do you ask the question? What is the correct choice of words?
Before, there was no before, fair enough. But that doesn’t mean it was nothingness.... Did the Big Bang result from a quantic fluctuation, was it a violent transition between two different states of the universe or whatever other speculation misguided or not, whatever the unknowable answer, - how do you merely formulate the question of the "upstream"of the Big Bang?

Re: APOD: Time Spiral (2024 Jul 01)

by Chris Peterson » Wed Jul 03, 2024 3:55 am

Avalon wrote: Wed Jul 03, 2024 2:40 am What kind of explanation is "before" not having any meaning in the context of the universe? The entire illustration is a timeline of the universe.
That doesn't mean there's a "before". That word is pretty hard to define when time doesn't exist.

Re: APOD: Time Spiral (2024 Jul 01)

by Avalon » Wed Jul 03, 2024 2:40 am

What kind of explanation is "before" not having any meaning in the context of the universe? The entire illustration is a timeline of the universe.

Re: APOD: Time Spiral (2024 Jul 01)

by Fred the Cat » Tue Jul 02, 2024 3:26 pm

When considering the vast amount of information we have at our fingertips, we should all follow the Ten Commandments. :yes:

Lest we spiral down the rabbit hole. :wink:

Re: APOD: Time Spiral (2024 Jul 01)

by zendae » Tue Jul 02, 2024 2:50 am

Congrats johnnydeep on your 3001 posts. That's quite an odyssey!

Re: APOD: Time Spiral (2024 Jul 01)

by Chris Peterson » Tue Jul 02, 2024 2:24 am

Avalon wrote: Tue Jul 02, 2024 2:11 am So, so many questions. What IS outside of time, like before the BB? How is it that humans existed for millions of years and the formation of cities only during the last 10,000 years? Were they without any intelligence or social skills before that? How convinced are we about the Theia event? How are events taking billions of years even calculated time-wise? Etc., etc.
"Before" need not have any meaning in the context of the Universe. Modern humans have existed for two or three hundred thousand years. Cities made sense with large populations and agriculture. Those didn't exist for most of human existence. It's not about intelligence, but about need. Support for the Theia event is pretty solid.

There are many questions. But we are fortunate to live in this brief moment of human existence when we actually have so many answers!

Re: APOD: Time Spiral (2024 Jul 01)

by Avalon » Tue Jul 02, 2024 2:11 am

So, so many questions. What IS outside of time, like before the BB? How is it that humans existed for millions of years and the formation of cities only during the last 10,000 years? Were they without any intelligence or social skills before that? How convinced are we about the Theia event? How are events taking billions of years even calculated time-wise? Etc., etc.

Re: APOD: Time Spiral (2024 Jul 01)

by Chris Peterson » Tue Jul 02, 2024 2:07 am

johnnydeep wrote: Mon Jul 01, 2024 11:04 pm
Chris Peterson wrote: Mon Jul 01, 2024 6:15 pm
johnnydeep wrote: Mon Jul 01, 2024 5:56 pm

Sure, but it must be possible to compare the two opposing forces operating between my two protons. But I suppose in retrospect, that in isolated space, it would take much more than a 1 meter spatial separation for dark energy to overcome the mutual attraction between them. I'm still interested in the quantities though.
Well, to further complicate things, the "force" of gravity is the product of a distortion of spacetime created by mass. That makes two masses want to "fall" towards each other. But dark energy isn't a distortion, because it is uniform. It doesn't care about mass (so it isn't like anti-gravity). It is just a steady expansive pull on all of spacetime. But spacetime can't expand against strong gravitational attraction (which is why galaxies and galaxy clusters are not getting larger or separating). Spacetime is held together locally by gravity. The gravitational attraction of a couple of protons (lets make them neutrons, okay... don't need to add EM forces to this problem) is extremely small, so if you could somehow get those particles isolated enough (or just take it as a thought experiment where they are the only things in the Universe), there will be some distance where dark energy dominates gravity. I wouldn't be surprised if it was a very small distance. But I don't know.
(Yeah, neutrons, except isolated neutrons are unstable. But I guess that doesn't matter for this thought experiment.)

I'm surprised you'd think that (in blue). But surely, this should be calculable based on the Hubble constant?

And one more thought: if dark energy content depends on the "amount" of space, what about when space is compressed in a black hole - does that concentrate the dark energy and result in a greater repulsive force?
I don't think it involves the Hubble constant. It involves some kind of calculation of energy density. And we don't have any physics that describes what happens "inside" a black hole. So who knows?

Re: APOD: Time Spiral (2024 Jul 01)

by johnnydeep » Mon Jul 01, 2024 11:04 pm

Chris Peterson wrote: Mon Jul 01, 2024 6:15 pm
johnnydeep wrote: Mon Jul 01, 2024 5:56 pm
Chris Peterson wrote: Mon Jul 01, 2024 5:48 pm
"Stronger" and "weaker" is probably not the best way to think of it. The force of gravity falls of with distance, while the force of dark energy, while very small, is uniform across all of space. So it dominates when space is nearly empty of mass, which only occurs over cosmological distances.
Sure, but it must be possible to compare the two opposing forces operating between my two protons. But I suppose in retrospect, that in isolated space, it would take much more than a 1 meter spatial separation for dark energy to overcome the mutual attraction between them. I'm still interested in the quantities though.
Well, to further complicate things, the "force" of gravity is the product of a distortion of spacetime created by mass. That makes two masses want to "fall" towards each other. But dark energy isn't a distortion, because it is uniform. It doesn't care about mass (so it isn't like anti-gravity). It is just a steady expansive pull on all of spacetime. But spacetime can't expand against strong gravitational attraction (which is why galaxies and galaxy clusters are not getting larger or separating). Spacetime is held together locally by gravity. The gravitational attraction of a couple of protons (lets make them neutrons, okay... don't need to add EM forces to this problem) is extremely small, so if you could somehow get those particles isolated enough (or just take it as a thought experiment where they are the only things in the Universe), there will be some distance where dark energy dominates gravity. I wouldn't be surprised if it was a very small distance. But I don't know.
(Yeah, neutrons, except isolated neutrons are unstable. But I guess that doesn't matter for this thought experiment.)

I'm surprised you'd think that (in blue). But surely, this should be calculable based on the Hubble constant?

And one more thought: if dark energy content depends on the "amount" of space, what about when space is compressed in a black hole - does that concentrate the dark energy and result in a greater repulsive force?

Re: APOD: Time Spiral (2024 Jul 01)

by Chris Peterson » Mon Jul 01, 2024 6:15 pm

johnnydeep wrote: Mon Jul 01, 2024 5:56 pm
Chris Peterson wrote: Mon Jul 01, 2024 5:48 pm
johnnydeep wrote: Mon Jul 01, 2024 5:31 pm

So this question just occurred to me: how much weaker (or stronger) is dark energy compared to gravity? Say, given two protons separated by a meter, how does their mutual attraction due to gravity compare to the dark energy expansion force due to the spatial separation between them?
"Stronger" and "weaker" is probably not the best way to think of it. The force of gravity falls of with distance, while the force of dark energy, while very small, is uniform across all of space. So it dominates when space is nearly empty of mass, which only occurs over cosmological distances.
Sure, but it must be possible to compare the two opposing forces operating between my two protons. But I suppose in retrospect, that in isolated space, it would take much more than a 1 meter spatial separation for dark energy to overcome the mutual attraction between them. I'm still interested in the quantities though.
Well, to further complicate things, the "force" of gravity is the product of a distortion of spacetime created by mass. That makes two masses want to "fall" towards each other. But dark energy isn't a distortion, because it is uniform. It doesn't care about mass (so it isn't like anti-gravity). It is just a steady expansive pull on all of spacetime. But spacetime can't expand against strong gravitational attraction (which is why galaxies and galaxy clusters are not getting larger or separating). Spacetime is held together locally by gravity. The gravitational attraction of a couple of protons (lets make them neutrons, okay... don't need to add EM forces to this problem) is extremely small, so if you could somehow get those particles isolated enough (or just take it as a thought experiment where they are the only things in the Universe), there will be some distance where dark energy dominates gravity. I wouldn't be surprised if it was a very small distance. But I don't know.

Re: APOD: Time Spiral (2024 Jul 01)

by johnnydeep » Mon Jul 01, 2024 5:56 pm

Chris Peterson wrote: Mon Jul 01, 2024 5:48 pm
johnnydeep wrote: Mon Jul 01, 2024 5:31 pm
Chris Peterson wrote: Mon Jul 01, 2024 5:18 pm

This is the point where the expansion rate of the Universe transitioned from slowing to speeding up. Where the "force" of dark energy became greater than the "force" of gravity.
So this question just occurred to me: how much weaker (or stronger) is dark energy compared to gravity? Say, given two protons separated by a meter, how does their mutual attraction due to gravity compare to the dark energy expansion force due to the spatial separation between them?
"Stronger" and "weaker" is probably not the best way to think of it. The force of gravity falls of with distance, while the force of dark energy, while very small, is uniform across all of space. So it dominates when space is nearly empty of mass, which only occurs over cosmological distances.
Sure, but it must be possible to compare the two opposing forces operating between my two protons. But I suppose in retrospect, that in isolated space, it would take much more than a 1 meter spatial separation for dark energy to overcome the mutual attraction between them. I'm still interested in the quantities though.

Re: APOD: Time Spiral (2024 Jul 01)

by Chris Peterson » Mon Jul 01, 2024 5:48 pm

johnnydeep wrote: Mon Jul 01, 2024 5:31 pm
Chris Peterson wrote: Mon Jul 01, 2024 5:18 pm
zendae wrote: Mon Jul 01, 2024 5:06 pm "Dark energy overtakes gravity."

Is this because gravity was universally weak at this stage due to less matter? I am not sure what exactly this statement really implies. What would be the difference between the Universe with no dark energy and the Universe after dark energy "overtook" gravity? I know that gravity is far, far, far weaker than the strong force, yet virtually nothing - perhaps absolutely nothing - overtakes gravity at a certain point. The term "overtakes" in the quote has me.
This is the point where the expansion rate of the Universe transitioned from slowing to speeding up. Where the "force" of dark energy became greater than the "force" of gravity.
So this question just occurred to me: how much weaker (or stronger) is dark energy compared to gravity? Say, given two protons separated by a meter, how does their mutual attraction due to gravity compare to the dark energy expansion force due to the spatial separation between them?
"Stronger" and "weaker" is probably not the best way to think of it. The force of gravity falls of with distance, while the force of dark energy, while very small, is uniform across all of space. So it dominates when space is nearly empty of mass, which only occurs over cosmological distances.

Re: APOD: Time Spiral (2024 Jul 01)

by AVAO » Mon Jul 01, 2024 5:39 pm

ww1y wrote: Mon Jul 01, 2024 2:43 pm "Within a few billion years, atoms formed," while technically correct, is somewhat misleading. Unless JADES-GS-z14-0 is made up of something other than atoms?

Pablo Carlos Budassi created this image for Wikimedia.org in 2020, i.e. "long" before WEBB started its work.

Nevertheless, your criticism is justified and worth discussing. The poster shows very well what challenges WEBB's latest findings pose for the cosmological standard model that has been established for almost 100 years.


Let's look at the APOD from June 24, 2024 ( https://apod.nasa.gov/apod/ap240624.html ).
"Pictured in the inset box is JADES-GS-z14-0, a faint smudge of a galaxy that formed only 300 million years after the universe started."


Well, even if new scientific facts challenge older models, these older models should be retained until they can be replaced by improved or alternative explanatory models.

Re: APOD: Time Spiral (2024 Jul 01)

by johnnydeep » Mon Jul 01, 2024 5:31 pm

Chris Peterson wrote: Mon Jul 01, 2024 5:18 pm
zendae wrote: Mon Jul 01, 2024 5:06 pm "Dark energy overtakes gravity."

Is this because gravity was universally weak at this stage due to less matter? I am not sure what exactly this statement really implies. What would be the difference between the Universe with no dark energy and the Universe after dark energy "overtook" gravity? I know that gravity is far, far, far weaker than the strong force, yet virtually nothing - perhaps absolutely nothing - overtakes gravity at a certain point. The term "overtakes" in the quote has me.
This is the point where the expansion rate of the Universe transitioned from slowing to speeding up. Where the "force" of dark energy became greater than the "force" of gravity.
So this question just occurred to me: how much weaker (or stronger) is dark energy compared to gravity? Say, given two protons separated by a meter, how does their mutual attraction due to gravity compare to the dark energy expansion force due to the spatial separation between them?

Re: APOD: Time Spiral (2024 Jul 01)

by zendae » Mon Jul 01, 2024 5:20 pm

Thanks Chris. I expanded my question, but it wasn't necessary.

Re: APOD: Time Spiral (2024 Jul 01)

by Chris Peterson » Mon Jul 01, 2024 5:18 pm

zendae wrote: Mon Jul 01, 2024 5:06 pm "Dark energy overtakes gravity."

Is this because gravity was universally weak at this stage due to less matter? I am not sure what exactly this statement really implies. What would be the difference between the Universe with no dark energy and the Universe after dark energy "overtook" gravity? I know that gravity is far, far, far weaker than the strong force, yet virtually nothing - perhaps absolutely nothing - overtakes gravity at a certain point. The term "overtakes" in the quote has me.
This is the point where the expansion rate of the Universe transitioned from slowing to speeding up. Where the "force" of dark energy became greater than the "force" of gravity.

Re: APOD: Time Spiral (2024 Jul 01)

by zendae » Mon Jul 01, 2024 5:06 pm

"Dark energy overtakes gravity."

Is this because gravity was universally weak at this stage due to less matter? I am not sure what exactly this statement really implies. What would be the difference between the Universe with no dark energy and the Universe after dark energy "overtook" gravity? I know that gravity is far, far, far weaker than the strong force, yet virtually nothing - perhaps absolutely nothing - overtakes gravity at a certain point. Yet do we even know why gravity has any power at all? I can defeat gravity by picking up a feather off the ground. Seemingly nothing defeats gravity at or beyond an event horizon. But even those two examples are local ones. A universal "overtaking" means what?
The term "overtakes" in the quote has me.

Re: APOD: Time Spiral (2024 Jul 01)

by johnnydeep » Mon Jul 01, 2024 4:35 pm

Chris Peterson wrote: Mon Jul 01, 2024 4:31 pm
johnnydeep wrote: Mon Jul 01, 2024 4:27 pm
Chris Peterson wrote: Mon Jul 01, 2024 4:24 pm
Electromagnetic radiation isn't the only medium we have for observation. Gravity waves (which we are increasingly able to detect) might provide a way of looking at the Universe during a time when it was optically opaque.
Ok, thanks. I always seem to forget about gravitational waves (note: not gravity waves which are about fluid dynamics).
Yes, gravitational waves. Who knows with what resolution and sensitivity we'll eventually be able to measure them, even to image with them. And I wonder about particles like neutrinos or dark matter, which might be unaffected by passing through neutral hydrogen. Lacking the technology, at the moment, to observe the dark ages doesn't mean they aren't observable.
✔️

Re: APOD: Time Spiral (2024 Jul 01)

by Chris Peterson » Mon Jul 01, 2024 4:31 pm

johnnydeep wrote: Mon Jul 01, 2024 4:27 pm
Chris Peterson wrote: Mon Jul 01, 2024 4:24 pm
johnnydeep wrote: Mon Jul 01, 2024 4:22 pm

What do you mean by being "in principle observable"? (assuming the "dark ages" was the period of time from the BB to about 380,000 years when photons were freed to travel)
Electromagnetic radiation isn't the only medium we have for observation. Gravity waves (which we are increasingly able to detect) might provide a way of looking at the Universe during a time when it was optically opaque.
Ok, thanks. I always seem to forget about gravitational waves (note: not gravity waves which are about fluid dynamics).
Yes, gravitational waves. Who knows with what resolution and sensitivity we'll eventually be able to measure them, even to image with them. And I wonder about particles like neutrinos or dark matter, which might be unaffected by passing through neutral hydrogen. Lacking the technology, at the moment, to observe the dark ages doesn't mean they aren't observable.

Re: APOD: Time Spiral (2024 Jul 01)

by johnnydeep » Mon Jul 01, 2024 4:27 pm

Chris Peterson wrote: Mon Jul 01, 2024 4:24 pm
johnnydeep wrote: Mon Jul 01, 2024 4:22 pm
Chris Peterson wrote: Mon Jul 01, 2024 3:41 pm
The Big Bang is not a hypothesis, it is a theory, and one which is well supported by multiple independent lines of objective evidence. The existence of inflation is similarly well supported, and doesn't violate any physical principles. We observe the CMB (which I assume is what you mean), and while we can't observe the "dark ages" in the electromagnetic spectrum, it is in principle observable. Our understanding of the formation of stars and galaxies is unlikely to be "wrong", simply incomplete.

...
What do you mean by being "in principle observable"? (assuming the "dark ages" was the period of time from the BB to about 380,000 years when photons were freed to travel)
Electromagnetic radiation isn't the only medium we have for observation. Gravity waves (which we are increasingly able to detect) might provide a way of looking at the Universe during a time when it was optically opaque.
Ok, thanks. I always seem to forget about gravitational waves (note: not gravity waves which are about fluid dynamics).

Re: APOD: Time Spiral (2024 Jul 01)

by Chris Peterson » Mon Jul 01, 2024 4:24 pm

johnnydeep wrote: Mon Jul 01, 2024 4:22 pm
Chris Peterson wrote: Mon Jul 01, 2024 3:41 pm
Syringa vulgaris wrote: Mon Jul 01, 2024 3:36 pm Really, now?

We don't know if there was a big bang, it is a hypothesis without any evidence to support it.

We have no idea what is this "inflation", except we know it must have violated all assumptions that are the foundation of modern physics.

We have no idea how things were in the part that says "SMB" and "dark ages".

Our current beliefs about the timeline of the appearance of stars and galaxies, the very first thing we can actually measure, appear to be very wrong.

Most of the remaining "spiral" (the outer 3 rings or so) is concerned with very local phenomena compared to what we believe is the size of the visible Universe.

And even there we can't see 80% of the phenomenon that acts on the visible stuff through gravity.

But yeah, let's pretend we can answer a question like "What's happened since the universe started?".

We can hypothesize, and make some claims about a small part of the Universe, but that's about all.

We know a few things, but let's not pretend a whole lot is set in stone.
The Big Bang is not a hypothesis, it is a theory, and one which is well supported by multiple independent lines of objective evidence. The existence of inflation is similarly well supported, and doesn't violate any physical principles. We observe the CMB (which I assume is what you mean), and while we can't observe the "dark ages" in the electromagnetic spectrum, it is in principle observable. Our understanding of the formation of stars and galaxies is unlikely to be "wrong", simply incomplete.

...
What do you mean by being "in principle observable"? (assuming the "dark ages" was the period of time from the BB to about 380,000 years when photons were freed to travel)
Electromagnetic radiation isn't the only medium we have for observation. Gravity waves (which we are increasingly able to detect) might provide a way of looking at the Universe during a time when it was optically opaque.

Re: APOD: Time Spiral (2024 Jul 01)

by johnnydeep » Mon Jul 01, 2024 4:22 pm

Chris Peterson wrote: Mon Jul 01, 2024 3:41 pm
Syringa vulgaris wrote: Mon Jul 01, 2024 3:36 pm Really, now?

We don't know if there was a big bang, it is a hypothesis without any evidence to support it.

We have no idea what is this "inflation", except we know it must have violated all assumptions that are the foundation of modern physics.

We have no idea how things were in the part that says "SMB" and "dark ages".

Our current beliefs about the timeline of the appearance of stars and galaxies, the very first thing we can actually measure, appear to be very wrong.

Most of the remaining "spiral" (the outer 3 rings or so) is concerned with very local phenomena compared to what we believe is the size of the visible Universe.

And even there we can't see 80% of the phenomenon that acts on the visible stuff through gravity.

But yeah, let's pretend we can answer a question like "What's happened since the universe started?".

We can hypothesize, and make some claims about a small part of the Universe, but that's about all.

We know a few things, but let's not pretend a whole lot is set in stone.
The Big Bang is not a hypothesis, it is a theory, and one which is well supported by multiple independent lines of objective evidence. The existence of inflation is similarly well supported, and doesn't violate any physical principles. We observe the CMB (which I assume is what you mean), and while we can't observe the "dark ages" in the electromagnetic spectrum, it is in principle observable. Our understanding of the formation of stars and galaxies is unlikely to be "wrong", simply incomplete.

...
What do you mean by being "in principle observable"? (assuming the "dark ages" was the period of time from the BB to about 380,000 years when photons were freed to travel)

Re: APOD: Time Spiral (2024 Jul 01)

by Chris Peterson » Mon Jul 01, 2024 3:41 pm

Syringa vulgaris wrote: Mon Jul 01, 2024 3:36 pm Really, now?

We don't know if there was a big bang, it is a hypothesis without any evidence to support it.

We have no idea what is this "inflation", except we know it must have violated all assumptions that are the foundation of modern physics.

We have no idea how things were in the part that says "SMB" and "dark ages".

Our current beliefs about the timeline of the appearance of stars and galaxies, the very first thing we can actually measure, appear to be very wrong.

Most of the remaining "spiral" (the outer 3 rings or so) is concerned with very local phenomena compared to what we believe is the size of the visible Universe.

And even there we can't see 80% of the phenomenon that acts on the visible stuff through gravity.

But yeah, let's pretend we can answer a question like "What's happened since the universe started?".

We can hypothesize, and make some claims about a small part of the Universe, but that's about all.

We know a few things, but let's not pretend a whole lot is set in stone.
The Big Bang is not a hypothesis, it is a theory, and one which is well supported by multiple independent lines of objective evidence. The existence of inflation is similarly well supported, and doesn't violate any physical principles. We observe the CMB (which I assume is what you mean), and while we can't observe the "dark ages" in the electromagnetic spectrum, it is in principle observable. Our understanding of the formation of stars and galaxies is unlikely to be "wrong", simply incomplete.

I don't think you understand science very well.

Re: APOD: Time Spiral (2024 Jul 01)

by Syringa vulgaris » Mon Jul 01, 2024 3:36 pm

Really, now?

We don't know if there was a big bang, it is a hypothesis without any evidence to support it.

We have no idea what is this "inflation", except we know it must have violated all assumptions that are the foundation of modern physics.

We have no idea how things were in the part that says "SMB" and "dark ages".

Our current beliefs about the timeline of the appearance of stars and galaxies, the very first thing we can actually measure, appear to be very wrong.

Most of the remaining "spiral" (the outer 3 rings or so) is concerned with very local phenomena compared to what we believe is the size of the visible Universe.

And even there we can't see 80% of the phenomenon that acts on the visible stuff through gravity.

But yeah, let's pretend we can answer a question like "What's happened since the universe started?".

We can hypothesize, and make some claims about a small part of the Universe, but that's about all.

We know a few things, but let's not pretend a whole lot is set in stone.

Top