Cosmology and the mediocrity principle

[otseng]

The mediocrity principle is the philosophical notion that "if an item is drawn at random from one of several sets or categories, it's likelier to come from the most numerous category than from any one of the less numerous categories" (Kukla 2009).[1] The principle has been taken to suggest that there is nothing very unusual about the evolution of the Solar System, the Earth, humans, or any one nation. It is a heuristic in the vein of the Copernican principle, and is sometimes used as a philosophical statement about the place of humanity. The idea is to assume mediocrity, rather than starting with the assumption that a phenomenon is special, privileged or exceptional.[2][3]

http://en.wikipedia.org/wiki/Mediocrity_principle

Current cosmology assumes that the mediocrity principle is true. Our solar system, the earth, and humans are not special. But, is this assumption true? Why or why not?

[otseng]

Not all flat universes are Euclidean.

Could you give an example of this?

I'm just reporting what I learned from the wikipedia "shape of the universe" page:

I would disagree that the 3-Torus universe is actually flat. It can perhaps be locally flat, but it would not be universally flat. If we're just considering something to be locally flat, pretty much any topology can then be posited.

Indeed, the answer remains inscrutable. At least from measurement alone.

I don't know about "inscrutable." We can at least make tentative conclusions based on the evidence that we currently have.

You're assuming the earth wouldn't also be moving in accordance to its non-central location. Sure, things from the center would be moving towards us, but we'd be moving away from them yet faster. This would give the appearance that they are moving away from us. The net result would be exactly what we observe.

Why would we be going yet faster? What would be causing everything to constantly accelerate?

Also, things on the other side of the center would be moving much faster away from us.

[FarWanderer]

Not all flat universes are Euclidean.

Could you give an example of this?

I'm just reporting what I learned from the wikipedia "shape of the universe" page:

I would disagree that the 3-Torus universe is actually flat. It can perhaps be locally flat, but it would not be universally flat. If we're just considering something to be locally flat, pretty much any topology can then be posited.

I wouldn't know. Wikipedia doesn't always clarify what kind of flatness it's talking about.

But the important point is that there exists one or more other models besides simple Euclidean space that are in perfect concordance with our observations.

Indeed, the answer remains inscrutable. At least from measurement alone.

I don't know about "inscrutable." We can at least make tentative conclusions based on the evidence that we currently have.

On what basis of expectation? It's not like we've seen or measured any other universes.

You're assuming the earth wouldn't also be moving in accordance to its non-central location. Sure, things from the center would be moving towards us, but we'd be moving away from them yet faster. This would give the appearance that they are moving away from us. The net result would be exactly what we observe.

Why would we be going yet faster? What would be causing everything to constantly accelerate?

It's not a matter of the cause. It's a matter of the observation. Everything appears to be moving away from us at a speed proportional to its distance from us.

My point is that this is possible in all kinds of universes, even ones with a center which is not Earth.

----------------

I'd like to remind you that I've asked for justification for why you take science as authoritative in the universe's origin, yet dismissive of it when it comes to the relative ages of celestial bodies. That's all this is about to me.

I don't have much interest debating the mediocrity principle, but I'd like to hear you explain why you think colonists building houses is analogous to how the universe expands to form stars. Do you think matter cannot form into stars while it's venturing away from a hypothetical center?

[otseng]

And it would clearly be wrong too. So obviously the lack of evidence we currently have is meaningless in terms of jumping to any conclusions at this time.

It would be a farce to use that information as an argument that there are not likely to be any fish in the ocean. And in precisely the same way, it's a farce to use our current "lack of evidence" as an argument that there isn't likely to be any life elsewhere in the universe.

This is why I say that it's a "dishonest" argument.

If this is true, then I can use your exact same argument to refute atheist claims about God. Atheists claim there is zero evidence for God. I can just then reply that it is a dishonest argument because they have not looked everywhere for God. Not only have we not looked everywhere in our universe for God, we have not looked everywhere outside our universe for God. The "lack of evidence" for God doesn't in any way show that God does not exist. As a matter of fact, since we have absolutely no idea how big all of reality actually is, God is sure to exist somewhere out there, esp if it is outside our universe. So, likewise, any atheistic argument that there is no evidence for God is a "dishonest" argument.

[otseng]

But the important point is that there exists one or more other models besides simple Euclidean space that are in perfect concordance with our observations.

Yes, I can think of another flat model that is not Euclidean also. But, the most simple and intuitively obvious is a flat Euclidean space.

It's not like we've seen or measured any other universes.

Right.

Everything appears to be moving away from us at a speed proportional to its distance from us.

Right. There's only two possible explanations. If the universe is non-Euclidean or the universe is Euclidean and we're at the center.

I'd like to remind you that I've asked for justification for why you take science as authoritative in the universe's origin, yet dismissive of it when it comes to the relative ages of celestial bodies. That's all this is about to me.

It all depends on what assumptions you start with. Different assumptions will lead to different conclusions. That is why I brought up the assumption of the mediocrity principle. If it's true, then it leads to one path. If it's false, then it leads to another.

I don't have much interest debating the mediocrity principle

It is a foundational assumption. This really is the whole crux of the debate.

but I'd like to hear you explain why you think colonists building houses is analogous to how the universe expands to form stars. Do you think matter cannot form into stars while it's venturing away from a hypothetical center?

Interstellar molecular material will need to first coalesce within its own gravitational field to form a solar system. The material at the center will not be rapidly moving so it can immediately coalesce. Material moving away from the center (most likely at high speeds), will not immediately be able to coalesce into a solar system.

Also, considering the distances involved, it would take light time to travel from the stars to the center of the universe. The closest star to us, Proxima Centauri, even if it formed at the exact same time as our sun, would take over 4 years for us to see it.

[scourge99]

What exactly in cosmology assumes the mediocrity principle?

I already stated it in post 4.

In post 4 you don't make any statements explaining what in cosmology assumes or relies on the mediocrity principle. You say and imply that some aspects of physics do but provide zero examples. You reference the copernican principle and the cosmological principle but fail to point out any part of physics that relies on these.

It seems you also try to move the goal posts by equating the mediocrity principle with the copernican principle and the cosmological principle.

I'm still waiting for you to explain what theories in physics are dependent in the mediocrity principle.

What scientific theories would change if the mediocrity principle was neither rejected or accepted?

That's a good question. And there's a lot to cover there.

What scientific theories would change or need reconsidering if the mediocrity principle was neither rejected or accepted?

It seems like you are attempting to shift the burden of proof. You make the vague claim that cosmology relies on the mediocrity principle (without showing how) then demand that scientists must disprove that the universe/solar system/earth/humans are special OR that scientists must prove the mediocrity principle without explaining why.

It's not a vague claim. Please read through the links I provided above about the Copernican principle and the Cosmological principle.

I'm not stating that cosmologists must prove the mediocrity principle. I actually agree that it's not provable. But, I do make the claim that the evidence points against the principle being true.

Then PROVE (make a strong argument with evidence based reasoning) that we are at the center or "special". Trying to shift the burden of proof doesn't help the case for theism one bit anymore than disproving or casting doubt on evolution proves theistic creationism.

It seems what's actually going on here is that certain theists are unwilling or unable to make a valid argument about how the universe/solar system/earth/humans is "special" so as to imply a theistic god so they try to shift the burden of proof onto others for their failure.

If you would read through the links, I trust you will then retract this statement.

Quite the opposite. You are a theist trying to make a case for a theistic god. But you don't seem to understand that casting doubt or rejecting the "mediocrity principle" doesn't get you any closer to demonstrating a theistic god. Its similar to how some theists try to poke holes in evolution thinking that it helps their case for a theistic god. It doesn't. Even if evolution were proven false, that doesn't help support the case for theism. You still have to make the argument for a theistic god creating life and humans.


Lastly, I think this focus on the mediocrity principle is largely irrelevant when we look at the big picture. I know of NO ONE who accepts or rejects theism because of some technicalities regarding some obscure argument about cosmology. As Sean Carroll has said " nobody really becomes a believer in God because it provides the best cosmology. They become theists for other reasons, and the cosmology comes later. That’s because religion is enormously more than theism. Most people become religious for other (non-epistemic) reasons: it provides meaning and purpose, or a sense of community, or a way to be in contact with something transcendent, or simply because it’s an important part of their culture. 

In other words, if the mediocrity principle was true or likely true, you wouldn't have serious doubts about theism. You might have to adjust some of your beliefs, but it wouldn't destroy theism. And if the mediocrity principle was proven false, I doubt anyone would think it is a strong argument for theism.

[otseng]

What scientific theories would change or need reconsidering if the mediocrity principle was neither rejected or accepted?

We're discussing several right now.

One is whether the universe is Euclidean or non-Euclidean. Prior to measurements being made that determined the universe to be flat, it was assumed to be non-Euclidean. Now, evidence points to it being Euclidean.

Another is why people believe aliens exist. There is no evidence of ETs actually existing (though I realize Divine Insight disagrees with this). The only reason people would believe they exist is because of the principle of mediocrity.

Another thing that would change if the mediocrity principle is wrong is inflationary theory.

"Many physicists also believe that inflation explains why the Universe appears to be the same in all directions (isotropic), why the cosmic microwave background radiation is distributed evenly, why the universe is flat, and why no magnetic monopoles have been observed."
http://en.wikipedia.org/wiki/Inflation_(cosmology)

Inflationary theory did not result from actual evidence that the universe underwent a brief period of hyperexpansion, but was theorized to account for things such as isotropy and homogeneity, which are assumptions of the cosmological principle.

[otseng]

And if the mediocrity principle was proven false, I doubt anyone would think it is a strong argument for theism.

Suppose that the Earth is special and unique. We are the only life in the entire universe. We are located at the center of the universe. Do you still think it would not be evidence for Theism?

[Divine Insight]

And it would clearly be wrong too. So obviously the lack of evidence we currently have is meaningless in terms of jumping to any conclusions at this time.

It would be a farce to use that information as an argument that there are not likely to be any fish in the ocean. And in precisely the same way, it's a farce to use our current "lack of evidence" as an argument that there isn't likely to be any life elsewhere in the universe.

This is why I say that it's a "dishonest" argument.

If this is true, then I can use your exact same argument to refute atheist claims about God. Atheists claim there is zero evidence for God. I can just then reply that it is a dishonest argument because they have not looked everywhere for God.

No you can't use that same argument, but I knew that you would try. What atheists deny are the religious claims that can be shown to have no evidence to support them. Prayer has been shown to not work in any measurable way. Even highly dedicated religious believers have confessed to the fact that their religions and gods have not kept the promises made in the doctrines. Mother Teresa comes to mind as prime example, but there are many others, and I would even include myself as a living example of proof that there is no evidence for the biblical God because if the Bible were true I should have clearly seen evidence which I have not seen.

That's evidence that should have been easily observed but simply doesn't exist.

Not only have we not looked everywhere in our universe for God, we have not looked everywhere outside our universe for God. The "lack of evidence" for God doesn't in any way show that God does not exist.

The lack of evidence for the Biblical God does indeed show that the Biblical dogma at least is false. If there exists a "God" it's not describe by the Bible verbatim to be certain. We can know that with 100% confidence.

As a matter of fact, since we have absolutely no idea how big all of reality actually is, God is sure to exist somewhere out there, esp if it is outside our universe. So, likewise, any atheistic argument that there is no evidence for God is a "dishonest" argument.

Not if they are specifically referring to the God described verbatim by Hebrew mythology.

But yes, if they are trying to claim that no possible concept of "god" in general can exist, then I agree with you that they are over-stepping their bounds.

I don't deny the possibility of a "god" in the general abstract sense. In fact, as many people have pointed out many times on these forums, the very term "god" is meaningless until it has been defined in enough detail to actually state what it is supposed to be.

So basically the term "god" is a meaningless term unless you define it before you use it.

Put a capital "G" on it and claim that it's the God described verbatim by the Hebrew mythological Biblical canon, and I can assure you with 100% confidence that it most certainly does not exist.

Refuse to accept the verbatim Hebrew description of 'God' and then we're back to square one again because as soon as you do that then I have no clue what you even mean by 'God'.

Also if you reject the Hebrew God verbatim, then as far as I'm concerned you're already in agreement with me. And if you demand that God is describe by Hebrew mythology verbatim, then I feel that I've already proven that that picture of God cannot possible exist because it's a self-contradicting oxymoron. And the evidence for that is quite clear right in the Hebrew mythology itself, IMHO.

No need to even look outside of the Bible to know that the Hebrew mythology is clearly false. Searching the universe or beyond for the Hebrew verbatim God would be an exercise in futility.

[Divine Insight]

And if the mediocrity principle was proven false, I doubt anyone would think it is a strong argument for theism.

Suppose that the Earth is special and unique. We are the only life in the entire universe. We are located at the center of the universe. Do you still think it would not be evidence for Theism?

Evidence for which Theism?

All it would be is evidence that we're special. But that certainly wouldn't point to Hebrew mythology as being special.

Also, why even speculate about such a thing? There is no evidence whatsoever that the Earth is special. At best all it could be is wishful thinking. By why bother with all that? You can imagine that life is spiritual without placing the earth and humans at the center of it all.

I'm sure that this is not the least bit important. If we had actually discovered a whole civilization on Mars that wouldn't have phased religious fanatics anyway. They would have just tried to preach the Gospel to Martians.

In fact, if aliens should happen to show up even from a far off planet or just pop in from another dimension of spacetime I can guarantee you that religious fanatics would either being trying to peach the Gospel to them or they would instantly proclaim that they are demons under the rule of Satan.

People don't need to have an evidence to hold these beliefs. They will continue to hold these beliefs no matter what evidence they might see to the contrary.

Personally I think Buddhism and Taoism have a far better chance of being true than the egotistical Godheads of religions like Greek or Hebrew mythologies.

If Buddhism and Taoism are true, then humans are not special at all. The only thing that is special is consciousness and any conscious being is then special and that even includes non-sentient animals.

The egotistical religions like Greek and Hebrew mythologies are just extreme human egotism. This is just a case where humans are dead set on trying to be extra special. But let's face it, even many of them believe that they will see their pets in heaven again.

They would be very upset to find out that their pets were just empty soulless biological robots. People who love their pets should convert to Buddhism.

[FarWanderer]

But the important point is that there exists one or more other models besides simple Euclidean space that are in perfect concordance with our observations.

Yes, I can think of another flat model that is not Euclidean also. But, the most simple and intuitively obvious is a flat Euclidean space.

Not everyone thinks that. Flat Euclidean space implies infinite extension, and quite a few people would have serious intuitive problems with that.

That being said, it's also hard for me to conceive of anything of infinite extension having a center.

Everything appears to be moving away from us at a speed proportional to its distance from us.

Right. There's only two possible explanations. If the universe is non-Euclidean or the universe is Euclidean and we're at the center.

Nonsense.

Take any Euclidean entity (with or without a center) in 1, 2, or 3 dimensnions and envision it evenly enlarging itself at a certain rate. From the vantage of any point within the entity, everything else of that entity will be moving away from the point at a speed in proportion to its distance.

Jashwell's link in post 11 demonstrates this clearly (in 2 dimensions).

I'd like to remind you that I've asked for justification for why you take science as authoritative in the universe's origin, yet dismissive of it when it comes to the relative ages of celestial bodies. That's all this is about to me.

It all depends on what assumptions you start with. Different assumptions will lead to different conclusions. That is why I brought up the assumption of the mediocrity principle. If it's true, then it leads to one path. If it's false, then it leads to another

I don't have much interest debating the mediocrity principle

It is a foundational assumption. This really is the whole crux of the debate.

but I'd like to hear you explain why you think colonists building houses is analogous to how the universe expands to form stars. Do you think matter cannot form into stars while it's venturing away from a hypothetical center?

Interstellar molecular material will need to first coalesce within its own gravitational field to form a solar system. The material at the center will not be rapidly moving so it can immediately coalesce. Material moving away from the center (most likely at high speeds), will not immediately be able to coalesce into a solar system.

Why not? How does this movement inhibit gravitational coalescence?

Also, considering the distances involved, it would take light time to travel from the stars to the center of the universe. The closest star to us, Proxima Centauri, even if it formed at the exact same time as our sun, would take over 4 years for us to see it.

This is an entirely different arguement from the mediocrity principle.

Even allowing this invented loophole (that stars don't count as "created" until their light reaches Earth), current scientific calculations indicate that there are quiiiiite a few stars older than Earth by a lot more than the time it would take for their light to reach us.

And four years is the kind of value that's well off the roster of significant digits when it comes to measuring the time it takes for stars to form. It's equal to zero for all practical purposes.