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Our planet is among the first of many, many Earths.


tar

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Saw this article on the web today.

 

http://www.msn.com/en-us/news/technology/our-planet-is-among-the-first-of-many-many-earths/ar-BBmzHNh?ocid=spartandhp

 

From what vantage point are statements like this made?

For instance, if the en​tire universe is currently 13.8 billion years old, then Earths that developed at the 13.8 billion year mark are already "present". Which would make another Earth like planet, that is sitting on the other side of the Milky Way hundreds of thousands of years older than it looks, and would make the status of halos of dark matter around a distant galaxy 100 million lys from here, rather old news. The "Earths" that are about to develop there and now as far as we can see, developed when the universe was 13.7 billion years old. Which would make that Earth first, not this o ne.

 

So​ when ordering events in the universe, do we go by what we see, or by what we know has to be the case?

 

From what vantage point are statements like "Our planet is among the first of many, many Earths​" made?

 

Wh​at are we considering first and later, and who is going to be around to verify that the ordering was correctly characterized?

 

TAR​

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I'm really not sure what you are saying (or asking).

 

The paper suggests that 80% of Earth-like planets formed before the Earth. But also that there is enough material around for star and planet formation to continue such that over 10 times more planets are likely to be created in future.

 

 

From what vantage point are statements like "Our planet is among the first of many, many Earths​" made?

 

It is a statistical argument based on the amount of material available, the rate at which stars and planets are thought to form, etc.

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Strange,

 

Well I suppose I took the 80 percent figure wrong. It would have been inconsistent with the title of the article to consider that 80 percent of Earth like planets had formed prior the Earth's formation. That would hardly make us the first Earth, more like the trillionth Earth or something. Besides the sentence with the 80 percent figure suggested that the new data contradicted the 80 percent idea.

 

But my question comes from the unreachable nature of the data we are using to make our probability curves in the first place.

 

Are we talking about extrapolating from what we see, or are we talking about extrapolating from what we imagine is out there?

 

I am always somewhat taken aback by statements that make no logical sense, when they are stated as fact, as things "we know" to be true, when they are built on conjecture and guesswork and imagination, and completely unknown and unseen things.

 

Like in the article where they state a number billions of trillions big, and follow it with the statement of fact that the universe is infinite.

 

Like talking about how many angels can fit on the head of pin.

 

Regards, TAR


And why stop at 10 times the number of planet already created. If the last star will not burn out for another trillion years that allows for a good number of generations of stars to be yet to inhabit the place, and any number of things to happen with dust and meteors and suns and dark matter and dark energy.

 

And why a trillion years? We only have 13.8 billion years of universe behavior to go on. If we are so early on in the process, it is very difficult to model the evolution of the place, which has not happened yet.

 

And the most important thing is that whatever happens does not happen everywhere at once. If the galaxy collapsed into a black hole, for instance, it would never be announced to places which had expanded "outside" the range to where the light from an event would ever reach it. That sort of assures that there can not be a date set at which the last star will burn out, because the light from that star will still be on its way out, and the light from every other star an infinite distance away will still be on its way in.

Edited by tar
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Well I suppose I took the 80 percent figure wrong. It would have been inconsistent with the title of the article to consider that 80 percent of Earth like planets had formed prior the Earth's formation. That would hardly make us the first Earth, more like the trillionth Earth or something. Besides the sentence with the 80 percent figure suggested that the new data contradicted the 80 percent idea.

 

I don't see the inconsistency. They estimate that we are in the last 20% of planets formed so far. But eventually, all the current planets will be in the first 10% of planets formed.

 

 

Are we talking about extrapolating from what we see, or are we talking about extrapolating from what we imagine is out there?

 

We can, obviously, only extrapolate from what we see. But it is a working assumption that the universe is roughly the same everywhere (because there is nothing to suggest it isn't) so we can, with some confidence, extrapolate beyond what we see.

 

 

I am always somewhat taken aback by statements that make no logical sense, when they are stated as fact, as things "we know" to be true, when they are built on conjecture and guesswork and imagination, and completely unknown and unseen things.

 

In my experience, that is a problem with journalism rather than science.

 

 

Like in the article where they state a number billions of trillions big, and follow it with the statement of fact that the universe is infinite.

 

I would be surprised if that was actually made as a statement of fact. But on the other hand, scientists are human and that may be what he believes. It is just as reasonable as believing it finite.

 

 

And why stop at 10 times the number of planet already created.

 

Because of the amount of material available for creating new stars and planets.

 

 

That sort of assures that there can not be a date set at which the last star will burn out, because the light from that star will still be on its way out, and the light from every other star an infinite distance away will still be on its way in.

 

The fact that there may be no one around to observe it (and if there were, they would not observe it for a very long time) doesn't mean you can't (in principle) calculate when it will happen.

By the way, if you want to look at the paper, it is available here: http://arxiv.org/abs/1508.01202(the link in the article is broken).

 

Nowhere do they say anything about the universe being finite or infinite.

 

They also do consider the increasing separation of galaxies:

 

as the Universe’s accelerating expansion is rapidly reducing the number of observable galaxies, most future planets formed in other galaxies will not be visible from the Milky Way.

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Strange,

 

Thank you for the link to the study.

 

I still am reading it though as if the extrapolation is done as if the current universe, within the hubble volume is all 13.8 billion years old, currently. This because the considerations include a formula that is a function of mass and cosmic time.

 

So if we are to be considered the first of 1 or 10 or 1000 intelligent civilizations, and at the same time to allow that 80 percent of the Earth like planets that are currently, in cosmic time, out there now formed prior the formation of the Earth, then any other planet within the 100% of Earthlike planets currently out there has an 8 out of 10 chance of being more advanced than us, in terms of the evolution of life, and possible intelligent life.

 

Which does not jive with the claim that we are likely to be the first. Out of 10 we are likely to be the 8th. Out of 1000 we are likely to be the 800th.

 

Regards, TAR


But my main consideration is that the place is so big and long lived, that even if there was a place on the other side of the Milky Way that was evolving in very similar fashion to the Earth and some civilization over there sent us a shout out, we would not hear the shout for 100,000 years, at which point their civilization would be 100,000 years more advanced then the shout we received as a 100,000 years more advanced civilization here.

 

So my problem is the use of the present tense, as if here is now and the rest of the universe is past, while at the same time sizing up the universe, as if the rest of the universe is currently present.

Edited by tar
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Which does not jive with the claim that we are likely to be the first. Out of 10 we are likely to be the 8th. Out of 1000 we are likely to be the 800th.

 

It doesn't say we are the first. We are among the first (in your example, we are no. 8 in the first 10).

 

 

But my main consideration is that the place is so big and long lived, that even if there was a place on the other side of the Milky Way that was evolving in very similar fashion to the Earth and some civilization over there sent us a shout out, we would not hear the shout for 100,000 years, at which point their civilization would be 100,000 years more advanced then the shout we received as a 100,000 years more advanced civilization here.

 

So what. This is not about when (or if) we hear from these advanced civilizations but about the number that might exist now, and the number that might exist in the future.

 

 

So my problem is the use of the present tense, as if here is now and the rest of the universe is past, while at the same time sizing up the universe, as if the rest of the universe is currently present.

 

The rest of the universe is currently present. You seem to back to a confusion between when you detect something and when it exists. If you get a postcard from someone on holiday, do you assume they are still in the same place as when they sent it? Even if they came back a few days ago and are standing next to you admiring the card, you assume they must still be in Baja because that is what the card says?

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Strange,

 

I am not confused by the rest of the universe being present well before we get the card. I am confused as to how people use the present tense. Like saying the universe is currently expanding at an accelerated pace.

 

You said yourself that we go by what we see. This is not what the universe is currently doing.

 

My question is, when a count is made, of existing planets, is that count made from a god's eye view, where every location in the universe is 13.8 billion years old?

 

So when it is supposed that we are among the first of a total of 10 existing and it is supposed that we are 8th out of the 10, then the two suppositions do not jive. To suppose we are among the first to evolve to intelligence in a universe that is 13.8 billion years old, and is scheduled to go on for another 600 billion at least, is quite simple to do, without any calculations at all.

 

Regards, TAR

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My question is, when a count is made, of existing planets, is that count made from a god's eye view, where every location in the universe is 13.8 billion years old?

 

Effectively, yes. Estimates like this are made based on observations of the number/density of stars, the rates at when they form, the rates at which they die, the number of planets per star, models for planetary formation given the amount of gas and different levels of metallicity, and so on.

 

These factors can be observed now (locally) and in the past (at a distance) and from that one can model what is happening now and what might happen in the future.

 

 

So when it is supposed that we are among the first of a total of 10 existing and it is supposed that we are 8th out of the 10, then the two suppositions do not jive.

 

But that isn't what they say. They are saying that we are currently 8th out of 10. In the future, when there are 10 times (or more) as many planets as now, we (and the others) will be the first ten out of 100.

 

 

To suppose we are among the first to evolve to intelligence in a universe that is 13.8 billion years old, and is scheduled to go on for another 600 billion at least, is quite simple to do, without any calculations at all.

 

And yet the paper is full of calculations supporting their argument. (I have no opinion on how valid their numbers or calculations are, but you can't deny their existence.)

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Strange,

 

Well I don't see how the paper has told us anything we could not have already guessed at.

 

And I don't see how it can nail down what the universe is going to do next.

 

We don't have any examples for instance of what the next generation of stars is going to look like, what the iron hydrogen ratio is going to be, and what size planets, with what characteristics the next generation of stars is going to spawn.

 

Plus we do not know what flavor soup the material currently in our solar system will turn into after self destruction of our sun. There might be some complex carbon chains that survive, that will influence the genesis of the next round of intelligent life.

 

If the Earth in all its complexity and beauty formed in 5 or 10 billion years, there is nothing to suggest that the next generation of stars might not spawn something even more spectacular, and conscious to boot.

 

So we could just as easily be among the last of Earth like planets as among the first. And there might be a different size planet with a different iron to hydrogen ratio that will provide the stage for future civilizations, that could very easily be completely unlike ours.

 

So what does the study let us know that we did not already guess? And philosophically, what does it matter what is currently going on across the Milky Way? We can hardly consider it our business or our neighborhood.

 

To make some grand prediction about the number of Earth like planets that exist within the hubble sphere is even further fetched.

 

Regards, TAR


For instance, as I have noted before there could be a life destroying cosmic burst headed toward the Earth, right now, but it hardly will effect us in the least, prior its arrival.


And if there are growing black holes at the center of galaxies like ours, at some point the entire galaxy could be consumed by it, but the material and energy it contained would not be gone from the universe. There might be some ejection of the material that happens, and material and energy that have been in a black hole, and then have been ejected from a black hole might have some characteristics associated with it, that we do not know about. That might not have yet happened.

 

We will have to wait and see what that might be like. The universe has not done that yet. It could easily provide material for star building and planet building of a "new" kind.

Edited by tar
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Strange,

 

Well I don't see how the paper has told us anything we could not have already guessed at.

 

The difference between guessing and calculation is the use of data.

 

 

And I don't see how it can nail down what the universe is going to do next.

 

No one is nailing it down. But we have a lot of information about how and where stars form. We know how this is affected by the availability of gas and dust, and how the size and lifetime of stars are affected by the metallicity.

 

Science is all about producing models that allow us to make predictions about what will happen.

 

 

We don't have any examples for instance of what the next generation of stars is going to look like, what the iron hydrogen ratio is going to be, and what size planets, with what characteristics the next generation of stars is going to spawn.

 

We don't need examples. We have data about what exists now and can use that to project what is likely to happen in the future.

 

When walking down the road do you ever stop dead in panic because the pavement ahead might turn to soup? Or a giant anvil might fall on your head? Or the Sun will go out? No, you use your knowledge of the world to predict that things will carry on in a reasonable way.

 

And philosophically, what does is matter what is currently going on across the Milky Way? We can hardly consider it our business or our neighborhood.

 

OK. All curiosity and scientific investigation is pointless. Got it.

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Strange,

 

I have nothing against the use of data.

 

My main question has to do with challenging the data, as to what is actual data, and what is interpolated, and questioning whether the universe is being modeled as all being the same age, or whether it is being modeled as we see it, with far away stuff younger, the further out you go.

 

When you make a calculation, based on the data, and you are interested in finding out how much energy there is or how much matter there is in a certain volume, its something you can do, when light and the energy its packing gets from one end of your volume to the other within a couple of seconds. You can take a measurement, write it down, take another measurement and see if its the same or has changed. The actual energy and matter you are measuring is within your view, and you can build an analog model of it in you brain, and in you formulae.

 

However, when the area or volume is very huge, and you have no place to call a focal point, and relate everything to, but are conceiving of the place none the less, as happening all at the same time, it is not true.

 

Your formula is not containing the whole operation properly, because the operation is connected to itself by the constraint speed of light, whereas you brain sees the whole thing at once. The energy calculations you would make, considering the whole thing at once, would not be actually true. The photon emitted at one corner has had no effect on the other corner yet,

 

In terms of the idea of the Earth being among the first of many many Earths, lets say that there are currently 1000 Earthlike planets, at different stages of the evolution of life on them...but they are all a billion light years away.

 

We can't see any of them. Not if we stared into the Hubble screen for a year, and sifted through the data.

 

Regards, TAR

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Ok - the universe is infinite - time is infinite. There has been an infinite number of planets with life, and there will be an infinite number of planets with life to come in the future.

 

If some scientist says the universe is 15 billion years old he is wrong. The universe has always been here - and will always be here.

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For instance, if the en​tire universe is currently 13.8 billion years old, then Earths that developed at the 13.8 billion year mark are already "present".

 

The "Earths" that are about to develop there and now as far as we can see, developed when the universe was 13.7 billion years old.

 

Using standard models, it's not possible.

Because 13.7 bln years ago, there was only Hydrogen-1 and Helium-4 in rates 12:1 quantity, which is 4:1 per mass.

Earth-like planet is made of plentiful of heavy atoms, starting from Iron in the core.

13.7 bln years ago, there was no Iron, yet.

It was made later by fusion in the first stars and supernovas.

Rock/metallic planets are made of dust and remains from them.

You need to take into account time needed for life of these stars, explosion, and cooling down remains to the level, they could be reused.

Edited by Sensei
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The fact is time, space and matter are all infinite.

 

That is not a "fact". At best it is a guess, or wild supposition.

If some scientist says the universe is 15 billion years old he is wrong.

 

The evidence seems to disagree with you.

My main question has to do with challenging the data, as to what is actual data, and what is interpolated, and questioning whether the universe is being modeled as all being the same age, or whether it is being modeled as we see it, with far away stuff younger, the further out you go.

 

The universe is all the same age, so that is how it is modelled. What we see is due to the limited speed of light. (And that can, of course, be taken into account) So, yes, when we look at distant stars or galaxies, we are effectively looking into the past. Which is very useful, because it tells us about how stars and galaxies were different in the past. Which means we can model how they change with changing conditions. Which means we can attempt to model how they will change in future.

 

 

However, when the area or volume is very huge, and you have no place to call a focal point, and relate everything to, but are conceiving of the place none the less, as happening all at the same time, it is not true.

 

I don't see why not. We can count the stars and measure the mount of matter in our galaxy. We can count the galaxies in our local cluster. and so on. From this we can get an estimate of the amount of mass locally. We can then extrapolate this (to the observable universe and beyond).

 

 

In terms of the idea of the Earth being among the first of many many Earths, lets say that there are currently 1000 Earthlike planets, at different stages of the evolution of life on them...but they are all a billion light years away.

 

We can't see any of them.

 

So what? Why do you need to see them?

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Our galaxy may be 15 billion years old - if that's what the scientists say im fine with that. However the universe is infinite - there was no beginning - that a fact. I understand that this simple concept may be beyond your comprehension, but that sounds like a personal problem and something you should work on.

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Sensei,

 

I agree that the generations of stars, need to be the case for the heavier elements required for iron core planet building to be present. I was talking about looking at a galaxy 100 million lys away, that reflects what the universe was doing when it was 13.7 billion years old. I was not talking about what the universe was doing 13.7 billion years ago.

 

Strange,

 

"Why do you need to see them?"

 

Well you don't, but the same thinking can be used for considering stuff outside the hubble sphere. Why does light from an event ever need to reach the Earth, in order for us to consider it existent?

 

What I am suggesting here is that the timing is important and how long it takes light to get around is exactly the reality of the situation.

 

If one is to conceive of the universe as happening now, all at the age of 13.8 billion years old, then the hubble sphere is not a limit of what we can consider within our universe. The term "observable" is not useful in my opinion, because, as you say "so what" if we can't see it. It is still there.

 

Regards, TAR

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Our galaxy may be 15 billion years old - if that's what the scientists say im fine with that. However the universe is infinite - there was no beginning - that a fact. I understand that this simple concept may be beyond your comprehension

 

Our galaxy is less than 15 billion years old. After all, the universe is only 14 billion years old!

 

Your claim is not beyond my comprehension, it is just that you provide no evidence to support it and the evidence that does exist contradicts it.

 

Feel free to provide some evidence, but without that, your "fact" is just an assertion. And, as such, can be ignored.

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The Universe is infinite - it has always been here. Anyone with any logic skills knows this. There is no scientific evidence that can prove this - only logic proves this - when you make claims that the universe isn't infinite you prove to this board how underdeveloped your logic skills are.

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"Why do you need to see them?"

 

Well you don't, but the same thinking can be used for considering stuff outside the hubble sphere. Why does light from an event ever need to reach the Earth, in order for us to consider it existent?

 

It doesn't. The universe beyond the observable is assumed to exist and be largely the same as what we can see.

 

 

What I am suggesting here is that the timing is important and how long it takes light to get around is exactly the reality of the situation.

 

But you haven't explained why that is relevant to our estimates of the current state of the universe.

 

 

If one is to conceive of the universe as happening now, all at the age of 13.8 billion years old, then the hubble sphere is not a limit of what we can consider within our universe. The term "observable" is not useful in my opinion, because, as you say "so what" if we can't see it. It is still there.

 

But the reason it is not observable is (partly) because light hasn't had enough time to reach us. It is only a ,imit of what we can see, not a limit of what "is".

The Universe is infinite - it has always been here. Anyone with any logic skills knows this.

 

I have an invisible pink unicorn in my garden. Anyone with logic skills knows this.

 

As you have no evidence, I see no reason to believe you.

Seriously, as there is no evidence for your belief, why do expect anyone else to accept it?

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The Universe is infinite - it has always been here. Anyone with any logic skills knows this. There is no scientific evidence that can prove this - only logic proves this - when you make claims that the universe isn't infinite you prove to this board how underdeveloped your logic skills are.

Your statements imply you are gifted with the requisite logic skills. It should therefore be simple for you to set down the clear, concise logical argument that supports your contention. I look forward to the fulsome education in logic and the state of the universe that I am about to receive.

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Strange,

 

I don't think we differ in understanding the reality of the situation. I think I am trying to point out, that there are two vantage points from which one can conceive of the universe, model the universe, if you will. One is how it looks from here, with far away stuff, very young and local stuff about our age. The other is to model it as if everything is currently present.

 

My point concerning the OP article is that it is difficult to discern which view one is to take, when reading an announcement that this is among the first of many many Earth.

 

 

Regards, TAR

 

And in either view, you suffer from a lack.

In the case of studying the universe as it happens, one is confronted with the fact that the events being witnessed already ​ happened and there is physically no way to get to the event and be there or affect it in anyway.

 

And in the case of considering the place currently happening, we suffer the opposite isolation. Its happening out there, and we will not see it for a year or a hundred...million...billion...trillion years.

 

So if you go by the data its old news. And if you go by the interpolation, its speculative imagination.


So under which view is the Earth among the first of many many Earths?

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I don't think we differ in understanding the reality of the situation. I think I am trying to point out, that there are two vantage points from which one can conceive of the universe, model the universe, if you will. One is how it looks from here, with far away stuff, very young and local stuff about our age. The other is to model it as if everything is currently present.

 

Or, one could say, the wrong way and the right way.

 

 

My point concerning the OP article is that it is difficult to discern which view one is to take, when reading an announcement that this is among the first of many many Earth.

 

Fairly obviously it is looking at the state of the universe now and comparing it with the state of the universe at some time in the future. As none else shares your warped view of how time works, you can be fairly certain that no one will be basing models on it.

 

So if you go by the data its old news. And if you go by the interpolation, its speculative imagination.

 

There is some speculation and imagination involved, I suppose. But you imply it is a fairly meaningless guess. That is obviously not the case as it is quite carefully calculated from a large amount of data and scientific theory (which you haven't bothered to question, so I assume you accept it all).

 

So under which view is the Earth among the first of many many Earths?

 

The only sensible one, of course (i.e. not yours).

Edited by Strange
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Strange,

 

You are avoiding the meat of the question.

 

You say I have a warped idea of how time works, yet I have merely stated two actual, accepted views, that of what we see, and that of what we imagine, and asked, under which view there are to be many more Earths.

 

There is a time lag, between there being an Earth, somewhere else in the universe a billion lys from here, and us seeing that Earth, or having any knowledge of that Earthlike planet.

 

In a sense, our seeing of that planet, or our progeny's seeing of that planet IS something that would happen in the future. So the question is, are we counting that Earthlike planet, which exists now a billion yrs from here, as currently existent or are we counting that as a future Earth?

 

Regards, TAR


Strange,

 

So answer me this. If a star 5 lys from here, goes super nova today, and we see it go super nova in 2020. Is that something happening now, or something happening in our future, in your view of time?

 

Regards, TAR

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