@heater: you see, this discussion can run endlessly... if we agree what an end is. In this case: if time is endless, there will be no end of time. But doesn't endless is always related to an end? Time is endless for you, if your time comes to an end before everybody else. ...
The universe by definition is closed. Because the Universe, as says the name, incorporated everything. That is: if the Universe is finite, nothing is outside the Universe and we have no need to discuss it.
Now you could say: in human terms the Universe exists, everything that exists came into existance, so there is a creator, .... a never ending story. The only way out to me: don't care, take everthing for given and closed, that's it.
We have a similarity in math, know about that since Goedel: a system can put more questions than it can answer. If you enumerate all questions, you have not numbers left to enumerate the answers.
You clearly said: there is evidence that energy is conserved. So is momentum. If you do not fully agree and take this as given, no physical discussion is needed. Then it is better to invest time in discussion about ranging programming languages.
People are not aware that the quantum of action is the only single quantum that is well defined by itself and this value has never changed from times of the big bang. I do not say: it is constant, I only say: all science is based on a constant h. Red shift can be explained by an evolving h. But we do not take this possibility in account, because then "planets would run backward".
That means: the geocentric model had the problem to explain, why the planets sometimes run in loops. With the helio centric model this question is answered with the help of simple geometry. Next the idea that planet run in circles had to be abandoned, because Kepler saw deviations and so he discovered the laws named after him. Now the movement is elliptical. But it is so, independent of our awareness!
The Big Bang only created the basic elements, e.g. hydrogen, helium etc, and (I should look it up, but IIRC) up to lithium[1]. That's all. When the first stars formed they started burning hydrogen in a fusion process, when that's empty it goes on to heavier elements, all the way to iron, where it stops. Heavier elements are created in supernovas. That's because after iron it takes more energy to fusion the elements than you get out of it. The supernova explosion is needed to get enough oomph to fusion the heavier elements.
So that's why all matter isn't the same age. The heavier the element, the younger it is. And when it comes to the age of the earth it's about when the earth formed, when all the dust and elements came together to make this spheric rock we're on. And that happened about 4.5 billion years ago.
In any case, we're all made of stardust. A star had to go through all its phases, and blow up to make the stuff our bodies are made of.
The supernova explosion is needed to get enough oomph to fusion the heavier elements....elements came together to make this spheric rock we're on. And that happened about 4.5 billion years ago.
Now there is a question I have for any passing cosmologist that I can strap down and interrogate for a few hours. Something here does not add up to me.
On the one hand it looks like the observable universe is some 14 billion years old. Since the big bang.
We are told many of the elements the Earth and us and everything useful around here have been created in supernova. Not only that but it may have taken many cycles of start birth, death, supernova to create some of the elements.
On the other hand the Earth appears to be 4.5 billion years old. So presumably the sun was here and swirls of gas, those heavy elements, around it for a long time before forming our rock.
Well, 4.5 billion years is a good chunk of the age of the universe. My impression is that it does not leave enough time between the big bang and Earth formation for all those elements to have been recycled through a few generations of star lifetime and supernova. or even one!
Seems 60 solar mass stars will fizz out after only 3 million years. Our 1 solar mass star is expected to last 10 billion. That is quite a range! http://www.astronomynotes.com/evolutn/s2.htm
Could we also assume that stars created soon after the big bang were generally bigger? On account of there being more stuff in less space perhaps.
I have a phone app pertaining to a timeline of the universe. To predict the past is tough enough, but to go out on a limb by predicting the future, there must be an agreement among physicists that the information they work with is solid. But how can predict the end of the universe? The end of time itself.
You do realize that is a contradiction in terms? "predict" is about the future not the past!
Thing is:
We can do experiments in the lab. And arrive at some conclusions as to how things behave.
We then assume that things behave the same no matter where or when they are in space. Sounds reasonable to me.
So, looking out into space we can come to some conclusions about what happened in the past, big bang and all that, and draw some conclusions about the future.
Problem is, unlike our lab experiments where we can do something and measure the effect. We cannot do any experiment on the universe. We can only watch.
Seems the results of watching are amazing. Starting from the observation of galaxies other than our own, to the expansion of the universe, Hubble and all that. Now to the accelerating expansion of the universe.
Can we ever say what we expect happened in the past or will happen in the future of the universe is "true" ?
You do realize that is a contradiction in terms? "predict" is about the future not the past!
Without a collaboration of witnesses to an event, wouldn't it be educated guesswork? or just a prediction of events as they happened.
EDIT: I get the "Pre" specifies future. Would the word "dictates" be a better choice. As in logic dictates that this certain thing happened at this certain time.
Without a collaboration of witnesses to an event, wouldn't it be educated guesswork?
That is an interesting point.
In school we did enough experiments to convince ourselves that the laws that Newton laid down were true. No appeal to witnesses required. We did it ourselves.
Similarly with experiments with heat. Thus convincing ourselves that Boltzmann and the rest had a good idea.
Later I found myself measuring the electric charge on a single electron. Or the spacing between atoms in a salt crystal.
So far, so good. I don't need to take the word of any "witness". I did it for myself.
Things get a bit muddy when talking of modern day physics and cosmology. The mathematics of it all is way over my head. The experiments I cannot do for myself. Who has a Large Hadron Collider in their garage? Who has a Hubble telescope?
End result is I have to trust those in the physics, mathematics and cosmology community. Without the possibility to measure or prove anything for myself by experiment.
Best we normal people can do is try to keep up with the mathematics of it all. So that we have some idea what these guys are talking about.
As an aside, "predicting the past" is very frequently used in the "soft" sciences, (economics being one of these everyone can relate to) and some argue, not sciences at all, due to the lack of some ability to repeat experiments, or even establish controls without either nature, or ethics getting in the way. Those models end up being used to both predict the future and to some degree shape it, depending on the need.
Without a collaboration of witnesses to an event, wouldn't it be educated guesswork?
In fact, it is! Here is Feynman on the scientific method:
Nature and or experience is the authority. It can falsify for us, and that's it!
Meaning, we never really KNOW anything at all! Not in the scientific sense. There is lots of knowing, and we call it knowledge. Science is about understanding, not knowing.
We understand something when we can do a thing and know what the outcome of doing that thing is. Same thing when nature does a thing.
At all times, our understanding is incomplete. However, it also has a scope. Even old, or basic understanding is very useful, given one understand the scope. Where it works.
As we find things work, we do the math, we run the experiments, or we observe to get data. Confidence grows, until it doesn't, and when it doesn't, we've got new science!
On the other hand the Earth appears to be 4.5 billion years old. So presumably the sun was here and swirls of gas, those heavy elements, around it for a long time before forming our rock.
- actually, no. The sun and the solar system formed around the same time, relatively speaking. The proto sun disc that created the sun also created the planets, soon after (for some value of "soon").
Well, 4.5 billion years is a good chunk of the age of the universe. My impression is that it does not leave enough time between the big bang and Earth formation for all those elements to have been recycled through a few generations of star lifetime and supernova. or even one!
The first stars were of the 'live fast, die young' type. As was mentioned, bigger stars have shorter lives. A few million years, or even shorter. 4.5 billion years is *plenty*. For all we know there may have been civilizations on other planets that came and went billions of years before us.
...4.5 billion years is *plenty*. For all we know there may have been civilizations on other planets that came and went billions of years before us.
Well, there is another thing. Life.
It seems life on Earth started off about 3.8 billion years ago. Call it 4 billion years to get from soup to humans. It's amazing that life kicked off very soon after the planet was formed.
We might speculate this is a normal time span for these things.
So actually, in the 14 billion years since the big bang there has not been many opportunities to grow life on a planet around a star.
Especially if those earlier stars were the 'live fast, die young' type. There just would not be enough time to evolve anything before the star went supernova.
Looked at that way, it seems quite probable that we are among the first generation of life in the universe. Of course what has happened here can also be happening in other places.
Conservation of energy gives you a chance to understand what happened. If for a short moment you imagine all energy to be represented by one single "thing" this "thing" can have no properties but energy. Not even a field to the outside of any kind, because such a field would content energy and so the presumption would be false. By dividing said "thing" into two, these two things will contain a fraction of the energy and there is some energy in between them, because they repell each other (Otherwise there is no reason to divide). This repelling force must have been extremly huge, so the two parts move with speed close to c. That means, the parts can travel a reasonable distance but time is developing very slowly, that means, the "things" can not change internally. Next the things again divide so now we have four particles, carrying about 1/4 of the energy available etc etc. After many particles exist, distributed over a huge space in a very short time, the big bang happens. That can be proved very easily from well understood physic.
Hmm.. I didn't really understand much of that. But you seem to also say that first some things happened, and then the big bang happened. The traditional view is that there's no "before" w.r.t. the big bang. Time zero. No time before BB.
I once came over one way of solving the "everything from nothing" paradox - it was claimed that the gravity of the universe exactly matches the mass and energy of the universe, so that if you look at gravity as negative energy and the rest as positive, it all cancels out (and all of use are in practice just a large version of virtual particles, something that we know exist - popping into existence (and disappearing) all the time, with no new energy created, because they're created in pairs. One positive, one negative).
As an aside, "predicting the past" is very frequently used in the "soft" sciences, (economics being one of these everyone can relate to) and some argue, not sciences at all, due to the lack of some ability to repeat experiments, or even establish controls without either nature, or ethics getting in the way. Those models end up being used to both predict the future and to some degree shape it, depending on the need.
Without a collaboration of witnesses to an event, wouldn't it be educated guesswork?
In fact, it is! Here is Feynman on the scientific method:
Nature and or experience is the authority. It can falsify for us, and that's it!
Meaning, we never really KNOW anything at all! Not in the scientific sense. There is lots of knowing, and we call it knowledge. Science is about understanding, not knowing.
We understand something when we can do a thing and know what the outcome of doing that thing is. Same thing when nature does a thing.
At all times, our understanding is incomplete. However, it also has a scope. Even old, or basic understanding is very useful, given one understand the scope. Where it works.
As we find things work, we do the math, we run the experiments, or we observe to get data. Confidence grows, until it doesn't, and when it doesn't, we've got new science!
I once came over one way of solving the "everything from nothing" paradox - it was claimed that the gravity of the universe exactly matches the mass and energy of the universe, so that if you look at gravity as negative energy and the rest as positive, it all cancels out (and all of use are in practice just a large version of virtual particles, something that we know exist - popping into existence (and disappearing) all the time, with no new energy created, because they're created in pairs. One positive, one negative).
Does that mean there is a negative me walking around somewhere in the universe. At least i'm hoping I am the positive one, just by using the word hope, makes me feel better about that.
Does that mean there is a negative me walking around somewhere in the universe. At least i'm hoping I am the positive one, just by using the word hope, makes me feel better about that.
No, only that if you add up all the energy and matter it's supposed to be equivalent to the energy of the universe's gravity (and that's presumably why the universe seems to be flat). So, subtract gravity from the rest and you end up with zero. So the big bang doesn't really create stuff. The virtual particles popping in and out of existence are just another example of "not getting something from nothing". You're still positive, and maybe there's only one of you..
Why do we create circles in our thoughts, when we do not now how to follow a straight line? There is one well accepted constant: the quantum of action, h. But what is a constant? It is a value that can not change. We can ask the question: if electrical field strength and magnetical field strength in the vacuum have a constant relation, which we call impedance, what is real? Is the impedance real or are the fields real? Hen and egg. If we look carefully to the concept of action we see, action numerically is energy times time. The value of energy is for sure not all the energy, but only the part, that is involved in the action. But what is time? It makes sense to identify time with the time that is needed to complete the action. And as the quantum of action, that is an elementary chunk is a constant, it follows, that an action just means: transfer an amount of energy from one state into another state takes an amount of time inverse to the amount of energy. Now a photon no longer has a frequency, but a duration, for example, the duration to pass a plane in free space.
But now answer a simple question: if you take the amount of energy in the universum (there are values in literature), you take the value of h, and then you calculate the time needed to have the most simple action taking place: create two from one. Any glue, what this time scale is?
As seen from the photon's point of view, it cannot have a duration. Time does not exist for photons (or any massless particle).
(And that's why people realized that neutrinos must have mass the moment it was confirmed that they are able to switch from one variant to another during flight - if it was truly massless there wouldn't be any time passing, so there wouldn't be any possibility to change.)
And we should not ask: is there a negative me, we always should ask: is there a positive me! ;-)
Is it possible that there is a culture on the other side of the universe, where nothing works the same as we have here. All the laws of physics we know are useless there. Their existence defies everything we believe to be impossible.
Well, according to string theory not only is everything possible, everything is possible to the Nth degree.. there are some 10^500 solutions, or possible universes, apparently. In comparision, the total number of atoms in our universe is estimated to around 10^80.
@Tor circling? I wanted to show a straight line. I do not look at a photon from the photon's point of view. And why introduce neutrinos? No way to conclude if there is no solide foundation. I just showed: if we all see, that the quantum of action is THE fundamental constant of nature, and all the interpretations of the measurement of background radiation are obsolete, the moment h changes over time, did the quantum of action became manifest in time at the big bang, or did it exist before? No physicist will tell you: there was no time before big bang, he will only say: I don't know. Therefore the question is valid: what happend before big bank under the assumption, that action was on the run.
ErNa: I admit to not understand anything of your description - my fault, I know - so I only grabbed at the single paragraph I could get and commented on that. The thing about neutrinos was just another data point about massless particles vs particles with mass - the massless ones don't experience time. So time and mass is interlinked somehow. You can't have one without the other.
I would very much like to better understand, WHY I am not understood. I see this as a common problem. This string is about: how to fool the nature. That can not work. And as there are endless discussions on this issue, over and over, implicite or explicite, my intention is to strip down what we know for sure and reconstruct the building of knowledge, omitting pitfalls. And do some experiments with the propeller to. Because if we once have a status were we coincide, we can start to create software like game of life, using different algorithms and so gain new insights. Bose and Einstein derived Planks law of radiation just from counting standing waves in a box.
Comments
The universe by definition is closed. Because the Universe, as says the name, incorporated everything. That is: if the Universe is finite, nothing is outside the Universe and we have no need to discuss it.
Now you could say: in human terms the Universe exists, everything that exists came into existance, so there is a creator, .... a never ending story. The only way out to me: don't care, take everthing for given and closed, that's it.
We have a similarity in math, know about that since Goedel: a system can put more questions than it can answer. If you enumerate all questions, you have not numbers left to enumerate the answers.
You clearly said: there is evidence that energy is conserved. So is momentum. If you do not fully agree and take this as given, no physical discussion is needed. Then it is better to invest time in discussion about ranging programming languages.
People are not aware that the quantum of action is the only single quantum that is well defined by itself and this value has never changed from times of the big bang. I do not say: it is constant, I only say: all science is based on a constant h. Red shift can be explained by an evolving h. But we do not take this possibility in account, because then "planets would run backward".
That means: the geocentric model had the problem to explain, why the planets sometimes run in loops. With the helio centric model this question is answered with the help of simple geometry. Next the idea that planet run in circles had to be abandoned, because Kepler saw deviations and so he discovered the laws named after him. Now the movement is elliptical. But it is so, independent of our awareness!
I saw what you wrote then deleted there
So that's why all matter isn't the same age. The heavier the element, the younger it is. And when it comes to the age of the earth it's about when the earth formed, when all the dust and elements came together to make this spheric rock we're on. And that happened about 4.5 billion years ago.
In any case, we're all made of stardust. A star had to go through all its phases, and blow up to make the stuff our bodies are made of.
[1] And beryllium - found a readable reference: http://www.haystack.mit.edu/edu/pcr/Astrochemistry/3 - MATTER/nuclear synthesis.pdf]
On the one hand it looks like the observable universe is some 14 billion years old. Since the big bang.
We are told many of the elements the Earth and us and everything useful around here have been created in supernova. Not only that but it may have taken many cycles of start birth, death, supernova to create some of the elements.
On the other hand the Earth appears to be 4.5 billion years old. So presumably the sun was here and swirls of gas, those heavy elements, around it for a long time before forming our rock.
Well, 4.5 billion years is a good chunk of the age of the universe. My impression is that it does not leave enough time between the big bang and Earth formation for all those elements to have been recycled through a few generations of star lifetime and supernova. or even one!
Seems 60 solar mass stars will fizz out after only 3 million years. Our 1 solar mass star is expected to last 10 billion. That is quite a range!
http://www.astronomynotes.com/evolutn/s2.htm
Could we also assume that stars created soon after the big bang were generally bigger? On account of there being more stuff in less space perhaps.
That's one less cosmologist in danger. For now...
Thing is:
We can do experiments in the lab. And arrive at some conclusions as to how things behave.
We then assume that things behave the same no matter where or when they are in space. Sounds reasonable to me.
So, looking out into space we can come to some conclusions about what happened in the past, big bang and all that, and draw some conclusions about the future.
Problem is, unlike our lab experiments where we can do something and measure the effect. We cannot do any experiment on the universe. We can only watch.
Seems the results of watching are amazing. Starting from the observation of galaxies other than our own, to the expansion of the universe, Hubble and all that. Now to the accelerating expansion of the universe.
Can we ever say what we expect happened in the past or will happen in the future of the universe is "true" ?
No.
There is no way to check.
I might have to take some of that back.
A good lot of Einstein's theories of relativity and gravitation are not demonstrable here in the laboratory.
They only seem to be plausible when we look outside. Gravitational lensing around galaxies for example.
Without a collaboration of witnesses to an event, wouldn't it be educated guesswork? or just a prediction of events as they happened.
EDIT: I get the "Pre" specifies future. Would the word "dictates" be a better choice. As in logic dictates that this certain thing happened at this certain time.
In school we did enough experiments to convince ourselves that the laws that Newton laid down were true. No appeal to witnesses required. We did it ourselves.
Similarly with experiments with heat. Thus convincing ourselves that Boltzmann and the rest had a good idea.
Later I found myself measuring the electric charge on a single electron. Or the spacing between atoms in a salt crystal.
So far, so good. I don't need to take the word of any "witness". I did it for myself.
Things get a bit muddy when talking of modern day physics and cosmology. The mathematics of it all is way over my head. The experiments I cannot do for myself. Who has a Large Hadron Collider in their garage? Who has a Hubble telescope?
End result is I have to trust those in the physics, mathematics and cosmology community. Without the possibility to measure or prove anything for myself by experiment.
Best we normal people can do is try to keep up with the mathematics of it all. So that we have some idea what these guys are talking about.
As an aside, "predicting the past" is very frequently used in the "soft" sciences, (economics being one of these everyone can relate to) and some argue, not sciences at all, due to the lack of some ability to repeat experiments, or even establish controls without either nature, or ethics getting in the way. Those models end up being used to both predict the future and to some degree shape it, depending on the need.
In fact, it is! Here is Feynman on the scientific method:
Nature and or experience is the authority. It can falsify for us, and that's it!
Meaning, we never really KNOW anything at all! Not in the scientific sense. There is lots of knowing, and we call it knowledge. Science is about understanding, not knowing.
We understand something when we can do a thing and know what the outcome of doing that thing is. Same thing when nature does a thing.
At all times, our understanding is incomplete. However, it also has a scope. Even old, or basic understanding is very useful, given one understand the scope. Where it works.
As we find things work, we do the math, we run the experiments, or we observe to get data. Confidence grows, until it doesn't, and when it doesn't, we've got new science!
Wash, rinse, repeat.
The first stars were of the 'live fast, die young' type. As was mentioned, bigger stars have shorter lives. A few million years, or even shorter. 4.5 billion years is *plenty*. For all we know there may have been civilizations on other planets that came and went billions of years before us.
It seems life on Earth started off about 3.8 billion years ago. Call it 4 billion years to get from soup to humans. It's amazing that life kicked off very soon after the planet was formed.
We might speculate this is a normal time span for these things.
So actually, in the 14 billion years since the big bang there has not been many opportunities to grow life on a planet around a star.
Especially if those earlier stars were the 'live fast, die young' type. There just would not be enough time to evolve anything before the star went supernova.
Looked at that way, it seems quite probable that we are among the first generation of life in the universe. Of course what has happened here can also be happening in other places.
I once came over one way of solving the "everything from nothing" paradox - it was claimed that the gravity of the universe exactly matches the mass and energy of the universe, so that if you look at gravity as negative energy and the rest as positive, it all cancels out (and all of use are in practice just a large version of virtual particles, something that we know exist - popping into existence (and disappearing) all the time, with no new energy created, because they're created in pairs. One positive, one negative).
A very good analogy of the process.
Does that mean there is a negative me walking around somewhere in the universe. At least i'm hoping I am the positive one, just by using the word hope, makes me feel better about that.
All very interesting stuff guy's.
But now answer a simple question: if you take the amount of energy in the universum (there are values in literature), you take the value of h, and then you calculate the time needed to have the most simple action taking place: create two from one. Any glue, what this time scale is?
(And that's why people realized that neutrinos must have mass the moment it was confirmed that they are able to switch from one variant to another during flight - if it was truly massless there wouldn't be any time passing, so there wouldn't be any possibility to change.)
Is it possible that there is a culture on the other side of the universe, where nothing works the same as we have here. All the laws of physics we know are useless there. Their existence defies everything we believe to be impossible.
I'm going to start a thread on alien specters.