• christian2017
    1.4k
    https://www.techexplorist.com/dark-matter-existed-before-big-bang-study/25576/

    In the above article it says that dark matter preceded the big bang. The article never says how many billions of years that dark matter may have preceded the big bang. I supposed that dark matter is what enabled the universe to get past the intense gravity of the initial big bang event. Please read the article before commenting.

    Questions and Comments?

    ___________________
    Dark matter may have existed before the big bang, study
    Testing the origin of dark matter by observing the signatures dark matter leaves on the distribution of matter in the universe.
    _________________

    One of the mysteries of our universe is that of dark energy and dark matter. Scientists all over the world are attempting to discover what particles make up dark energy and matter. However, it is believed that dark matter makes up about 80% of the universe’s mass.

    However, it is believed that dark matter makes up about 80% of the universe’s mass. But a new study by scientists at Johns Hopkins University, suggests that dark matter may have existed before the Big Bang.

    The study also represents a new idea of how dark matter was conceived and how to distinguish it with galactic observations.

    Tommi Tenkanen, a postdoctoral fellow in Physics and Astronomy at the Johns Hopkins University, said, “The study revealed a new connection between particle physics and astronomy. If dark matter consists of new particles that were born before the Big Bang, they affect the way galaxies are uniquely distributed in the sky. This connection may be used to reveal their identity and make conclusions about the times before the Big Bang too.”

    Well, the origin of dark matter is still a mystery, yet astronomers have shown dark matter assumes a vital role in the formation of galaxies and galaxy clusters. Despite the fact that not legitimately observable, scientists know dark matter exists by its gravitational energy consequences for how visible matter moves and is dispersed in space.

    For quite a while, scientists believed that dark matter must be an extra substance from the Big Bang. Specialists have long looked for this sort of dark matter, however, so far every trial search has been fruitless.

    Tenkanen said, “If dark matter were truly a remnant of the Big Bang, then in many cases researchers should have seen a direct signal of dark matter in different particle physics experiments already.”

    For this study, scientists used a simple mathematical system and suggested that the dark matter has emerged before the Big Bang. It might be formed during an era known as cosmic inflation when space was expanding very rapidly.

    Tenkanen said, “With the proposed mathematical scenario, we don’t have to assume new types of interactions between visible and dark matter beyond gravity, which we already know is there.”

    “While the idea that dark matter existed before the Big Bang is not new, other theorists have not been able to come up with calculations that support the idea. The new study shows that researchers have always overlooked the simplest possible mathematical scenario for dark matter’s origins.”

    “While this type of dark matter is too elusive to be found in particle experiments, it can reveal its presence in astronomical observations. We will soon learn more about the origin of dark matter when the Euclid satellite is launched in 2022. It’s going to be very exciting to see what it will reveal about dark matter and if its findings can be used to peak into the times before the Big Bang.”
  • Banno
    8.5k
    ...and therefore, god is dark matter? What is it that we are supposed to conclude?

    What justifies your "~3 billion years" if it is not mentioned in the article?
  • christian2017
    1.4k


    Oh i forgot that a guy by Haim Shore came to that conclusion from studying ancient Hebrew and the book of Genesis.

    Actually no i don't necessarily believe that God is dark matter. I do believe in pan-psychism (there are over 11 forms). Did you read the article?
  • christian2017
    1.4k


    for whatever reason this post will probably be taken down due to supposed "poor quality".
    I'm sure they'll give me a poor reason for why it had to be taken down.
  • Banno
    8.5k
    Oh i forgot that a guy by Haim Shore came to that conclusion from studying ancient Hebrew and the book of Genesis.christian2017

    For fuck's sake.
  • christian2017
    1.4k


    the forum moderators say i have to turn the other cheek 100% of the time. so:

    thats fair.
  • Pfhorrest
    2.5k
    NB that in contemporary inflationary cosmology, "the Big Bang" doesn't refer to a singularity at the beginning of time, but rather to the end of the inflationary period, a phase shift in which the energy of the expansion of space (the "inflaton field") converted to energy of the quantum fields that underlie matter as we know it. The universe stopped being a mostly empty and cold and rapidly expanding space, and converted instead into a slowly expanding extremely hot and energy-dense state, which then evolved to the state we see it in today.

    The article is saying that dark matter was possibly around already before that phase shift. Which isn't very surprising, since it's apparently some kind of stuff very different from the stuff made of excitations of quantum fields that we're familiar with.
  • fishfry
    1.5k
    That's interesting. So is dark matter somehow outside of the universe? If the universe is everything that happened after the big bang? Was the dark matter always there? This raises a lot of new questions.
  • Pfhorrest
    2.5k
    In contemporary inflationary cosmology, the universe isn't "everything that happened after the big bang". The big bang is just an important early event in the history of the universe as we know it (which may be only a small part of the total universe, which may be infinitely old, if eternal inflation is correct).
  • Kenosha Kid
    622


    I think the thing that maybe interests you about this isn't the dark matter bit but the "before the Big Bang" bit, which this paper (I read the preprint as that article was awful) takes as a starting point.

    The leading theory of the origin of the universe is the inflaton field. The idea is that this field is in a metastable state, i.e. in a state with a probability of spontaneously collapsing into a lower-energy state. The difference between the metastable energy and the "true vacuum" energy is the potential. Whatever this potential is must account for the energy of the universe, so is likely very high, higher perhaps than we can produce in particle accelerators.

    Excitations of this field are the hypothesised inflaton particles responsible for the rapid expansion of the early universe before those unstable inflatons decayed to the sorts of matter we see today.

    The author is deliberately not explicit about whether he thinks dark matter itself was created before the big bang (e.g. is itself an excitation of the inflaton field or another pre-bang field) or was "sourced" from such a thing. The latter seems the simplest and most sensible. The early universe is supposed to have been teeming with inflatons of energy outside or at the limits of our technologies, which then decayed to lighter particles, which may then have decayed to yet lighter particles, and so on.

    In this instance, dark matter would be presumed to be extremely heavy and stable matter terminating a decay chain which is itself extremely high-energy. Dark matter as a direct product of inflaton decay would fit this picture. But to stress: inflaton creation was the Big Bang itself.

    Dark matter is supposed to make up 80% of massive matter in order to explain the rotational velocity of galaxies. As accurate mass estimates for galaxies are on-going (e.g. only recently have we realised the abundance of supermassive black holes), it's worth treating with some scepticism. Dark matter is, sceptically, an error between current cosmological estimates of mass and current astronomical measurements of mass.
  • Pfhorrest
    2.5k
    Dark matter is supposed to make up 80% of massive matter in order to explain the rotational velocity of galaxies. As accurate mass estimates for galaxies are on-going (e.g. only recently have we realised the abundance of supermassive black holes), it's worth treating with some scepticism. Dark matter is, sceptically, an error between current cosmological estimates of mass and current astronomical measurements of mass.Kenosha Kid

    Don’t we now have direct confirmation of dark matter as a stuff in the universe (WIMPs specifically) from the Bullet Cluster observation?
  • Kenosha Kid
    622
    Don’t we now have direct confirmation of dark matter as a stuff in the universe (WIMPs specifically) from the Bullet Cluster observation?Pfhorrest

    It's not direct evidence, no, but it is a +1 for astronomical estimates of masses, i.e. the gravitational lensing is not consistent with heavier-than-expected galaxies. It also suggests that dark matter is not a very light WIMP like a neutrino.
  • Kenosha Kid
    622
    It's not direct evidence, no, but it is a +1 for astronomical estimates of masses, i.e. the gravitational lensing is not consistent with heavier-than-expected baryonic galaxies. It also suggests that dark matter is not a very light WIMP like a neutrino.Kenosha Kid

    Correction to above. I'm not doing good posting today.

    I appreciate there was nothing in this to justify my earlier suggestion of caution.

    The rotational velocities of galaxies suggest that the total mass at these distances is higher than the diminished luminosity would suggest, i.e. the distribution of density with increasing radius is not falling off correctly.

    The bullet cluster and others appear to have centres of masses not coincident with the centre of luminous mass, again suggesting that the true mass is concentrated in a different way.

    Fundamentally then dark matter is the difference between cosmological predictions and astronomical observations, both fields being ones where changes of knowledge are rapid. (It wasn't that long ago that we discovered that the universe is expanding at an increasing rate, and that black holes not only exist but are abundant.)

    There are lots of candidate particles: it may be none, one or several of them, so long as they are gravitational and weakly electromagnetic (dark).

    Modified gravity theories note and encode the relationships between baryonic (visible) mass distributions and the purported dark matter distributions necessary to explain the former's velocities. (These theories are like the social psychologists of cosmology: their raison d'etre is sound, but their MO is to claim every DM victory for themselves.) These relationships aren't explicable in DM terms because DM is not that well defined. They are more explicable in modified gravity terms, though.

    That's not to say particular modified gravity theories are any more believable, but they do allow for the possibility that cosmological models of the future may yield different results from today, something that can be expected in rapidly changing fields. A general class of modified gravity theories is scalar gravity theories that predict a new gravitational field that would impact lensing observations. Such a field is present in the leading modified gravity theory which was shown to be consistent with the bullet cluster observations when one takes into account the three distinct centres of mass of the binary cluster system. That is, it states that the very relationship between baryonic and purported dark matter in rotational velocity observations is what knocks off the centre of mass in a three-mass system (the third mass being the mass of gas ripped from one cluster by another).
  • Gregory
    1.1k
    When physicists say "we are working the math" they are admitting they know nothing of philosophy. Cosmology is all guesswork. It's all fiction. The elephant with the longest toenail is dark matter, duh!
  • A Seagull
    542
    However, it is believed that dark matter makes up about 80% of the universe’s masschristian2017

    You are confusing dark matter with dark energy.
  • Professor Death
    454
    you can play it on here; no following required
  • Kenosha Kid
    622
    Cosmology is all guesswork. It's all fiction.Gregory

    Cosmologists, like any other scientist, build theoretical models to test against empirical evidence. If your point is that they do not know in advance that the model is the correct one, then yes, you have correctly distinguished science (which proceeds from not knowing but wanting to find out) from religion (which proceeds from pretending to know and fearing being found out).
  • Pfhorrest
    2.5k
    correctly distinguished science (which proceeds from not knowing but wanting to find out) from religion (which proceeds from pretending to know and fearing being found out).Kenosha Kid

    Nice turn of phrase!
  • tilda-psychist
    53
    Cosmologists, like any other scientist, build theoretical models to test against empirical evidence. If your point is that they do not know in advance that the model is the correct one, then yes, you have correctly distinguished science (which proceeds from not knowing but wanting to find out) from religion (which proceeds from pretending to know and fearing being found out).Kenosha Kid

    Thats a common theme on most forums such as this by religionists and non-religionists. If scientists have problems understanding everything then so do most people on forums like this.

    Puking out information from a popular physics book doesn't make us experts.

    I'm sure you are aware to the concept that when one question is answered that 10 more questions pop up in its place (a common proverb). Missing one small detail in a concept can throw off the proper conclusion for that concept. This is similar to if we have an equation missing one variable and one coefficient for example. The whole output of the equation or function can change drastically.
  • Kenosha Kid
    622
    Thats a common theme on most forums such as this by religionists and non-religionists. If scientists have problems understanding everything then so do most people on forums like this.

    Puking out information from a popular physics book doesn't make us experts.

    I'm sure you are aware to the concept that when one question is answered that 10 more questions pop up in its place (a common proverb). Missing one small detail in a concept can throw off the proper conclusion for that concept. This is similar to if we have an equation missing one variable and one coefficient for example. The whole output of the equation or function can change drastically.
    tilda-psychist

    This is a justification for considering science a work of fiction? Or, to put it another way, how does this relate to what you quoted?

    You seem to be taking not knowing something as being seen as inferior. But you just quoted me as saying not knowing is the starting point.

    Welcome to the forum by the way :)
  • tilda-psychist
    53
    Thats a common theme on most forums such as this by religionists and non-religionists. If scientists have problems understanding everything then so do most people on forums like this.

    Puking out information from a popular physics book doesn't make us experts.

    I'm sure you are aware to the concept that when one question is answered that 10 more questions pop up in its place (a common proverb). Missing one small detail in a concept can throw off the proper conclusion for that concept. This is similar to if we have an equation missing one variable and one coefficient for example. The whole output of the equation or function can change drastically.
    — tilda-psychist

    This is a justification for considering science a work of fiction? Or, to put it another way, how does this relate to what you quoted?

    You seem to be taking not knowing something as being seen as inferior. But you just quoted me as saying not knowing is the starting point.

    Welcome to the forum by the way :)
    Kenosha Kid

    Thanks for your welcome. No sarcasm intended. Basically i'm saying some people know more than others however there is no end in sight of Scientists still having major discoveries of how the Universe operates and also things that relate to 10 dimensions and beyond. Like i said if we get one variable or coefficient wrong it can change our whole view of reality.
  • Kenosha Kid
    622
    Basically i'm saying some people know more than others however there is no end in sight of Scientists still having major discoveries of how the Universe operates and also things that relate to 10 dimensions and beyond. Like i said if we get one variable or coefficient wrong it can change our whole view of reality.tilda-psychist

    Yes, you're right and, as I said, all scientists do is model reality with empirically-verified theory. So while it's right to say our whole "view of reality" (i.e. theoretical model of it) can massively change, the change in what it predicts (phenomena) have to be extremely restricted to match prior observations. The universe may behave as if it has precisely 11 dimensions, say. It might have 111. It might only have 4 or 5. But it behaves like it has 11.

    Likewise it behaves as if there's dark matter and dark energy in a universe and otherwise follows current cosmological models. And it will behave differently in future cosmological models. More dark matter, less, none, dark matter made of one thing, dark matter made of fudge. As I said before:

    Dark matter is supposed to make up 80% of massive matter in order to explain the rotational velocity of galaxies. As accurate mass estimates for galaxies are on-going (e.g. only recently have we realised the abundance of supermassive black holes), it's worth treating with some scepticism. Dark matter is, sceptically, an error between current cosmological estimates of mass and current astronomical measurements of mass.Kenosha Kid
  • tilda-psychist
    53
    Basically i'm saying some people know more than others however there is no end in sight of Scientists still having major discoveries of how the Universe operates and also things that relate to 10 dimensions and beyond. Like i said if we get one variable or coefficient wrong it can change our whole view of reality.
    — tilda-psychist

    Yes, you're right and, as I said, all scientists do is model reality with empirically-verified theory. So while it's right to say our whole "view of reality" (i.e. theoretical model of it) can massively change, the change in what it predicts (phenomena) have to be extremely restricted to match prior observations. The universe may behave as if it has precisely 11 dimensions, say. It might have 111. It might only have 4 or 5. But it behaves like it has 11.

    Likewise it behaves as if there's dark matter and dark energy in a universe and otherwise follows current cosmological models. And it will behave differently in future cosmological models. More dark matter, less, none, dark matter made of one thing, dark matter made of fudge. As I said before:

    Dark matter is supposed to make up 80% of massive matter in order to explain the rotational velocity of galaxies. As accurate mass estimates for galaxies are on-going (e.g. only recently have we realised the abundance of supermassive black holes), it's worth treating with some scepticism. Dark matter is, sceptically, an error between current cosmological estimates of mass and current astronomical measurements of mass.
    — Kenosha Kid
    Kenosha Kid

    probably true. I'm about high school calculus level so i guess your right.
  • Enai De A Lukal
    112
    Here's the official press release, and the actual paper, for anyone who is interested:

    https://releases.jhu.edu/2019/08/08/dark-matter-may-be-older-than-the-big-bang-study-suggests/

    https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.061302

    (as Pfhorrest already noted, this is less of a shocking result than it may seem since the "Big Bang" in this context is the post-inflationary period in the inflationary model, not the hypothetical "t=0" spacetime singularity of non-inflationary big bang cosmology often referred to as "the big bang")
  • tilda-psychist
    53


    thanks i'll add it to my journal.
  • fishfry
    1.5k
    In contemporary inflationary cosmology, the universe isn't "everything that happened after the big bang". The big bang is just an important early event in the history of the universe as we know it (which may be only a small part of the total universe, which may be infinitely old, if eternal inflation is correct).Pfhorrest

    Have you a specific reference to that meaning of the universe? I know that Lawrence Krauss says that the universe "came from nothing," meaning in a technical sense that it spontaneously big banged out of the fluctuating quantum fields. He was certainly using universe in the sense I did: whatever happened after the big bang.

    Other than Penrose's cyclic conformal cosmology, there is an endless succession of universes But even then, a universe is what happens between successive big bangs.

    I'd like to see a reference to the definition of the universe as something that includes the big bang plus something else, other than Penrose's theory. This would be new to me.

    Secondly, do you have a reference for any physicist claiming (while doing physics, not metaphysical speculation) that the universe is infinite in duration? Did it have a beginning or is there an infinite regress? Perhaps it goes back as 1/2, 1/4, 1/8, etc., so that although there's an infinite regress yet there is also a greatest lower bound.

    Since I don't believe there are any physics grants going to postdocs to investigate these questions, I must -- at the risk of appearing overly blunt -- call bullpucky on each of your two claims that (1) the word universe commonly or standardly or even occasionally means something other than whatever happened after the big bang or the most recent big bang; and (2) that anyone seriously claims the universe is infinite either in the past or the future.

    If you have references I'd be glad for the education.

    ps -- The Wiki page on eternal inflation contradicts your claim about an infinite past.

    "Alan Guth's 2007 paper, "Eternal inflation and its implications",[3] states that under reasonable assumptions "Although inflation is generically eternal into the future, it is not eternal into the past."" My emphasis.

    https://en.wikipedia.org/wiki/Eternal_inflation
  • Pfhorrest
    2.5k
    I'm not saying anything about the definition of the word "universe", just that in a lot of contemporary physics, people use "big bang" to refer not to a singularity at the start of time, but to the end of cosmological inflation; there was already a universe before "the big bang". Like Enai De A Lukal just said upthread:

    (as Pfhorrest already noted, this is less of a shocking result than it may seem since the "Big Bang" in this context is the post-inflationary period in the inflationary model, not the hypothetical "t=0" spacetime singularity of non-inflationary big bang cosmology often referred to as "the big bang")Enai De A Lukal

    Some inflationary models do still posit a singularity at the beginning of time, in which case the universe had a beginning just as in ordinary non-inflationary big bang models. But there is also a model of eternal inflation, where there wasn't necessarily any start of time, just a local stop of inflation, which is the "big bang" for all intents and purposes as we usually mean it, in such a model. It seems to be in that context of eternal inflation specifically that the term "big bang" is used that way, rather than to mean a singularity.

    You can start here for info on eternal inflation:

    https://en.wikipedia.org/wiki/Eternal_inflation

    The YouTube channel PBS Space Time also has a great series of five video about it, full playlist here:

    https://www.youtube.com/playlist?list=PLsPUh22kYmNCc3WCKb5yF136QSRf0xErm

    But I think these are probably the two that are most relevant:



  • Enai De A Lukal
    112
    Sure, a pretty important distinction I should have mentioned. And Matt O'Dowd is awesome, btw.
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