The standard and inflationary models
* Have you read the preceding page on the Big Bang- "a universe from nothing"?
Just to add to the confusion, there are not one but two big bang theories: standard big bang and the inflationary cosmology version, sometimes described as a “front end” for the standard big bang model[1], and there's also another inflationary cosmology version on the next page.
The originator of the inflationary model was a young particle physicist and postdoctoral fellow named Alan Guth. In 1981, he postulated that in the roiling frenzy of the early universe, a random quantum fluctuation or “small patch of weirdness” took place when a configuration of matter and radiation became trapped in an area of space which super cooled. It stayed in this high-energy negative-pressure state for only the briefest of moments but while there the latent heat it generated gave rise to a repulsive gravitational push causing the early universe to suddenly expand in a monumental way driving every region of space away from every other, filling space with a large potential energy and negative pressure[2].
The standard model offers no explanation as to why the universe suddenly expanded the way it did, nor does it explain the surprising uniformity of temperature throughout the universe (originally 1032 Kelvin, about 1 x 10-43 seconds after the bang, presently 2.7K in deep space), nor the apparent flatness and homogeneity of the universe, whereas the inflationary cosmology model offers explanations for all these.
[1] See generally Greene (2005), Chs 9, 10, 11.
[2] Greene (2005), 281-2.
Inflationary theory [0]
According to one of the "less well known aspects of Einstein’s theory of general relativity", described by Brian Greene, gravity depends not only on mass and energy (heat), but also on pressure. In a nutshell, whereas positive or outward-directed pressure contributes to ordinary attractive gravity, negative or inward pressure contributes to repulsive gravity, and if the negative pressure in a region is negative enough it will triumph over the attractive force of gravity arising from ordinary mass and energy and will force things apart rather than draw them together[1].
Under the inflationary cosmology model, just as a stick of dynamite explodes only when it is properly lit, the bang happened only when conditions were right – in other words, when there was a field whose value provided the energy and negative pressure that fuelled the outward burst of repulsive gravity – and that moment need not necessarily have coincided with the creation of the universe. For this reason the inflationary bang is best thought of as an event that the present universe experienced, but not necessarily the event that created the universe[2].
Inflationary cosmology is not a single, unique theory. Rather is it a cosmological framework built around the realisation that gravity can be repulsive and thus drive a swelling of space. The precise details of this outward burst – when it happened, how long it lasted, the strength of the outward push, the factor by which the universe expanded during the burst, the amount of energy the field deposited in ordinary matter as the burst drew to a close, and so on – depend on details that are presently beyond our ability to determine from theoretical considerations alone[3]. The difference between the two models is graphically illustrated in the illustrations below[4].
[0] The concepts of inflationary cosmology, the inflaton field and repulstive gravity are all considered in the Brian Cox documentary "Life of a universe: Creation" at https://www.youtube.com/watch?v=Or2Itbzxo6A
[1] See also Michael S Turner, op cit, p 41- “In the Dark”.
[2] Greene (2005), 285-6.
[3] Greene (2005), 286-7.
[4] Source: Greene (2005), 270, 286.
Just to add to the confusion, there are not one but two big bang theories: standard big bang and the inflationary cosmology version, sometimes described as a “front end” for the standard big bang model[1], and there's also another inflationary cosmology version on the next page.
The originator of the inflationary model was a young particle physicist and postdoctoral fellow named Alan Guth. In 1981, he postulated that in the roiling frenzy of the early universe, a random quantum fluctuation or “small patch of weirdness” took place when a configuration of matter and radiation became trapped in an area of space which super cooled. It stayed in this high-energy negative-pressure state for only the briefest of moments but while there the latent heat it generated gave rise to a repulsive gravitational push causing the early universe to suddenly expand in a monumental way driving every region of space away from every other, filling space with a large potential energy and negative pressure[2].
The standard model offers no explanation as to why the universe suddenly expanded the way it did, nor does it explain the surprising uniformity of temperature throughout the universe (originally 1032 Kelvin, about 1 x 10-43 seconds after the bang, presently 2.7K in deep space), nor the apparent flatness and homogeneity of the universe, whereas the inflationary cosmology model offers explanations for all these.
[1] See generally Greene (2005), Chs 9, 10, 11.
[2] Greene (2005), 281-2.
Inflationary theory [0]
According to one of the "less well known aspects of Einstein’s theory of general relativity", described by Brian Greene, gravity depends not only on mass and energy (heat), but also on pressure. In a nutshell, whereas positive or outward-directed pressure contributes to ordinary attractive gravity, negative or inward pressure contributes to repulsive gravity, and if the negative pressure in a region is negative enough it will triumph over the attractive force of gravity arising from ordinary mass and energy and will force things apart rather than draw them together[1].
Under the inflationary cosmology model, just as a stick of dynamite explodes only when it is properly lit, the bang happened only when conditions were right – in other words, when there was a field whose value provided the energy and negative pressure that fuelled the outward burst of repulsive gravity – and that moment need not necessarily have coincided with the creation of the universe. For this reason the inflationary bang is best thought of as an event that the present universe experienced, but not necessarily the event that created the universe[2].
Inflationary cosmology is not a single, unique theory. Rather is it a cosmological framework built around the realisation that gravity can be repulsive and thus drive a swelling of space. The precise details of this outward burst – when it happened, how long it lasted, the strength of the outward push, the factor by which the universe expanded during the burst, the amount of energy the field deposited in ordinary matter as the burst drew to a close, and so on – depend on details that are presently beyond our ability to determine from theoretical considerations alone[3]. The difference between the two models is graphically illustrated in the illustrations below[4].
[0] The concepts of inflationary cosmology, the inflaton field and repulstive gravity are all considered in the Brian Cox documentary "Life of a universe: Creation" at https://www.youtube.com/watch?v=Or2Itbzxo6A
[1] See also Michael S Turner, op cit, p 41- “In the Dark”.
[2] Greene (2005), 285-6.
[3] Greene (2005), 286-7.
[4] Source: Greene (2005), 270, 286.
Above: the standard big bang model with temperature cooling time frame (from 1028 K 10-35 seconds after the big bang to 2.7k today. The inflationary cosmology model appears below. The fuzzy areas on the left of each represent the areas whose origins are unknown to us.
In the illustration above, (a) represents a quick, enormous burst of energy early on in the universe; and (b) shows that after the burst, the evolution of the universe merges into the standard evolution theorised in the big bang model.
What then seems to have happened under the inflationary model
10-47 after the bang the universe was trillions of times smaller than the size of a proton (10-24 m)[1]. Its size then increased by a factor larger than a million trillion trillion in less than a millionth of a trillionth of a second[2]: in astronomy-speak, 1 x 10-43 seconds, when the temperature was about 1032 Kelvin[3] [3.1]. 1 x 10-43 seconds is the time it then took light to travel across the universe.
It is represented by a decimal point followed by 42 zeros and a one[4] in seconds, and is known as the Planck time after the person who formulated the calculation, the renowned German scientist Max Planck, a leading figure in quantum mechanics who also devised similar formulae governing the discrete units of energy, mass and the other components into which the microscopic world is partitioned. This enormous expansion smoothed out any irregularities and meant that the universe was uniform on scales much larger than our cosmic horizon.
How to explain this sudden inflation? Initially, all four fundamental forces (strong, weak, electromagnetic, gravity) were fused and radiation and mass were coupled together. Gravity separated from the other forces (at 10-43 seconds after the big bang) and then the strong nuclear force. The ramifications of this latter departure were dramatic, as we shall shortly see.
Theoretical physicists then think that when the universe was about a millionth of a millionth of a second (10-12 seconds) old, the electromagnetic and weak forces, once a single unified force, separated as the universe cooled. We deal here with the two phase transitions involved in reverse order, thus:
(EM and W combined as electroweak force) // W separates >> Phase transition 2
This is known as the phenomenon of spontaneous symmetry breaking, which describes what happens when forces once unified become separate.[5] The result was a phase transition, endowing once empty space with a background field (the Higgs field) which affected the way particles propagate through empty space. “Those particles that interact with the field – the ones that convey the weak force, for example – experience a resistance that causes them to behave as massive particles. Those that do not interact with the field – for example, the photon, carrier of the electromagnetic force – remain massless. As a result, the weak force and the electromagnetic force began to behave in different ways, breaking the symmetry that otherwise unified them”. This scenario was validated at the LHC at CERN near Geneva in 2012 with the discovery of the Higgs Boson.
But perhaps, reasoned Guth, a similar symmetry-breaking event happened even earlier in the universe’s past when three of the universe’s forces: the electro-magnetic, weak and strong forces (the later responsible for holding protons and neutrons together) - but excluding gravity - which were once connected, separated when the universe cooled when it was approximately 10-36 of a second old. There is a great deal of indirect evidence to this effect. As it cooled, the universe may then have undergone a phase transition that also changed the nature of space involving a background field that caused the electroweak force to begin to behave differently from the strong force, thereby spontaneously breaking their symmetries or connectedness, thus:
(E-M, Weak and Strong combined) // S separates, leaving EM and W remaining as a combined electroweak force >> Phase transition 1.
Such an event would also lead to exotic and very massive particles, much higher than the mass of the Higgs boson.
Alan Guth realised that such spontaneous symmetry breaking in the early universe could solve all the problems of the standard big bang if, for a short period at least, the field responsible for this symmetry-breaking got stuck in a so-called “metastable state”, one verging on stability and non-stability, in which its high energy was harbouring tremendous latent heat which was then released resulting in a grand repulsive gravitational push through space.
Drawing upon an analogy from a more familiar context, water turning to ice is a phase transition, involving two different forms of the same substance. A metastable state occurs where the ambient temperature drops quickly below freezing, but water on the street does not immediately freeze. When it eventually does freeze, the water releases its stored energy in the form of latent heat[6]. Lawrence Krauss also gives the example of a beer in liquid form in a fridge. Take it out and open it releasing the pressure and it will freeze in your hand. This happens because at high pressure the preferred lowest energy state of the beer is in liquid form, whereas once the pressure has been released, the preferred lowest energy state of the beer is the solid state, and during this phase transition, energy can be released because the lowest energy state in one phase can have lower energy than the lowest energy state in the other, which then becomes the high energy state of the phase transition[7].
In similar fashion, the field that caused the Grand Unified Theory’s phase transition from a state when all the forces bar gravity were unified might have briefly stored tremendous latent energy throughout space. This was the high energy or “liquid” phase of the transition. It stayed in this high-energy negative-pressure state for only the briefest of moments, but while there the latent heat it generated gave rise to a repulsive gravitational push causing the early universe to suddenly expand in a monumental way driving every region of space away from every other, filling space with a large potential energy and negative pressure. The repulsion lasted only about 10-36 to 10-35 seconds, but it was so powerful that even in that brief moment, the universe swelled by a huge factor, possibly by a factor of 1030, 1050 or 10100.[8]
An expansion factor of 1030 - a conservative estimate – would be like scaling up a molecule of DNA to roughly the size of the Milky Way galaxy, and in a time interval that’s much shorter than a billionth of a billionth of the blink of an eye. Such extreme expansion would also tend to make the universe we observe today flat and isotropic, thus naturally addressing the two apparent paradoxes on the large-scale structure of the universe”. We still do not know the precise energy levels at which the forces would have been unified, something which may be able to be gleaned from gravitational waves. Being a direct echo of the big bang and spreading out thereafter at the speed of light, gravitational waves may provide an opportunity to probe for evidence that the universe actually underwent inflation and the means by which it may have done so.
Roughly 10-35 seconds after the burst began, this repulsive push subsided as the inflation field released its pent-up energy in the production of a uniform bath of ordinary particles of matter “like a foggy mist settling on the grass as morning dew”, and with radiation, uniformly filling the expanding spatial expanse. Under the standard model, the further back in time the theory looks the greater the amount of mass/energy which must be explained, whereas the inflationary model offers a cogent explanation as to how and when they came into being[9]. According to Greene, inflation is far and away the front-running cosmological theory, so much so that it bears description as “our generation’s most important and most lasting contribution to cosmological science”[10].
From this point on, the story is essentially that of the standard big bang theory: space continued to expand and cool in the aftermath of the burst, allowing particles of matter to clump into structures like galaxies, stars and planets, which slowly arranged themselves into the universe we currently see.
A link between the vastness of the universe and the cosmos' tiniest particles via inflation
It has recently (2019) been suggested that the cosmos' smallest particles and the distribution of matter such as galaxies and the CMBR across the vast universe are in fact linked.
In fact, researchers argue the cosmos is like one big particle accelerator, and that the study of the vast distribution of cosmic matter could offer new insights into the nature of quantum mechanical particles. "Ongoing observations of cosmological microwave background and large scale structures have achieved impressive precision, from which valuable information about primordial density perturbations can be extracted," said Yi Wang, a professor at the Hong Kong University of Science and Technology.
The Standard Model of physics describes the behaviour of all known particles, but researchers believe the large-scale structures of the universe could reveal modes of particle behaviour beyond the Standard Model. Researchers used advanced astrophysical algorithms to measure the distribution of the Standard Model spectrum during cosmic inflation. The spectrum of the Standard Model particles turned out to be very different at the time of inflation from what it is now due to the inflationary background.
Through inflation, the spectrum of elementary particles is encoded in the statistics of the distribution of the contents of the universe, such as the galaxies and cosmic microwave background, that we observe today. This is the connection between the smallest and largest. If some new particles can mediate stronger interactions between these two sectors, we would expect to observe a stronger signal of new physics.[11]
[1] Helen Johnston, From the Big Bang to Life, CCE course.
[2] Greene (2005), 14-15.
[3] The Kelvin scale is an absolute thermodynamic temperature scale using as its null point absolute zero, the temperature at which all thermal motion ceases in the classical description of thermodynamics.
[3.1] Juan Garcia-Bellido and Sébastien Clesse make the comparison of two points separated by less than an atomic radius becoming separated by four light years, a distance comparable to that of the closest stars in an infinitesimal amount of time, 10-35 seconds: see their article on dark matter and primordial black holes, "Black holes from the beginning of time", Scientific American, July 2017, 30 at 33.
[4] 1043 means 1 followed by 42 zeros, and 10-43 stands for 1/1043. This is the standard powers-of-ten notation. A power-of-ten is also known as an order of magnitude. To get a feel for this, see the You Tube video https://www.youtube.com/watch?v=0fKBhvDjuy0 Also, the illustrated Scientific American text by Caleb Scharf, The Zoomable Universe (2017). These standard forms of notation appear frequently throughout the text.
[5] For this scenario which bears elaboration in subsequent paragraphs, see Lawrence M. Krauss, “A beacon from the Big Bang”, Scientific American, October 2014, 47 at 51-2.
[6] Ibid at 51-2.
[7] From his book A Universe from Nothing – Why there is something rather than nothing, Free Press, 2011, New York, 95ff, esp 96. See also his article, referred to later in the context of gravitational waves, “A beacon from the Big Bang”, Scientific American, October 2014, 46.
[8] Greene (2005), 312-3.
[9] Ibid. See also Michael S Turner, op cit, 41.
[10] Greene (2005), 303.
[11] This is an edited summary of the article "Scientists find link between vastness of the universe, cosmos' tiniest particles", by Brooks Hays at https://www.upi.com/Science_News/2017/07/19/Scientists-find-link-between-vastness-of-the-universe-cosmos-tiniest-particles/9391500484261/
The universe consists of a hot quark-gluon soup
As it continued to expand and cool, the universe consisted of a hot, formless quark-gluon soup comprised of the most elementary particles, including leptons (electrons and neutrinos) and antiparticles[1]. At this very early period of the universe’s existence, the scales under consideration were most minute (distance and time) and incredibly dense (mass): about 10 billion billion times the mass of a proton; about one hundredth of a thousandth of a gram; about the mass of a small grain of dust[2] (the Planck mass). This hot soup of mostly unconnected subatomic particles was too hot to allow them to come together to form atoms and molecules. Photons, the smallest component of light, were bounced back and forth by the electrically charged particles before the light could travel very far. There has also been speculation that dark matter was created at this early ‘quark soup’ stage of the universe’s formation[3].
[1] Michael S Turner, “Origin of the Universe”, op cit, 38. Remember, quarks and leptons represent the stuff matter is composed of (fermions). Gluons are the particles of the strong nuclear force.
[2] Brian Greene, The Elegant Universe – Superstrings, Higher Dimensions and the Quest for the Ultimate Theory, Vintage, Great Britain, 2000, 149, 419.
[3] Michel S Turner, op cit, 40.
Footnote
In Scientific American’s February 2017 edition, an article appeared under the hands of Anna Iljas, Paul J Steinhardt and Abraham Loeb (IS&L) entitled “POP goes the universe”. The article argued against the dominant idea that the early cosmos underwent an extremely rapid expansion, and suggested another scenario – that our universe began not with a bang but with a bounce from a previously contracting universe. The article concluded by asserting that “inflationary cosmology, as we currently understand it, cannot be evaluated using the scientific method” and went on to assert that some scientists who accept inflation have proposed discarding empirical testing of the theory.
In Scientific American’s July 2017 edition at pages 4 to 5, a vigorous defence of the theory appeared under the hand of no less than 33 physicists who study inflationary cosmology, with names such as Alan Guth, Andrei Lindt, Stephen hawking, Lawrence Kraus, Juan Maldacena, Leonard Susskind, Michael Turner, Steven Weinberg, and Ed Witten prominent among them. The authors assert, inter alia, that the various inflationary models can indeed be tested empirically, predicting as they do that the universe should have critical mass density (that is, it should be geometrically flat) and they also predict the statistical properties of the faint ripples we detect in the CMBR.
The former, say the authors, has now been measured to an accuracy of almost half of a percent, agreeing perfectly with inflation’s predictions; further that the CMBR’s ripples have been measured by satellite experiments including the WMAP and the Planck satellite, as well as many ground- and balloon- based experiments, all confirming the predictions of the standard models of inflation. A response by IS&L appears on the following page.
10-47 after the bang the universe was trillions of times smaller than the size of a proton (10-24 m)[1]. Its size then increased by a factor larger than a million trillion trillion in less than a millionth of a trillionth of a second[2]: in astronomy-speak, 1 x 10-43 seconds, when the temperature was about 1032 Kelvin[3] [3.1]. 1 x 10-43 seconds is the time it then took light to travel across the universe.
It is represented by a decimal point followed by 42 zeros and a one[4] in seconds, and is known as the Planck time after the person who formulated the calculation, the renowned German scientist Max Planck, a leading figure in quantum mechanics who also devised similar formulae governing the discrete units of energy, mass and the other components into which the microscopic world is partitioned. This enormous expansion smoothed out any irregularities and meant that the universe was uniform on scales much larger than our cosmic horizon.
How to explain this sudden inflation? Initially, all four fundamental forces (strong, weak, electromagnetic, gravity) were fused and radiation and mass were coupled together. Gravity separated from the other forces (at 10-43 seconds after the big bang) and then the strong nuclear force. The ramifications of this latter departure were dramatic, as we shall shortly see.
Theoretical physicists then think that when the universe was about a millionth of a millionth of a second (10-12 seconds) old, the electromagnetic and weak forces, once a single unified force, separated as the universe cooled. We deal here with the two phase transitions involved in reverse order, thus:
(EM and W combined as electroweak force) // W separates >> Phase transition 2
This is known as the phenomenon of spontaneous symmetry breaking, which describes what happens when forces once unified become separate.[5] The result was a phase transition, endowing once empty space with a background field (the Higgs field) which affected the way particles propagate through empty space. “Those particles that interact with the field – the ones that convey the weak force, for example – experience a resistance that causes them to behave as massive particles. Those that do not interact with the field – for example, the photon, carrier of the electromagnetic force – remain massless. As a result, the weak force and the electromagnetic force began to behave in different ways, breaking the symmetry that otherwise unified them”. This scenario was validated at the LHC at CERN near Geneva in 2012 with the discovery of the Higgs Boson.
But perhaps, reasoned Guth, a similar symmetry-breaking event happened even earlier in the universe’s past when three of the universe’s forces: the electro-magnetic, weak and strong forces (the later responsible for holding protons and neutrons together) - but excluding gravity - which were once connected, separated when the universe cooled when it was approximately 10-36 of a second old. There is a great deal of indirect evidence to this effect. As it cooled, the universe may then have undergone a phase transition that also changed the nature of space involving a background field that caused the electroweak force to begin to behave differently from the strong force, thereby spontaneously breaking their symmetries or connectedness, thus:
(E-M, Weak and Strong combined) // S separates, leaving EM and W remaining as a combined electroweak force >> Phase transition 1.
Such an event would also lead to exotic and very massive particles, much higher than the mass of the Higgs boson.
Alan Guth realised that such spontaneous symmetry breaking in the early universe could solve all the problems of the standard big bang if, for a short period at least, the field responsible for this symmetry-breaking got stuck in a so-called “metastable state”, one verging on stability and non-stability, in which its high energy was harbouring tremendous latent heat which was then released resulting in a grand repulsive gravitational push through space.
Drawing upon an analogy from a more familiar context, water turning to ice is a phase transition, involving two different forms of the same substance. A metastable state occurs where the ambient temperature drops quickly below freezing, but water on the street does not immediately freeze. When it eventually does freeze, the water releases its stored energy in the form of latent heat[6]. Lawrence Krauss also gives the example of a beer in liquid form in a fridge. Take it out and open it releasing the pressure and it will freeze in your hand. This happens because at high pressure the preferred lowest energy state of the beer is in liquid form, whereas once the pressure has been released, the preferred lowest energy state of the beer is the solid state, and during this phase transition, energy can be released because the lowest energy state in one phase can have lower energy than the lowest energy state in the other, which then becomes the high energy state of the phase transition[7].
In similar fashion, the field that caused the Grand Unified Theory’s phase transition from a state when all the forces bar gravity were unified might have briefly stored tremendous latent energy throughout space. This was the high energy or “liquid” phase of the transition. It stayed in this high-energy negative-pressure state for only the briefest of moments, but while there the latent heat it generated gave rise to a repulsive gravitational push causing the early universe to suddenly expand in a monumental way driving every region of space away from every other, filling space with a large potential energy and negative pressure. The repulsion lasted only about 10-36 to 10-35 seconds, but it was so powerful that even in that brief moment, the universe swelled by a huge factor, possibly by a factor of 1030, 1050 or 10100.[8]
An expansion factor of 1030 - a conservative estimate – would be like scaling up a molecule of DNA to roughly the size of the Milky Way galaxy, and in a time interval that’s much shorter than a billionth of a billionth of the blink of an eye. Such extreme expansion would also tend to make the universe we observe today flat and isotropic, thus naturally addressing the two apparent paradoxes on the large-scale structure of the universe”. We still do not know the precise energy levels at which the forces would have been unified, something which may be able to be gleaned from gravitational waves. Being a direct echo of the big bang and spreading out thereafter at the speed of light, gravitational waves may provide an opportunity to probe for evidence that the universe actually underwent inflation and the means by which it may have done so.
Roughly 10-35 seconds after the burst began, this repulsive push subsided as the inflation field released its pent-up energy in the production of a uniform bath of ordinary particles of matter “like a foggy mist settling on the grass as morning dew”, and with radiation, uniformly filling the expanding spatial expanse. Under the standard model, the further back in time the theory looks the greater the amount of mass/energy which must be explained, whereas the inflationary model offers a cogent explanation as to how and when they came into being[9]. According to Greene, inflation is far and away the front-running cosmological theory, so much so that it bears description as “our generation’s most important and most lasting contribution to cosmological science”[10].
From this point on, the story is essentially that of the standard big bang theory: space continued to expand and cool in the aftermath of the burst, allowing particles of matter to clump into structures like galaxies, stars and planets, which slowly arranged themselves into the universe we currently see.
A link between the vastness of the universe and the cosmos' tiniest particles via inflation
It has recently (2019) been suggested that the cosmos' smallest particles and the distribution of matter such as galaxies and the CMBR across the vast universe are in fact linked.
In fact, researchers argue the cosmos is like one big particle accelerator, and that the study of the vast distribution of cosmic matter could offer new insights into the nature of quantum mechanical particles. "Ongoing observations of cosmological microwave background and large scale structures have achieved impressive precision, from which valuable information about primordial density perturbations can be extracted," said Yi Wang, a professor at the Hong Kong University of Science and Technology.
The Standard Model of physics describes the behaviour of all known particles, but researchers believe the large-scale structures of the universe could reveal modes of particle behaviour beyond the Standard Model. Researchers used advanced astrophysical algorithms to measure the distribution of the Standard Model spectrum during cosmic inflation. The spectrum of the Standard Model particles turned out to be very different at the time of inflation from what it is now due to the inflationary background.
Through inflation, the spectrum of elementary particles is encoded in the statistics of the distribution of the contents of the universe, such as the galaxies and cosmic microwave background, that we observe today. This is the connection between the smallest and largest. If some new particles can mediate stronger interactions between these two sectors, we would expect to observe a stronger signal of new physics.[11]
[1] Helen Johnston, From the Big Bang to Life, CCE course.
[2] Greene (2005), 14-15.
[3] The Kelvin scale is an absolute thermodynamic temperature scale using as its null point absolute zero, the temperature at which all thermal motion ceases in the classical description of thermodynamics.
[3.1] Juan Garcia-Bellido and Sébastien Clesse make the comparison of two points separated by less than an atomic radius becoming separated by four light years, a distance comparable to that of the closest stars in an infinitesimal amount of time, 10-35 seconds: see their article on dark matter and primordial black holes, "Black holes from the beginning of time", Scientific American, July 2017, 30 at 33.
[4] 1043 means 1 followed by 42 zeros, and 10-43 stands for 1/1043. This is the standard powers-of-ten notation. A power-of-ten is also known as an order of magnitude. To get a feel for this, see the You Tube video https://www.youtube.com/watch?v=0fKBhvDjuy0 Also, the illustrated Scientific American text by Caleb Scharf, The Zoomable Universe (2017). These standard forms of notation appear frequently throughout the text.
[5] For this scenario which bears elaboration in subsequent paragraphs, see Lawrence M. Krauss, “A beacon from the Big Bang”, Scientific American, October 2014, 47 at 51-2.
[6] Ibid at 51-2.
[7] From his book A Universe from Nothing – Why there is something rather than nothing, Free Press, 2011, New York, 95ff, esp 96. See also his article, referred to later in the context of gravitational waves, “A beacon from the Big Bang”, Scientific American, October 2014, 46.
[8] Greene (2005), 312-3.
[9] Ibid. See also Michael S Turner, op cit, 41.
[10] Greene (2005), 303.
[11] This is an edited summary of the article "Scientists find link between vastness of the universe, cosmos' tiniest particles", by Brooks Hays at https://www.upi.com/Science_News/2017/07/19/Scientists-find-link-between-vastness-of-the-universe-cosmos-tiniest-particles/9391500484261/
The universe consists of a hot quark-gluon soup
As it continued to expand and cool, the universe consisted of a hot, formless quark-gluon soup comprised of the most elementary particles, including leptons (electrons and neutrinos) and antiparticles[1]. At this very early period of the universe’s existence, the scales under consideration were most minute (distance and time) and incredibly dense (mass): about 10 billion billion times the mass of a proton; about one hundredth of a thousandth of a gram; about the mass of a small grain of dust[2] (the Planck mass). This hot soup of mostly unconnected subatomic particles was too hot to allow them to come together to form atoms and molecules. Photons, the smallest component of light, were bounced back and forth by the electrically charged particles before the light could travel very far. There has also been speculation that dark matter was created at this early ‘quark soup’ stage of the universe’s formation[3].
[1] Michael S Turner, “Origin of the Universe”, op cit, 38. Remember, quarks and leptons represent the stuff matter is composed of (fermions). Gluons are the particles of the strong nuclear force.
[2] Brian Greene, The Elegant Universe – Superstrings, Higher Dimensions and the Quest for the Ultimate Theory, Vintage, Great Britain, 2000, 149, 419.
[3] Michel S Turner, op cit, 40.
Footnote
In Scientific American’s February 2017 edition, an article appeared under the hands of Anna Iljas, Paul J Steinhardt and Abraham Loeb (IS&L) entitled “POP goes the universe”. The article argued against the dominant idea that the early cosmos underwent an extremely rapid expansion, and suggested another scenario – that our universe began not with a bang but with a bounce from a previously contracting universe. The article concluded by asserting that “inflationary cosmology, as we currently understand it, cannot be evaluated using the scientific method” and went on to assert that some scientists who accept inflation have proposed discarding empirical testing of the theory.
In Scientific American’s July 2017 edition at pages 4 to 5, a vigorous defence of the theory appeared under the hand of no less than 33 physicists who study inflationary cosmology, with names such as Alan Guth, Andrei Lindt, Stephen hawking, Lawrence Kraus, Juan Maldacena, Leonard Susskind, Michael Turner, Steven Weinberg, and Ed Witten prominent among them. The authors assert, inter alia, that the various inflationary models can indeed be tested empirically, predicting as they do that the universe should have critical mass density (that is, it should be geometrically flat) and they also predict the statistical properties of the faint ripples we detect in the CMBR.
The former, say the authors, has now been measured to an accuracy of almost half of a percent, agreeing perfectly with inflation’s predictions; further that the CMBR’s ripples have been measured by satellite experiments including the WMAP and the Planck satellite, as well as many ground- and balloon- based experiments, all confirming the predictions of the standard models of inflation. A response by IS&L appears on the following page.