"Unintelligent design"
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Teeth are evidence for a creator!
- Thread starter Spiderman
- Start date
stvdv
Veteran Member
****, I recently lost 50% of my evidence
osgart
Nothing my eye, Something for sure
Thank you. Could you explain a little more what inspired the last two sentences of the quoted post? Thank you!
The guy up earlier argued that intellectual honesty was needed to see that mindless natural processes produce all of function in nature without purposes. So I took offense to that.
Spiderman
Veteran Member
God is not nice sometimes, but we all have to die. This is a brief journey.
I would actually be relieved if tomorrow I found out I have cancer that will kill me in six months with no cure, not because cancer is a pleasant way to die. I'm sure it's miserable , from what I hear.
But I could spend those six months not worrying about what to do with my life, making amends, being kind to others, free of responsibilities, being humble, being prayerful, enjoying nature, forgiving everyone, and preparing for the other side.
I respect those who don't believe we go on living after death, but too many factors have caused me to have unshakable conviction otherwise, and so this world is brief, I don't like it much, and truly I welcome death. It's very much a part of everyone's life.
When it was time for Jesus to be crucified, he explained the crucifixion as being the cup his Father prepared for him.
I suppose cancer could be a similar cup.
In Christian Theology, if you take away the cross and crucifixion, you take away redemption, the glory of the resurrection, and atonement.
I would prefer cancer didn't exist, but if victims of cancer are awarded, exalted, and glorified as martyrs, for the sufferings they endured on earth, rewarded for their pain + affliction/misfortune, they probably won't see it as a bad thing once it's over.
But I respect those who see it differently.
And I get angry at God, and think he should eliminate cancer, ticks, and mosquitoes, and countless other terrible crosses, annoyances, pests, or disasters on earth.
But we have to practice radical acceptance of what is out of our control.
What is displayed in this picture is galactic filaments as seen in the early universe. (1+ billion light years).
So could you please explain how gravitational attraction of various sized galaxies can cause them to pull into what is essentially a random web can in any way be considered highly organised?
But this is all explained by natural selection, isn't it?
Why would you consider magic when ordinary, familiar processes already explain a phenomenon?
What is the source of this picture? Is this a computer generation of what we would at + 1 billion years or an actual picture.
To be random it has to be without order or pattern and without pcause.
Careful 'arguing from ignorance' concerning what we see. First nothing is found go be truly random. The is why I mentioned 'fractal patterns as in 'chaos theory,' which is best to explain the pattern we see. I am not arguing that all has been answered just that the causes for the
In the earliest time of our universe 'Quantum Mechanics and Quantum Gravity' ruled.
There are a number of possible explanations for what occurred during the earliest history of the universe.
Physics - A Glance at the Earliest Universe
A Glance at the Earliest Universe
Parampreet Singh- Department of Physics & Astronomy, Louisiana State University, Baton Rouge, LA 70803, USA
A new cosmological theory tackles the description of the earliest era of the Universe, a period inaccessible by current models.
APS/Alan Stonebraker
Figure 1: Scheme of the evolution of the Universe according to the model of Agullo et al., based on a loop-quantum-gravity (LQG) extension of the inflationary paradigm (figure is not to scale). LQG is used to describe the early Universe of the Planck era. The ... Show more
Cosmological inflation, the hypothesis that the early Universe underwent an extremely rapid expansion, is a popular paradigm in modern cosmology. The theory successfully explains how quantum mechanical fluctuations of the vacuum, starting about 10-36" role="presentation" style="box-sizing: border-box; display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">10−3610-36 seconds after the big bang, could have given rise to the large-scale structure of our Universe, leading to predictions that have been confirmed by a range of cosmological observations. However, inflationary cosmology cannot be the ultimate theory of the Universe. If one projects the Universe backward in time, it gets so hot and dense that the laws of physics on which inflation is based (classical general relativity) break down. In the so-called Planck era, lasting up to one Planck second ( 10-43s" role="presentation" style="box-sizing: border-box; display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">10−43s10-43s) after the big bang, the force of gravity would have reached values comparable to the other fundamental forces. In this regime, quantum gravity effects would have been important, creating conditions that go beyond the conventional understanding of space and time.
What conditions existed prior to inflation and to what extent do they affect the predictions of the inflationary model? Such fundamental cosmological questions remain unanswered, since we don’t yet have a theory that can tackle the physics of the preinflation era and smoothly connect it to the inflationary period. Writing in Physical Review Letters, Ivan Agullo and colleagues at Pennsylvania State University in University Park, take loop quantum gravity (LQG)—one candidate theory of quantum gravity—and use it to extend the inflationary scenario all the way to the Planck era [1]. The authors also find that features of the preinflationary phase could result in observable cosmological signatures, thus providing an opportunity to test quantum gravity and probe preinflationary physics in future astronomical observations.
In the 1980s, Guth, Linde, Albrecht, and Steinhardt proposed the theory of cosmological inflation [2] to explain two puzzles in the big bang model of cosmology: why our Universe is approximately flat (i.e., it can be described as a Euclidian space, with a vanishingly small curvature) and why very distant regions in our Universe appear to have a nonrandom correlation in their temperatures (which suggests they were once causally connected). Inflation provides answers to these questions by postulating that the volume of the Universe rapidly expanded by a factor of at least 1078" role="presentation" style="box-sizing: border-box; display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">10781078 in an early period of cosmic evolution. Many models of inflation exist, but qualitatively they all lead to similar physics: during inflation, quantum fluctuations of the vacuum lead to density fluctuations that acted as the seeds of the large-scale structure of the present Universe. Since these density fluctuations were accompanied by temperature fluctuations, they left an observable imprint on the cosmic-microwave-background (CMB) radiation—the thermal radiation released once the Universe expansion allowed photons to travel freely in space. The predictions made by the inflationary theory have been largely confirmed by state-of-the-art CMB measurements [3].
Despite its remarkable successes, the theory of inflation has several problems. The first is the so-called “singularity problem.” In 2003, Borde et al. showed that inflation predicts that the Universe, when evolved backward in time, would shrink to a point—the big bang singularity—at which energy density, spacetime curvature, and temperature are infinite [4]. Since general relativity breaks down under these conditions, the current inflationary theory cannot remain valid as the singularity is approached. Another difficulty is the “trans-Planckian” problem [5]: according to inflation, current cosmological scales could have developed from features that were smaller than the Planck length at the onset of inflation. The Planck length (the distance traveled by light in 1" role="presentation" style="box-sizing: border-box; display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">11 Planck second) is the natural length scale in the Planck era. But on such a small scale, the classical description of spacetime and gravity is believed to be invalid.
At the high densities and energies of the preinflationary regime, it is expected that quantum effects on the force of gravity come into play. Under such conditions, a new quantum theory of gravity, yet to be completed, is needed to describe the “microstructure” of spacetime, similar to the way quantum mechanics describes the microstructure of matter. Loop quantum gravity is one such attempt to merge quantum mechanics and general relativity. In LQG, the classical continuum geometry of spacetime is replaced by a quantum discrete geometry: space can be viewed as made of a fine fabric of finite “loops.”
Over the past decade, LQG has been applied to cosmology (a field known as loop quantum cosmology), with the hope of understanding Planck-era physics and solving the singularity problems of different cosmological models, including inflation [6,7]. When the discreteness of space does not matter, the equations of LQG approximate classical models of cosmology extremely well (much like quantum mechanics merges into classical physics when quantum effects are negligible). Yet differences arise when the curvature of the spacetime starts to be significant. In LQG, the Universe does not emerge from a singularity. Instead, the big bang is replaced by a “big bounce”: the beginning of a period of expansion that followed a period of contraction of a previous phase of the Universe [6].
The work of Agullo et al. adopts the bounce paradigm of LQG and thus it is free of the singularity problem. Their key physical idea is that in the phase close to the bounce, vacuum fluctuations occurred over a nonclassical, quantized spacetime geometry in a tiny volume of approximately 103" role="presentation" style="box-sizing: border-box; display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">103103 cubic Planck lengths. These are the fluctuations that act as the seeds of the large-scale structure of our Universe. Since a full theory of quantum gravity is not yet available, the authors had to restrict themselves to an approximation: they treat fluctuations with standard quantum field theory (as in inflationary cosmology), but they take advantage of recent theoretical results [8] and study how these fluctuations evolve in a spacetime that is quantized by LQG techniques. Since the inflationary paradigm is extended via LQG to the Planck-era, trans-Planckian inconsistencies are also resolved, as LQG can treat rigorously sub-Planck lengths. One should note that the consistency of their analysis relies on one important assumption: the quantum vacuum fluctuations do not, in turn, affect the underlying quantum geometry. The authors show that this is true for a large class of possible initial conditions, for which vacuum fluctuations at the onset of inflation turn out to be essentially the same as the ones considered in the standard inflationary. Their LQG-based model, schematically illustrated in Fig. 1, is thus consistent with the predictions of inflationary theory and extends it in a continuous way to the Planck era.
Spiderman
Veteran Member
Because it makes me more law abiding, helps with sobriety, honesty, integrity, being kind to others, having a clean conscience, and following the golden rule, if I believe there are Spiritual entities I can please by doing so, who see what I do in secret.
I say, "one ought to do and believe what helps a person be better for society, and more charitable to themselves and others."
If faith in a creator or spirit entities accomplishes that, or creates higher moral standards, greater noble sacrifices that are healthy, and makes a person overcome vices that make them better for society, go with what works.
TEETH ARE EVIDENCE OF A CREATOR!
I have often thought as I brush my teeth, that teeth are evidence of an intelligent Sentient creator being.
The teeth are the hardest substances in the human body. Besides being essential for chewing, the teeth play an important role in speech. Parts of the teeth include:
Enamel: The hardest, white outer part of the tooth. Enamel is mostly made of calcium phosphate, a rock-hard mineral.
View attachment 61934
There are actually birds that go into a crocodiles mouth to clean it's teeth, and the crocodile knows by instinct that the bird is doing an important job, and the bird some how knows he/she has the Crocs permission, and won't get killed.
View attachment 61935
View attachment 61936 View attachment 61937
But to me, it seems obvious teeth are clearly not there by accident , and are designed to chew up food so it can be swallowed and properly digested.
Teeth are right where they are needed and belong, save for sometimes wisdom teeth or teeth come in wrong, and need to be removed, but as a general rule, for most humans, teeth are where they need to be, are there for a good reason, and serve a very important purpose.
I don't abuse chemicals anymore, have developed a deep hatred for drug abuse (and how it ruins lives) but I haven't had a cavity in five years, and took better care of my teeth when I abused chemicals, ironically.
When I abused chemicals, because that chemical has a reputation for damaging teeth, I avoided anything high in sugar, and when I did eat something high in sugar, brushed teeth right after consumption.
I don't brush teeth as often now that I'm sober, but brushed them twice today, and brush daily with flouride toothpaste.
So, with good dental hygiene, and living a drug free life, and seeing a dentist yearly for cleaning and cavity checks, don't think dental problems are going to be an issue.
But if evolution without the help of a creative sentient being, came forth from a big bang, to the Sun being in a good place so everything can survive, the moon in a good location, and single cell organisms that evolved into mammals, I'd say evolution was very kind to us, putting teeth where they need to be.
Seems suspicious that there was an artist manipulating evolution though.
(Even if he/she doesn't seem very nice at times, it doesn't mean he/she doesn't exist).
Yes, children get cancer. If they have great eternal reward , a mansion, the first degrees of beauty, power, glory, perfection, euphoria, and dreams come true , forever, in God's kingdom, or another Spirit realm, they won't care that they got cancer as a child, if they are rewarded [heaven] for their pain , suffering, or martyrdom! The cross leads to a glorious resurrection supposedly!
Clara Tea's opinion:
I don't buy the arguments:
1. Teeth exist, therefore God exists.
2. Teeth are complicated, therefore intelligent design (God) exists (couldn't evolution make complicated designs?)
Some atheists would think that such arguments are silly. They might counter that with silly arguments of their own (knowing that they are also being silly):
1. God knows everything, therefore God knows that God doesn't exist. (Proof of the nonexistence of God).
2. If God made teeth, teeth shouldn't get cavities (Proof of the nonexistence of God).
3. Dental problems can put us through hell (pain, expense). What good God causes pain?
4. What good God would create poop?
Steve Martin as a sadistic dentist in Little Shop of Horrors (above). "When I was younger, just a bad little kid"....."make your natural tendancies pay"....."be a dentist."
Bill Murray (as a masochistic dental patient who enjoys pain in Little Shop of Horrors (above)) won't be treated by Steve Martin because he'd enjoy it too much (and sadists want to hurt, not cause joy).
If we see something beautiful, functional, or complicated, should we jump to the conclusion that God exists?
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Because it makes me more law abiding, helps with sobriety, honesty, integrity, being kind to others, having a clean conscience, and following the golden rule, if I believe there are Spiritual entities I can please by doing so, who see what I do in secret.
I say, "one ought to do and believe what helps a person be better for society, and more charitable to themselves and others."
If faith in a creator or spirit entities accomplishes that, or creates higher moral standards, greater noble sacrifices that are healthy, and makes a person overcome vices that make them better for society, go with what works.
Or you could just do it because it's the right thing. Wouldn't that be more impressive?
Because it makes me more law abiding, helps with sobriety, honesty, integrity, being kind to others, having a clean conscience, and following the golden rule, if I believe there are Spiritual entities I can please by doing so, who see what I do in secret.
I say, "one ought to do and believe what helps a person be better for society, and more charitable to themselves and others."
If faith in a creator or spirit entities accomplishes that, or creates higher moral standards, greater noble sacrifices that are healthy, and makes a person overcome vices that make them better for society, go with what works.
What are you offering to support you ID assertion concerning human teeth?
Spiderman
Veteran Member
I'm more inclined to display greater degrees of integrity , sobriety, and virtue, the more motive I have for it.
If there are no sentient Spirit beings aware of what I do in secret, who are pleased with and bless my good deeds and charity, and who will reward or consequence me in another realm after death... my motivation for integrity (when no one else can see ) goes way down, and if I lost all hope in supernatural entities existing or caring, I would kill myself, and in fact did jump off a three story building in a suicide attempt, when I lost hope and faith.
I simply don't like this world, find it too disgusting, and what gives me strength and motive to stay sober and have integrity , is faith, prayer, and studying the life, examples, and writings of the Saints.
But if a person can always do the right thing, without requiring motives like pleasing a Spiritual entity, I very much admire and respect that!
I just find that a hundred years is a short amount of time in my opinion, and if there are not people in Heaven who can benefit from the good I do, as well as the people on earth who I do the good things for, and if I can't rely on any supernatural powers or forces, I have no interest in living, because what the world has to offer, material possessions, money, passing fleeting pleasures , sports, movies, video games, erotic experiences etc, none of that really means much to me.
In the 35 years of my life, I met one person who makes life wonderful, and life is really worth living when she is my companion. Being around her could make the worst day of my life quickly euphoric, and I cherished every moment I was around her.
Consequently, I grew a little too fond of her, she established boundaries, and that relationship is over.
Other than the idea of having a friendship or relationship with her, I really don't like being alive, and think the world is an ugly, disgusting, horrifying place for countless people.
If I lose faith , I start seeking ways to kill myself, and that probably isn't best, so probably better i keep the faith.
Spiderman
Veteran Member
Because teeth seem like they are there for a reason, a purpose, in the right place, which increases my faith and hope in supernatural entities.
I'm more inclined to display greater degrees of integrity , sobriety, and virtue, the more motive I have for it.
If there are no sentient Spirit beings aware of what I do in secret, who are pleased with and bless my good deeds and charity, and who will reward or consequence me in another realm after death... my motivation for integrity (when no one else can see ) goes way down, and if I lost all hope in supernatural entities existing or caring, I would kill myself, and in fact did jump off a three story building in a suicide attempt, when I lost hope and faith.
I simply don't like this world, find it too disgusting, and what gives me strength and motive to stay sober and have integrity , is faith, prayer, and studying the life, examples, and writings of the Saints.
But if a person can always do the right thing, without requiring motives like pleasing a Spiritual entity, I very much admire and respect that!
I just find that a hundred years is a short amount of time in my opinion, and if there are not people in Heaven who can benefit from the good I do, as well as the people on earth who I do the good things for, and if I can't rely on any supernatural powers or forces, I have no interest in living, because what the world has to offer, material possessions, money, passing fleeting pleasures , sports, movies, video games, erotic experiences etc, none of that really means much to me.
In the 35 years of my life, I met one person who makes life wonderful, and life is really worth living when she is my companion. Being around her could make the worst day of my life quickly euphoric, and I cherished every moment I was around her.
Consequently, I grew a little too fond of her, she established boundaries, and that relationship is over.
Other than the idea of having a friendship or relationship with her, I really don't like being alive, and think the world is an ugly, disgusting, horrifying place for countless people.
If I lose faith , I start seeking ways to kill myself, and that probably isn't best, so probably better i keep the faith.
No one ever has always done the right thing, maybe you're a little harsh on yourself. Anyway if your beliefs work for you then that's great. Sorry if my previous comment sounded critical, it wasn't intended that way.
"Seems" and "my faith and hope" are not remotely evidence for the support for ID though the discovery Institute relies on this for their argument for Intelligent Design. Religious "my faith and hope" based on ancient scripture without providence and any basis in science fails.
Spiderman
Veteran Member
I was not offended by anything you said. Thank you, and take care.
Spiderman
Veteran Member
I never said there was proof of anything in the OP.
I feel like there is evidence in creatures, plants, planets, and stars, for a creator, and it is an opinion, not a fact.
Maybe I should have specified in the OP that it was a feeling, a hunch, an opinion that I cannot prove.
I personally disagree with much of ancient Scripture because it seems irrational and goes against my conscience often.
I simply pray to whichever spirit is omnipotent, wise, loving, and compassionate, ask it to guide my mind, heart, conscience, desires, and will, then follow my conscience and heart (independent of Scripture).
Spiderman
Veteran Member
That is cool.What is the source of this picture? Is this a computer generation of what we would at + 1 billion years or an actual picture.
To be random it has to be without order or pattern and without pcause.
Careful 'arguing from ignorance' concerning what we see. First nothing is found go be truly random. The is why I mentioned 'fractal patterns as in 'chaos theory,' which is best to explain the pattern we see. I am not arguing that all has been answered just that the causes for the
In the earliest time of our universe 'Quantum Mechanics and Quantum Gravity' ruled.
There are a number of possible explanations for what occurred during the earliest history of the universe.
Physics - A Glance at the Earliest Universe
A Glance at the Earliest Universe
December 17, 2012• Physics 5, 142
Parampreet Singh
- Department of Physics & Astronomy, Louisiana State University, Baton Rouge, LA 70803, USA
A new cosmological theory tackles the description of the earliest era of the Universe, a period inaccessible by current models.
APS/Alan Stonebraker
Figure 1: Scheme of the evolution of the Universe according to the model of Agullo et al., based on a loop-quantum-gravity (LQG) extension of the inflationary paradigm (figure is not to scale). LQG is used to describe the early Universe of the Planck era. The ... Show more
Cosmological inflation, the hypothesis that the early Universe underwent an extremely rapid expansion, is a popular paradigm in modern cosmology. The theory successfully explains how quantum mechanical fluctuations of the vacuum, starting about 10-36" role="presentation" style="box-sizing: border-box; display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">10−3610-36 seconds after the big bang, could have given rise to the large-scale structure of our Universe, leading to predictions that have been confirmed by a range of cosmological observations. However, inflationary cosmology cannot be the ultimate theory of the Universe. If one projects the Universe backward in time, it gets so hot and dense that the laws of physics on which inflation is based (classical general relativity) break down. In the so-called Planck era, lasting up to one Planck second ( 10-43s" role="presentation" style="box-sizing: border-box; display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">10−43s10-43s) after the big bang, the force of gravity would have reached values comparable to the other fundamental forces. In this regime, quantum gravity effects would have been important, creating conditions that go beyond the conventional understanding of space and time.
What conditions existed prior to inflation and to what extent do they affect the predictions of the inflationary model? Such fundamental cosmological questions remain unanswered, since we don’t yet have a theory that can tackle the physics of the preinflation era and smoothly connect it to the inflationary period. Writing in Physical Review Letters, Ivan Agullo and colleagues at Pennsylvania State University in University Park, take loop quantum gravity (LQG)—one candidate theory of quantum gravity—and use it to extend the inflationary scenario all the way to the Planck era [1]. The authors also find that features of the preinflationary phase could result in observable cosmological signatures, thus providing an opportunity to test quantum gravity and probe preinflationary physics in future astronomical observations.
In the 1980s, Guth, Linde, Albrecht, and Steinhardt proposed the theory of cosmological inflation [2] to explain two puzzles in the big bang model of cosmology: why our Universe is approximately flat (i.e., it can be described as a Euclidian space, with a vanishingly small curvature) and why very distant regions in our Universe appear to have a nonrandom correlation in their temperatures (which suggests they were once causally connected). Inflation provides answers to these questions by postulating that the volume of the Universe rapidly expanded by a factor of at least 1078" role="presentation" style="box-sizing: border-box; display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">10781078 in an early period of cosmic evolution. Many models of inflation exist, but qualitatively they all lead to similar physics: during inflation, quantum fluctuations of the vacuum lead to density fluctuations that acted as the seeds of the large-scale structure of the present Universe. Since these density fluctuations were accompanied by temperature fluctuations, they left an observable imprint on the cosmic-microwave-background (CMB) radiation—the thermal radiation released once the Universe expansion allowed photons to travel freely in space. The predictions made by the inflationary theory have been largely confirmed by state-of-the-art CMB measurements [3].
Despite its remarkable successes, the theory of inflation has several problems. The first is the so-called “singularity problem.” In 2003, Borde et al. showed that inflation predicts that the Universe, when evolved backward in time, would shrink to a point—the big bang singularity—at which energy density, spacetime curvature, and temperature are infinite [4]. Since general relativity breaks down under these conditions, the current inflationary theory cannot remain valid as the singularity is approached. Another difficulty is the “trans-Planckian” problem [5]: according to inflation, current cosmological scales could have developed from features that were smaller than the Planck length at the onset of inflation. The Planck length (the distance traveled by light in 1" role="presentation" style="box-sizing: border-box; display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">11 Planck second) is the natural length scale in the Planck era. But on such a small scale, the classical description of spacetime and gravity is believed to be invalid.
At the high densities and energies of the preinflationary regime, it is expected that quantum effects on the force of gravity come into play. Under such conditions, a new quantum theory of gravity, yet to be completed, is needed to describe the “microstructure” of spacetime, similar to the way quantum mechanics describes the microstructure of matter. Loop quantum gravity is one such attempt to merge quantum mechanics and general relativity. In LQG, the classical continuum geometry of spacetime is replaced by a quantum discrete geometry: space can be viewed as made of a fine fabric of finite “loops.”
Over the past decade, LQG has been applied to cosmology (a field known as loop quantum cosmology), with the hope of understanding Planck-era physics and solving the singularity problems of different cosmological models, including inflation [6,7]. When the discreteness of space does not matter, the equations of LQG approximate classical models of cosmology extremely well (much like quantum mechanics merges into classical physics when quantum effects are negligible). Yet differences arise when the curvature of the spacetime starts to be significant. In LQG, the Universe does not emerge from a singularity. Instead, the big bang is replaced by a “big bounce”: the beginning of a period of expansion that followed a period of contraction of a previous phase of the Universe [6].
The work of Agullo et al. adopts the bounce paradigm of LQG and thus it is free of the singularity problem. Their key physical idea is that in the phase close to the bounce, vacuum fluctuations occurred over a nonclassical, quantized spacetime geometry in a tiny volume of approximately 103" role="presentation" style="box-sizing: border-box; display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">103103 cubic Planck lengths. These are the fluctuations that act as the seeds of the large-scale structure of our Universe. Since a full theory of quantum gravity is not yet available, the authors had to restrict themselves to an approximation: they treat fluctuations with standard quantum field theory (as in inflationary cosmology), but they take advantage of recent theoretical results [8] and study how these fluctuations evolve in a spacetime that is quantized by LQG techniques. Since the inflationary paradigm is extended via LQG to the Planck-era, trans-Planckian inconsistencies are also resolved, as LQG can treat rigorously sub-Planck lengths. One should note that the consistency of their analysis relies on one important assumption: the quantum vacuum fluctuations do not, in turn, affect the underlying quantum geometry. The authors show that this is true for a large class of possible initial conditions, for which vacuum fluctuations at the onset of inflation turn out to be essentially the same as the ones considered in the standard inflationary. Their LQG-based model, schematically illustrated in Fig. 1, is thus consistent with the predictions of inflationary theory and extends it in a continuous way to the Planck era.