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Our future, our universe, and other weighty topics


Showing posts with label quantum gravity. Show all posts
Showing posts with label quantum gravity. Show all posts

Tuesday, August 19, 2025

Periodically Repeating "Big Bang Was Not the Beginning" Story Never Has Substance

The fact that our universe seems to have suddenly originated is one of the most important facts that a human can learn, and also a fact with the utmost philosophical significance.  To understand the importance of this fact, we can consider what positions were taken before it was discovered that the universe suddenly originated. The principle philosophy of ancient materialism was a philosophy called atomism or Epicureanism.  There survives from antiquity one great literary work stating this philosophy, the famous work De Rerum Natura by Lucretius. In that book Lucretius denied all claims of purposeful teleology in nature, and states the doctrine that the universe has always existed. Early in the work he states this about changeless simple particles that were called "atoms" before the modern atom was discovered:

"The various bodies of which things are made

Must have continued from eternal time"

Such a doctrine was very convenient for a materialist such as Lucretius. For one thing, it allowed him to deny that there was ever any purposeful creation event in which the universe began, something he did not want to believe in.  Secondly, the doctrine allowed him to suggest a possible explanation for how humans exist on a planet with such enormous biological order.  The explanation was simply that order had arisen from incredibly lucky combinations of atoms,  combinations that we would never expect to occur in, say, a trillion years of time, but which we might expect to occur if the universe had existed for an infinite length of time.  Lucretius stated the doctrine on this page of his De Rerum Natura:

"So much can letters by mere change of order

Accomplish; but these elements which are atoms

Can effect more combinations, out of which 

All different kinds of things may be created."

This idea of an eternal universe was a bedrock principle of materialists for centuries after Lucretius. In the eighteenth century the principle atheist writer was Holbach, who asked in his main book, "Is  is  not  evident  that  the  whole  universe  has  not been,  in  its  anterior  eternal  duration,  rigorously  the same  that  it  now  is?"  Holbach wrote this: "Motion,  then,  is  co-eternal  with  matter :  from  all eternity  the  particles  of  the  universe  have  acted  and reacted  upon  each  other,  by  virtue  of  their  respective energies  ;  of  their  peculiar  essences  ;  of  their  primitive elements ;  of  their  various  combinations." Later he wrote this: "Matter  has  existed  from  all  eternity, seeing  that  we  cannot  conceive  it  to  have  been  capable of  beginning."  Holbach and  atheists of the nineteenth century believed that the universe had existed forever, an idea that conveniently allowed them to dispose of any idea of a divine creation.

Believers in an eternal universe got a rude surprise in the twentieth century. Scientists discovered that our universe had a sudden beginning, seemingly about 13 billion years ago, in an event they called the Big Bang.  There were two types of observations that established this idea. The first were a great number of observations of galactic redshifts establishing that the entire universe was expanding.  The second type of observations were observations of what is called the cosmic background radiation. The scientists Arno Penzias and Robert Wilson won the Nobel Prize for their discovery of the cosmic background radiation, made around 1965.  Since then fancy space satellites have observed this radiation in great detail. The cosmic background radiation is a type of radiation that was predicted before 1965 as a consequence of a universe that had a hot, dense beginning.  

The discovery of the Big Bang was a very great blow against all those who believe that human existence is accidental or that the universe is accidental. The rather unfortunate term "Big Bang" is somewhat misleading, because it causes some to imagine something like a giant bomb that exploded. The theory actually depicts no such thing, but something far more radical: the idea of all of the matter and energy in the universe arising from an infinitely small mathematical point. It is rather hard to imagine anything that could be more suggestive of a universe being purposefully created out of nothing.   

The Big Bang is a thorn in the side of the modern materialist scientist. Such a scientist wants to believe that the universe has existed forever, because if the universe had existed forever, it takes off the table all talk of the universe being specially created by some divine power.  But, contrary to the wishes of materialist scientists, nature is telling us that the universe has not existed forever. 

It is therefore no surprise that we occasionally get some science news articles giving us what we might call "cosmic beginnings backlash."  There is a type of article that shows up every several months on the science news sites. It is an article that attempts to tell a "the cosmic origins story has been revised" narrative.  The article may claim that now scientists are not so sure that the Big Bang was the beginning. Or, more deceptively, the article may attempt to insinuate that the idea of a sudden cosmic beginning is no longer maintained by most cosmologists. There is never any substance in the articles of this type that periodically appear.  No actual news is being reported. All that is going on is a little "clouding the waters" analgesic activity trying to make atheists feel a little better. 

The latest example of this type of story is an article in the frequently misspeaking and frequently misinforming BBC Science Focus site, an article entitled "Scientists now think we CAN know what came before the Big Bang." The title is bogus, and there is nothing of any substance in the article. We have this deceptive subtitle:

"New theories from leading physicists offer compelling possibilities about what existed before the early Universe. One thing they’re agreed on is that the Big Bang wasn’t the start."

The subtitle is deceptive because no new theories are discussed, and none of the theories mentioned are theories describing a state before the Big Bang with any credibility. No one advancing such wildly speculative theories seems to actually claim that anything can be known about some state before the Big Bang. The theories mentioned are the cosmic inflation theory, something called loop quantum gravity, something called causal set theory, something called horava gravity, something called the epkyrotic universe, cosmic natural selection or cosmological natural selection, a cyclic theory of Paul Steinhardt and a cyclic theory of Roger Penrose.  All of these theories have been around for many years. 

  • Cosmic inflation theory has been around since about the year 1980, wasting endless millions in research money without producing any results. Cosmic inflation theory is not a theory of something happening before the Big Bang. It is a theory that something special (exponential expansion) happened during a tiny fraction of the first second of the Big Bang. Cosmologist Ethan Siegel likes to pull a very misleading hairsplitting trick in which he redefines the term "Big Bang" so that it is defined as everything that happened at the beginning of the universe after the first tiny fraction of a second. That is misleading trickery, designed to sneak in some illegitimate claim of "before the Big Bang." The BBC article tries a little of the same empty semantic trickery, saying, "Therefore, if we use the Hot Big Bang definition (which most physicists believe we should), then inflation must be considered a pre-Big Bang scenario." No, the cosmic inflation theory is a theory of what happened during the first second of the Big Bang, and is not a theory of something before the Big Bang. 
  • Loop quantum gravity is a theory that has been around since at least 2002, and is some version of quantum gravity, which is well-known to be a groundless never-well-established swampland of speculation. Page 7 of the 2024 paper here asks some cosmologists what is the "best candidate for a theory of quantum gravity." Loop quantum gravity was chosen by only 5%. 
  • Causal set theory is another version of quantum gravity, and since quantum gravity is a very much a "castle floating in the clouds" type of thing, it is premature to grant any weight to causal set theory. The theory dates from 2008, as shown here. Page 7 of the 2024 paper here asks some cosmologists what is the "best candidate for a theory of quantum gravity." Causal set theory was one of the choices, but 0% chose that choice. 
  • Cosmological natural selection is a very silly theory that I have discussed in four posts dating back to 2014.  The theory was some nonsense about black holes spitting out universes, which failed to ever explain how that could happen. The author of the theory (Lee Smolin) stated in a 2004 paper (page 38) that the theory made a firm prediction. He stated, "There is at least one example of a falsifiable theory satisfying these conditions, which is cosmological natural selection. Among the properties W that make the theory falsifiable is that the upper mass limit of neutron stars is less than 1.6 solar masses. This and other predictions of CNS [cosmological natural selection] have yet to be falsified, but they could easily be by observations in progress.” By now this prediction has been falsified. A 2019 news story told us that a neutron star has been discovered with a mass of 2.17 solar masses. A Google search for "most massive neutron star" will tell you that one neutron star (the "black widow pulsar") has a mass of 2.35 solar masses. Smolin now seems to have lost interest in his cosmological natural selection theory, which never actually explained how a universe could be born from a black hole. 
  • Horava gravity is another version of quantum gravity, and at present no theories of quantum gravity have any credibility. The theory dates from 2009, so it is not a new theory. The wikipedia.org article on the theory states, "Observations of gravitational waves emitted by the neutron-star merger GW170817 contravene predictions made by this model of gravity." The article makes no mention of the theory predicting a state before the Big Bang. 
  • The article mentions a cyclic theory of cosmologist Paul Steinhardt. It's something called the ekpyrotic universe theory, and has existed since 2001.  The theory has not attracted any support outside of Steinhardt and his handful of collaborators. 
  • The article mentions a cyclic theory of cosmologist Roger Penrose. It is something called conformal cyclic cosmology, and has since existed since the year 2012. The theory has not attracted any substantial number of supporters. 
Quantum Gravity

None of the speculations mentioned above have any substance, because none are supported by observations. It is intrinsically impossible that there could ever be any observations supporting some theory of what happened before the Big Bang. The reason is that the Big Bang was a state of such extreme heat and incredibly high density that any traces of a state before the Big Bang would have been wiped out. 

An important fact of nature that will never change is that it forever will be physically impossible for any technology to ever "look back at the earliest moments of the universe," or to look back prior to such a moment. In its  first 100,000 years the universe was so dense that every type of radiation coming from such a time must have hopelessly scattered, with all of its information as mangled as a top secret document passed through 1000 different paper shredders, and all of the resulting paper scraps being passed through 1000 paper scrap shredders.  It will therefore be forever impossible to ever "look back at the earliest moments of the universe," or to ever get signals from a time before the Big Bang. Such an impossibility is one reason why all theories of a state before the Big Bang are pseudo-science. Because no such theory can ever be verified or falsified, no such theory should be called scientific.  

Tuesday, July 22, 2014

Not Even Half Baked: The Premature Project Known as Quantum Gravity

Two of the biggest theories of modern science are quantum mechanics (which deals with the subatomic world) and general relativity (a theory of gravity that works on a large scale, dealing with large massive objects). For decades, scientists have had the hope of uniting the two into a single theory. Einstein spent the last years of his life working on such a project, but came up empty-handed.

In the past few decades, some physicists have continued to work on theories that attempt to unify quantum mechanics and general relativity. Such theories are called quantum gravity theories. One class of these theories is called loop quantum gravity.

One occasionally sees news stories based on the predictions of loop quantum gravity. An example is this recent one, suggesting that black holes eventually become white holes that gush out matter.

But whenever you hear the phrase “quantum gravity” you should also think to yourself: not even half-baked. Or perhaps it might be better to think: not even tenth-baked. This is because it is perhaps centuries too early to be advancing a theory that tries to unite quantum mechanics and gravitation. One reason is that there are too many mysteries involved in gravitation and quantum mechanics. Uniting quantum gravity and gravitation might have to wait until we solve such mysteries.

The following might be a logical plan:
  1. We solve the basic mystery of what causes gravitation, something we don't understand. We know that gravitation is proportional to density of matter, but as it is easy to imagine a universe with no gravitation, we don't really understand why gravitation exists.
  2. We solve the mystery of why gravity is a trillion trillion trillion times weaker than all of the three other fundamental forces of the universe.
  3. We solve the basic problem of the nature of the collapse of the wave function, something which is still furiously debated by quantum mechanics theorists.
  4. We solve the incredibly perplexing problem of quantum entanglement, and how this spooky mysterious “action at a distance” can be occurring.
  5. We solve the mysterious “observer effect” in quantum mechanics, the bizarre fact that matter can behave very differently depending only on the way we observe matter.
  6. We clarify the mysterious “double slit” experiment, which suggests that both electrons and energy photons can switch back and forth between wave behavior and particle behavior.
  7. Then, after gaining a vastly clearer understanding of both quantum mechanics and gravitation, we attempt to create a single theory uniting both of them.
But some of our physicists have jumped straight to item 7 in this list before understanding the first six. This seems to make no sense. How can you unite quantum mechanics and gravitation into a single theory, when there are so many unsolved mysteries involved in both of them?

quantum gravity

Quantum gravity is a nice little niche for some physicists. If you are a quantum gravity theorist, you can spend your year working on some theory that no one will expect to work, piling on one far-out speculation after another. If anyone complains about a lack of verification or predictions, you can say: come on, this is quantum gravity, what do you expect? I'm reminded of that Broadway song with the lyric: nice work if you can get it.

Quantum gravity theorists are good at speculations, but are not very good at justifying their work. One quantum gravity theorist admits that there is no evidence for quantum gravity, but she tries to justify her funding by saying this:

The irony is that quantum gravity phenomenology is as safe an investment as it gets in science. We know the theory must exist. We know that the only way it can be scientific is to make contact to observation. Quantum gravity phenomenology will become reality as surely as volcanic ash will drift over Central Europe again.

This is very unpersuasive reasoning. We are not sure that any workable theory of quantum gravity will ever be discovered, and it is very unclear whether such a workable theory will be developed anytime in the next 500 years. Far from “as safe an investment as it gets in science,” investing in quantum gravity theoretical research seems no more safe than betting on a horse race or buying a lottery ticket. A safe investment, on the other hand, is one that has a high likelihood of giving you a good return within the next decade (such as a mutual fund with a 50% mix of stocks and bonds).

Perhaps the main type of quantum gravity theory is what is called loop quantum gravity theory. Such a theory is based on the idea that time is quantized. You can get kind of an idea of quantized time by imagining that each second is a stack of time-slices, and that there are a limited number of these time-slices in each second.

I think this idea is misguided. The idea of quantized time reinforces the assumption of a strict segregation between this instant and the next instant. But rather than thinking in such a way, we should perhaps be moving in the opposite direction. Although it may shock our expectations, experiments on precognition suggest that there may well rarely be some kind of partial intermingling or information exchange between the future and the present. The same thing is suggested by many human experiences very well described in the book The Science of Premonitions by Larry Dossey MD. A particularly striking example is given on page 41 of the book. On May 2, 1812 an Englishman named John Williams had a dream of the assassination of the British prime minister Spencer Perceval. Williams had the dream three times on the same night, and the dream included very specific details. Nine days later Perceval was assassinated. As Dossey puts it, “The details of the assassination were identical to those of the dream, including the colors of the clothing, the buttons on the assassin's jacket, and the location of the bloodstain on Perceval's white waistcoast.” (See here for another author's discussion of this incident.)

It is hard enough to explain such experiments and experiences with our normal assumptions about time, and it seems even harder to explain them under some assumption of quantized time. If physicists wish to create some exotic new theory of time, they would do better to create one that can help explain experiments on precognition and human experiences of premonitions that came true. Rather than imagining a rigid “one-way street” leading between the past and the future, such a theory might allow for the possibility of a limited degree of mingling or communication between the past and the future, possibly in both directions. Such a theory might describe a separation between the past and the future that is more fuzzy and blurred than we normally imagine.

But such a theory may be a long way off. For the present, I simply suggest: when you hear that something is suggested by quantum gravity, remember that quantum gravity may be centuries away from being ready for prime time.