What is Planck time and Planck length?
During the Planck era, all four fundamental forces of nature were unified (gravity, strong force, weak force, and electromagnetic force).
See https://courses.lumenlearning.com/atd-fscj-introastronomy/chapter/the-planck-era/
Compare https://web.njit.edu/~gary/202/Lecture26.html
Professor Dale E. Gray states:
The amazing fact is that we can trace the Big Bang back to its earliest moments, at least as far back as 10-10 s, and possibly as far back as 10-43 s! This is an incredibly short time, and we can truthfully say that we can trace the evolution of the universe back to the first instant of creation. In so doing, we are probing not just the very earliest universe, but also the highest energy particle physics, so that particle physicists and astronomers are working on two aspects of the same puzzle.
For a somewhat technical explanation of Planck time, see https://astronomy.swin.edu.au/cosmos/p/Planck+Time
The Planck time value is tp = 5.39 × 10-44 s
One source points out:
Looking backward, the general idea is that back beyond 1 Planck time we
can make no meaningful observations within the framework of classical
gravitation. One way to approach the formulation of the Planck time is
presented by Hsu. One of the characteristics of a black hole is that there is an event horizon beyond which we can obtain no information - scales smaller than that are hidden from the outside world.
See http://hyperphysics.phy-astr.gsu.edu/hbase/Astro/planck.html
https://www.academia.edu/47577764/Non_dark_hyperbolic_universe
ReplyDeleteUseful comments in the introduction especially regarding unverifiable assumptions.
I want to be clear that what I'm posting here is not meant to be taken dogmatically. I'm trying to learn more about Planck time/space and all the associated ideas attendant upon it. This whole dark matter/energy issue is interesting. The link you posted contains a lot of complexities but the author is far from convincing the scientific community. See https://www.technologyreview.com/2021/05/28/1025574/dark-matter-map-smooth-dark-energy-survey/
ReplyDeleteDoes not really matter if the community does not like it. It all boils down to proof, what one has and does not have.
ReplyDeleteThe notion of constants is highly fluid in this circumstance.
"Planck units do not incorporate an electromagnetic dimension. Some authors choose to extend the system to electromagnetism by, for example, adding either the electric constant ε0 or 4πε0 to this list. Similarly, authors choose to use variants of the system that give other numeric values to one or more of the four constants above."
"So all of the matter in the universe would fit into about 1 billion cubic light years, or a cube that's approximately 1,000 light years on each side. That means that only about 0.0000000000000000000042 percent of the universe contains any matter."
ReplyDeleteHow can this actually be ascertained? Much of what is called science is actually total guess work.
https://www.bbc.com/future/article/20200117-what-if-the-universe-has-no-end
ReplyDeletehttps://bigthink.com/starts-with-a-bang/big-bang-beginning-universe/
ReplyDeletehttps://en.wikipedia.org/wiki/Ecotone
ReplyDeleteI still think that what can be observed here on earth may have more in common with cosmology than most think.
https://physicsworld.com/a/exposing-the-flaw-in-plancks-law/
ReplyDeleteWe've had discussions about proof before: it's a very complicated notion. If only it were as simple as having proof or evidence, but proof comes in many different varieties and some thinkers claim it is person-relative. In a court of law, the defense and prosecution set forth "proof" to establish their case or cast reasoanble doubt on it. Although both sides have proof, only one side wins.
ReplyDeleteIn science, theories that have been refuted had "proof," but other theories prevailed because their proof was superior. Evidence or proof has to be sifted through human minds, it has to be analyzed and weighed. Hardly any proof meets the highest standard of apodicticity.
One last point is that some facts apparently are not provable or verifiable, and some truths appear to be axiomatic--not capable of being proved. Everybody has to have logical starting points.
I'm not a scientist but my understanding of science is that it operates on observation, experimentation and math. Science has to make certain assumptions or else it would not work just like we do in logic. However, I will admit that science does engage in rank speculation at times and it's hard to tell where science ends and metaphysics begins.
ReplyDeleteHere's another article regarding dark matter: https://phys.org/news/2015-03-dark.html
ReplyDeleteI'm reminded of how black holes were first discovered. Long before there was observational evidence for black holes, someone worked out mathematically that such things should exist. Of course, we know that mathematical modeling does not map onto the world 1:1 but many things have been discovered after the math was worked out, or elements were predicted, etc.
The Big Bang and Big Bounce are theories. In talking with a colleague of mine who is a scientist, he says we can't be dogmatic about either theory. We were not there. And I agree that I can't affirm that the Big Bang happened. However, the Bible suggests the universe had a beginning and from the standpoint of a Jew or Christian, it's self-defeating and incoherent to deny that God created the universe. While both Maimonides and Thomas Aquinas conceded that an eternal universe was logically possible, both seem to argue that Judaism and Christianity say otherwise. Someone who believes matter is eternal or was not created by God puts himself/herself outside the Judeo-Christian camp.
ReplyDeleteI'm not trying to use ad hominem argumentation but simply pointing out that it's incoherent to be a Christian or Jew who rejects creation. On the other hand, I believe there is enough compelling scientific "proof" or evidence to hold a reasonable belief that the world did have a beginning. Philosophy, theology and science seem to converge on this understanding of the world.
I would counter by saying that court cases are judged often by non experts and it depends on what argument they like the sound of according to pre-understandings (even for "experts").
ReplyDeleteI am not in favour of bang or bounce as we just don't have enough data, just as we have no real proof of black holes, which is understandable by the supposed nature.
I don't think that scripture deals with the universe's origins and I am happy to leave it at that rather than force the issue.
There are many issues with the nature of time itself and the definition of a (or the) beginning. The nature of the genesis creation accounts are uncertain.
I see no reason to disagree with the creation of this planet & having a beginning.
Psalm 146:6- the sky,the land,the sea and all that is in them. CF psalms 147:8.
Psalms 147:4 count 147:5 no count. Also compare Hosea 2:17 & Zechariah 13:2
Judeo Christian tradition and the biblical text may not be one and the same and our understanding of these issues are not what should define us.
https://www.openbible.info/labs/cross-references/search?q=John+13%3A35
I agree that court "proof" or evidence is usually heard by non-experts and juries can be swayed by emotion. However, does that change the fact that proof comes in many varieties and it has to be filtered through human minds? There is no such thing as bare proof (per se). Proof is also domain/field-specific.
ReplyDeleteYou say we have no proof of black holes, but is that really the case? We certainly have observational evidence for black holes even if the evidence/proof is not apodictic. Hardly anything in life meets the high standard of apodicticity: that does not mean we have no proof or evidence for black holes or the big bang/bounce, etc.
There is room for disagreement about the scriptures and origins. I think Genesis 1:1, Revelation 4:11 and other verses do touch on the universe's origins. There is no doubt that the Bible discusses animal and human origins. So why not the origins of the universe? If the Bible says that God created all things, why exclude the universe from "all things"? And if you look at what Judaism and Christianity have claimed, the overwhelming consensus is that God brought the universe into being. After all, he is the Creator.
Did God create some of the stars and not all of them? Did he create angels and the earth? What did God not create?
Lastly, does the universe exist? If so, has it always existed or was it created? Has matter always existed or was it created? It's hard for me to believe in a Creator, who only created some things but not others. If Jehovah says there was no deity before him nor will there be another after him, what does that say about universal origins?
https://www.degruyter.com/document/doi/10.1515/9783110901184.79/html
Who created the stars, according to Tanakh? See Gen. 1:16; Isa. 40:26.
ReplyDeleteI am pointing out that the stars are not the specific teaching of those verses, they are saying something else.
ReplyDeletehttps://biblehub.com/hebrew/vaiyaas_6213.htm
Isaiah 40:21
https://biblehub.com/text/isaiah/40-28.htm
https://biblehub.com/hebrew/ketzot_7098.htm
https://biblehub.com/text/jeremiah/49-36.htm
https://biblehub.com/text/2_samuel/22-8.htm
https://biblehub.com/hebrew/strongs_1254.htm
Deletehttps://arxiv.org/abs/1409.1837
ReplyDeleteWhat does "heavens" mean in Rev 4?
ReplyDelete"A rainbow that shone like an emerald encircled the throne."
Where does one get a rainbow?
I will read the verses you posted in your latest comments but you realize that Revelation 4 is a vision, right, and it's packed with symbols? The context shows God's residence is the heavens under consideration. The rainbow does not refute this interpretation because John is relating a visual experience. See verses 1-4.
Deletehttps://factsanddetails.com/world/cat56/sub368/item2088.html
ReplyDelete“As he was entering the city on his return from Apollonia after Caesar's death, though the heaven was clear and cloudless, a circle like a rainbow suddenly formed around the sun's disc, and straightway the tomb of Caesar's daughter Julia was struck by lightning."
More than one Bible verse says YHWH created the stars. Psalm 8:3-4, etc.
ReplyDeleteLet us not forget we now have a black hole photo. See also https://news.yale.edu/2021/12/16/black-holes-and-dark-matter-are-they-one-and-same
ReplyDeletehttps://www.bbc.co.uk/news/science-environment-47891902
ReplyDeleteQuestion - In this construct (not a photo) how would one differentiate between a black hole an an eclipse?
https://biblehub.com/text/genesis/2-3.htm
ReplyDeletehttps://hermeneutics.stackexchange.com/questions/29777/why-does-%D7%9C%D7%94%D7%91%D7%A8%D7%99%D7%90%D7%9B%D7%9D-mean-to-make-yourselves-fat-in-1-samuel-229
ReplyDeleteComments by Joshua are useful.
An explantation o the above paper.
ReplyDeletehttps://youtu.be/qBfo4SNZq7I
She may or may not be correct but again, we have no evidence to differentiate a black Star from a black whole.
When we look into the night sky we see nothing where is actually sits in the true polar coordinates because all planets and stars bend light around themselves to a certain degree. In fact large enough or dense enough objects are used as lenses to see further.
See how she struggles, as they all do-
ReplyDeletehttps://youtu.be/QgcsIyoC3vs
A year later - https://www.bbc.co.uk/news/science-environment-53151106
ReplyDeleteThe article you linked from BBC calls what Dr. Bouman produced an "image" and "photo." And there is a world of difference between black holes and eclipses. Start with the pull of gravity and the event horizon of a black hole.
ReplyDeleteI don't see how you can say there is no evidence to differentiate a black hole from aa black star: black holes have a certain mass, for one thing. Only stars with a particular mass can be defined as black holes. Reams of literature has been produced about black holes and lots of hours has been devoted to studying them. I think cosmologists know how to distinguish black holes from black stars.
I will read the thread about 1 Samuel 2, but you might recall that this point was addressed in the past, likely more than once. The verse in Samuel has nothing to do with Genesis 1:1. Lots of info to debunk the idea. See https://fosterheologicalreflections.blogspot.com/2018/11/edward-p-arbez-and-john-p-weisengoff.html
Genesis 1:1 uses bara with the qal stem: 1 Samuel 2:29 has the niphal. The verbal stems make a difference and so does the context of use.
ReplyDeleteThe difference between a black Star and a black whole is a quantum singularity for which no evidence exists.
ReplyDeleteThis is why we get the ridiculous notion that some black holes are darker than others. A singularity is a singularity, so there is a significant problem here.
Correction: hiphil stem.
ReplyDeleteTo have a photo can imply that a photo was taken and that is not the case. It is easy enough to construct an image and print on photo paper, but it is not a photo. If it was an image captured by Hubble for example in a relatively unprocessed form, but this is not so I see no point in knit picking over the words.
ReplyDeletehttps://www.bbc.co.uk/news/science-environment-47891902
ReplyDelete8 ways we know black holes exist-https://www.livescience.com/how-we-know-black-holes-exist.html
ReplyDeletehttps://www.bbc.co.uk/news/science-environment-47891902
ReplyDeleteDoes the Big Bang Prove God Created the Universe?
ReplyDeletehttps://www.youtube.com/watch?v=beOB387jeC8
I'm not going to nitpick over the words either, Duncan, but BBC called it a photo and so do scientists. The larger point is whether we have observational evidence for black holes.
ReplyDeletehttps://www.livescience.com/black-holes-not-black-planck-hearts.html
ReplyDeleteWe know that something exists, but that's about it.
One has to prove a big bang before one can use it to argue anything.
ReplyDeleteAs for bara in a pastoral agricultural society, that also has much bearing on the understanding.
"This burst can radiate as much energy into space as an ordinary star emits in its entire lifetime. And telescopes on Earth have detected many of these bursts, some of which come from galaxies billions of light-years away; so we can actually see black holes being born."- patently false assumption.
ReplyDeletehttps://www.quantamagazine.org/brighter-than-a-billion-billion-suns-gamma-ray-bursts-continue-to-surprise-20210630/
ReplyDeleteFar too many assumptions regarding cause in this and do not reconcile with the time scales.
https://skipmoen.com/2012/06/back-to-bara/
ReplyDeletehttps://arxiv.org/abs/2102.07769
ReplyDeletehttps://www.researcher-app.com/paper/6885659
ReplyDeleteWell Duncan, I guess we go in circles. There is proof for the big bang, both observational and mathematical. It's not true to say there's no proof at all. It may turn out to be wrong, but there is proof for the big bang theory and for black holes.
ReplyDeleteOn bara, a pastoral society wouldn't necessarily be limited to pastoral usages. Denotations are more complicated than that although I concede that social setting affects usage
Just a couple of other things I will post about this subject. Do you remember why Roger Penrose won 1/2 of the Nobel prize in physics back in 2020? See https://www.nobelprize.org/prizes/physics/2020/press-release/
ReplyDeleteNote the other contributors to our knowledge of black holes.
It's pretty difficult to claim there's no proof or evidence for black holes, whether Penrose, Hawking, and others turn out to be wrong.
For bara, see http://www.paultanner.org/English%20Docs/Creation/07_Rooker_Genesis%201,1-3_BibSac%20Part%202.pdf
https://frame-poythress.org/wp-content/uploads/2013/09/2013ChristianInterpretationsOfGenesis1.pdf
https://www.ctc.cam.ac.uk/outreach/origins/black_holes_one.php
ReplyDeletehttps://www.wtamu.edu/~cbaird/sq/mobile/2013/09/13/does-every-black-hole-contain-a-singularity/
ReplyDeleteIf this is true then they are all blacks stars and with powerful enough detection something always escapes. If our detectors were good enough there woule be no black background to images of space at all.
What simple mathematical models tell scientists.
ReplyDeletehttps://www.insidescience.org/manhattan-project-legacy/atmosphere-on-fire
https://www.cam.ac.uk/research/news/roger-penrose-wins-2020-nobel-prize-in-physics-for-discovery-about-black-holes
ReplyDelete"David Haviland, chair of the Nobel Committee for Physics, said: “The discoveries of this year’s Laureates have broken new ground in the study of compact and supermassive objects. But these exotic objects still pose many questions that beg for answers and motivate future research. Not only questions about their inner structure, but also questions about how to test our theory of gravity under the extreme conditions in the immediate vicinity of a black hole”.
Still have no evidence that they are holes. If they are not holes then they are dark stars. There is a significant difference in terms of implications and the naming of such objects is important to the general understanding.
Enūma Eliš is one of many Sumerian creation myths and probably the biggest parody. I find it disingenuous how people only compare and contrast this one with genesis. It's quite unproductive.
ReplyDeleteA black hole is just a star of sufficient density or size that has used up all of its gas and then collapses inwardly, likely to the singularly point. There is observational evidence for them and general relativity implies their existence. At any rate, it's not inconceivable that a star would undergo this process.
ReplyDeleteI can agree with what you are saying apart from "likely to the singularly point". I presume you meant singularity? That's just an artefact of incomplete maths. A black Star also collapses inwardly and of sufficient density to bend light inwardly, but not completely. There is no observational evidence of singularity. The singularity is why the were called holes. Without it they are called stars.
ReplyDeleteI think my tablet auto-corrected, but yes, I meant the singularity point. In black holes, the mass is important and it must emit no light: this would distinguish a black hole from a black star. If the singularity is a point, there would not be observational evidence for it, but rather mathematical proof. There is no observational evidence for a geometrical point either. However, I understand that the math doesn't prove singularities exist but in this case, the math is a natural consequence of general relativity, which has been highly successful in making predictions.
ReplyDeletehttps://www.pbs.org/wgbh/nova/article/are-singularities-real/
ReplyDeleteBrian Greene explaining black holes: https://www.youtube.com/watch?v=Vn45HE-3Acg
ReplyDeleteWith things as complex and unknown as the depths of space and interactions, I would be vary wary of anyone saying "that's the only explanation of the data".
ReplyDeletehttps://medium.com/twodigits/3-reasons-quantum-computing-is-overrated-9d87d11aa248
ReplyDeleteAs someone who has been involved in low level software engineering and the transputer in the past. I am going to need considerable convincing to believe that quantum computing is such a quantum leap foreward in technology. To me there is no such thing as AI and energy dictates the long term development of any technology.
Scientist are very good at making technological claims that don't pan out.
I think I have said before that theories such as chaos theory turns out to be the opposite. Even PI has a practical limit. Even fractals may seem mathematically infinite but practically they are not.
When I mention Ecotone, the online explanations of the concept are poor but this is reasonable for the basics: https://www.google.com/amp/s/eco-intelligent.com/2016/12/15/ecotones-and-edges-explaining-abrupt-changes-in-ecosystems/amp/
But the real question is more why than what regarding productivity on edges and energy flows. This is why it may be useful regarding the idea of an event horizon. I see no reason to think that it is unidirectional.
Did you get the point about the atom bom, that the math at the time did not indicate a limit to the reaction.
https://youtu.be/vqave0V5qAA
ReplyDeleteQuantum theory reduced to basic mathematics, without explanation, because we don't have one as yet.
https://www.mdpi.com/2077-0472/9/10/228/htm just as mysterious.
ReplyDeleteDuncan, I agree that the gap between math and real world events is huge and it's been said that if you can explain QM, then you don't understand it.
ReplyDeleteWho says black holes are the only explanation for certain phenomena? The scientists I read say otherwise.
I was referring to the Brian Greene video you posted regarding the quote.
ReplyDeleteAlthough not at the quantum level, I have designed operational amplifier circuits that can be simulated, but once attempt is made to physically monitor a working example it alters the working characteristics.
ReplyDeleteI appreciate your background in this subject. I'm sure your math ability is much stronger than mine and the type of work you did was undoubtedly helpful.
ReplyDeleteIt would surprise me if Greene thought there was only 1 explanation for black holes, etc. He's very philosophical and I consider him to be one of the finest popular scientists. See https://www.space.com/black-holes-string-theory-brian-greene-interview
He says: "There was a time, 10 years ago, when you could still make an argument that maybe black holes aren't real; they're just a figment of the mathematics. But with LIGO, with the collision of two black holes giving that first ripple in the fabric of space, and with EHT — even the Nobel Prize this year was awarded to work on black-hole physics. So black holes have really come into their own."
But I'm pretty sure that Greene would be open to a revised understanding of the status quo.
https://eventhorizontelescope.org/blog/astronomers-image-magnetic-fields-edge-m87s-black-hole
ReplyDeleteIs it emission or just castoff? I think this is where assumptions are dictating the narrative.
What Greene thinks and what he said are not nessasarily the same thing, but IMO that makes it worse.
They give the impression in popular general media of certainty where none exists. There are many mathematical formula that have good explanatory power in the majority of practical situations but nothing here demonstrates singularity, only super density.
You can interpret this how you like:-
https://ec.europa.eu/commission/presscorner/detail/en/IP_19_2053
'I'm especially glad to see that scientists funded by the European Research Council contributed decisively to this breakthrough. The EU's bold approach to funding such paradigm-shifting blue-sky research leads once more to a success story. It also further validates the ERC's objective to fund high-risk/high-gain research.”
https://dblp.uni-trier.de/rec/journals/mst/Hajek71.html?view=bibtex
ReplyDeleteOn the cutting edge.
FYI, from Brian Greene:
ReplyDelete"Hawking radiation is a mathematical consequence of general relativity and quantum mechanics. Our confidence in these two pillars of physics give us confidence in Hawking radiation, even without detecting it."
"However the key feature that causes the radiation is the presence of a horizon, so alternatives to general relativity like Brans-Dicke theory also predict Hawking radiation as long as a horizon is present. General relativity would have to fail so badly that no event horizon exists for there to be no Hawking radiation."
ReplyDeletehttps://www.quantamagazine.org/the-most-famous-paradox-in-physics-nears-its-end-20201029/
ReplyDeleteHere's a 2021 paper as well: https://arxiv.org/abs/2102.04930
ReplyDeletePenrose Singularity and Black Holes: https://www.youtube.com/watch?v=z4odQd8q3xY&list=WL&index=37
ReplyDeleteI have to give you extra points for humor: good one :-)
ReplyDeleteAs for proof, there is more than one kind of proof. Things are proved in a court of law sometimes, there are logical proofs, lexical/grammatical proofs, and mathematical proofs. Are we really going to compare complex math to alchemy? Furthermore, what Penrose did is perfectly in line with general relativity.
Duncan, I inadvertently deleted your last comment. I received 2 of them, and deleted one, but then the other comment disappeared. If you still have it, please send again. My apologies.
ReplyDeleteRepost - "plus a couple of assumptions"?
ReplyDeleteHe definitely did not prove singularity.
I will not make any more comments on this - no point 😀
A singularity is unnecessary at the center to control orbits, only a mass at planck compression. We do not have the tools required to prove or disprove much of this, but we are dealing with modern day alchemists.
General relativity - can we truly say what is "general" for a universe & lest not forget that to push it to extremes we would be calling it universal relativity.
ReplyDeleteTo quote Tim Garrison - "Theoretical physics can prove that an elephant can hang from a cliff with its tail tied to a daisy. But use your eyes, your common sense.”
But we cannot use our eyes & does our common sense apply out their? Numbers on a piece of paper are only proved by practical application, and we cannot do that. This is why the claims on any side are alchemy & even what many claim that Penrose has "proved" remain unproven.
https://www.forbes.com/sites/startswithabang/2018/07/27/there-was-no-big-bang-singularity/?sh=34399b447d81
Einstein: "As far as the laws of mathematics refer to reality, they are not certain; and as far as they are certain, they do not refer to reality."
ReplyDeleteMaybe a bit overstated, but lots of truth in these words. I don't see how we could predict or explain what's happening in the universe as a whole, whatever it all encompasses. The mystery remains--there is still plenty to learn and that's an understatement.
One dictionary defines "proof" this way (it's one definition): "evidence or argument establishing or helping to establish a fact or the truth of a statement."
I know for a fact that there are logical proofs like the ontological argument for God's existence or the cosmological argument. Do these proofs settle the question of God's existence? Not in a conclusive or definitive sense. Yet they are still proofs, even if someone can challenge their premises or the conclusions they generate.
Similarly, there is such a thing as a mathematical proof like Penrose produced. It can be challenged but that doesn't mean it's not a proof. Now does Penrose prove his claims beyond a shadow of a doubt? Far from it, but it's still a proof.
See Acts 1:3 for another example: Jesus showed proofs that he was raised from the dead. People all around the world doubt Jesus' resurrection but that doesn't mean he did not give positive proofs for it.
As the last article I posted concludes:-
ReplyDelete"There may have been a singularity at the very beginning of space and time, with inflation arising after that, but there's no guarantee. In science, there are the things we can test, measure, predict, and confirm or refute, like an inflationary state giving rise to a hot Big Bang. Everything else? It's nothing more than speculation."
But he does also provide arguments against a singularity - so its not one proof VS null.
It is not "best guess" either.
"shadow of a doubt" - I think there is considerably more than a shadow.
https://en.wikipedia.org/wiki/Proofs_and_Refutations
ReplyDeletehttps://www.imdb.com/title/tt0787524/?ref_=nm_flmg_act_11
ReplyDeleteThe life story on which this is based demonstrates the difference between proofs and genius. Proofs did correct him occasionally but not always.
The author of that article overstates matters. The singularity idea hasn't gone anywhere as evidenced by the Nobel prize for Penrose's work. I will admit that plenty of speculation exists in science/physics but black holes and singularities are not based simply on speculation. Anybody can muster an argument against just about anything like a Trinitarian arguing against antitrinitarianism or a flat earther arguing for his/her view. As Immanual Kant wrote, there are times when both sides have good arguments and we essentially come to a stalemate. Often, we need more evidence to make a firm decision about a matter.
ReplyDeleteAnd I don't call mathematical proofs, best guesses. What Penrose did was not just a guess or hunch :)
The other wiki link reminded me of Euclid: https://artofproblemsolving.com/wiki/index.php/Proof_by_contradiction
ReplyDeleteA Nobel Prize for evolution
ReplyDeleteD. Allan Drummond and Jesse D. Bloom (2019)
Also, what were the "plus a couple of assumptions" and how do they weigh in significance to the proposed solution?
https://www.quantamagazine.org/physicists-debate-hawkings-idea-that-the-universe-had-no-beginning-20190606/
ReplyDeleteYou have to read most of the article, but here's the part about his assumptions:
ReplyDelete"The power of Penrose’s argument rests in its minimal assumptions, which only require the existence of a trapped surface and the weak energy condition. As a result, the singularity theorem applies very broadly and shows that singularities arise in many situations in general relativity. However, because Penrose’s argument is so general, it also does not give us any information about the singularity, beyond its existence. In fact, Penrose’s argument does not show that there must be an event horizon, and thus a black hole, surrounding the singularity."
https://www.einstein-online.info/en/spotlight/the-singularity-theorem/
And theorems normally have assumptions known as axioms or conceptual starting points. It's difficult to have a theorem without having assumptions, but note that the article says the assumptions of Penrose are minimal. At the very least, he showed the possiblity of black holes in nature.
Like every other argument - it can be interpreted as minor or as major:-
ReplyDeletehttps://www.researchgate.net/publication/317577551_Cosmic_censorship_and_the_third_law_of_black_hole_dynamics
https://s3.cern.ch/inspire-prod-files-1/189531adc0eb13e7a6d1ee3655fe681f
ReplyDelete"In addition, the proofs of the various laws of black hole mechanics require
certain assumptions about what is meant by the various terms. Parameters such as the surface gravity and mass need to be defined and their variations can either be physical in a given spacetime or between different spacetime solutions in phase space. Historically one has relied on concepts such as the surface gravity of a 40 A. B. Nielsen Killing horizon in a stationary state, normalised at infinity and the ADM mass in an asymptotically flat region to measure these quantities. The investigation of local horizons has also allowed some of these properties to be more locally defined."
https://scitechdaily.com/how-many-black-holes-are-in-the-universe-40000000000000000000/
ReplyDeletehttps://iopscience.iop.org/article/10.3847/1538-4357/ac34fb
ReplyDeleteAs referenced but to be clear, "stellar mass black holes" are black stars.
No reference or speculation on singularity. I would say that the estimated number is conservative.
This article does mention singularities in the context of SMBHs: https://astronomy.com/news/2021/09/what-are-stellar-mass-black-holes
ReplyDelete"At the center of a black hole lies the singularity, a theoretical point in space which has zero volume but contains all of the object’s mass. It is here that the black hole truly lives.
German theoretical physicist Karl Schwarzschild was the first to use Einstein’s theory of general relativity to show this point was mathematically possible. Encapsulating the singularity lies what most people picture when they think of a black hole: the event horizon. This is the spherical boundary beyond which nothing, not even light, can escape a black hole's clutches.
However, contrary to the name, black holes are not (always) entirely invisible."
Again, not trying to make a major point about the numbers of black holes, but I thought the other article I posted was worth perusing.
We have what is observable and that which is theoretical including a true event horizon.
ReplyDeleteAs someone once said (if I recall it correctly), "Theory without practice is empty, practice without theory is blind."
ReplyDeleteThe math or theory often comes before the discovery that a certain phenomenon or material object exists. Just because something is not observable at the time does not mean it doesn't exist: absence of empirical evidence is not evidence of absence. Sorry but I'm neither an empiricist nor a naturalist.
The math or theory often comes before the discovery and also comes with the interpretation of a discovery. It also comes before many more failures.
ReplyDeletehttps://www.tandfonline.com/doi/full/10.1080/13803611.2012.695513?scroll=top&needAccess=true
ReplyDeletehttps://www.livescience.com/65200-black-hole-event-horizon-image-questions-remain.html
ReplyDeleteContemporary education theory is now encouraging us to learn from "failures" or mistakes. Nothing ventured, nothing gained. I'm not contending that math perfectly models reality; far from it. It's just that theory or math often paves the way for praxis and it seems that praxis cannot do without theory.
ReplyDeleteFair enough.
ReplyDelete2021 article about a new image of a black hole: https://news.artnet.com/art-world/most-detailed-black-hole-photograph-1955942
ReplyDeletehttps://www.smithsonianmag.com/smart-news/new-black-hole-image-shows-plasma-jets-blasting-space-180978238/
ReplyDeleteSo, the question is, how does blasting jets our into space fit with the idea of a singularity, from which nothing escapes?
I think Hawking floated the idea that energy possibly could escape from a black hole, even with the singularity. I will have to confirm that point later.
ReplyDeleteSee https://www.bbvaopenmind.com/en/science/physics/stephen-hawking-and-the-history-of-black-holes/
ReplyDeleteParticularly, the accretion disk and Hawking radiation.
I think with future developments in the science of patterning that this may become velevant - https://youtu.be/0v6VE4aNkN8
ReplyDeleteWe have only just found out that rivers flow in the atmosphere. Where else will currents be found to flow?
What was shot out was material, not just radiation.
I'm sure we'll continue to learn more Job speaks about the fringes of God's ways. We just touch the iceberg's tip.
ReplyDelete