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#1401 |
Illuminator
Join Date: Nov 2020
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#1402 |
Philosopher
Join Date: Oct 2009
Posts: 5,047
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Details matter.
Tom Knight was one of the lead designers of the MIT Lisp Machines. This story says a lot about the previous post. A novice was trying to fix a broken Lisp machine by turning the power off and on. |
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#1403 |
Ovis ex Machina
Join Date: Jan 2006
Location: Sir Ddinbych
Posts: 6,963
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__________________
I’d rather be a rising ape than a falling angel. - Sir Terry Pratchett |
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#1404 |
Penultimate Amazing
Join Date: Jun 2003
Posts: 53,938
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To paraphrase from here:
https://despair.com/products/dysfunction The only consistent feature in all your failed theories is you. That's why I'm emphasizing you. The details of an individual failure are pretty secondary, far more significant is the consistent cause of those failures, and that's you. So you deserve attention, because that's the only possible source for a fix to any of this. Not tweaking your theory with yet another revision, but a fundamental change in how you approach everything. You need to start by learning, and not in this half-assed way you're currently doing it.
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![]() I just don't understand why it won't fly.
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"As long as it is admitted that the law may be diverted from its true purpose -- that it may violate property instead of protecting it -- then everyone will want to participate in making the law, either to protect himself against plunder or to use it for plunder. Political questions will always be prejudicial, dominant, and all-absorbing. There will be fighting at the door of the Legislative Palace, and the struggle within will be no less furious." - Bastiat, The Law |
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#1405 |
Graduate Poster
Join Date: Oct 2013
Posts: 1,609
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The Robertson-Walker metric is for an isotropic homogeneous Universe. In such a Universe, time passes at the same rate at all locations. You can write a 3 dimensional spatial metric for a given time which describes the intrinsic curvature and other properties, such as distances between points and angles between lines which are invariant under coordinate transformations.
If the rate of time is a function of location then the Universe is no longer homogeneous. But the Universe appears to us to be the same in all directions. The only way that can be is if the non-homogeneous Universe is spherically symmetric with us at its centre. That would make you a geocentrist. Is that what you arguing for? |
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Gulielmus Princeps Haroldum Principem in catino canino impulit |
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#1406 |
Illuminator
Join Date: Nov 2020
Posts: 3,643
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#1407 |
Illuminator
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#1408 |
Illuminator
Join Date: Nov 2020
Posts: 3,643
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https://arxiv.org/abs/1804.10047
"At redshift z, the vacuum speed of light in comoving coordinates is a−1c = (1 + z)c" |
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#1409 |
Philosopher
Join Date: Oct 2009
Posts: 5,047
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time line of another bad idea
So I call these things Cargo Cult Science, because they follow all the apparent precepts and forms of scientific investigation, but they're missing something essential, because the planes don't land.Today is 2 April.
Details matter. That's why I analyzed two of Mike Helland's specific wrong guesses about a metric form for Helland physics, relying on Mike Helland's explicit description of his coordinates: His unit for the time coordinate is a million years, and his unit for spatial coordinates is a million light years. My specific analyses of Mike Helland's two specific wrong guesses do not generalize to "something like" the highly abstracted metric form he wrote above. Because, knowing his specified coordinates, I know how to analyze Mike Helland's specific wrong guesses. Something does happen, but it would be a stretch to say it's something similar. I'll be happy to explain this stuff to Mike Helland, after he learns the relevant mathematics. For most people, it takes several years to learn enough calculus, linear algebra, topology, and differential geometry to understand general relativity and the variety of metric forms that describe various spacetime manifolds. Truth be told, most people never learn enough math to understand general relativity, so his own failure to understand doesn't make him special. The first principle is that you must not fool yourself—and you are the easiest person to fool. |
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#1410 |
Illuminator
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#1411 |
Philosopher
Join Date: Oct 2009
Posts: 5,047
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yet another example of the cargo cult
From that very same paper:
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By the way, the equation a−1c = (1 + z)cis an immediate consequence of the equation a−1 = (1 + z)which is an immediate consequence of the mainstream equation 1 + z = a(t0) / a(t1)(where t1 is the time at which the redshifted photon was emitted, and t0 is the present time) because a(t0) = 1 by convention.
Originally Posted by Wojtak and Prada
In particular, Helland physics insists the universe is not expanding, which implies a(t1) = 1, from which the equation quoted by Mike Helland implies z = 0. Helland physics is not based on an FLRW model, however, so Helland physics is not constrained by the equation Mike Helland quoted. It is of course completely unclear why Mike Helland quoted that equation, apart from his habit of randomly quoting things he finds online in the hope some readers will make the mistake of assuming his random quotations of real science somehow transform the cargo cult we refer to as Helland physics into real science. For an example of that behavior, see what Mike Helland wrote a little more than half an hour ago. |
Last edited by W.D.Clinger; 2nd April 2023 at 03:52 AM. Reason: added link to final sentence; corrected a subscript |
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#1412 |
Illuminator
Join Date: Nov 2020
Posts: 3,643
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Seems pretty clear to me.
I asked if the FLRW metric meant that stretching space resulted in a faster speed of light. Seems like it does. v = c(1+z) 1+z = v / c We also know v > c, so v = c + v2, where v2 > 0. That seems to be copacetic with relativity, so my derivation should be ok with it too. The metric I'm suggesting simply changes the rubber ruler for a lazy clock. |
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#1413 |
Philosopher
Join Date: Oct 2009
Posts: 5,047
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Quoting here for the record, to protect against the possibility of subsequent edits:
Assuming z > 0, that first inequality doesn't have anything to do with comoving coordinates because it is equivalent to c < c * (1 + z)The second inequality also doesn't have anything to do with the speed of light in comoving coordinates. The two posts quoted above tell us Mike Helland doesn't have a clue about comoving coordinates. But we could have guessed that. ETA: I'm going to let others respond to the nonsense Mike Helland wrote immediately above. Why should I have all the fun? |
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#1414 |
Illuminator
Join Date: Nov 2020
Posts: 3,643
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This first link in your chronology is:
http://www.internationalskeptics.com...6#post14033386
Originally Posted by hecd2
1+z = (c + v) / c Does that violate special relativity? Let's say it does. But in an expanding universe according to general relativity, that the speed of light is greater than c when z>0 seems to be a given. We wouldn't say that general relativity violates special relativity. So it seems the dynamic time conjecture can still operate in the framework of relativity as an alternative to the FLRW metric. |
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#1415 |
Graduate Poster
Join Date: Oct 2013
Posts: 1,609
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Leaving aside all the misunderstandings about tensor algebra that you demonstrate so clearly in your cargo cult posts, I pointed out to you that a metric in which the rate of time is a function of location (unlike FLRW which is based on a homogeneous, isotropic Universe where the gravitational potential, the mass-energy density and the pressure are uniform) would demand that we live in the centre of the Universe - and you ignored me. Are you a geocentrist?
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Gulielmus Princeps Haroldum Principem in catino canino impulit |
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#1416 |
Illuminator
Join Date: Nov 2020
Posts: 3,643
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I did notice your attempt to change the subject.
"If the rate of time is a function of location then the Universe is no longer homogeneous." Is it? The rate at which galaxies move apart is a function of distance, and causes clocks to move slower. That's homogeneous? Seems like your definition is pretty arbitrary. You say the universe is observed to homogeneous. Is it? https://en.wikipedia.org/wiki/Lambda...of_homogeneity
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That's the direction you want to go with this? I take it you realized it's not internally inconsistent, and that it can be relativistic (and I take it you'll deny that up and down) hence resorting to a more dubious argument involving the cosmological principle. |
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#1417 |
Philosopher
Join Date: Oct 2009
Posts: 5,047
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Someone who doesn't know the difference between a map and the territory might look at a Mercator projection and conclude Greenland is the same size as Africa. People who know enough to distinguish the map from the territory will say instead that the Mercator projection gives Greenland as much space on the map as it gives to Africa, but in reality Africa is about 14 times as large as Greenland. The Mercator projection is great when you want to keep track of true north and south, and when you want the mapped shapes of land masses to approximate their real shapes, but it's quite misleading when what you care about is the areas of those land masses. Mike Helland has consistently failed to distinguish maps from territories. The two quotations below are just the most recent examples of his confusion. As background, consider this metric form for isotropic flat space in Cartesian coordinates: ds2 = – c2 dt2 + a(t)2 dx2 + a(t)2 dy2 + a(t)2 dz2Although that metric form is often called the FLRW metric, it is considerably more general; it expresses the metric of any isotropic flat spacetime. (To obtain an FLRW model, you combine that metric form with assumptions about the cosmological constant and the tensor on the right hand side of the Einstein field equations.) The comoving coordinates that appear within that metric form are <t, x, y, z>. In what follows, keep in mind that although the actual speed of light in vacuo is invariant, the coordinate-dependent speed of light depends upon the coordinates you're using. To calculate the coordinate-dependent speed of light in those comoving coordinates, consider a photon moving through a vacuum along the x axis at some time t. Photons follow null geodesics, so 0 = – c2 dt2 + a(t)2 dx2High school algebra then tells us c2 dt2 = a(t)2 dx2 c2 / a(t)2 = dx2 / dt2 dx/dt = c / a(t) That is the comoving coordinate velocity of the photon. We can rewrite that equation as c = a(t) dx / dtwhich says the true velocity of light is obtained by multiplying the coordinate-dependent velocity by the scale factor. Which makes perfect sense if you understand comoving coordinates. A comoving object is an object following a geodesic that preserves its view of the universe as isotropic. In an expanding universe, the distance between comoving objects increases as the universe expands. The comoving coordinates x, y, and z ignore that. By ignoring the time-dependent scale factor a(t), the comoving coordinates essentially pretend a comoving object has always had and always will have the same coordinates x, y, and z that place it at a distance (as of today!) of sqrt(x2 + y2 + z2) from the (arbitrary) origin of the spatial coordinates. So comoving coordinates are convenient for calculations that need to keep track of the spatial coordinates of comoving objects, because their comoving spatial coordinates don't change over time. When you need to calculate actual distances and velocities, however, you have to take the scale factor into account. Assuming the coordinate-dependent speed of light in comoving coordinates is the actual speed of light is like assuming the area of a Mercator projection devoted to land masses such as Greenland and Africa accurately quantifies the relative areas of those land masses. It's a novice's mistake. So Mike Helland made that mistake, and based everything he wrote in the quotations below upon that error. |
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#1418 |
Illuminator
Join Date: Nov 2020
Posts: 3,643
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This is pretty unrelated, but I always like to point out that Greenland is closer in size to Mexico, and then show people this website:
https://thetruesize.com/
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Ok. So are you saying: Where f(L) = -(1 - HL2), makes the speed of light slower in that coordinate system? |
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#1419 |
Philosopher
Join Date: Oct 2009
Posts: 5,047
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I have never said that. Until now, you have never even hinted at what f(L) might be in that matrix. Even now, you have not even hinted at what L might be.
And while I would ordinarily assume H is the Hubble parameter, which changes over time, you have insisted that the Hubble parameter does not change over time, and you have responded to irrefutable proofs that Helland physics requires the Hubble parameter to be zero by saying those proofs depend upon the Hubble parameter having the meaning it has in mainstream science. In Helland physics, you are using H to stand for something altogether different, something we might call the Helland parameter. And you have never given us any quantifiable indication of what the Helland parameter might be. So I'd be a fool to take your f(L) = -(1 - HL2) seriously, inasmuch as it contains two distinct letters whose meaning you have left completely undefined. |
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#1420 |
Illuminator
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#1421 |
Penultimate Amazing
Join Date: Jun 2003
Posts: 53,938
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__________________
"As long as it is admitted that the law may be diverted from its true purpose -- that it may violate property instead of protecting it -- then everyone will want to participate in making the law, either to protect himself against plunder or to use it for plunder. Political questions will always be prejudicial, dominant, and all-absorbing. There will be fighting at the door of the Legislative Palace, and the struggle within will be no less furious." - Bastiat, The Law |
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#1422 |
Illuminator
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#1423 |
Philosopher
Join Date: Oct 2009
Posts: 5,047
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more cargo cultism
Then you are posting gibberish. You haven't said anything about the units you're using now, but H0 has units of inverse time and L2 has units of area (i.e. length squared), so your f(L) = -(1 - HL2) subtracts something with units area/time from the dimensionless constant 1, which probably yields a negative number, which you negate, thereby most likely yielding a non-Lorentzian metric form. You really and truly have absolutely no idea of what you're doing. Oh dear. Oh dear. Your f(L)2 c2 dt2 = L2can be rewritten as dt2 = L2 / (f(L)2 c2)which says dt is a pure function of the location (via L and f(L)) independently of dx, dy, or dz. That's a truly impressive pile of ackamarackus you dumped there. |
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#1424 |
Illuminator
Join Date: Nov 2020
Posts: 3,643
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H0 has units of distance / time / distance.
L2 is a mistake. The 2 should be outside the parenthesis. And that too might be a mistake. Because:
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dL2 = dx2 + dy2 + dz2 |
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#1425 |
Illuminator
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#1426 |
Philosopher
Join Date: Oct 2009
Posts: 5,047
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![]() FYI: "units of distance / time / distance" is just a complicated way to say units of inverse time. Moving the exponent outside the parenthesis doesn't fix anything. In one important sense that I explained to you a couple of weeks ago, it actually makes things worse. But you ignored me then, because you don't know enough high school algebra and calculus to understand even the simplest explanations of what you're doing wrong. Actually, I misread your definition of L as L2 = x2 + y2 + z2. You are correct, however, that writing L instead of dL led me to jump to the conclusion that there were no differentials on the right hand side either. See above. Please take note, however, that your gibberish has quite a few other obvious problems that I haven't mentioned and probably won't ever bother to mention. There's no use. |
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#1427 |
Illuminator
Join Date: Nov 2020
Posts: 3,643
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Yes, very true.
It's just a different way to follow the units. distance/time/distance = velocity / distance So in Hubble's law, v = H0d, you get velocity = velocity / distance * distance Rather than using natural units (c=1), the coefficient for the time coordinate should be: |
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#1428 |
Penultimate Amazing
Join Date: Jun 2003
Posts: 53,938
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I was asking how to do it in general, given a metric tensor. If you are asking if that's the right answer, then you don't know, and if you don't know, you don't understand any of what you're talking about. This isn't news, but you're acting like you think you are on the cusp of understanding and you aren't. You don't have the foundation necessary to understand any of the answers you are being given.
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"As long as it is admitted that the law may be diverted from its true purpose -- that it may violate property instead of protecting it -- then everyone will want to participate in making the law, either to protect himself against plunder or to use it for plunder. Political questions will always be prejudicial, dominant, and all-absorbing. There will be fighting at the door of the Legislative Palace, and the struggle within will be no less furious." - Bastiat, The Law |
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#1429 |
Philosopher
Join Date: Oct 2009
Posts: 5,047
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This is what cargo cult physics looks like. Just within the past day or so, Mike Helland has made at least five different wild guesses (in the spoiler) concerning what he guesses he hopes to be a plausible metric form for Helland physics.
I sincerely hope Mike Helland will clean up that mess by giving us just one last guess at a metric form, complete with a description of its coordinates and units, so we can have one last laugh before turning to the next chapter of this cargo cult physics. |
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#1430 |
Illuminator
Join Date: Nov 2020
Posts: 3,643
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Ok. Well, the lookback time for an FLRW universe with ΩΛ=1 is:
It gives the right graph when I plot this: https://www.wolframalpha.com/input?i...%2Bx%5D%2Cx%5D So that should give the coordinate time. Whereas the "true" or "actual" time as you put it is L/c. |
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#1431 |
Philosopher
Join Date: Oct 2009
Posts: 5,047
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ackamarackus
So that is Mike Helland's very best guess at what the metric form for Helland physics should look like.
Mike Helland's very best guess at the metric form for Helland physics does not resemble a metric form in any way. But that's the very best he can do: quoting some random thing he found on the World-Wide Web, hoping it will fool some readers into thinking it has some remote relevance to the issue at hand. |
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#1432 |
Graduate Poster
Join Date: Oct 2013
Posts: 1,609
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How on earth is it a change of subject to point out to you that your silly attempts to write down a metric tensor with a function of location in g00 results in a description of a non-homogeneous Universe. We observe the Universe to be isotropic. The only way that we can combine observed isotropy with inhomogeneity is if the Universe is spherically symmetric with us at its centre. (For example the Schwarzschild solution is spherically symmetric but not homogeneous).
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Gulielmus Princeps Haroldum Principem in catino canino impulit |
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#1433 |
Illuminator
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#1434 |
Illuminator
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#1435 |
Graduate Poster
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Gulielmus Princeps Haroldum Principem in catino canino impulit |
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#1436 |
Graduate Poster
Join Date: Oct 2013
Posts: 1,609
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Gulielmus Princeps Haroldum Principem in catino canino impulit |
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#1437 |
Illuminator
Join Date: Nov 2020
Posts: 3,643
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That ol' strawman.
H0 is a measured constant in Helland physics. The FLRW model to which it is analogous is ΩΛ=1. H(t) / H0 = E(z) Which is 1 for the ΩΛ plus 0 for ΩM and ΩR. H0 = Ht Because the constant doesn't change in that model, that's why its dobs exactly matches d=zc/H0 and demit exactly matches d=z/(1+z) * c/H0. FWIW, it should be: |
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#1438 |
Philosopher
Join Date: Oct 2009
Posts: 5,047
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What Mike Helland wrote above implies a(t) = eH0tIn other words, Mike Helland is saying that, in Helland physics, the size of the universe increases exponentially with time. But Mike Helland doesn't know enough mathematics to realize he's saying that, and will undoubtedly respond to the facts stated above with more ackamarackus. |
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#1439 |
Illuminator
Join Date: Nov 2020
Posts: 3,643
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I said that expanding model is analogous to my model, in the sense that the same z, lookback time, and demit values are predicted identically by both models.
There is no big bang in a "pure" expanding universe, ΩΛ=1, ΩM=0. Lookback time grows and grows. Not that I'm advocating that. But it is analogous to what I am suggesting for said values. |
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#1440 |
Philosopher
Join Date: Oct 2009
Posts: 5,047
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That's because, looking backwards in time, the size of the universe shrinks exponentially. Exponential decay converges toward zero, but never actually reaches zero. Mike Helland didn't know that either. Which is why we're seeing more of the old ackamarackus. |
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