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posted by martyb on Friday April 10 2020, @02:19PM   Printer-friendly
from the uneven-is-odd dept.

Isotropy of the universe is the idea that the universe is the same in all directions, and is a founding principle of the laws of physics. However, that principle has been called into question by observations of galaxy cluster temperatures and luminosities.

https://scitechdaily.com/fundamental-principle-of-cosmology-cast-in-doubt-by-compelling-new-study/

"No matter where we look, the same rules apply everywhere in space: countless calculations of astrophysics are based on this basic principle. A recent study by the Universities of Bonn and Harvard, however, has thrown this principle into question. Should the measured values be confirmed, this would toss many assumptions about the properties of the universe overboard. The results are published in the journal Astronomy & Astrophysics, but are already available online."

The paper (open access):
https://www.aanda.org/articles/aa/abs/2020/04/aa36602-19/aa36602-19.html

Journal Reference (open access):
K. Migkas, G. Schellenberger, T. H. Reiprich, F. Pacaud, M. E. Ramos-Ceja and L. Lovisari. Probing cosmic isotropy with a new X-ray galaxy cluster sample through the L X – T scaling relation , 8 April 2020, Astronomy & Astrophysics.
DOI: 10.1051/0004-6361/201936602


Original Submission

 
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  • (Score: 5, Interesting) by Anonymous Coward on Friday April 10 2020, @03:21PM (6 children)

    by Anonymous Coward on Friday April 10 2020, @03:21PM (#980830)

    In my opinion the age of the universe is where astrophysics started to get into really poor science.

    We have many things that we can use to roughly measure the age of the universe, including the cosmic microwave background radiation. You assume there was a boom and stuff spread out roughly evenly then you can measure how cool (and distributed) stuff is and create a workable date from there. The problem is that what we observe doesn't work if you do this. Areas of the universe that should *not* be causally connected (in other words, even at the speed of light - nothing from region A would have had time to interact with stuff in region B) *are* causally connected.

    We patched this with cosmic inflation. Cosmic inflation basically says there was a magical period of faster than light hyperinflation in some microsecond period after the big bang, and then equally magically slowed down and everything returned to normal. If you make this assumption then what we observe matches much more closely with what you'd expect to see. But this is horse shit science and a big part of the reason I fell out of love with cosmology. It's completely unfalsifiable, has absolutely no physical bases whatsoever, has 0 predictability, and is driven entirely by the desire to retrofit an observation to reality. It's like social science level science - and it's now a fundamental part of all of astrophysics. This [physicsoftheuniverse.com] article provides more detail on the issue.

    The problem I have with this is that, like social science, when you start to indulge in pseudoscience you create an invalid foundation which can make genuine progress difficult if any of your pseudoscience ends up being incorrect. To take a less theoretic example, consider the question of whether the universe revolves around the Earth, or whether we have what we know to be accurate - where the Earth revolves around the sun which revolves around the center of our galaxy, and so on. In times when science believed that the Earth was the center of the universe, imagine trying to accurately model astronomical models. They did come up with some mind bogglingly complex models that were able to provide some basic astronomical projections (when you'd see the planets, etc) but the process of trying to wrap that into a geocentric universe required tremendous mental gymnastics when reality ended up being quite simple and describable with a single simple equation: F=G*M1*M2/r^2.

    Anyhow, imagine trying to make any further progress from that geocentric model. It would not have really been possible, and any 'progress', as such, would have been inherently tainted and simply wrong. And indeed cosmic inflation theory was developed around the 70s, which is about the time that astrophysics began to freeze in terms of meaningful progress.

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  • (Score: 3, Informative) by khallow on Friday April 10 2020, @05:57PM

    by khallow (3766) Subscriber Badge on Friday April 10 2020, @05:57PM (#980871) Journal

    The problem is that what we observe doesn't work if you do this. Areas of the universe that should *not* be causally connected (in other words, even at the speed of light - nothing from region A would have had time to interact with stuff in region B) *are* causally connected.

    We patched this with cosmic inflation. Cosmic inflation basically says there was a magical period of faster than light hyperinflation in some microsecond period after the big bang, and then equally magically slowed down and everything returned to normal. If you make this assumption then what we observe matches much more closely with what you'd expect to see. But this is horse shit science and a big part of the reason I fell out of love with cosmology. It's completely unfalsifiable, has absolutely no physical bases whatsoever, has 0 predictability, and is driven entirely by the desire to retrofit an observation to reality. It's like social science level science - and it's now a fundamental part of all of astrophysics. This article provides more detail on the issue.

    First, let us note that cosmic inflation does explain the phenomenon of the first paragraph. If that phenomenon hadn't happened then inflation would be falsified. Also, consider this quote from your link:

    It is still not clear to scientists, however, exactly what caused the inflationary phase, the best guess being some kind of a negative "vacuum energy density" (or positive "vacuum pressure") triggered by the separation of the strong nuclear force from the other elementary forces at this time. It is hypothesized that this separation caused a kind of symmetry breaking or phase transition (analagous to the phase transition when water turns to ice), which left the universe in a highly unstable state with much more energy than it would otherwise have had, causing a sharp outward antigravitational effect, smoothing out most of the irregularities in the existing matter and creating vast quantities of particles in a very short time.

    That best guess shows us a way. We can find such a phase change by experiment. If it's not there at the necessary range of energies/temperatures, then the theory is falsified.

  • (Score: 2, Interesting) by leon_the_cat on Friday April 10 2020, @06:26PM (1 child)

    by leon_the_cat (10052) on Friday April 10 2020, @06:26PM (#980885) Journal

    Ah but why? Remember our Gods must be infallible.

    "Human beings live in a state of mind called 'sanity' on a small planet in space. They are not quite sure whether the space around them is infinite or not (either way it is unthinkable). If they think about time, they find it inconceivable that it had a beginning. It is also inconceivable that it did not have a beginning. Thoughts of this kind are not disturbing to 'sanity', which is obviously a remarkable phenomenon and deserving more recognition." Celia Green

    Big bang theory "solves" this metaphysical problem. You can then ask useful questions like what happened at 1X10^-52 seconds after the big bang. You may not however ask what happened 1 week before the big bang as presumably there was no time or enthropy. To join these points would require some cosmic space ghost and well you know that would kind of defeat the point of getting our metaphysical house in order.

    • (Score: 0) by Anonymous Coward on Saturday April 11 2020, @04:15PM

      by Anonymous Coward on Saturday April 11 2020, @04:15PM (#981174)

      +1 for the Celia Green quote. Unfortunately she got stuck in her head (yes, we HEARD about your high school already) rather than putting that gift to any use.

  • (Score: 3, Interesting) by Anonymous Coward on Friday April 10 2020, @09:25PM (2 children)

    by Anonymous Coward on Friday April 10 2020, @09:25PM (#980916)

    I don't know why you call it pseudoscience. Cosmic inflation is a conjecture that seems to explain the current observations. I think it lies in a similar vein as Einstein's relativity. Was it falling into pseudoscience by conjecturing that time and space change? Or postulating that energy is only delivered in discrete packets? Imagine that, somebody coming along and saying that the reason we don't have an ultraviolet catastrophe is because energy is actually quantized. It sure fit the data very nicely, but like with relativity there was nothing from our everyday experience to base it on.

    Astrophysics is in a particularly tough position because we can't directly measure most things. We can only measure the things that come to us and we can only look at everything else. There are a very few things we can try to reproduce on Earth, but we're stuck with assuming that the physics we know here applies there. But it is also entirely acceptable to say that there is new physics going on, provided that observation agrees, or at least doesn't disagree. Some people really don't like quantum mechanics, just like some people really don't like evolution, but the problem those people have is the fact that those two things are VERY good at providing explanations and making predictions. Fred Hoyle hated the expanding universe idea, but his steady state universe model kept breaking down under the weight of observation. In fact, it gets tweaked every decade or so and makes a comeback, but it keeps coming up short with observation. Who knows, maybe Fred's basic idea is right and we haven't hit the right tweak for it yet, but until then, I'm in with the expanding universe crowd. (The tired parable of the blind men and the elephant always gets thrown out in discussions about this point.)

    I've never been too crazy about inflation either, because it does seem like an ad hoc explanation, but it does describe the general observations. As khallow pointed out, it also suggests things to test, which is the hallmark of a decent physical model.

    What alternative do you propose to get us away from such pseudoscience? (I'm waiting for our resident Electric Universe guy to pop in--I haven't read anything from him in a while)

    • (Score: 0) by Anonymous Coward on Saturday April 11 2020, @06:01AM (1 child)

      by Anonymous Coward on Saturday April 11 2020, @06:01AM (#981030)

      Inflation is nothing like relativity. Relativity has all the hallmarks of extremely good science: [extreme] falsifiability, put forth a large number of testable predictions that could not even be tested at the time (yet would imminently be able to), and the proposed predictions ran contrary to all normal logic. And finally of course it also provided a physical explanation to the phenomena in the form of the curvature of spacetime. Relativity is probably the single best example of what "real" science in the most idealized fashion possible looks like.

      Again the key issues with cosmic inflation:

      0 predictivity: it's used as a patch to make the big bang fit reality - the things it "predicts" and the things it was retrofitted to explain are one and the same.
      0 falsifiability: there is nothing you could ever do to falsify it, ever. even if you could simulate other big bangs, since you're appealing to magic you could argue that our big bang was simply different.
      0 physical method: suddenly everything broke all laws of physics as we know them, then everything went back to normal. it's, again, an appeal to magic.

      It is *exactly* like a social science study, and that sort of science has no place in any field that wants to actually make meaningful progress.

      • (Score: 2, Interesting) by Anonymous Coward on Saturday April 11 2020, @10:28AM

        by Anonymous Coward on Saturday April 11 2020, @10:28AM (#981085)

        Most of cosmology is like this. Cosmology is not something that can ever be tested in a lab. The only possible experiment is the universe itself. It's not really like a social science, but maybe it's kind of like archaeology. Nobody is ever going to make a new Ancient Egypt in a lab, but that doesn't mean there's no value in studying their history, and it certainly doesn't mean they never existed. Similarly, something created the odd universe that we currently see. A universe without inflation doesn't look like what we see. Maybe the observations are wrong, maybe the physics is wrong, but something has to be the truth. Science is the search for that truth, not the answer to it.

        There is a certain overlap between cosmology, physics, and mathematics where mathematical developments can give the theoretical physicists new tools, that they can use to come up with ideas that the astronomers or experimental physicists can then check. Most of the time it does not work like this. Instead, strange observations come in, theorists figure out a plausible explanation, and then someone devises a test. There is always a delay, sometimes months, sometimes decades, between when the theory is formulated and when it can be thorougly tested. The most important statement in all of science is not "Eureka!" but rather "Huh, that's odd."

        Important discoveries do come from odd cosmological observations. The "Solar Neutrino Problem" and "Ultraviolet Catastrophe" are two problems of astronomy/cosmology that were once unsolved but gave rise to important developments in physics and have now been tested in many ways. All the branches of science work together, and the fact that science does not always have all the answers does not invalidate the results it produces.