Astrophysicists Puzzle over Webb's New Universe

(quantamagazine.org)

41 points | by jnord 2 hours ago

4 comments

  • dvh 1 hour ago
    Only two things are infinite: the cosmos, and a web designer’s obsession with discovering new ways to break scrolling.
    • CrzyLngPwd 2 minutes ago
      And no one can be sure about the cosmos :-p
  • phyzix5761 29 minutes ago
    > Faced with observations of early black holes and galaxies that weren’t expected to exist, scientists have come up with a wealth of new theories to explain them. Now they just need to figure out which ones are true.

    This subtitle really bothers me. Science isn't about finding out what is true. Science is about finding out what is false and building models to explain the rest. We can never confidently say we know something to be true because that closes the door for future science to disprove our beliefs and that's exactly the purpose of science.

    The best we can do is come up with increasingly more useful models accepting that in the end all models are wrong but different models are useful for different purposes.

  • gbjcantab 1 hour ago
    This is one of my favorite phenomena: again in again, across various fields of study, breakthroughs in discovery allow us to go from relative ignorance to a level of knowledge and understanding that enables clear and clean conceptual models; then, as we learn even more, we realize how much more complex and weird and multifaceted reality really is.

    It’s like a Dunning-Kruger effect on a field-wide scale, but in a good way. Rather than an example of hubris, it’s an opportunity for awe.

    • qsera 1 hour ago
      >It’s like a Dunning-Kruger effect on a field-wide scale, but in a good way.

      But not in in medical field. The unjustifiable over confidence can lead to application of bad things on a generational and population wide scale, damaging many many generations of human beings.

      • sdoering 13 minutes ago
        WTF. We have such great medical advancement in cancer treatments, vaccines, reconstructive surgery h just to name a few.

        Not sure what you are referring to, but the only unjustifiable things in the (so called) medical field are snake oil sales men trying to make a quick buck by instilling a fear of science into people's minds. Like anti-vax idiots. Or homeopathic bullshit.

  • jdw64 1 hour ago
    As observations become too numerous, it seems like it can be summarized as there now being too many possible candidate explanations. As data increases and becomes clearer, more and more things don't fit the existing theories.

    What are the current theories explaining the early universe? What happened to the Big Bang? I only studied astronomy up to an undergraduate level, so I don't really know.

    I imagine that various non-uniform gases were scattered around, and due to spatial distortions, those uniform gas regions clumped together, forming stars and other structures. Perhaps the expansion of space wasn't uniform either—it expanded unevenly, sometimes bulging, and when space expands or contracts, energy is generated, causing spacetime changes to shake the field, and that shaking might have created matter. Maybe the dynamic interaction between changing spacetime and fields revealed the energy stored in the field in the form of particles.

    What do scientists think about this in modern cosmology? My knowledge is far too limited and I lack intuition, but reading science-related articles always excites me. Maybe it's because I still have some childlike curiosity left in me

    • ben_w 4 minutes ago
      With the caveat I'm summarising from what PBS Space Time and Dr Becky* say:

      • Big Bang: we can only see back to surface of last scattering, i.e. the CMB, extrapolating backwards goes "???" at much the same point as it did a few decades back because we still have not unified quantum mechanics and general relativity

      • CMB should only have isotope distribution of Big Bang nucleosynthesis, that hasn't changed in the last decades, dunno if that's what you meant by "various non-uniform gases were scattered around"?

      • Variations in density of CMB do exist, key phrase is "Baryon acoustic oscillations", while they're very small magnitude they're also massive in distance scale, so they're how galactic clusters formed (that scale rather than stars directly): https://en.wikipedia.org/wiki/Baryon_acoustic_oscillations

      https://www.youtube.com/watch?v=PPpUxoeooZk

      https://www.youtube.com/watch?v=LRUTnoveZs8

      • Re: "Perhaps the expansion of space wasn't uniform either": I heard about specifically "Timescape Cosmology", but a quick search says that's part of a broader category of inhomogeneous cosmologies: https://en.wikipedia.org/wiki/Inhomogeneous_cosmology#Timesc...

      https://www.youtube.com/watch?v=SXg6YVcdOcA

      https://www.youtube.com/watch?v=JlNVZz5D6WE

      • Re: "and when space expands or contracts, energy is generated": no, general relativity does not in general conserve energy, and it is related to the curvature of spacetime. Simple example is that the photons in the CMB have much less energy to us than they did to the atoms they were emitted from: https://www.youtube.com/watch?v=04ERSb06dOg

      * I assuming I'm correctly judging the level and attention to detail they're providing, given the detail they put in and references to specific research publications. My degree is Software Engineering.

    • tigerlily 8 minutes ago
      I took a good long look at the CMB picture, including the caption. It basically says the Universe was one big hot apparently uniform ball at one stage.

      I don't know what conditions were like before that stage, but like Eric Idle says, nothing can come from nothing.

      Dark energy is a horse shit name for a theory that was horse shit to begin with. The Universe is probably just inhomogeneous, like your intuition is saying.

    • jvs76 1 hour ago
      I dont think about it because my days are occupied by very specific problems. Theory of Bounded Rationality and its implications apply.
      • jdw64 1 hour ago
        Right. When you don't have any breathing room, it's hard to think about anything else. That's why I take about two hours a day to just watch the news and clear my head. I'd probably forget all about it too if I were working 70-hour weeks on a contracted project, haha. Hang in there. Have a good day