alt Hacker NewsAstrophysicists Puzzle over Webb’s New Universe
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I thought I read somewhere that many of these little red dots are turning out to be nothing more than bog-standard brown dwarfs in our own galaxy that are confusing the signal. These days we have some pretty powerful agents who can read these things faster than I can, so I went and found the paper: https://arxiv.org/abs/2506.04004
It turns out that brown dwarfs are actually corrected for, so my remembrance is correct but factored in. I’m posting anyway because 1) it’s interesting and mildly relevant and 2) others might have the same “vague but unclear” recollection I had and appreciate the elaboration.
Little red dots are my favorite new concept in astrophysics. This idea that there could be so much matter orbiting a black hole that the matter reaches sun levels of pressure which in turn starts steller fission without there being an star. Mind-blowing
There was a time where Hawking's A brief history of time gave a decent overview of the universe to beginners. Does anyone know how well it holds up today and if anything better exists?
You won't make it to the next iteration without wrapping yourself in a black hole and appearing as an anomaly to future observers.
Such a fun read, looking forward to more
Nancy Grace Roman Telescope is also going to be amazing for raising new questions
and I hope the attempt to lift the Swift telescope to a higher orbit is successful
if you really want to stay on top of what is breaking astrophysics in realtime, I highly recommend following DrBecky on youtube or elsewhere, she is fantastic
So I wonder, where are these giant black holes now? There should be some closer to us than at the edge of the universe, unless something happens to them.
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.
The most exciting idea to me that JWST has bolstered is primordial black holes. Many models already predict them but JWST has provided the first good indirect evidence in the form of too-early galaxies. The models that predict PBHs predict that.
If they exist, they would not be constrained to stellar mass and above. There could be a population of little black holes floating around. Anything under the mass of a decent size asteroid would have evaporated by now but anything that mass and above would still exist.
They are a dark matter candidate, and one that doesn’t require new physics. But even if they don’t account for a significant amount of dark matter they still probably exist.
The most exciting thing about PBHs is that one or more may exist in our solar system. They might have been captured over billions of years. Finding them would be incredibly challenging, especially if they are low mass, but if we did it means we could directly examine and experiment on a black hole.
It could be something with the mass of a large asteroid but the size of a hydrogen atom. We could only find it by its gravitational effects. It would be utterly invisible otherwise unless it encountered matter and even then there might only be a tiny gamma ray flash, a nano accretion disc that lasts femtoseconds. We might also find smaller objects that appear to be orbiting nothing and find it that way.
Directly accessing one could allow us to test theories of quantum gravity and things like string theory, and maybe more. A black hole could be like a Rosetta Stone of deep fundamental physics.
The film Interstellar involved using plot magic to visit a black hole and solve physics, but this would allow it for real. It would just be an itty bitty one.
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
That’s a beautiful article showcasing our predicament in having access to more information about the universe. Now i have to be the one to ask the dumb defensive question:
what makes us so certain that we can trust what we see on James Webb? Can we definitely discard a measurement problem?
Only two things are infinite: the cosmos, and a web designer’s obsession with discovering new ways to break scrolling.
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Quanta magazine is a glorified university press release and marketing shop for Simons associated institutions.
Take it with a grain of salt, and know for sure its leaving out a huge range of scientists views.
> 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.
Instead of questioning whether the Big Bang assumption is true, astrophysicists prefer to perform endless "gymnastics" to try to make the mounting contrary data fit their theory about how the universe began.
> Recent ideas suggest that little red dots could be black holes cocooned in thick gas, possibly representing a completely new type of object called a black hole star, in which the tight shroud of gas emits light like a stellar atmosphere.
Just be sure to name the members of Soundgarden on the paper.