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Four years on, new experiment sees no sign of ‘cosmic dawn’
- djohnston 5y agoGreat to see the scientific method at work! I am a layman but curious to see the next report here.
- willis936 5y agoI'm so excited for JWST's data. Observations from the inflationary period have the potential to completely upend cosmological dogma. Findings like this are the precursor. I'm sure theorists are furiously working on alternative models. This is an exciting period to watch.
- astro123 5y agoInflation happened during the first tiniest fractions of a second post big bang. No telescope is going to make direct observations of the inflationary period so I'm not sure what you mean by this.
- jazzkingrt 5y agoWell, I guess measurements of the early universe (100-250 million years after the big bang) can test predictions made by models of the inflationary period.
- astro123 5y agoMeasurements of pretty much any time in the universe can test predictions made by models of the early universe. One of the main reasons we think there was inflation is from late time (near today) observations of matter density (see https://en.wikipedia.org/wiki/Flatness_problem https://en.wikipedia.org/wiki/Flatness_problem).
- willis936 5y agoI'm referring to the earliest era of transparent space, when conventional matter supposedly coalesced. If we look back to that period and still see red-shifted mature galaxies then something is very wrong with the current models. I'm under the impression that we don't have good observations of the period 375k-400M years after inflation and that infant galaxy observations have not been confirmed.
- metalliqaz 5y agoThe earliest moment of transparent space is the CMB. I know JWST can't detect Pop3 stars, but is there even expectations that it could detect proto galaxies with those stars? I thought it was still much later, like the early Pop2 generation.
- throwawaycities 5y ago> No telescope is going to make direct observations of the inflationary period so I'm not sure what you mean by this. Isn’t this an engineering problem and what we are attempting to do with gravitational wave detectors? I know at one time it was believed gravitational waves were detected that provided direct evidence for inflationary theory but then the data was determined to be dust from the Milky Way. I thought this was still one of the major ongoing efforts in gravitational wave detection, was this ruled out?
- metalliqaz 5y agoBut those aren't really "telescopes", are they? :)
- throwawaycities 5y agoYes gravitational wave telescopes is commonly used along with gravitational wave detectors, gravitational wave instruments and gravitational wave observatories.
- slowmovintarget 5y agoThis isn't just an engineering problem. Photons couldn't move around for the first 380K years or so. Space was nearly uniform, hot, and dense. The CMB is literally the heat wave left over from the point where the heavy soup thinned out just enough to allow photons to fly away in all directions. The gravitational waves from those events would have already warped space, and the ones just now reaching us would be from the edge of the observable universe, and so too weak for any instruments we could conceivably build in the next few decades. Not that we shouldn't try, mind you. There are new frontiers in quasimatter and time crystals that could yield far more accurate gravitational wave detectors. Also fascinating would be to attempt to decipher the deformations left in the metric already. There are some theories that basically say gravity waves permanently "crumple" spacetime, and it might be possible to read signatures of such events if this is so.
- dataflow 5y ago
- 9wzYQbTYsAIc 5y agoSeems like cosmologists, astronomers, and physicists might now have enough new food for thought to fill in their boredom with quantum mechanics. Apparently, this result implies new information about dark matter.
- 77pt77 5y ago> to fill in their boredom with quantum mechanics What does this even mean?
- 9wzYQbTYsAIc 5y agohttps://cosmosmagazine.com/science/physics/future-of-physics-killing-quantum-mechanics/?amp=1 https://cosmosmagazine.com/science/physics/future-of-physics...
- SiempreViernes 5y agoNo, this is rather a case of the old models probably being the more correct ones: the EDGES result itself was quite unexpected and hard to explain in the existing framework as it was much stronger than expected. Now that EDGES looks to be dead, the old predictions of a weaker effect are validated.
- 9wzYQbTYsAIc 5y agofrom the article: “a radio astronomer at McGill University in Montreal who wasn’t involved in either experiment, says that both EDGES and SARAS were extremely thorough in their calibration and analysis procedures, and that it’s too soon to say which result is correct. “The level of disagreement is enough to make people uncomfortable, but I think it’s far from the end of the story,” she said. “From my perspective, it adds to the excitement.” And “Stranger still, the dip was very pronounced, suggesting that hydrogen in the early universe was colder than theoretical models predicted, possibly because of exotic interactions with the dark matter that fills the cosmos. Or perhaps the EDGES dip had a more mundane origin.” The article seems to imply that the EDGES dip may be due to mundane, faulty experiment design, instead. In any case, a little bit of excitement for those scientists.
- overthemoon 5y agoThe photos of the EDGES antennas are beautiful. Tools used to study something so remote, set in remote places.
- akeck 5y agoMaybe we can get one of these experiments onto the side of the moon not facing us...
- deleted 5y ago[deleted]
- nobody9999 5y ago>Maybe we can get one of these experiments onto the side of the moon not facing us... I'd expect that it's a matter of when, not if. See references below: https://www.upi.com/Science_News/2021/05/19/nasa-moon-astronomy-observatories/4601621372283/ https://www.upi.com/Science_News/2021/05/19/nasa-moon-astron... https://www.space.com/moon-far-side-radio-quiet-telescope-project https://www.space.com/moon-far-side-radio-quiet-telescope-pr... https://www.science.org/content/article/could-humanity-s-return-moon-spark-new-age-lunar-telescopes https://www.science.org/content/article/could-humanity-s-ret... https://earthsky.org/space/lunar-crater-radio-telescope-lcrt-phase-2-duaxel-radio-waves-dark-ages/ https://earthsky.org/space/lunar-crater-radio-telescope-lcrt...
- digitcatphd 5y agoWouldn't the James Webb telescope be the optimal device for collecting and deciphering this data? Seems like we're on the brink of potentially the most significant scientific discovery since Copernicus, or are about to feel awfully stupid.
- adrian_b 5y agoNo, these signals are at a low frequency of around 1.4 GHz, not at the high frequencies of infrared or visible light. For such radio signals, much larger antennas are needed than what we can expect to have on space telescopes in the near future. A much more likely improvement, compared to what can be done on Earth, could be obtained by building a large radiotelescope on the Moon (i.e. with a large array of antennas), on its hidden face.
- deleted 5y ago[deleted]
- SiempreViernes 5y agoI think that EDGES probably didn't see a real signal is more or less the expectation of the field. I remember that the feelings towards the result at the time was quite sceptical, and it seems it didn't take long before someone discovered that the published result wasn't very robust: https://telescoper.wordpress.com/2018/09/03/edges-and-foregrounds/ https://telescoper.wordpress.com/2018/09/03/edges-and-foregr... The people from the follow up instruments are very polite about all this, which I guess makes sense if you've used the EDGES result to get money for your own antenna.
- wolverine876 5y agoWhich critics have funding that depends on the EDGES result holding up (rather than, for example, finding something new themselves)? Do you work in that field? I've always read that competition is pretty brutal in natural sciences.
- simonh 5y agoThey don't necessarily depend on the EDGES result holding up, but may be to confirm/refute it. Even if your experiment refutes EDGES, you don't want to imply EDGES was utter bunk from the start, because if that was so why did you spend so much money bothering to test it? Your funding and project still depends on it having some credibility.
- Zenst 5y agoFascinating image and reminded me momentarily of Frogspawn, which is kind of fitting as they are looking at the Frogspawn of time itself.
- strainer 5y agoThe big image in the article is just an illustration of the subject, alas.
- jxoxsknd 5y ago
- deanCommie 5y agoFor any physicists reading, I have a question about the Big Bang: Is the standard consensus that the specific physical description is literal or just the closest approximation/visual model we have that matches the data? I ask because I was in my 30s before I learned that Dark Matter and Dark Energy are effectively metaphors. There is something that contributes more gravity in the universe than our understanding of the it predicts. And there is something that contributes energy to accelerating the expansion of the universe, and we have no idea what. So we call them "matter" and "energy" but TECHNICALLY they don't have to be right? It could also be that something exists that is completely beyond our bounds of understanding. I ask because this feels very much the situation with the Big Bang. Even if all the data shows the universe rapidly expanding in fractions of a second, it is incomprehensible to understand where the energy for it came from, or what happened "before". And the answer "nothing happened before because that's when time started" feels like an acknowledgement of the limitations of our human understanding. So here's my follow-up question: Obviously we build an understanding of the universe based on observations of the data. And sometimes the data doesn't match and we have to upgrade Newtonian Physics to Einsteinian, or introduce Quantum Mechanics, etc. So are there comparable/equivalent investigations/experiments going on today that reveal numbers/observations that are basically fundamentally unexplainable without looking beyond the realms of our understanding of the limitations of our universe?
- jbakhos 5y agoI've proposed a modified gravity theory that you might be interested in taking a look at. If correct, it would answer a lot of these questions. You may look at a pdf of it here: https://vixra.org/pdf/2203.0032v1.pdf https://vixra.org/pdf/2203.0032v1.pdf
- arcadi7 5y agoNot metaphors . We know these are out there — we just don’t know a lot about them. The situation is similar to atoms in second half of 19th century : we knew they are there , we knew some of their properties but only it the first quarter of 20th century we learned how much more there is to learn about atoms
- 5y ago
- eisvogel 5y agoI've never heard it mentioned, but I strongly suspect that cosmological redshift is simply the result of photons losing energy over vast distances due to some as-of-yet-undiscovered interaction with the quantum vacuum. It was a couple of vatican-sponsored jesuits with an obvious creationist agenda who turned the observation of redshift into an assumption of spatial expansion to support the theory of a single-point-of-origin universe with a finite age and a finite size. I think western science is predisposed, due to religious cultural influence, to being uncomfortable with an infinite universe, because it implies our own ultimate insignificance.
- jl6 5y agoScience does not suppose a finite or infinite universe, but rather an observable universe of finite size plus an unobservable universe which may or may not be finite in size. Science is a lot more comfortable and accepting of uncertainty and unknowns that you give it credit for here.
- eisvogel 5y agoThis is a reasonable, and i don't accuse all of Science. I am just very suspicious of the certainty with which astrophysics has pursued proof of a big bang for most of a century. There are number of glaring assumptions, many of which point back to an unreasonable level of faith in the Standard Model.
- eisvogel 5y agoAlso, the infinty that i think scares people the most is temporal, not spatial.
- snarfy 5y agohttps://en.wikipedia.org/wiki/Tired_light https://en.wikipedia.org/wiki/Tired_light
- eisvogel 5y agoHey thanks for that snarfy. I love this topic.
- cozzyd 5y agoI always found it slightly suspicious how the EDGES dip was right between the ITU region 3 broadcast bands. Obviously they do filtering and are far away from everything, but perhaps the gazillion FM stations in Indonesia + some TV stations + meteor scatter (or some other sort of odd propagation) could maybe escape the RFI filtering and mimic the dip.
- CamperBob2 5y agoIntermod has got to be the real nightmare in that business. There's absolutely no way to guarantee it isn't happening. A rusty bolt on a gutter on a completely unrelated building near a couple of transmitters may be all it takes to re-radiate a signal in a completely different band.