I follow this stuff (as a non-physicist) so I understood it. It’s a pretty shallow article and mentions there there’s still evidence for the widely-accepted Lambda-CDM model. But like most coverage of MOND it declines to give good alternate explanations for specific key observations like the Bullet Cluster, gravitational lensing, and galactic outer rotational speeds.
So yeah a new observation that fits better with MOND than LCDM is certainly interesting, but it doesn’t flip the tables unless it does a better job explaining the prior phenomena too.
I understand the two theories and the difference between them, but when my brain tries to comprehend how gravity actually works I experience a comprehension failure.
Haha, well if it’s any consolation, nobody fully understands it. That’s why we’re still looking at various theories of quantum gravity or even random gravity.
Ok, so: you know how Earth is part of the solar system? And the solar system is part of a large collection of stars and planets called a galaxy?
Well, there’s lots of galaxies out there! And scientists for a long time have been trying to figure out how they formed - how did all the stars get close to each other? Why aren’t they just randomly drifting around?
Currently, everyone believes that there’s this magic stuff called “dark matter” that pulled the stars together to make galaxies. Kinda like how magnets pull things close to them!
And because galaxies are so big it would take a long time to pull the stars close together! Which means young galaxies would look less bright because the stars aren’t all close together yet, like they are with older galaxies.
So that’s what everyone believes.
But we’re getting pictures from a really strong telescope that’s showing us that young galaxies are brighter than we expected! Which is weird and exciting because it means that young galaxies might have been pulled together faster than we used to think! And our old theories about galaxy creation might be wrong!
There’s a theory that explains how galaxies could come together quickly, without dark matter, but it doesn’t really fit with many other theories we have about how the world works, so lots of people are thinking really hard to figure out how they might fit together.
And that’s what science is all about! Finding out new information that shows you that you were wrong in the past, and using that information to figure out new ways to act and think in the future!
Ooh new pbs spacetime will be sweet. (Although mond seems kinda meh).
🙏 wrong distance measurement (or light speed shenanigans) would be most fun to observe from outside of astronomy field, although they seemed kinda solid
As with nearly everything in astronomic optics, it’s named after people associated with its creation. Robert Jones and Thomas Bird are the two in this case. Here’s a thread on Cloudy nights with good info.
my fav from that thread (and i propose to make this a copy pasta):
My entire gripe around these scopes is the instruments being offered today, the sub-aperture lens arrangement is not doing any corrections. The lens is a straight up Barlow, nothing more.
If you look at the Bird-Jones design, the design is very specific in the design of both the primary & correcting lens. This means that both elements need to be not only matched but also well manufactured in order to work as designed. When you then look at the few true Bird-Jones instruments that were manufactured, such as the Tasco 8V (which was manufactured by Vixen), the Celestron G8-N and one other (escapes my mind right now but I’ll add it when I remember), these scopes were not cheap but pushing flagship status for these brands & supplied with swish mounts. And none of these scopes can be readily collimated by the end user as the alignment of the optics is so precise it is done in-factory. The 8V alone still maintains almost cult status.
The Bird-Jones design is not without its own shortcomings. It is not perfect without aberration. It is important to remember the ideas behind its design, to provide a short tube OTA option with what was able to be readily manufactured at the time, that being good spherical mirrors.
What is made today is a far cry from what a Bird-Jones offers performance wise. Made cheap with a poor spherical primary & that they are totally collimateable by the end user shows these are not a precision scope. Add to this that not a single Bird-Jones instrument is to be found anywhere else besides these cheap things. Doesn’t this say something?
These cheap instruments, really all cheap instruments are a double edge sword. They make astro more accessible, yes, but their poor quality ends up killing off more people’s enthusiasm for astro than firing it up. Add to this that for many novices if the mount is not a complicated equatorial one then it isn’t an astronomical instrument, & the difficult manner of using a wobble-tron mount & tripod with the mental gymnastics required just too much for most people who buy these and just give up way too soon.
Yes, there will be a few people who will be able to make these scopes work, being all they can afford, and all power to them. I will support such persons. But these are very few compared to the overwhelming number of people who just give up after the poor experience they get from these instruments. Too them astro is just all too hard, and mainly because of a poor instrument.
Call these cheap instruments what they are, a barlowed Newtonian.
astronomy
Najstarsze
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