"Here's looking at Euclid"
Lovely stuff, well done :)
Astronomers are breathing a sigh of relief that the 600-megapixel Euclid wide-angle space telescope's instruments appear to be working well, despite discovering a gap in the orbiter's hull that allowed sunlight to leak through and contaminate some images. Launched a month ago, Euclid will snap billions of galaxies to help …
I’m not for one moment accusing the author of intentional plagiarism, but I do feel bound to point out that this very joke was used by Chris Addison in his Radio 4 comedy show “The Ape That Got Lucky” way back in 2005.
Introducing a guest he rattles off a list of the guest’s alleged works, including “‘Pop Goes The Weasel’ - A Treasury Of Vivisection Anecdotes”, “‘Fruits Of The Forest’ - The Truth About Robin Hood And His Merry Men”, and of course, “‘Here’s Looking At Euclid’ - Geometry In The Films Of Humphrey Bogart”.
And I suspect it predates that too :)
Regardless, seek out the show; it’s bound to be on YouTube or the ilk. It’s very very funny if you like that sort of absurdist humour.
ESA remembered to send the heavy wooden tripod, got everything nicely focussed on the ground-glass screen and removed the dark slide, but the heavy black cloth had failed to unfurl properly.
Luckily the older galaxies have stopped the young ones in the front row from fidgeting so they can take the shot again.
If we could just have the First XV cluster together now, very nice: hold it, hold it...
ESA publishes some really good high resolution photographs of the STM (Structural and Thermal Model) and in some of them it is possible to see there is a platform that the tubular sunscreen connects to, then a gap, then below it the instruments (this organisation can be seen in some sketch/CAD diagrams of the instruments found elsewhere).
The gap between instruments and platform appears to be covered with flaps of gold foil which in some photographs are unclipped and others partially clipped. It looks likely that when the telescope is oriented such that the solar panels aren't aimed perpendicular to the sun, light can pass the edge of panels and is supposed to be reflected away by the tube and these foil flaps. It is possible that one or more foil flaps isn't correctly overlapping - that would explain why light pollution only occurs at specific angles to the sun.
See this and its list of "Related" images:
I still have a fiver which says that dark matter and dark energy will turn out to be modern physics' epicycles.
"Hey, our models don't work, but we don't need to fix them. All we need to do is invent a new sort of matter which forms most of the mass of the universe but doesn't affect anything except the things our models don't predict correctly."
Only a fiver, but it stinks of defensive bodge.
In fairness, my understanding is that Dark Matter and Dark Energy are merely theoretical placeholders for effects that we don't yet understand, which makes me wince whenever I hear about them being referred to as something that we expect to physically find.
It's not a given that Dark Matter or Dark Energy actually exists in the way that we think of energy and matter. Certainly, we might find that the current model is wrong and what we think of as energy and mass in this case just don't exist. The fact that we haven't found *anything* that resemble either yet leads me to suspect that we never will and we are concentrating our efforts in the wrong direction. Mind you, if we can confirm their non-existence, that is still progress.
I've never been very comfortable with the use of dark to express "unknown", "missing" might be better but we really need something that is both expressive but not everyday so that it can't crop up in other contexts. As has been said, they're placeholders for observed phenomena (rotation of galaxies and expansion) that can't account for with current theories.
"which makes me wince whenever I hear about them being referred to as something that we expect to physically find."
That's the hope. When what's going on IS found, the Nobel laureate that makes the discovery (provided they live long enough for the committee to get around to them) can change "Dark" to something else.
They all built their model upon the concept that gravity emanates from the centre of a mass object, this planet being a good example, and pulls everything towards it, See Scientific American February 2002 ask the experts; Why are planets round? Again Issac Asimov came up with his suggestion, from the same thinking; that gravity would be minimal at the centre so that one would float around in the centre without any problems.
All of that was in turn caused by eminent scientists not reading Issac Newton's Principia, of if they did, not understanding the meaning of his words, particularly in his opening remarks, where he tells us that he made the decision to place his calculation of the mass of any object, right at the centre of a circle on the page which he regularly describes as "P", and then in Definition 1 he writes:
"I have no regard in this place to a medium, if any there is, that freely pervades the interstices between the parts of bodies. It is this quantity that I mean hereafter everywhere under the name body or mass"
And adds in Definition VIII: "For I here design only to give a mathematical notion of these forces, without considering their physical causes and seats."
Ergo, his real interest is mathematics; he is thus less concerned with any underlying physical aspects of the debate and he continues: “I likewise call attractions and impulses, in the same sense, accelerative, and motive; and use the words attraction, impulse or propensity of any sort towards a centre, promiscuously, and indifferently, one for another; considering these forces not physically, but mathematically: wherefore, the reader is not to imagine, that by those words, I anywhere take upon me to define the kind, or the manner of any action, the causes or the physical reason thereof, or that I attribute forces, in a true and physical sense, to certain centres (which are only mathematical points); when at any time I happen to speak of centres as attracting, or as endued with attractive powers”
Newton laid down the foundations for modern mathematics and Principia; Mathematical Principles of Natural Philosophy is a towering monument to his undoubted genius. However, as you will now discover, by entirely concentrating upon presenting mathematical solutions; while at the same time deliberately avoiding distractions caused by physical aspects of the solutions he was presenting; he misunderstood the importance of just a few words he had written.
As did it would seem did everyone else since.They all ignored Newton's 3rd Law.
And yes that has been available since 2017 and I expect they are indeed waiting for me to die before acknowledging it; perhaps wanting to then "Discover" me.
Well Pauli first postulated them then. We still don't have a consistent capacity to describe them. (see Sabine Hossenfelder (https://www.youtube.com/watch?v=p118YbxFtGg)). When you find things that are seriously interesting but don't seem to want to know the rest of the universe, me, I personally think of Terry Pratchets (https://discworld.fandom.com/wiki/History_Monks#The_role_of_The_Order). The real and obvious question (carrying on with the neutrinos) is we are pretty terrible at watching them; how good are they at watching us?
So, if we are being honest, hoping to find out life changing models of things that we can observe because they happened about 3 bn years ago (or is this " dating back to ten billion years" meant to mean 10 billion years ago) when we can't even explain what is happening in our own neck of the woods seems a bit like building on the sand on a sandbank in the Goodwin Sands (running out of sands there) and expecting it to survive because we built it on a set of sands (got another one in) and that will be a sandtastic discovery. (not going to ack the last one, it was terrible. If (and I hope some of you can) you can post better please do).
We all should know that the Standard model of particle physics has some pretty big problems, even ignoring the neutrino (alleged) problem. It doesnt fit with gravity nor, the standard model of astrophysics. Maybe it's just me, but we seem to be searching for more and more defects that are a long way away whilst ignoring the mote in the models eye.
It's not a bodge. Pop science often confuses "having a name" with "being explained".
"Dark matter" is a short way to say "these observations behave as if there was a whole lot of mass just there, but we can't see any; we don't have an explanation for that". Ditto for "dark energy".
It's not a way to fix the models; it's a way to label the bits of the models that don't work, so that we can talk about them.
The idea that dark matter is definitely, certainly, literal matter that's literally dark (or invisible), is mostly from sci-fi. Real scientists don't know, they know they don't know, and they don't dislike the idea of poking holes in models; it's one of their favorite pasttimes.