Macavity

Many years ago, I DARED to ask what eyepiece astigmatism *really* meant. Someone (on CN) produced an excellent "flower" pic! Very different from eyeball astigmatism! 😉 [Unfortunately, I cannot find it now!] 😉 Astrigmatism... Field curvature? A lot of us bandy terms? I'm "guilty as charged" too! Some of this might be a problem with the "Sharp End" of the telescope? 😛 It seems difficult to illustrate/quantify "sharp" in a visual scope sense.

Whatever - I find this truly amazing! 😎 https://en.wikipedia.org/wiki/HR_8799

Impressive scale Certainly a fair old way to walk! Even back on earth. 🙃 Just reading about some other Apollo stuff. The episodic "return visits" of the Apollo 12 third stage! The Apollo 11 LEM (Eagle) still in orbit around moon? 🙃

You can always "jiggle it a bit"! (Or leave it well alone?) 😁 If it fails to bond, you can DRILL the blocks and add bolts? It may "kill" a standard drill, but I was surprised how easy it was to drill (at least) standard concrete blocks! 😉

Gotta hand it to the Swiss... Some nice locations for observatories! 😁 Noticed the DOMES, some Forty Years ago, but never thought... https://stellarium-gornergrat.ch/instrumente/ Website is only in DE/FR - But one can look at the pictures too! lol Always "dig" the Officina Stellare Red/Black! 😎 Other (EN) stuff about what they do... https://www.hfsjg.ch/en/home/

Sadly so, Jim. The "Big Science" tradition of ad-hoc, friendly (productive!) collaboration between diverse groups: (Theoreticians, Scientists, Engineers, Technicians, Programmer) is replaced by formal "Service Level Agreements"! The previously hierachy-free system gets invaded by "job titles", the now, rigidly defined, "seniority structures". 🙁 Office memos get sent round (often to highly qualified staff) telling us we must: "Answer telephone calls within Three Rings (sic!)... speak politely to "Customers"! Focus shifts to annual appriasals... promotion... "taking credit". Instead of actually doing stuff, we now spend half a working week reporting to "progress meetings" - Ironically on overall LACK of progress - 'Cos we are in meetings! Resentment grows... No one does "that little bit extra"... 😔 MAYBE that goes some way to explaining why some of us feel a tad MIFFED, when "Scientists" on Social Media, seem to be trying to circumvent *Peer Review* - To influence *budget* allocations, by direct appeal to a mottley bunch of "conspiracy theorists" and "anti-science rhetoricians"? To get OTHER areas of science "cancelled" etc. 😒 Not without odd chuckle tho! Sometimes I checkout the profile of "Super Fans", these folk re-tweet/re-post. Dunno about "Scientist", but ONE certainly earned the moniker "Biggus D....." Aargh, my eyes! 😱 N.B. It's always worthwhile checking on the company you (appear to) keep?!? lol. 🤣

Often a good idea *is* to read a Book, or look up a *authoritative* reference! That a scientist (subsets of?) may make "simple" mistakes, or "not know stuff", does not prove the opposing idea. Devil's Advocacy is pretty much infinite? 😁 I also think that one cannot constantly go back to (scientific) first principles or "Philosophy of Science" arguments. Some things you do have to take as "read" - Or at least, have some trust in (quite often!) "rather clever" people. 😛

For a general impression, the above "thin lens" ray diagram is sufficient. Detailed optical design references might feature the full ray tracing... for "thick lenses"... Cardinal Points ... nodal planes all that sort of stuff?!? 😉

Just something I came across recently... And (for a change) I enjoyed! 😎 For me, "Particle Physics" has always been rather *honest* about this... And I just feel sometimes, there is a need for a reasonable perspective! Perhaps her lectures can seem a tad "haphazard", but I find her style fun! Zeee French (Canadian?) accehnt! But, makes a change from each time I logon to Twitter, Sabine Hossenfelder's: "Zees is all Vayst of Time!" 🤣

Ah, SGL! lol. I had anticipated everything... That Sailors would tell me ropes were "sheets" etc. 😁 P.S. I HATED "Applied Maths", but sometimes the "small things" still intrigue...

I found a good START was to buy (in stages even!) a Baader Hyperion series: 5, 8, 13, 21mm (or their Vixen predecessors). The Fibonacci series... The Golden Ratio... appealed to me. lol. If you have more/less money "root two (1.4)" or "root three (1.7)" might be another idea? 😛 Coming from a "science background" (Don't worry, I have forgotten almost ALL of it now!)? But then I sometimes find Amateur Astronomer debates about STUFF slightly scary? lol. Then we commend ourselves for showing "admirable restraint"? [teasing] 🤣

OK, a slightly clickbait title. But intriguing things... Capstans? 😎 https://en.wikipedia.org/wiki/Capstan_equation A baby could (theoretically) "hold the USS Nimitz" apparently! As a hobby guitarist, I was interested to actually READ that you don't NEED to wind more than a few turns of a string around an electric guitar's tuning (machine) heads, to stop strings slipping. Be careful not to overlap strings. Capstans are self-centering etc. But such ideas are probably familiar to Sailors, Climbers etc. 😛 P.S. I suppose many of us have thought about using an (obsy) rope to help lift Scopes onto Mounts, but it's usually "easier" NOT to. 😏

I suspect that's the VERY thing! (Two/more issues?) 🙂

I imagine a large "Palomar-sized" (Amateur Super-Dob?) might be a concern re. such things. A typical shop-bought reflector, rather less so? But I may be quite wrong! If you can demonstrate such effects! 😎

ISTR it is held that... "blowing on stuff" induces more turbulence? Computer CPU fans blow rather than suck? Misspent-youth, "Case Modder", reluctantly concedes (brute force) blowing is better? 😅

I did track "Cosmic Girl" using Flight Radar 24 - SHE seemed to do the "loop" in an opposite direction to that previewed - and took the commentators by surprise? 😏 The "drop" occurred on the 90 deg turn -- "bottom right"? Still a shame though. 😐

I TIRE of this. Reply deleted to protect personal anonymity etc. 🥳

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🥳 Got a (cheerfully irreverent?) chuckle from that one! But you raise several excellent points... And indeed, large SCTs and TAKs! (That "Bloomin Brian Cox and his expensive LHC" thing? lol). Hey, it's an important (and fascinating) topic - How we "interest" people in Astronomical stuff! I sometimes worry that even "popular science" has become more of a... lifestyle thing now? 😈 Dare I suggest that some might find Astro Imaging a little intimidating... a tad... "exclusive"? 🙀 (Hey, perhaps that was another time/forum? Were I allowed a "repeat life", I'd give it a go! lol) An odd thing, my few attempts at Afocal (I had to check) "Camera to eyepiece" photography ended in total discouragement? Perhaps the most difficult of all types of Astrophotography? Heheh. Reminded me: "random girl on station", who seemed unusually eager to engage me in conversation? Apparently Arriva Trains had located her (left on train) £800(!) phone (mate)! 😏

Ah, the eternal question! On Facebook, a (random) member of our local Astro Soc. asked the same thing! A *fixed* budget was specified. There were ZERO replies... Finally, I weakened and suggested a modest 70mm AZ refractor (within budget). 🥳 Immediately, another (so far silent member) suggested (with apologies), mine was NOT a good choice! That, something FAR better could be obtained second hand?!? I didn't argue. We WERE then in the middle of a pandemic? Total Newbies are not in the best position to evaluate the quality of a *second hand* telescope etc. etc. 🤔 But then, perhaps a FIRST telescope is but a TOKEN - Albeit to be cherished! And, ultimately, by whatever means, eventually, doomed to be replaced. 😅

Just watched this - "So you don't have to"? lol! Uhm "Fair enough", I thought? For me, the idea of scientists (Amateur OR Pro) doing the talking - "Warts and All" is great! And, if someone is REALLY interested, they can "follow it up"? 😎 Sometimes, there will be people who take up Amateur astronomy, because "the wife tells them they need a hobby"... And, sometimes "inate geniuses"! But such programs are also a prompt to Search the Internet... Read BOOKS? There is ultimately (fairly so?) a bit of "Darwinian Selection" re. Astronomy! 🤡 ++1 for Maggie (A-P!) regarding his "Dichroic Filters"? "Atta Girl Scientist"! 🥳

These days, you'd need to define "Video"? lol. Sometimes think I was "seduced" far too EARLY? 🥳 But I still have my Watec internal integrating Cameras - Around here somewhere. Were it not for "real life stuff", I might have followed the TRENDS re. technology / ideas? 😉 These days, it's more of "hybrid thing"? Ever closer to *conventional* imaging? The appeal of "doing something different", rather less, these days? 🤔 Sadly, "Video" CHIP technology is a thing of the past too?

I DID *finally* "take them out". Under "milky" skies etc. 😏 Stars came into good (impressively colour free) focus. The "right side focus" adjustment JUST accomodated my (extreme) eye variance! Nice to revist the "Winter Stars"? Orions Nebula...Pleiades etc. Leaning against house wall revealed the satellites of Jupiter etc. 😎