8 ms·
2.7-meters Telescope mirror shot 7 times (1970)
- jeanlucas 2y agoThis is no news by any metric, but I found curious that: 1. It only reduced the telescope efficiency by 1% 2. The original report from 1970 is still up! This is the video that made me aware of the incident: https://www.youtube.com/watch?v=59cw_bDbEqA https://www.youtube.com/watch?v=59cw_bDbEqA
- worstspotgain 2y agoTo be fair, it's Texas. Even the state motto is 1% riddled with bullet holes.
- pmb 2y agoThe state motto of Texas is "Friendship". (this is true)
- worstspotgain 2y agoIf it was Frıendshıp before the Alamo I'd say that works out about right.
- deleted 2y ago[deleted]
- lb1lf 2y ago...whereas that of New Hampshire is 'Live free or die' Incidentally, NH licence plates are stamped out by prison inmates. Now THAT is cruel and unusual punishment, right there! Edit: For those not well versed in NH plates, the state motto is embossed on each and every number plate. (This may be the case for every US state, for all I know)
- tialaramex 2y ago> This may be the case for every US state, for all I know Nope. What the jurisdictions choose to write on plates varies, often for a fee you can have something different, either of your choice (within limits) or from some limited selection. Famously DC has plates quipping about the "Taxation Without Representation" which was notionally the reason the United States wanted independence. The District of Columbia of course does pay federal taxes but does not receive proper democratic representation in exchange, exactly the situation the colonists complained of and with exactly the same retort offered in response†. [This is a very small hypocrisy compared to say declaring that "All men shall be free" and continuing to literally enslave some of them for example] † The Congress insists, just like the Westminster Parliament, that these tax payers are represented, but virtually, with the entire institution actually somehow representing their interests. If this strikes you as poppycock for Westminster, it should feel no different closer to home.
- eadmund 2y agoIt seems to me that it makes a great deal of sense for the seat of the federal government to be located in a federal district independent of any state’s control. It also would not make sense for that federal district to be represented as a state — that would end up being a circular dependency, since the federal government is created by the states, and it doesn’t make sense for the federal district to participate in creating and sustaining itself. Those who choose to live within the federal district have a privilege others in the United States do not have: direct physical interaction with and influence over the individuals composing the federal government. It makes sense to me that the privilege is balanced with a lack of representation in the Senate and House. Note that they do have representation in the Electoral College. It also makes sense to me to retrocede the majority of the current federal district back to the state of Maryland.
- mhb 2y agoAnd, incidentally, you can choose to cover or remove the motto on your plate: https://news.ycombinator.com/item?id=41488122 https://news.ycombinator.com/item?id=41488122
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- 404mm 2y agoYou know the news is from 1970 because back then there was a mental institution for people like him. And it’s not like we have fewer issues now.
- dghughes 2y agoYeah that stood out. There's basically zero mental health resources now after Reagan gutted it. Now the shooter would himself be shot or thrown in jail only to come out worse. Repeat.
- WarOnPrivacy 2y agoBetween genealogy and caring for a MI spouse, I learned it went down like this. Late 18th to early 19th c. people with compassion and insight opened sanitariums to provide care for folks with brain disorders. Much of the care was truly revolutionary and helpful. Some of it was other things. The public was impressed and inspired. The founders died off and institutions continued on without their vision. The public lost interest; funds waned but need did not. By the 1980s institutions were no longer safe or caring. The public had moved on. Few in power knew or cared. Politicians saw funding streams they could grab w/o risking reelection and forced our MI population into homelessness. We're still there. My 5 state institutions are dangerous hellholes. Homeless are everywhere here. source: w/o long-term inpatient care, wife left the family to become homeless
- TremendousJudge 2y agoI completely agree that mental institutions are important and need more funding/attention. However, your comment implies that all homeless people have mental problems that need treatment. Many are just very poor and most of their problems (mental or otherwise) are caused/exacerbated by homelessness itself. I consider myself sane but if I didn't have a permanent shelter and had to face the streets every night I'd go crazy too
- samatman 2y agoIt implies nothing of the sort. What it states, without making implications, is that the very mentally ill who would otherwise be in institutions, are instead homeless. Which is the case.
- tjpnz 2y agoWatched this last night and had a chuckle at how his initial attempt to damage it failed - hammer flew right off the surface. Also how seemingly nonchalant they were about the event.
- eternauta3k 2y ago7 10 cm diameter circles have 1% of the area of a 2.7m diameter circle.
- avidiax 2y agoReminds me of the article from Lensrentals about how much front element scratches affect photo quality. Apparently not very much. Wait, did they say scratches? They meant a completely cracked front element. https://www.lensrentals.com/blog/2008/10/front-element-scratches/ https://www.lensrentals.com/blog/2008/10/front-element-scrat...
- Zobat 2y ago"tis but a scratch".
- krackers 2y agoGiven that, why are specs of dust on glasses so noticeable?
- consp 2y agoNever notice them, only big stains. Maybe it depends on the strength and type?
- qq66 2y agoYour eyes are a "wide angle lens." Scratches on wide angle lenses are also very noticeable
- imhoguy 2y agoOr damn eye floaters.
- left-struck 2y agoLike with scratches on lenses, those floaters are only visible when your eyes have a small aperture, like when you’re outside in broad daylight
- wkat4242 2y agoFloaters are a bit different because they are behind the lens. It's more comparable with dust on the sensor in an SLR (or dust in the sensor cavity) That is also more noticeable with lower aperture but for a different reason. With a low aperture the light comes more from a single direction so the shadow from the dust particles is more defined. The same happens with the floaters. The reason you only see them when looking at the sky is because they're pretty transparent and you need a bright detailless surface to see the low contrast they provide. But it's very different from scratches on a lens surface because those are in front of the optics.
- WarOnPrivacy 2y agoA 1970 historical image: https://historicimages.com/cdn/shop/products/nex48799_1200x.jpg https://historicimages.com/cdn/shop/products/nex48799_1200x....
- Leo_Verto 2y agoBesides the report on mirror damage this telegram also appears to contain observations of "periodic comet Curmumov-Gerasimenko", which had been discovered a year earlier, and happens to be the one ESA's Rosetta mission visited in 2016.
- Mistletoe 2y agohttps://astroanecdotes.com/2015/03/26/the-mcdonald-gun-shooting-incident/ https://astroanecdotes.com/2015/03/26/the-mcdonald-gun-shoot... If you would like to see the bullet holes. Bigger than I imagined based on the telegram.
- dwighttk 2y agoAs a Cub Scout we went on a tour of the observatory and I think we were able to see the pictured view, but I may just be remembering the story and imagining the image. They definitely told us the story and all the kids were like “coool!”
- lexicality 2y ago> When the sheriff arrived, the employee was arrested and later committed to a mental health institution. In the report following the incident, the sheriff, clearly being unfamiliar with telescope designs, stated that the mirror had indeed been destroyed as it had a big, circular hole, right in the middle! "no sir, that bigger hole was there before the incident... yes sir, it is supposed to be there"
- mnky9800n 2y agoI wish there was more information about why the guy shot the telescope. But so far I find nothing.
- bovermyer 2y agoYou could try contacting the university to see who worked there at the time. Dr. Smith, mentioned in the article, died in 1991. His obituary is here: https://quasar.as.utexas.edu/BillInfo/HJSmithObits.html https://quasar.as.utexas.edu/BillInfo/HJSmithObits.html Alternatively, you could try contacting the sheriff's office in Austin to see if their records include a mention of the incident, but that information is probably protected.
- throwanem 2y agoOnce ages ago I heard a story like this, itself not young at time of telling, from a professor of physics. That story might have been set in Texas and did involve a handgun being fired into a telescope mirror which was not meaningfully damaged by the experience, but had it as a revolver wielded by a revivalist-type preacher who smuggled the weapon in during a tour to redress what he saw as a violation of God's domain. It's been ages since I was in touch with the fellow who told the story, so I can't immediately confirm whether these were the same events. But the similarities are striking.
- helsinkiandrew 2y agoNew York Times: https://www.nytimes.com/1970/02/07/archives/texas-man-fires-into-a-telescope-extent-of-damage-to-mirror-by-7.html https://www.nytimes.com/1970/02/07/archives/texas-man-fires-... > An employe of the Mc Donald Observatory, described as drunk by the sheriff and as mentally depressed by his superiors > Sheriff W. B. Medley said that the shots “completely de stroyed the telescope — it was ruined.” University of Texas astronomers in Austin said the damage was minor.
- WarOnPrivacy 2y ago> Sheriff: Drunk suspect destroyed telescope > People who know better: Depressed employee did some minor damage Modern LEO techniques seem to have history.
- gcanyon 2y agoThe telescope is still in use today, and Wikipedia says that the damage effectively reduced the telescope from a 107 inch mirror to a 106 inch mirror. https://en.wikipedia.org/wiki/Harlan_J._Smith_Telescope https://en.wikipedia.org/wiki/Harlan_J._Smith_Telescope
- alt227 2y agoThe article itself says: "The damage is limited to small craters about 3 to 5cm in radius, which reduce the light collecting efficiency by about 1 percent"
- mrb 2y agoHere is a pic showing the bullet holes in the mirror: https://starhopper.org/2020/11/19/a-telescope-with-bullet-holes/ https://starhopper.org/2020/11/19/a-telescope-with-bullet-ho...
- Rinzler89 2y agoHow did the mirror not just shatter though?
- dredmorbius 2y agoThe mirror (third largest in the world at the time) is composed of fused silica. Apparently manufactured in segments, then joined. The cooling process itself took two years. That's described in one of the linked YouTube videos in this thread: <https://news.ycombinator.com/item?id=41459171 https://news.ycombinator.com/item?id=41459171> The result is a glass that's remarkably immune to shattering. Possibly similar to a Prince Rupert's Drop, though that's my own speculation. <https://en.wikipedia.org/wiki/Fused_quartz https://en.wikipedia.org/wiki/Fused_quartz>
- adolph 2y agoGiven years long cooling process (aka annealing), the mirror would be the opposite of a Prince Rupert's Drop, which is created by quenching the glass very quickly, similar to the process known as tempering. https://en.wikipedia.org/wiki/Annealing_(glass) https://en.wikipedia.org/wiki/Annealing_(glass) https://en.wikipedia.org/wiki/Tempered_glass https://en.wikipedia.org/wiki/Tempered_glass
- dredmorbius 2y ago"Possibly" is doing some heavy lifting in my comment. The similarity is in the end result, not, obviously, the fabrication process. The strength of the Prince Rupert's Drop comes from the differential tensions and stresses in the head-end of the drop. The tail, of course, is remarkably fragile and will lead to the explosive failure of the entire drop. The head can withstand hammer and even bullet impacts, as Destin Sandlin has demonstrated multiple times on his "Smarter Every Day" YouTube channel. I'd suspect a similar tensile arrangement in fused silica, though of course I may be wrong on that.
- MeteorMarc 2y agoProven to be vandalproof!
- moffkalast 2y ago> McDonald Observatory, University of Texas And all right in the world.
- geocrasher 2y agoLast year I built a Hadley telescope, which is a 3d printed structure with some inexpensive optics from China. https://www.printables.com/model/224383-astronomical-telescope-hadley-an-easy-assembly-hig https://www.printables.com/model/224383-astronomical-telesco... One of the things that surprised me, being new to telescopes (and certainly never having built one) was that it was deemed better to leave dust on the optics than to potentially damage them by trying to clean them. The dust just doesn't affect image quality. I had no ide athat would scale up to gunshots however! Very impressive.
- verandaguy 2y agoI say this having read the mailing list and specifically the part that mentions the mirror is made of fused silica: What the hell is that mirror made of? Is this kind of behaviour a well-documented/practical property of silica? I would assume that it'd shatter after any amount of shots and a hammer blow.
- throwway120385 2y agoFused silica is very pure quartz.
- verandaguy 2y agoWouldn't that be quite brittle, though?
- lazide 2y agoIt Depends(tm). Usually on the grain alignment/lack thereof. As long as the grains are suitably randomized, it can be very durable. [https://en.m.wikipedia.org/wiki/Quartzite https://en.m.wikipedia.org/wiki/Quartzite]
- dredmorbius 2y agoThe McDonald Observatory is open to the public (a consequence, as I understand, of it being on the highest-elevation public highway (6,814 ft, 2,077m) in Texas, and hence having right of public access), with both guided and self-guided tours of several of the telescopes / domes, including the 2.7m Smith scope. The damage is visible from the public gallery as I recall. The scope is primarily used for spectroscopic studies, though it can also be used for direct visual imaging, which might account for why it's even less susceptible to mirror damage than might otherwise be the case. The region is quite rural, with the nearest settlements being Fort Davis to the southeast and Fort Stockton to the northeast. Among other local attractions are Alpine ("AL-peen"), home to a federal courthouse, and Marfa, a remarkably liberal artist colony. Remarkably beautiful following a freezing frost in winter time, as well.
- deleted 2y ago[deleted]
- willguest 2y agoWhen all you've got is a hammer, but then remember that you're carrying a 9mm...
- dekhn 2y agoyou can always tell a reflector scope person because they'll just say "all it did was reduce contrast"
- tempodox 2y agoIs the right to shoot at things (in civil life) really that essential in this day and age? When was the last time you required a gun to ensure your safety? Or even to use it as a bottle opener?