[HN Gopher] Why lasers are so brilliantly useful
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Why lasers are so brilliantly useful
Author : prostoalex
Score : 108 points
Date : 2021-01-12 16:24 UTC (1 days ago)
(HTM) web link (www.economist.com)
(TXT) w3m dump (www.economist.com)
| gdebel wrote:
| Lasers revolutionized medicine, particularly in two specialties
| where the organ is accessible to light: dermatology and
| ophthalmology. We use : - excimer laser (UV) for their
| photoablative properties, to change to anterior corneal radius of
| curvature in refractive surgery (fun fact: the first attempt to
| use this laser was pure serendipity : "oh I got this excimer in
| my lab, here is a chicken sandwich, let's see what is gives on
| organic tissues") - ND:Yag laser to pierce a small hole in the
| iris when it is necessary to establish a communication, or to
| locally break the posterior lens capsule when it opacifies after
| cataract surgery ; those two procedures where far from benign
| when they had to be performed surgically , today it is made in
| the office in a few seconds - femtosecond lasers to cut a thin
| layer of cornea , which is lifted , before applying the excimer
| laser, in LASIK procedures - diode lasers to reduce the
| intraocular pressure by destroying parts of the ciliary body in
| very specific cases - various lasers to photocoagulate lesions on
| the retina....
|
| Ophthalmology without lasers would look like a middle-ages
| practice.
| DoingIsLearning wrote:
| A few more I can think of, Laser Doppler imaging of blood
| vessels, and certain types of oxymetry also use laser diodes
| instead of LEDs.
|
| Laser is pretty much everywhere.
| sillyquiet wrote:
| Tangential, but there are so many common in-use technologies we
| should be in awe of but aren't. I mean, just look at the average
| home or apartment built relatively recently.
|
| For example, we have reached standards of insulation, weather-
| proofing, and energy efficiency that would just blow the mind of
| any builder from just 30 years ago (not that there isn't room for
| improvement).
|
| It's not flying cars or robot butlers, but it impresses _me_ at
| least.
| porphyra wrote:
| I'm pretty excited about the future of VCSEL technology. Not only
| is it profoundly useful for lidar and stuff, dense arrays of
| lasers could also be used for all kinds of display technology.
|
| If we can somehow make cheap VCSELs that emit blue or green
| light, red, green, and blue VCSELs could even take over general
| purpose lighting. One imagines a TV where each subpixel is a
| VCSEL. It would potentially be better even than microLED
| displays. The spectral purity would give really amazing colors.
| wincy wrote:
| A lifetime ago I worked a retail job. I'd often say to coworkers
| "isn't it amazing we get to work in the future, we get to use
| laser beams all the time!" They'd stare at me blankly, and I'd
| squeeze the "laser gun" I was holding in my hands to scan a UPC.
| The most I'd ever get was a groan like I'd told a dad joke. No
| one was ever impressed.
|
| To me it's amazing how such wondrous technological advances
| become mundane so quickly, the future is here and nobody is
| astonished.
| pfdietz wrote:
| The rejection of lasers is simply incoherent.
| ingsoc79 wrote:
| It really is a polarizing topic.
| lisper wrote:
| Relax, it's just a phase. :-)
| KIFulgore wrote:
| But a stimulating discussion topic!
| samstave wrote:
| Why are you so phocused on this topic?
| TeMPOraL wrote:
| Can definitely amplify divergence of opinions.
| DoingIsLearning wrote:
| We are certainly diving into the lattice of this subject.
| opwieurposiu wrote:
| These spontaneous emissions of laser puns have me in an
| excited state.
| TeMPOraL wrote:
| Looks like red, it.
| umvi wrote:
| Occasionally on this site I'll see a truly brilliant joke
| or pun, and I will upvote. But this is not one of those
| cases. I downvoted this pun train because this is not
| reddit and I don't want HN to turn into reddit.
|
| Pun trains are so lazy - all you do to join the train is
| create a low effort sentence out of (in this case)
| something remotely related to lasers - Light,
| Amplification, Stimulation, Emission, Radiation, etc.
| It's not clever, and it spams up the thread enough that
| you have to collapse the train to see the next
| interesting comment.
| leetcrew wrote:
| I disagree but thanks for at least shedding some light on
| your voting decision.
| Humdeee wrote:
| Amplifying the subject further is totally dope
| agumonkey wrote:
| Or just lasey
| cosmodisk wrote:
| I get you. And it's not just lasers, it's so many more.
| Sometimes I catch myself thinking that the technological
| progress is quite slow, but then I slap myself in the face to
| remind myself that in just couple of decades we ended up having
| devices in our pockets just like those from sci-fi films!
|
| Lasers are great tech,I used to be fascinated by them when I
| was a kid devouring science literature. I hope I'll more great
| use cases in the near future.
| hutzlibu wrote:
| "the future is here and nobody is astonished."
|
| Maybe thats because that is always the case (even though
| progress accelerated).
|
| But since for most people the future still means they slave
| away in a boring job, that might be a reason they are not
| thrilled all the time.
| leetcrew wrote:
| on a similar note, most people only get to experience "future
| stuff" after it has been relentlessly optimized for cost to
| the point where it can be economically deployed to a mass
| audience. a lot of the coolness has been stripped out at that
| point.
|
| on a couple occasions, I've flown in small GA planes. a bit
| bumpy for my tastes, but there really is a sense of wonder
| and awe when you can just ask the pilot to fly anywhere and
| see what stuff looks like from the sky. I don't get the same
| feeling on commercial flights; I just experience being stuck
| in a metal tube with beige plastic trim for a few hours. I'm
| still amazed by what computers can do, but to most people
| they are just "the thing I use to browse instagram".
| superkuh wrote:
| When I was a child I'd often stare into the laser scanners at
| store checkouts in awe. They were so cool. Full of rotating
| mirrors and lasers. The modern handheld ones are a little less
| cool.
|
| But, re: "why lasers are useful", it's in the name. They're a
| way to get a spatial and phase coherent light source that's
| actually high power. In the old days they'd have to take a
| mercury arc lamp and put a pinhole in front of it. The pinhole
| gave it coherence but traded away all the intensity.
| throwaway314158 wrote:
| > To me it's amazing how such wondrous technological advances
| become mundane so quickly, the future is here and nobody is
| astonished.
|
| When they're ubiquitous they lose a lot of wonder. But
| furthermore, a lot of these advances are buried/not directly
| visible to the end-user. Think of a CD player: You use a
| _laser_ to produce _sound_ from (what apppears to be) a smooth
| plastic disc.
|
| I bet the concept of the wheel was pretty damn wondrous in the
| beginning too.
| d33lio wrote:
| I just bought a _proper_ $250 Zebra scanner for some personal
| inventory projects / projects that utilize pdf417 and data
| matrix 2d bar codes and I have to say... this is the absolutely
| coolest piece of "plug and play" tech I've bought in years!
| Granted, these scanners largely use machine vision tech but
| lasers are still used as a form of "dumb" auto focus aid.
|
| On another tangent, I still CANNOT believe that one company at
| least within the US controls 100% of the issuance of UPC codes.
| They sell them for up to *$30 A PIECE*! We need a "LetsEncrypt"
| for UPC codes - granted they serve an important role in load
| balancing across online stores, preventing counterfeit goods
| and in Amazon's case... penalizing sellers when they find the
| same UPC being sold on another online platform at a lower price
| ;)
|
| Lasers will always be cool
| cameronh90 wrote:
| Reminds me of that Louis CK bit about internet on aeroplanes:
| https://www.youtube.com/watch?v=nUBtKNzoKZ4
|
| "You're flying! It's amazing! Everybody on every plane should
| just constantly be going: "Oh my God! Wow!" You're flying!
| You're sitting in a chair, in the sky!""
| atoav wrote:
| I think bringing back that absolute bafflement intentionally
| once in a while is good habit, especially for people working
| in technology.
|
| I am constantly amazed that computers work at all. The more I
| learn about it the more amazed I am that anything works.
| Especially software wise I see soo much duct tape on so many
| layers, like looking at a house of cards that could (or
| rather should!) crumble down any minute, because it seems to
| defy reality.
| pengstrom wrote:
| My illusions of technology were lifted after a course in
| advanced computer architecture. The true technical
| complexity is unfathomable enormous. I mean, correctly
| flickering 3 billion times per second on nm scale and being
| super sure you got the designs right? Cannot imagine.
| cosmodisk wrote:
| Yes,sometimes we need to be reminded:
| https://youtu.be/yFj46Ei61Mg [7:30-8:00] I nearly took off
| the sofa just by watching it.
| dver wrote:
| And just skipping over the running out of money thing.
|
| Old enough that ATM's were a big change.
|
| Before that, it was a Friday trip to the bank to get cash for
| the weekend. Credit
| nearbuy wrote:
| On the topic of how wondrous technologies become mundane, I
| find it amazing how we surpassed some of the magic from Harry
| Potter, and no one is impressed.
|
| The first book was published in 1997. The characters have very
| handy magic wands, which among other things can be used as
| flashlights. They can send magical letters (howlers) that can
| yell at someone in the sender's voice.
|
| Fast forward to 2021, and suddenly everyone is walking around
| with a fancy tool in their pocket that can be a flashlight,
| instantly video chat with people, and answer questions on
| nearly any topic.
|
| Even the offensive spells seem inferior to modern weapons. The
| wizards have to recite an incantation for every shot, while
| assault rifles can spray 900 rounds per minute.
| ampdepolymerase wrote:
| The fidelius charm violates every known law of information
| theory and machine learning heuristics, not to mention the
| philosophical implications.
| cogman10 wrote:
| I graduated high school in 2004. It constantly amazes me how
| far we've come.
|
| Back in the 90s, CDs were the height of getting music. 1 disk
| would carry around 24 songs. That's it. The internet was
| accessible, but limited to around 56kbps on a desktop. Mobile
| data wasn't a thing. Texting wasn't a thing. Cell phones were
| barely a thing, but coverage was practically non-existent.
|
| Most people got their media only from broadcast stations. You
| had radio, television, and the newspaper and that was pretty
| much it.
|
| The fact that data is available pretty much everywhere is
| incredible. Even in the last 10 years, we've went from data
| being only available in the cities to being able to stream
| video in all but the most remote parts of the US.
|
| On top of that, something not really appreciated by the
| general public is just how good codecs have gotten. It is
| INCREDIBLE what can be done with the same amount of bandwidth
| we had in the 90s. AV1 + Opus can very nearly stream SD
| content at 56kbps! 1Mbps wasn't enough for SD content with
| MPEG2 and MP3 audio. Now, 1Mbps is enough for 1080p HD
| content.
| dividedbyzero wrote:
| I'm not from the US, at what age do people typically
| graduate highschool?
| cogman10 wrote:
| 18
| Ajedi32 wrote:
| See also: Why Harry Potter should have carried an M1911 [1]
|
| [1]: https://www.reddit.com/r/guns/comments/gwl0v/why_harry_p
| otte...
| TeMPOraL wrote:
| I have a sketch of a HP fanfic short story I should really
| flesh out one day. It involves muggles launching an
| operation to retrieve a key person from Hogwarts just as
| the final battle with Voldemort is about to erupt there.
| The story would follow a bunch of SAS soldiers who fly in
| on helicopters, while covered by a wing of fighter jets
| that intercept a dragon, and then provide distraction / air
| support for the good guys. The overall tone was meant to be
| similar to the start of Gulag mission from Modern Warfare
| 2[0].
|
| I'm not a good writer, so this will likely end up a
| military porn story to the tune of Salvation War[1] - so
| perhaps it's best if it remains unwritten. But really, if
| you think about it, the Wizarding World wouldn't stand a
| chance against even single organized operation by a modern
| muggle state military.
|
| --
|
| [0] - https://www.youtube.com/watch?v=BDX5uToKuPY
|
| [1] - https://tvtropes.org/pmwiki/pmwiki.php/Literature/The
| Salvati...
| zabzonk wrote:
| Not HP, but see
| https://www.goodreads.com/book/show/24997064-the-
| nightmare-s... which pits elves and dragons against the
| British military and intelligence services. All books in
| the Laundry Files, of which this is one, are great reads.
| TeMPOraL wrote:
| Oh, 'cstross is still writing Laundry Files? Awesome!
| I've read up to book 4 or 5, then dropped for reasons I
| don't remember. Time to read it all from the beginning
| then; thanks for reminding me.
|
| My favorite little bit of the series so far was how
| humans eventually figured out what makes Basilisks tick,
| managed to replicate it on an FPGA, and turned CCTV
| cameras into defense turrets.
| leetcrew wrote:
| I get that this is not entirely serious, but it's easy to
| build a case for why muggle weaponry would not pose a
| serious threat to witches/wizards in the harry potter
| universe. the series makes several references to passive
| defensive enchantments. if the entire campus of hogwarts
| can be made almost impenetrable to hostile magical forces,
| it doesn't seem like much of a stretch to imagine that
| robes could be enchanted to be bulletproof. a skilled
| enchanter might be able to create passive defenses against
| most/all conventional weapons.
| WrtCdEvrydy wrote:
| Even Star Trek with it's PADD was susperseeded but it's just
| normal for people...
| zwieback wrote:
| Technically it should be LASER, since it's an acronym.
| sleavey wrote:
| I am part of an organisation called the LAAC, which is the LVK
| Academic Advisory Committee. The LVK is the LIGO-Virgo-KAGRA
| collaboration. LIGO is the Laser Interferometric Gravitational-
| wave Observatory, and Laser is Light Amplification from
| Stimulated Emission of Radiation. So the L of LAAC is a 5th
| order initialism...
| porphyra wrote:
| Reminds me of
|
| GTK which stands for GIMP Toolkit where
|
| GIMP stands for GNU Image Manipulation Program where
|
| GNU stands for GNU is Not UNIX where
|
| UNIX stands for Uniplexed Information and Computing System
|
| And on top of that there is a variety of software built on
| GTK whose names are acronyms containing a G that stands for
| GTK.
| jandrese wrote:
| It makes you want to address a paper to:
|
| Light Amplification from Stimulated Emission of Radiation
| Interferometric Gravitational-wave Observatory-Virgo-Kamioka
| Gravitational Wave Detector Academic Advisory Committee.
|
| It's like looking at the preprocessor output from some
| template heavy C++ code.
| porphyra wrote:
| By now the word laser is so common that it is a just an
| uncapitalised word accepted by major dictionaries [1][2]. There
| are also inflections (lased, lasing) [3]. Nobody spells it in
| all caps now. Likewise with radar and soon lidar.
|
| [1] https://www.lexico.com/definition/laser
|
| [2] https://www.merriam-webster.com/dictionary/laser
|
| [3] https://www.lexico.com/definition/lase
| phailhaus wrote:
| It's since entered the vernacular as just "laser".
|
| https://www.merriam-webster.com/dictionary/laser
| ralusek wrote:
| I think anything that does a controlled, specific, and consistent
| behavior is typically much easier to use in an experiment or
| utility. A laser is like a log statement for light.
| iOmkarBirje wrote:
| If you use Twitter and got some amazing tweets then you must try
| this https://twitter.com/LaserTweets
| b5 wrote:
| In high school, my physics teacher told us about his time at
| Glasgow University where he'd worked on Scotland's first laser.
| This would have been in the '60s. He said it was fascinating, but
| they had no idea what to do with it then. He called it "a
| solution in search of a problem".
| sleavey wrote:
| I studied physics at Glasgow. You can still see the pipes in
| the ceiling of the corridors on the ground floor of the Kelvin
| Building which were intended to be used to heat the building
| using the laser's cooling fluid. That was apparently the only
| way they got permission to install something requiring so much
| power! I heard though that the laser coolant was never actually
| used for heating in the end...
| 1-6 wrote:
| I think "a solution in search of a problem" isn't a bad thing
| the more it's closer to first principles. It's another meaning
| when the solution is farther away from first principles.
| k__ wrote:
| I once read that they needed a powerful energy source for
| nuclear fusion. In the fusion bomb they could use a fission
| bomb as source, but that was overkill for a fusion reactor.
|
| Then someone invented the laser and it was like you build a
| cart and someone with a horse to pull it came around the
| corner.
| aqme28 wrote:
| Thankfully it found quite a few problems to solve.
| [deleted]
| nikanj wrote:
| The phrase "a solution in search of a problem" really reminds
| me of block chain. It's a really cool piece of tech, that so
| far has mostly enabled speculative investing and anonymous drug
| trade.
| Scarblac wrote:
| I disagree. It's a neat solution to exactly one, pretty
| theoretical problem: how to have digital currency without any
| trust involved in the system whatsoever.
|
| And nothing else, because tracking things in the real world
| instead of currency requires trust that what's on the chain
| really is what is in the real world, and besides there are
| lots of highly trusted institutions in the world that it's
| not practical to do without, like the judiciary system.
| xanax wrote:
| Optical Tweezers. Basically people use lasers to move microscopic
| particles around. Lasers can also levitate things. Here's a
| really interesting video on this topic.
| https://www.youtube.com/watch?v=Sq7GaO8iqu8
| the_only_law wrote:
| I've been interested in applications of visible light for a short
| time now, but I started watching styropyro videos on YouTube even
| more recently and find myself suddenly interested in lasers, even
| for stupid, impractical usages.
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