[HN Gopher] DARPA program sets distance record for power beaming
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       DARPA program sets distance record for power beaming
        
       Author : gnabgib
       Score  : 139 points
       Date   : 2025-06-15 22:40 UTC (1 days ago)
        
 (HTM) web link (www.darpa.mil)
 (TXT) w3m dump (www.darpa.mil)
        
       | janalsncm wrote:
       | Could this also be a viable alternative to HVDC lines for
       | civilian applications?
        
         | theamk wrote:
         | No. 800 watts (vs megawatts for HVDC). 5 miles vs thousands of
         | miles. 20% efficiency optical to electrical - so electrical vs
         | electrical is much worse - vs 90%+.
         | 
         | This is so much worse in every aspect it's not really
         | compareable.
        
           | naruhodo wrote:
           | It's great if you hate birds, though.
        
         | other_herbert wrote:
         | The key thing they aren't saying is how much power it took to
         | "send" 800 watts 5.3 miles...
        
           | bracketfocus wrote:
           | They mentioned that it was 20% efficient at a closer
           | distance.
           | 
           | So likely much lower than that.
        
             | throwaway81523 wrote:
             | Wow that's a long way from the proposals for sending GW of
             | microwave power from satellites.
        
               | pfdietz wrote:
               | Laser power beaming from space could be useful at lower
               | power levels than that, for example for powering
               | aircraft.
        
               | conradev wrote:
               | But pretty close to powering drones from ground stations
        
               | aurizon wrote:
               | Those sat to ground power sources use gallium arsenide
               | switched FETs = synchronous rectification, avoiding the
               | voltage drop of diodes has been tested on a small scale,
               | the 10GW orbital 35% efficient solar arrays, maybe next
               | week... Solar boilers, end to end, are more efficient
               | than solar cells, but mechanical complexity(leaks,
               | corrosion, worker avarice) made one US plan in the South
               | West non viable. As we sit silicon-perovskite tandem
               | solar cells will top out around 42-45% - unless Schockley
               | is end runned? Ternary -??. A good lecture = https://www.
               | youtube.com/watch?v=Ft0VJX0_Td0&t=2s&ab_channel=...
        
               | PaulHoule wrote:
               | Solar thermal as well as solar-chemical systems have the
               | problem of start-up.
               | 
               | PVs do not have any problem starting up, they produce
               | less than full power with less than full illumination but
               | they produce something and once the illumination is full
               | they produce full power immediately.
               | 
               | Many solar thermal power plants are fired with natural
               | gas in the morning to get them spun up to the point where
               | they can take advantage of the solar energy. Without that
               | they'd probably lose a few hours of production.
        
             | PaulHoule wrote:
             | 20% efficiency in terms of light -> electricity. A 50%
             | laser efficiency (electricity -> light) is really good,
             | possible for some diode lasers, if you pump a fiber laser
             | with diodes to get a high quality beam for cutting
             | materials or weapons purposes maybe you get 25%.
             | 
             | That demo would require about 45 kW of laser power with
             | good beam quality which would be totally possible with a
             | fiber laser
             | 
             | https://www.rp-photonics.com/wall_plug_efficiency.html
        
           | HenryBemis wrote:
           | I was thinking of"how much is enough" so they can power
           | 'instruments'. I am also thinking of 'how can we use this
           | tech to revive space-instruments (the next generation of
           | 'Voyagers' may be equipped with such receivers?)
           | 
           | I also wonder how difficult/impossible would it be, and the
           | 'throughput'. Assuming that you want to recharge a recon
           | drone (or the 'next generation of Voyagers flying in space)
           | that flies over XYZ area/country/etc. Would it take 1sec or
           | 10seconds 'of beam', and the accuracy/waste/total amount one
           | would have to 'dispense' in order to give that drone the X
           | seconds of 'juice' to keep it running for 1000x X seconds of
           | flight duration. And what about
           | clouds/mist/rain/snow/birds/etc.
           | 
           | 'Infinite energy' for a drone (I mean no dependency to come
           | down to refuel) is a game changer.
           | 
           | Would that work with 'instruments buried underground? And at
           | what depth? ('War of the worlds' scenario). Could someone
           | bury a device, with only the receiver protruding from the
           | ground, with a battery to keep it alive, and waiting to be
           | activated by a satellite passing by giving it the "10 seconds
           | beam" to fully charge it and.. (I am thinking of the recent
           | drone-related incidents/attacks within Russia and Iran)(if
           | you park a drone for 10 months, its battery will deplete,
           | right?)(I don't have a drone, but batteries are batteries).
           | 
           | A second thought on the matter, can one 'program' the light
           | to be also transferring data? Park the drones in <insert
           | foreign territory>. No programming. In the middle of nowhere
           | (no 4G-5G). You fly a satellite over it, beam down the
           | 'juice' (together with the instructions - no interception of
           | the transfer is possible). Someone finds it 'before', they
           | only get the hardware but no info/intel.
           | 
           | "The possibilities are endless" (and so are the nightmares)
        
         | _fizz_buzz_ wrote:
         | This can only be used where efficiency doesn't matter, like
         | military applications for powering a drone. The overall
         | efficiency i.e. grid -> laser -> pv -> grid would be atrocious.
        
       | jauntywundrkind wrote:
       | The application to drones seems most clear: beam drones some
       | extra power as needed. Or continually!
       | 
       | I wonder how big that receiving apparatus is. Whether the
       | receiver is gimballed, or whether the drone itself has to fly a
       | heading to aim at the sender: TBD.
        
         | larodi wrote:
         | And have a great opportunity to drill some holes in birds
         | heads.
         | 
         | Sorry I really fail to recognise how beaming 1kw of excited
         | particles is a safe thing to do just like this...
        
           | ChocolateGod wrote:
           | It must not be safe to be out in the sun then.
        
             | _Algernon_ wrote:
             | Last time I forgot sunscreen at a UV index of 10 my skin
             | started peeling of after half an hour so...
        
             | ben_w wrote:
             | Density (and wavelength), rather than total power, is
             | important.
             | 
             | Sun's 1kW/m^2, and even then you shouldn't look directly at
             | it, and being out in it all day without protection leads to
             | sunburn.
        
             | nkrisc wrote:
             | It's not, for an extended period of time. Now imagine it
             | was collimated rather than diffuse.
        
               | kurble wrote:
               | That's the thing, sunlight _is_ collimated. It only gets
               | diffuse once it reflects of a diffuse surface.
        
               | nkrisc wrote:
               | Fair enough, poor choice of words on my part. What I
               | meant was concentrated further (in terms of energy per
               | area) than the typical concentration received at the
               | surface of the Earth.
        
             | vikramkr wrote:
             | So there's this thing called sunburn...
        
           | fleischhauf wrote:
           | if you are the military and you are using drones to win a
           | war, I don't think birds are your primary concern tho
        
             | cap11235 wrote:
             | That's basically an ad that appears to defense companies.
             | Raytheon engineers love going "pew pew motherfucker".
        
               | mensetmanusman wrote:
               | Hand egg enthusiasts also love...
        
             | larodi wrote:
             | sure in that case everything goes, and is curious why has
             | it not yet been done with... drones routing the laser or
             | repeaters reinforcing it with every loop.
             | 
             | i can't recall a scifi story promoting such system either.
        
         | Traubenfuchs wrote:
         | How about drones with a solar panel case? Would require a sunny
         | day to work at all though.
         | 
         | Tiny nuclear reactor?
        
           | ben_w wrote:
           | On the scale that useful nuclear reactors operate, a "tiny
           | nuclear reactor" is the size of a shipping container.
           | 
           | Even a tiny _RTG_ is in the same range as a dumbbell.
        
             | Traubenfuchs wrote:
             | While not reactors, how about nuclear batteries without
             | heavy shielding?
        
               | ben_w wrote:
               | Nuclear batteries are a superset of RTGs.
               | 
               | There are other kinds of nuclear battery, but the ones
               | I've heard of outside labs, are extremely low power
               | betavoltaics.
        
               | cap11235 wrote:
               | The biggest issue for weight is that you are using trans-
               | uranic materials. By their fundamental nature, they are
               | heavy as fuck.
        
               | ben_w wrote:
               | Nope.
               | 
               | Betavolatics can be just about anything that emits an
               | electron. Could be tritium. Low power due to long half
               | life and low decay energy, but not because it is low-Z.
               | 
               | RTGs can be anything that gets hot from its own
               | radiation. Loads of things with a short half-life and
               | high decay energy, so phosphorus-32 would be a low-Z
               | option, and polonium-210 (which still isn't transuranic)
               | if you're completely disregarding safety.
               | 
               | Big part of the mass budget is shielding, not source.
               | This gets proportionally worse for small sources, as you
               | need a certain thickness (proportional to r^2), while the
               | emitter power is proportional to volume (r^3).
        
         | contrarian1234 wrote:
         | Why not just beam power down the optical fiber? Optical fiber
         | is exceptionally clear and works in fog and rain
        
           | malfist wrote:
           | Fiber transmits light, not rf. To get power out of fiber
           | optics you have to have a photovoltaic cell on the other side
           | and there's a limit for how much those can produce with such
           | a collaminated light source.
           | 
           | Using fiber optics for power is like trying to make a solar
           | panel generate electricity from a laser beam.
        
             | contrarian1234 wrote:
             | just have a tiny steam turbine equivalent...? (some
             | thermoelectric generator) You don't really need to be
             | efficient. You have fans to blow air and dissipate heat on
             | the other end after all
        
               | 0_____0 wrote:
               | You should do the first round of engineering calculations
               | on this.
        
             | TeMPOraL wrote:
             | > _Using fiber optics for power is like trying to make a
             | solar panel generate electricity from a laser beam._
             | 
             | Isn't that exactly what power beaming is, except typically
             | with frequency range in microwaves instead of visible
             | light?
        
               | malfist wrote:
               | > except typically with frequency range in microwaves
               | instead of visible light
               | 
               | That's a big freaking deal.
        
               | cap11235 wrote:
               | eg, consider WiFi. They choose their bands carefully for
               | wireless standards, and terahertz is pretty far from
               | microwave GHz. I've never seen direct THz synthesis
               | outside of partially-insane radar engineers.
        
             | ben_w wrote:
             | I have no idea why this might be limited by the light
             | source being collimated?
             | 
             | I mean, you _can_ get electricity from PV illuminated by a
             | laser, and everything I 've heard so far says it's easier
             | than with sunlight because you can match the frequency of
             | the laser to the band gap of the PV.
        
               | malfist wrote:
               | Sure, you absolutely can do it. But material science
               | quickly becomes a major limit.
               | 
               | For something 15% efficient like a high quality PV cell,
               | for every 100 watts you want to be usable on the
               | receiving side, the receiver has to bleed off 566 watts
               | of heat. And that's 566 watts of waste heat that is
               | highly concentrated.
               | 
               | Consider a single residental power circuit. 12A maximum,
               | 120v, that's 1440 watts at delivery. For PV power
               | delivery via laser, that PV would need to dissipate 8
               | kilowatts of waste heat. One a very small surface
        
               | ben_w wrote:
               | It sounds like you're mistaking PV for a thermal system.
               | 
               | In a PV cell, you have a semiconductor. Semiconductors
               | have this thing called a "band gap", which is the energy
               | needed to get an electron from the valence band to the
               | conduction band: https://en.wikipedia.org/wiki/Band_gap
               | 
               | The limits to efficiency of a solar panel is that
               | sunlight has photons of many energy levels; the photons
               | with energy less than the band gap do nothing, those with
               | more, waste the excess.
               | 
               | A laser can have energy _tuned to this band gap_ , at
               | which point the PV part becomes ~99.9% efficient. (The
               | _laser_ part is not close to that efficiency).
        
               | malfist wrote:
               | I'm not talking about a thermal system, I'm talking about
               | having to deal with the thermals of your inefficiencies.
               | That energy that doesn't get converted to electricity is
               | converted to heat. And you have to deal with it.
               | 
               | The type of laser based PV that you're taking about
               | that's highly tuned is at maximum 27% efficient. Not 99%.
               | 
               | That's a 73% waste you have to manage
        
             | demod6 wrote:
             | "trying to make a solar panel generate electricity from a
             | laser beam" is literally what the article is about.
        
           | Maxsnijders wrote:
           | If you were to go that way, why not a wire?
        
         | Havoc wrote:
         | Seems like that has a high chance of frying sensors on sats
         | flying behind the drone though
        
       | b00ty4breakfast wrote:
       | This seems very silly. It's either a death ray project in a fake
       | mustache or somebody had earmarked a bunch of money that they had
       | to spend before it expired.
        
         | kulahan wrote:
         | This is kinda surprising to read. I've never known anyone who
         | isn't incredibly excited at least at the prospect of wireless
         | energy transfers. If you can do 800 watts over 8 km, surely we
         | can do 150 watts across 3 feet in the household, and MANY of
         | our most important discoveries come from DARPA essentially
         | being a black budget skunkworks team.
         | 
         | But much of the stuff DARPA does seems weird. It's not about
         | ideas with solid foundation and thorough engineering, it's
         | about crapshoots that might work and would pay off in some way
         | - often any financially feasible way.
         | 
         | They once put "cats" on guns in hopes it would surprise
         | opponents even just for a quarter second, giving your spec ops
         | dudes the advantage. They tried to create angled guns that
         | could shoot around corners like 20 years ago. All kinds of
         | crazy stuff! It would be a lot of fun to work there, I think.
        
           | christkv wrote:
           | The germans tried the curved gun with an attachment called
           | Krummlauf during ww2. It would break after just a couple of
           | magazines being fired.
           | https://en.wikipedia.org/wiki/Krummlauf
           | 
           | Not sure how you would build one of those without the stress
           | of the bullet during firing would not damage the barrel.
        
             | alanbernstein wrote:
             | I'm amazed that worked for even one shot. Presumably gp was
             | referring to cornershot or something similar, which seems
             | like a much more reasonable approach.
        
               | cap11235 wrote:
               | Yeah, every gun person on youtube capable of getting one
               | has demonstrated it. Unsurprisingly, you cannot aim for
               | shit on these things, and their intended use can be fully
               | replaced by a hand-mirror with a much better rifle (aka,
               | most rifles), without fucking up your barrel trying to
               | curve bullets.
        
             | kulahan wrote:
             | I meant a 90deg angled gun. You pull at one end, but all
             | firing happens at the other, out of a straight barrel. Idea
             | being that you can then collapse it to a flat rifle.
        
           | erikerikson wrote:
           | The actual work is usually done by private companies under
           | contract
        
           | robertlagrant wrote:
           | > They tried to create angled guns that could shoot around
           | corners like 20 years ago
           | 
           | The IDF got a gun that does this[0] into service in 2003.
           | 
           | [0] https://en.wikipedia.org/wiki/CornerShot
        
             | HenryBemis wrote:
             | Reminded me of "Wanted" (2008)[0]
             | 
             | [0] https://www.imdb.com/title/tt0493464/
        
               | JetSpiegel wrote:
               | It's the same gun, Angelina Jolie trained with the IDF.
        
           | Workaccount2 wrote:
           | The problem with wireless energy is that the efficiency
           | losses are mostly because of physics, not because of
           | technology just needing to scale up a bit more.
           | 
           | A future with having wireless energy transfer everywhere is
           | one where energy is so abundant that we don't mind throwing
           | out 80% of it powering wireless things.
        
             | cap11235 wrote:
             | Ignoring efficiency, you can deal with "physics" by just
             | eliminating matter in the way, like air, via a strong
             | enough laser. I'm not sure I'd suggest this as a consumer
             | product, though.
        
       | petermcneeley wrote:
       | "reflects onto dozens of photovoltaic cells arranged around the
       | inside of the device which convert the energy back to usable
       | power."
       | 
       | This is no different that what we were considering two decades
       | ago for the space elevator competition. One of the problems with
       | this approach is that as the photovoltaic cells heat up their
       | overall efficiency decreases.
        
         | bagels wrote:
         | They'll only get so hot, and you can just spread the energy
         | across more cells, right?
        
           | IX-103 wrote:
           | You end up with a thermal runaway situation where the hotter
           | the photovoltaics get, the more energy they convert to heat
           | (instead of reflecting or converting to electricity).
        
       | inasio wrote:
       | "It's a lot easier to send a power beam directly up or down
       | relative to the ground because there is so much less atmosphere
       | to fight through," Jaffe explains. "For PRAD, we wanted to test
       | under the maximum impact of atmospheric effects."
       | 
       | Super impressive! My only complain is that this was done at the
       | White Sounds desert in New Mexico, at over 1200 meters of
       | elevation. For maximum impact they should have done it in Florida
       | on a hot humid day
        
         | AndrewKemendo wrote:
         | There's no range in Florida large enough for this test
         | otherwise I'm sure they would have.
         | 
         | Even Eglin wouldn't be large enough.
        
         | madaxe_again wrote:
         | Humidity would most likely attenuate the beam from 20% end to
         | end to less than 1% - water vapour absorbs energy like nobody's
         | business.
         | 
         | This is a tech for arid environments - which seem to be where
         | the US does most of its deployments these days.
        
         | contrarian1234 wrote:
         | "maximum impact of atmospheric effects" would be simply a foggy
         | day...
        
           | tnel77 wrote:
           | Both your example and theirs would be better tests than a
           | desert.
        
             | PaulHoule wrote:
             | The desert is bad enough. On a hot day you get convection
             | which will vary the refractive index of light and spread
             | out the beam. I wonder if they have active optics on the
             | transmitter to fight this.
        
               | cap11235 wrote:
               | Then you also have the day vs night weather patterns,
               | resulting in intense sun-downer winds. I suggest everyone
               | actually visit a real desert once in their life, where as
               | people seem to think its like a beach, but bigger.
        
               | PaulHoule wrote:
               | Around Elephant Butte Lake which is quite close to WSMR
               | [1], I remember those really strong winds around sunset.
               | 
               | [1]
               | https://en.wikipedia.org/wiki/Elephant_Butte_Reservoir
        
             | freeone3000 wrote:
             | The US is always geared up and ready to fight the previous
             | war.
        
             | sailfast wrote:
             | Unless, you know, we often fight in deserts that are
             | remote?
        
               | tnel77 wrote:
               | This is a good point. I just meant that a very humid
               | climate might be a more challenging environment for this
               | technology, but it doesn't mean it's as useful for real
               | world fighting conditions.
        
       | cryber wrote:
       | The popcorn is a very nice touch
        
       | ChrisMarshallNY wrote:
       | _> New Mexico_
       | 
       | Great stuff.
       | 
       | Do Seattle, next.
        
       | Szpadel wrote:
       | what concerns me is that it's wild laser beam in potentially
       | public space. anyone that would accidentally cross that
       | potentially invisible line could get killed or severely hurt.
       | 
       | imagine something reflective entering this beam, it could blind
       | people in a very large radius.
       | 
       | for me it means that thus would still need some pipe/fiber that
       | would protect world from this laser.
        
         | seberino wrote:
         | The eventual goal is to use it at extremely high altitude with
         | drones so that that isn't much of a risk.
        
           | DaftDank wrote:
           | That will be quite a sight -- seeing the videos of people on
           | the ground, filming future drone laser battles
        
           | xattt wrote:
           | The laser would ricochet from disintegrating drones (think of
           | the props) and cause collateral damage to people on the
           | ground.
           | 
           | Also see this (with remaining eye):
           | https://www.funraniumlabs.com/2024/07/how-i-got-my-laser-
           | eye...
        
             | echelon wrote:
             | There's danger and risk in everything worth doing.
             | 
             | The dams could burst and drown millions.
             | 
             | The highrise you live in could topple over or burn.
             | 
             | The bridge carrying the train could crash into the valley.
             | 
             | The passenger plane could lose lift and crash into a
             | residential building.
             | 
             | The power source in your car could catch fire.
             | 
             | We engineer around it.
        
               | probably_wrong wrote:
               | Counterpoint:
               | 
               | We've known about global warming for almost 50 years and
               | yet to this day the debate is divided between "eh" and
               | "no, it isn't".
               | 
               | Coal plants have been consistently depositing smog in our
               | lungs with no end in sight.
               | 
               | Boeing has successfully lobbied itself out of criminal
               | charges for the deadly consequences of their (IMHO)
               | negligence regarding the 737 Max.
               | 
               | Companies have stopped pretending that they'll put human
               | lives before profit. As a human, I am therefore beyond
               | giving any company the benefit of the doubt that they'll
               | "engineer around it" when it comes to safety.
        
               | cap11235 wrote:
               | Counterpoint: Military doesn't care or get prosecuted by
               | anyone other than the military. Pew pew, motherfucker.
               | 
               | Defense companies are rather refreshing to read for
               | corporate postings, since they see to always be proud of
               | how many Iraqi's they bulldozed to death.
        
               | echelon wrote:
               | > We've known about global warming for almost 50 years
               | and yet to this day the debate is divided between "eh"
               | and "no, it isn't".
               | 
               | So much work is being done on that front.
               | 
               | > Coal plants have been consistently depositing smog in
               | our lungs with no end in sight.
               | 
               | Not the #1 killer of humans. We're still making lots of
               | progress on healthspan, especially in pulling people out
               | of poverty. We're well ahead of where we were 50 years
               | ago. People are no longer starving to death at
               | unprecedented scale.
               | 
               | > Boeing has successfully lobbied itself out of criminal
               | charges for the deadly consequences of their (IMHO)
               | negligence regarding the 737 Max.
               | 
               | Sometimes bad things happen. Not to diminish these lives,
               | but this is just a footnote in the list of impressive
               | things technology and society have accomplished, though.
               | Boeing and execs should face punishment, but this is a
               | very small downside to a much greater set of
               | accomplishments that vastly outweighs the bad.
               | 
               | > Companies have stopped pretending that they'll put
               | human lives before profit. As a human, I am therefore
               | beyond giving any company the benefit of the doubt that
               | they'll "engineer around it" when it comes to safety.
               | 
               | What are you talking about? To just cite one instance,
               | Waymo is already going to be one of the biggest needle
               | movers in terms of human lives saved. Or another - look
               | at what Moderna did during Covid.
               | 
               | Life is better than it used to be, not worse. You're
               | wearing miasma-tinted glasses.
        
               | probably_wrong wrote:
               | > _So much work is being done on that front._
               | 
               | Yes, it is, but not nearly enough and it had to be done
               | by dragging corporations kicking, lying and screaming
               | every step of the way. Corporations, mind you, powerful
               | enough to drive several of the wars of the last 50 years.
               | 
               | > _We 're still making lots of progress on healthspan_
               | 
               | Yes, as long as your health insurance covers the
               | treatment. UnitedHealth investors are suing the company
               | for not willing to follow the "aggressive, anti-consumer
               | tactics" that got their CEO murdered [1].
               | 
               | I've also personally heard a mildly drunk executive of a
               | Fortune 500 company brag about how, on a cancer-related
               | lawsuit, the US government would never let them go
               | bankrupt because that would dry up the taxes they would
               | collect otherwise. Time proved him right.
               | 
               | > _Boeing and execs should face punishment, but..._
               | 
               | They should, but they won't. And they are not the
               | exception.
               | 
               | > _Waymo is already going to be one of the biggest needle
               | movers in terms of human lives saved (...) look at what
               | Moderna did during Covid._
               | 
               | Uber made ignoring the laws at a worldwide scale their
               | whole business model. And how has the market rewarded
               | Moderna for their to humanity? Their stock is at its
               | lowest since 2020.
               | 
               | People have been making the comparison to the robber
               | barons recently, but I think they miss the point where
               | the robber barons didn't have a worldwide surveillance
               | apparatus and the kind of propaganda power that Orwell
               | could only dream of.
               | 
               | I agree that technology has advanced for good in a lot of
               | areas, but I also think it's worth noticing that many of
               | these advances are behind gatekeepers who will burn a
               | forest to the ground before upgrading infrastructure
               | that's one hundred years old to keep shareholders happy.
               | 
               | [1] https://futurism.com/neoscope/unitedhealthcare-
               | investors-wil...
        
               | cryptonector wrote:
               | Yes, but this [beaming large amounts of power wirelessly
               | over long distances] isn't worth doing.
        
           | cap11235 wrote:
           | Also, an implicit but obvious goal is military applications.
           | Murder laser beams are a potential benefit in those cases.
        
         | PaulHoule wrote:
         | They tested that thing at the White Sands Missile Range where
         | the public is excluded.
         | 
         | A friend of mine was looking for a stargazing spot between WSMR
         | and the Rio Grande River a fair bit south of San Antonio, NM
         | and got her Chevy Blazy stuck and figured her best bet was to
         | walk across the security perimeter and get caught by the
         | security force and they caught her pretty quickly.
        
           | Xevion wrote:
           | TIL San Antonio is not just a city in Texas where I live, but
           | also a place in New Mexico. That's crazy.
        
             | mulmen wrote:
             | San Antonio is Spanish for "Saint Anthony". The city in
             | Texas is well known but there are many places in the world
             | that share the name.
        
             | PaulHoule wrote:
             | Famous (or not) for a few things:
             | 
             | (1) You always hear it wrongly repeated that the first
             | nuclear bomb was tested at Alamagordo but Alamagordo is 100
             | miles from the Trinity Site. San Antonio, NM was the
             | closest settlement.
             | 
             | (2) Conrad Hilton, founder of the hotel chain, was born
             | there (in his autobiography "Be My Guest" he talks about
             | riding his horse up to Socorro, where I went to undergrad
             | school)
             | 
             | (3) The Owl Bar and Cafe still serves a great green chili
             | cheeseburger
             | 
             | https://sanantonioowl.com/
             | 
             | there was that time I ran from Socorro to San Antonio in a
             | race and, despite being underage, got offered a beer from
             | the bartender.
        
             | triceratops wrote:
             | It's crazy that two states have cities of the same name?
        
           | dooglius wrote:
           | This strategy went very poorly for the Death Valley Germans
           | https://news.ycombinator.com/item?id=34676129
        
         | _verandaguy wrote:
         | IMO there's two safe ways to implement this:
         | 
         | - Ground-satellite-ground relaying, with at least one
         | geostationary satellite between the ground stations. The
         | satellites being geostationary means that the path of the beam
         | through the atmosphere is constant, and air traffic can be
         | routed around them in a reasonable way. (You could do this with
         | lower orbits, but it'd be a hassle with current aviation
         | industry technology).
         | 
         | - Beaming by tunnel! Can't get hit by a laser if it's under
         | your feet. Obviously, this negates the benefits of the
         | technology, and just turns into fibre lines without the fibre,
         | over shorter distances, with all the pain in the ass of laying
         | underground cable.
         | 
         | In the first approach, there'd have to be an effective
         | exclusion zone around the receiving station (how big, I don't
         | know), and it'd be nice to have satellites fail safe, so that
         | if they end up pitching or rolling off axis, the beam will be
         | shut off before becoming an accidental weapon.
        
           | iwontberude wrote:
           | Geostationary orbit is way way too far and tunnels? Really?
        
             | cap11235 wrote:
             | As opposed to?
        
             | _verandaguy wrote:
             | Geostationary orbit is very far, yes. If you read my
             | comment you can see my reasoning for this.
             | 
             | And tunnels, not really, no, if you read my comment you'll
             | see that this is a comically impractical option.
        
           | pjaffeva wrote:
           | Safety has been demonstrated with a "virtual enclosure",
           | albeit at a smaller scale: https://youtu.be/Xb9THqrXd4I
        
       | westurner wrote:
       | Is it possible to steer the weather by heating the atmosphere
       | with power beaming microwaves?
       | 
       | Is it possible to cancel the vortical formation of a tornado or a
       | hurricane with microwave power beam(s)?
       | 
       | Does heating the atmosphere with microwaves change the weather,
       | or the jet stream, or the cloud cover?
       | 
       | What sort of a fluidic weather simulator could answer this
       | question?
       | 
       | Is there a fluid simulation device that allows for precise
       | wireless heating of certain points in the fluid?
       | 
       | If so, there could be international space law to study and
       | control for the known and presumed risks of space-based microwave
       | power beaming.
        
         | gus_massa wrote:
         | Nuking a hurricane would not break it because nukes are not big
         | enough https://edition.cnn.com/2019/08/26/weather/hurricane-
         | nuclear...
         | 
         | I think it's possible to nuke a tornado, but if someone does it
         | to try to save a city, I expect even more destruction.
         | 
         | I don't expect the beam to be energetic enough to change
         | anything. The closest method I can think of is
         | https://en.wikipedia.org/wiki/Cloud_seeding but it doesn't
         | distribute energy, just tiny crystals to condense oversaturated
         | vapor.
        
           | westurner wrote:
           | Theoretically there is at least one point where a butterfly
           | flapping its wings sufficiently affects seemingly nonlocal
           | global weather.
           | 
           | Presumably it's easier to prevent formation of vortices far
           | before visible formation.
           | 
           | A "cancel vortices" sim table might be more useful than the
           | average CFD simulation.
        
       | williamDafoe wrote:
       | This will come in handy when DARPA builds the Phaser Cannon used
       | to blast the Talosian fortress under the direction of Number One
       | in the 23rd Century ...
        
       | neya wrote:
       | Finally they decided to open up Nikola Tesla's work huh? :)))
        
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