DARPA zaps popcorn with laser power beamed 5.3 miles through air

Wireless power transmission is moving from lab curiosity toward real-world utility, at least if the Defense Advanced Research Projects Agency's latest test is any indication. DARPA says the Persistent Optical Wireless Energy Relay (POWER) team program managed to transmit more than 800 watts of power from a laser emitter to a …

[DJO]

This may work well as long as battlefields are always free from rain or smoke and have perfect unobstructed line of sight.

Also it might be a good idea to place this high up to avoid toasting too many grunts.

A laser and big parabolic dish about 20 feet off the ground would never be an inviting target so I can't see any problems here.

I just suppose it's a good thing no potential enemy has any form of IR vision because when you are painting your battlefield with bright lasers, you really would not want to give away your forward positions.

[Yet Another Anonymous coward]

General we have equipped all our drones with solar panels so they don't need batteries.

What happens at night ?

We thought of that, we have mounted a giant rotating light on a big tower at HQ.

[Anonymous Coward]

Avian bionics...

Baldrick: "General we have equipped all our drones with solar panels so they don't need batteries."

Melchett: "What happens at night ?"

Baldrick : "Glad you asked that sir. Our cunning plan is to have them roost in trees†."

_{† although not noticeably in great abundance in Flanders at the time.}

[Alan Brown]

Re: Avian bionics...

I know it's a joke, but "roosting" drones isn't such a bad idea, especially for surveillance/intelligence purposes. Vastly reduces power consumption even if you're using soaring designs

There are a few SF stories which include them, some disguised as birds (and some real world examples)

[jake]

Battlefields are constantly changing.

Does this thing have an automated method of maintaining the connection? How much power does that use? Around trees/hedgerows/buildings/rocks/hills/gullys? What does a light breeze or strong wind do to the alignment? How about atmospheric effects? (We've all seen heat shimmering blurring out traffic down a hot street or highway, over distances of yards, never mind a couple miles.) Rain, snow, sleet?

How do the optics handle the smoke, dust, dirt and general grime of a battlefield?

How do they let light in .... and keep bullets out? Bullet-proof glass is not 100% transparent.

What's it weigh, compared to (for example) a 1200W generator? Or a battery, which can be recharged with virtually any vehicle?

Come to think of it, what's the benefit of this thing over a series of gensets (fuel of choice) built into a dirt-bike, a SXS and a jeep? Could quite easily go 2kW, 4kW and 8kW on the three without too much difficulty, and also have the ability of being mobile, bringing in (some) supplies, evacuating the wounded, etc., as conditions warrant.

[Anonymous Coward]

Re: Battlefields are constantly changing.

Come on Jake, we expect better from you.

The "R" in DARPA stands for research. This is a research project not the finished product. I'm sure they're clever enough to have also noticed that heat haze, trees and hedges exist in the real world.

[PRR]

A century ago, Tesla (the man not the car) proposed transmitting all the world's power through air/space. He demoed small systems and Wardenclyffe was going to be world-wide. Naturally the Edison Cartel and Marconi's telegraph undercut his funding and reputation so they could keep billing for power and messages.

[DS999]

And there is exactly zero evidence that he could do what he claimed at scale, or without laughable inefficiency. Do you honestly believe that someone 100 years ago cracked this and today's leading scientists and engineers can't even make wireless transmission of power across a room work safely and efficiently?

[LybsterRoy]

Plus I'm not so sure I'd want to walk through the beam powering any major piece of equipment - 800watts for a second or two - OK multimegawatts -hmmmm

[DS999]

Heck with 800 watts

I think it would be dandy if it could do 5 or 10 watts, which if you mounted it on the ceiling (maybe as a replacement bulb for an existing fixture) would be good enough to charge the phone laying next to you or the watch you're wearing. If you moved in the way and blocked the transfer it wouldn't be a problem (at least not for the device being charged)

If you had that at home and at work you may never need to hook your phone or watch to a charger. If it could handle a bit more power it could take care of your laptop as well.

If there was anything to Tesla's claims you'd think by 2025 someone would have delivered this to us! Plus if it was actually safe it would be fun watching the "electrosensitive" nuts and 5G conspiracy theorists go wild.

[goblinski]

Naturally the Edison Cartel and Marconi's telegraph undercut his funding and reputation so they could keep billing for power and messages

..............

Et alors la marmotte, elle met le chocolat dans le papier alu.

Speaking of papier alu - I still can't fathom the fact that tinfoil hats do feed the brains under them precious eyes-only information and deep secret knowledge from the source, BUT refuse to stream basic info on how Evil and business entropy really works...

Which is that - if Tesla had anything similar at an operational level - the Evil ones would have let him finish it then steal it from him and start charging for it, for an even greater profit.

So he had it ready, but they cut his wings. Somehow - they (the bad guys) had the power to sabotage Nikola Tesla's work, in an efficient and all-destroying way, BUT were scared crapless of the the mighty laws in the US that would have left them penniless should Tesla have finished his work :-P

This is deliciously cute cherry-picking.

The reality is that if free energy/wireless energy transmission/internal combustion engines running on water/fill the blanks here COULD and DID exist, the nasty ones would be the first to exploit them and make them PAID.

The free energy sources would be taxed, the area over which the wireless energy beam would flow would be taxed, the water that goes in that magic engine would get taxed, the blanks that were left to be filled with something else magic would be taxed too.

Most basic example - home heating diesel fuel in, say, France. Costs a fraction of what diesel at gas stations costs. There are heavy fines if you're caught using it in your car - with all the matching roadblocks, and chemical tracers in heating diesel that make it easy to detect by those smiling mobile customs. Rumor is there are also little chemical "aids" that would "help" your engine to an untimely death should you use heating diesel exclusively. But that's a rumor. The roadblocks at night - I've seen myself.

There is no vacuum in business and in taxes. There's no benevolent wise lawmen watching from the side, and no Johnny Mnemonic. If wireless electricity transmission was invented tonight at midnight, it would be taxed at one past midnight. And in the morning, we'll be celebrating the abolition of cables and poles, while still paying the same electricity bills or higher.

[Anonymous Coward]

"Et alors la marmotte, elle met le chocolat dans le papier alu."

Probably the last person on the planet to wonder why a marmot (woodchuck) puts the chocolate in (between) aluminium foil† and that vermin's relation to (Nikola) Tesla conspiracy rabbit holes.

The youtube video of the Milka advertisement and the mademoiselle's «Mais, bien sûre» at end seems to indicate that "If you say so" is a fair translation.

"Nature, the taxes gatherer and merchant all abhor a vacuum" could be a Latin aphorism.

_{† I was imagining it was a malediction "may a woodchuck shit in your tinfoil hat."}

[Alan Brown]

"Rumor is there are also little chemical "aids" that would "help" your engine to an untimely death should you use heating diesel exclusively"

No need to cause premature death, although I can think of a couple of ways this might happen (home heating oils being more "kerosene" based than "diesel" based being one example. It'll kill most injection pumps over time)

A chemical signature which allows optical remote sensing of the tailpipe emissions as car drive past is a fairly straightforward way of operating - these kinds of cameras for SMOG checks have existed for several decades. California routinely used/used them to detect badly tuned cars and contact the owners to get them fixed up (they didn't issue fines, although the tinfoil hat brigade were up in arms about it). They can also detect decatted vehicles, etc

[Kevin McMurtrie]

Tesla did not invent efficient power over air.

If anything, Tesla might have invented a reasonably efficient gas discharge tube that made him think he was transmitting huge amounts of energy through air. Carbon filament lights back then were probably less than 1% efficient. A 10% efficient glow tube right next to a Tesla coil might have appeared to be a clever invention. You can read the details of his plans and it was definitely crazy nonsense.

I lived a mile from an AM radio station at one point. The energy transfer is anything but efficient, but it does end up where it's unwanted. There was 1V @ 1MHz on practical everything. You could get free power if dimly glowing LEDs counted.

Back on topic, DARPA clearly made this to access funding that's not available for weapons. The power density of laser light is key for weaponizing it. Stating a goal of sending high power through a fine cable is clever.

[An_Old_Dog]

Radio Station

"KGAL, The Rock of the Valley": similar distance from home, 920 Khz, 1KW daytime, 500W nighttime. It was enough to light a neon bulb hooked between my untuned longwire antenna and ground.

[Anonymous Coward]

Ah, its amazing what they tell us these days.

They've been working on this since the late 1950s. The only real change over the last 50 years is that the equipment to generate the laser has shrunk in size, power consumption, and cycle time, and increased in durability/reliability.

I'm sure there are lawn ornaments that are 12" steel cubes with a hole burned through in back yards around Burbank.

[Alan Brown]

Re: Ah, its amazing what they tell us these days.

Laser weapons have been amazingly resistant to development.

Atmospheric blooming is a very real problem which necessitates ever larger transmission mirrors as powers and distances increase

I'd hate to use a shipboard laser defence weapon against a _swarm_ of drones. It takes long enough to shoot down each one that enough drones will overwhelm the defences and it only takes one or two with a thermite grenade to ruin your defence systems (antennas or laser emitters are particularly vulnerable)

(Kinda like the old way to deal with a heavily armed ship is to have more cheap drones than they have expensive defence missiles - and this works even better if your drones are landbased hypersonic ASBMs laumched a few thousand miles away. You don't need to sink your enemy to cause a mission kill, merely cause them to expend all their defence ammunition and be forced to withdraw from the area)

[HuBo]

Really Genius

800 Watts ... pfaaah! Call me back when they have the "six-megawatt excimer laser" spaceborne version precise enough to straight commit illegal political assassinations vaporize environmental irritants from beyond yonder ... and make instantaneous all-you-can-eat field scale popcorn at the same time!

[Anonymous Coward]

Re: 800W...

I wonder - enough to fry a President's brain?

[Paul Crawford]

Re: 800W...

If you can find it first...

[Anonymous Coward]

I'm looking forward to Popcorn-as-a-service, delivered wirelessly, with just a modest subscription.

[Evil Scot]

Is that not Spotify et al?

Min is the one playing music by the muppets.

[Mark Exclamation]

I'll bet the Chinese are waaaaaay beyond this, only they're not telling anyone.

[John Robson]

A small fridge?

"800 watts isn't a ton of electricity, but it's enough to run a small fridge, lights, or an RV setup"

The various fridges in my house use ~200W when the compressor is running...

800W of lights nowadays is enough to light a hundred rooms nowadays...

800 watts is a typical microwave, or a dedicated popcorn maker, or a small hob, or a dozen slow cookers - it's enough to do real heating work...

[Phil O'Sophical]

Re: A small fridge?

dedicated popcorn maker

Cut out the middleman, just drop the kernels into the laser beam.

[John Robson]

Re: A small fridge?

Particularly with the 20% efficiency reported.

But I looked at the article, and the image looked to me like it was a specialised glass container, from a popcorn machine of some sort... maybe?

[Alan Brown]

Re: A small fridge?

That's pretty much what I inferred they did. You're talking 4-8kW focussed on a fairly small spot

How did they manage to not melt the solar panels, or were they lighting up a 3x3 foot array?

[Alan Brown]

Re: A small fridge?

When I read this, my first thought was "20% efficiency of solar cells, that's 4-8kW at the noisy end of the laser and HOW MUCH input power will you need?

[O'Reg Inalsin]

Re: A small fridge?

A pc with an rtx 3090 gpu requires an 800w power unit.

[SnailFerrous]

Shark mounted?

All this discussion abiut the receiver end of the experimental set up, but no one has yet asked the most important question. Is the laser transmitter frikking shark head mounted?

[Alan Brown]

Re: Shark mounted?

The second question is "can Bruce handle the weight/size strapped to his head?)

[andy gibson]

Real Genius

https://www.youtube.com/watch?v=rthHSISkM7A&pp=0gcJCdgAo7VqN5tD

[Gene Cash]

Re: Real Genius

You know you're old when you look up Michelle Meyrink and find out she's 62 now.

And that Real Genius is a 1985 film. That's 40 years ago.

[Spherical Cow]

Is there anything new here?

There is a science museum, optimised for school children, near where I live. It has a feature which has been there for at least three decades that i know of: a pair of parabolic steel mirrors on opposite sides of a large courtyard. When one child whispers at the focal point of one mirror, their friend can clearly hear the whisper at the focal point of the opposite mirror.

"the beam strikes a parabolic mirror that reflects it onto dozens of photovoltaic cells housed within the device"

OK, that checks out, but it's hardly ground-breaking tech, is it?

[NXM]

But can you..

... mount this frikkin laser on a shark's head?

More to the point, could you power an IP phone directly from the fibre? It rats me off that our phones are useless during a power cut, unlike the old analogue ones.

[Alan Brown]

Re: But can you..

" It rats me off that our phones are useless during a power cut, unlike the old analogue ones"

Once upon a time, every house had a couple of Ever Ready No6 cells attached to their phone to drive the carbon microphone. That went away when "central battery working" was introduced (it was less work to maintain a central battery than employ people to change the cells every 5 years or so)

it's not that difficult to have a battery backup for your phones/routers. I had a Uniden digital cordless with the feature in the 1990s

Yes it'd be nice to make battery maintenance a phone company problem, but that's not going to happen.

[Stevie]

Bah!

So still no sol-orbiting solar power sat ring with microwave transmission back to Earth for cheap-as-air leccy then?

<sigh>