While the technology is still at an early stage, it may one day allow drones to fly indefinitely.

Scientists in China have demonstrated a wireless power transmission system that uses a ground-based microwave emitter to beam energy to an antenna array mounted on the aircraft’s underside. Importantly, they were able to do this while both the drone and charging system were in motion.

In tests, the car-mounted system kept fixed-wing drones in the air for up to 3.1 hours at an altitude of 15 metres (49 feet). The key challenge that the team overcame was maintaining alignment between the emitter and the drone during flight, wrote Song Liwei, the project’s leader.

  • notgold@aussie.zoneEnglish
    2·
    3 days ago

    I remember arguing with a mate in school about the damage a misaligned beam would cause to a city. I think the prevailing theory was a lot of cooked people without much structural damage.

    • HiTekRedNek@lemmy.worldEnglish
      1·
      2 days ago

      Except that theory has no basis in reality.

      Microwave ovens work by concentrating that energy into a very small space.

      When is the last time you were cooked by radio waves?

      Microwaves ARE radio waves.

      • notgold@aussie.zoneEnglish
        1·
        20 hours ago

        I was in primary school. My understanding of physics was that water is wet not what it was made of.

      • sp3ctr4l@lemmy.dbzer0.comEnglish
        4·
        2 days ago

        Are you somehow entirely unaware of the DEW crowd control devices that have been being used for like 2 decades now?

        https://en.wikipedia.org/wiki/Active_Denial_System

        Yeah, the whole point of these things is they basically microwave the outer layer of your skin, when in wide beam mode.

        Or, they can be dialed in to be a more concentrated beam… to uh, internally heat up a bit more than just your skin.

        But uh, for legal reasons of course nooo they do not do that and cannot do that.

        While it is claimed not to cause burns under “ordinary use”,[50][51] it is also described as being similar to that of an incandescent light bulb being pressed against the skin,[14] which can cause severe burns in just a few seconds. The beam can be focused up to 700 meters away, and is said to penetrate thick clothing although not walls.[52] At 95 GHz, the frequency is much higher than the 2.45 GHz of a microwave oven. This frequency was chosen because it penetrates less than 1⁄64 of an inch (0.40 mm),[53] which – in most humans, except for eyelids and the thinner skin of babies – avoids the second skin layer (the dermis) where critical structures are found such as nerve endings and blood vessels.

        I would imagine that if you had an emorous amount of microwave energy from an orbiting solar array, being beamed to a recieving station on earth, (ie, a very small small space compared to the distance involved) and it uh, missed, yeah, yeah it would microwave people.

        There’s also this:

        https://pmc.ncbi.nlm.nih.gov/articles/PMC8733248/

        Brief but intense pulses of radiofrequency (RF) energy can elicit auditory sensations when absorbed in the head of an individual, an effect known as the microwave auditory or “Frey effect” after the first investigator to examine the phenomenon (1). The effect is known to arise from thermoacoustically (TA)-induced acoustic waves in the head (2).

        Lin has proposed that the Frey effect may be linked to unexplained health problems reported by U.S. officers in Cuba and elsewhere, the so-called Havana syndrome (3).

        Probably don’t tell any schizophrenics you may or may not know about that.

      • LincolnsDogFido@lemmy.zipEnglish
        1·
        2 days ago

        Yeah, xrays are also radio waves. That doesn’t make them inherently less dangerous. Plenty of people have made mistakes around ground and ship based radar systems too and have accidentally cooked their insides. Just because 5G conspiracy theorists took over that argument doesn’t mean it has no basis in reality.

    • SaveTheTuaHawk@lemmy.caEnglish
      11·
      2 days ago

      That makes no sense. It’s the wrong frequency to cook anything.

      JFC…is US STEM education really this bad? Lemmy seems to struggle between STEM and Star Trek.

      • notgold@aussie.zoneEnglish
        1·
        20 hours ago

        No Idea, never went to.school in USA. They haven’t cooked anyone while sending them to the moon so can’t be that bad.

      • drosophila@lemmy.blahaj.zoneEnglish
        2·
        2 days ago

        It’s the wrong frequency to cook anything.

        The idea that microwave ovens use some specific frequency that’s good for cooking is a myth.

        Dielectric heating occurs over a very broad range of frequencies. What actually matters is the energy density of the EM field. A microwave oven cooks food because its putting more than 1000 watts into a small confined space, your cellphone doesn’t because its transmitter is shooting less than 1 watt into the open air (where the energy density quickly diminishes by the square cube law).