5 ms·

I was really skeptical about her company but the pictures in the article and the article itself seem legit. I wonder how they'll combat the inverse square law

by ogezi 9y ago

I was really skeptical about her company but the pictures in the article and the article itself seem legit. I wonder how they'll combat the inverse square law and make their technology actually feasible.

MichaelGG 9y ago
From this no details article, how can you determine that versus a small battery pack in the case?
- jclarkcom 9y ago
  I'm thinking about drones if it could work over longer distances, 24hr survailence
  - jacquesm 9y ago
    That's significantly more energy than they are able to transmit. Drones consume a lot of power.
trsohmers 9y ago
Not to be defending/advocating that uBeam's tech is actually any good, but the inverse square law refers to omnidirectional transmission, while uBeam's claims are related to directional transmission of power.
- jacquesm 9y ago
  Have you ever seen an audio frequency transducer (say up to 200 KHz) that delivered an actual beam? Usually the inverse square law is very much in effect when it comes to audio, this is because the medium (waves in air) behaves as water does with waves do in a pond rather than say the light coming out of a laser or any other focused source of electromagnetic radiation. Distance from the transmitter will very much be a factor.
  - trsohmers 9y ago
    I wasn't saying it wa snot a factor, and I totally agree with you, but the inverse square law per its exact definition does not apply here. I think uBeam is another Theranos, but granted at a much smaller scale. Still can't believe it has raised so much money and so much press without basic questions really being answered.
    - dnautics 9y ago
      The inverse square law generally applies for focused beams as well. Why wouldn't it?
  - jdietrich 9y ago
    uBeam is probably bullshit, but it's definitely possible to steer a focused beam of high-frequency audio. https://en.wikipedia.org/wiki/Phased_array_ultrasonics https://en.wikipedia.org/wiki/Phased_array_ultrasonics
    - jacquesm 9y ago
      Yes, I mentioned phased arrays in my earlier comment. Even so that's a lot less focused than what you might believe it does, it's more like a directional wavefront than a focused beam. So you'll still lose lots of power due to the expanding wavefront (conveniently left out of the wikipedia drawings but I can see why they did that).
      - watmough 9y ago
        Back when my dad still worked at Aberdeen University, they had a phased array of maybe 7 or 8 transducers of about 8 cm each, that at a range of 6 inches or so, could deliver a focused beam that would penetrate a phantom / lab animal enough to cook a 2 - 3 cm sphere several cm below the skin. The research was aimed at basically heating carcinomas above the 44 oC needed to kill the cells. So you can focus an ultrasound beam, but it seems like a heck of a way to charge a phone.
agumonkey 9y ago
Maybe it won't be a mainstream idea but something that can open a few valuable niches.
- jacquesm 9y ago
  > something that can open a few valuable niches. Or some valuable wallets.
2_listerine_pls 9y ago
ever heard of directional speakers? or radars arrays?

by ogezi 9y ago

MichaelGG 9y ago

From this no details article, how can you determine that versus a small battery pack in the case?

jclarkcom 9y ago
I'm thinking about drones if it could work over longer distances, 24hr survailence
- jacquesm 9y ago
  That's significantly more energy than they are able to transmit. Drones consume a lot of power.

trsohmers 9y ago

Not to be defending/advocating that uBeam's tech is actually any good, but the inverse square law refers to omnidirectional transmission, while uBeam's claims are related to directional transmission of power.

jacquesm 9y ago
Have you ever seen an audio frequency transducer (say up to 200 KHz) that delivered an actual beam? Usually the inverse square law is very much in effect when it comes to audio, this is because the medium (waves in air) behaves as water does with waves do in a pond rather than say the light coming out of a laser or any other focused source of electromagnetic radiation. Distance from the transmitter will very much be a factor.
- trsohmers 9y ago
  I wasn't saying it wa snot a factor, and I totally agree with you, but the inverse square law per its exact definition does not apply here. I think uBeam is another Theranos, but granted at a much smaller scale. Still can't believe it has raised so much money and so much press without basic questions really being answered.
  - dnautics 9y ago
    The inverse square law generally applies for focused beams as well. Why wouldn't it?
- jdietrich 9y ago
  uBeam is probably bullshit, but it's definitely possible to steer a focused beam of high-frequency audio. https://en.wikipedia.org/wiki/Phased_array_ultrasonics https://en.wikipedia.org/wiki/Phased_array_ultrasonics
  - jacquesm 9y ago
    Yes, I mentioned phased arrays in my earlier comment. Even so that's a lot less focused than what you might believe it does, it's more like a directional wavefront than a focused beam. So you'll still lose lots of power due to the expanding wavefront (conveniently left out of the wikipedia drawings but I can see why they did that).
    - watmough 9y ago
      Back when my dad still worked at Aberdeen University, they had a phased array of maybe 7 or 8 transducers of about 8 cm each, that at a range of 6 inches or so, could deliver a focused beam that would penetrate a phantom / lab animal enough to cook a 2 - 3 cm sphere several cm below the skin. The research was aimed at basically heating carcinomas above the 44 oC needed to kill the cells. So you can focus an ultrasound beam, but it seems like a heck of a way to charge a phone.

agumonkey 9y ago

Maybe it won't be a mainstream idea but something that can open a few valuable niches.

jacquesm 9y ago
> something that can open a few valuable niches. Or some valuable wallets.

2_listerine_pls 9y ago

ever heard of directional speakers? or radars arrays?