[Gratsby]

At some point every piece of technology that we use was impossible. It's very easy to sit on the hilltop and say "it's not possible". What's not easy is climbing the hill anyways and figuring out a way to make the impossible happen.

I'm not here to defend this company. I don't know a thing about them or their technology. I'm just saying... "what kind of world would we live in if we never looked past what we thought was possible?"

EDIT: I think that a few of you have missed an important piece of this post, so once again...

I'm not here to defend this company. I don't know a thing about them or their technology.

[extrapickles]

There is a spectrum of "Its not possible", generally from not feasible with current tech to fundamental laws of physics say no. Things on the "not possible with current tech" side are open for someone finding a nifty trick, things leaning towards the fundamental physics side, are not.

For this specific piece of tech its in the middle ground of the "its not possible" spectrum as human/animal safety and the air we breathe are the limiting factors, so if someone figures out how to very tightly generate the beam with no reflections/spillage and can detect when someone or a pet wanders into the beam, then its possible with high losses due to air.

All forms of wireless power suffer from effectively the same limitations of safety and air. Magnetic/RF have problems with unwanted heating of nearby metallic objects, RF spectrum rights and beam size issues (and at high freqs, air losses), optical have mild-moderate air resistance issues and issues with reflections (very small amounts of reflection=blind people), ultrasonic have severe air loss issues and beam power limitations for safety. Physics doesn't say no to wireless power, but it does say "Only if humans are not nearby or you want small amounts of power (<1w)".

Also, the best way to prove that you have conquered the limitations with a tech is to demonstrate to the world at large that it works in a practical enough manor. None of these "It's not possible" startups that I've seen have demonstrated a working prototype that people can wander up to an look at.

Disclaimer: I have worked for a company that does industrial optical wireless power.

[petra]

>> Physics doesn't say no to wireless power, but it does say "Only if humans are not nearby or you want small amounts of power (<1w)".

Wouldn't the limit be raised if you could build a system that detects whether a human is in the power path(or stray paths) to turn the power off, and do that fast and accurate ?

[jerf]

Well, sure. Next question: Would you trust your life to that system?

'Cause your answer really shouldn't be "yes" unless there is some very, very compelling reason that there is absolutely no other choice, and there pretty much always is.

[Retric]

No, not really. 60 years ago people thought building 14nm transistors was possible. They had no idea how to do it but that's a very different argument.

It's one thing to say your building a cheap 40% efficient solar cell, it's another thing to say your 10x the energy of current designs because light simply does not have that much energy.

[jaydub]

I'm no physicist, but I think that while it may be theoretically possible to distribute power wirelessly doing so in practice seems like it will be necessarily dangerous so as to be impractical. To quote a previous comment I made on HN:

To distribute sound over long distances 'wirelessly' you need to make it loud. That typically means cranking up the power. And ultrasound can be harmful at high power [1]. [1] "Occupational exposure to ultrasound in excess of 120 dB may lead to hearing loss. Exposure in excess of 155 dB may produce heating effects that are harmful to the human body..." https://en.wikipedia.org/wiki/Ultrasound

https://news.ycombinator.com/item?id=10352177

[kiba]

It's physically impossible, different from extraordinary difficult.

[adwf]

Yep, a lot of people are confusing the impossible of eg. "We can never go to the moon", which was actually just an exaggerated infeasible - it was possible, but only at great expense - with the literally physically impossible.

The moonshot wasn't about the laws of physics, it was about the laws of economics. A scale-up problem in terms of money. Whereas this charger is about trying to evade some very difficult laws of physics.

Even if you exclude the extreme physical improbability of the device, it still has massive problems in terms of practicality. It would require installing a large number of expensive ultrasound emitters in every coffee shop and fast food joint. Then installing recievers in every phone. And it will still be massively inefficient power-wise. Whereas the alternative is to install comparatively low power, more efficient wireless charging pads in every table.

So even ignoring the physics, this was going to be an incredibly hard sell.

[Florin_Andrei]

Yup. Some things (not all) are impossible in a literal sense.

Want to extract 2 kW / m^2 from solar radiation somewhere near the Earth? Won't work, the Sun doesn't pump out that kind of power density (the max is 1.whatever kW). Literally impossible.

[eric_arrr]

Wrong -- we could move the earth closer to the sun. Or make the sun burn hotter. Either way, totally possible.

/s ;)

[thrownaway2424]

Can't I just put a lens above the surface to concentrate it? I think you picked a poor example.

[TheSpiceIsLife]

No you can't, because you're increasing the surface are of the collector so the 1.366kWh / square meter still stands.

From Wikipedia:

Average annual solar radiation arriving at the top of the Earth's atmosphere is roughly 1366 W/m2. The Sun's rays are attenuated as they pass through the Atmosphere, leaving maximum normal surface irradiance at approximately 1000 W /m2 at sea level on a clear day.[1]

Therefore it is impossible to get more than about 1kW / m2 from any solar panel. Until such times as something fairly fundamental changes, like a loss of atmosphere or an increase in energy output from the sun.

1. https://en.wikipedia.org/wiki/Insolation

[mjevans]

Well, you're mostly correct; but not technically correct.

From /just/ a solar panel it isn't possible to achieve higher density, however you can use reflectors in the spectrum that your solar panel operates in to increase the energy available for capture at a focal point.

[simoncion]

So, there's this: http://what-if.xkcd.com/145/

But there's also TheSpiceIsLife's opening comment which says:

> ...you're increasing the surface are of the collector so the 1.366kWh / square meter still stands.

It feels like your second sentence

> ...[H]owever you can use reflectors in the spectrum that your solar panel operates in to increase the energy available for capture at a focal point.

plays rhetorical games by ignoring the existence of large parts of your solar collector (namely the reflectors) in order to arrive at an inflated energy density figure.

[gvb]

No. Your lens is the collection surface area.

Trivia: According to https://en.wikipedia.org/wiki/Sunlight#Solar_constant The sun puts out approximately 1.361 kW/m²

[etendue]

No. In addition to the others, another link of interest might be on etendue: https://en.wikipedia.org/wiki/Etendue

[theresistor]

The lens wouldn't be "somewhere near the earth".

[thrownaway2424]

Exactly my point!

[tluyben2]

You have been downvoted but you do make a good point although it's a cliche obviously (you could've used things like; people said planes and even trains were not possible which would push that cliche). However some things are actually outside the realm of what is possible at the moment and in the foreseeable future and if science agrees on that with solid proof and foundation it is just silly to try imho.

I am curious if investors think you like when they invest in the impossible or they just are not really interested in fact and just want portfolio or another reason?

I was close to the Jan Sloot[0] who invented impossible compression. And got invested into by prominent investors who believed him. And some of them not ignorant of the math behind it either and yet they invested. My company got asked by a 'friend' of Sloot who also lived in Nieuwegein (my company was there too) to recreate the algorithm based on discussions this guy had with Sloot and notes he wrote down during those discussions. I presented, to my colleagues and this guy, a proof based on (Kolmogorov) complexity that we cannot do that and that his writings were gibberish; some of my friends and colleagues told me I was insane in not pursuing something revolutionary like this and, as you said; a lot of great technology was perceived as 'impossible' and yet we have that as well. No-one became a billionaire on this tech yet as was promised so I'm going to say it was a good call.

[0] https://en.wikipedia.org/wiki/Jan_Sloot

[jellicle]

Impossible meaning "we aren't sure how to build this today" and impossible meaning "this grossly violates our understanding of the basic physical laws of the universe" are two different sorts of impossible.

[corndoge]

And with a better understanding of the basic physical laws of the universe, things that were once thought impossible may become possible. One day, perhaps, even the speed-of-light constraint will need to be revised in light of newfound physical knowledge.

[jerf]

An obvious analog of the correspondence principle [1], usually stated in terms of QM and Newtonian physics, holds here. It's going to take more than "new physics" to change the behavior of sound in this rather-well-understood regime, it's going to take physics-breaking-physics.

There's a time and a place for "we may learn new things in the future". This is not that time. There's no room for "new physics" to be hiding here, short of postulating outright magic, which will probably have a great deal more applications in the world than salvaging something that was always frankly a silly idea anyhow.

I mean, why go to bat for this idea anyhow? It's not flying cars or FTL, it's an incredibly annoying, inferior way of doing something you probably do every day already, and you aren't sitting there going "Gosh, this is a really inconvenient way of charging my phone and there's nothing I can do about it", because there already is something you can do about it if you just can't stand wires. Inductive chargers work and are years-old off-the-shelf tech. I have a cousin-in-law that was involved in marketing them. (It doesn't "beam" the power, but, well, that's why it works. EM beaming certainly seems to be "less" impossible, but probably never practical for ambient personal electronic charging.) Even if this all worked as claimed it would still be yawn-worthy tech. Hardly a reason to resort to nuke-the-entire-philosophical-world arguments about our complete ignorance of everything everywhere ever.

[1]: https://en.wikipedia.org/wiki/Correspondence_principle

[mitchty]

Maybe, but your point is nothing more than heresay.

The speed of light constraint also has nothing to do with light, it is the speed of information travel.

What is being proposed by ubeam is like lifting a 50 ton rocket with 10 tons of thrust. It doesn't really matter what future physics we have, fundamentally its impossible as stated. Bringing future physics into the mix is moving goalposts in an attempt to appear open minded. The rockets never going to lift off with 1/5 of its mass in thrust.

[corndoge]

I had no point other than exactly what I stated. I am not contesting the infeasibility of uBeam.

[matchagaucho]

The laws of physics just don't allow for recharging a smart phone battery from across the room given the current constraints.

[iaw]

What do you mean by "current constraints?"

The properties of the medium (air), being the core constraint, is fairly well rooted in the laws of physics and observed experimental results.

What constraints are there that can actually be changed?

[dingo_bat]

What if you could locally change the relevant characteristics of air?

[iaw]

You can, it just makes the environment inhospitable for humans and requires orders of magnitude more energy than just what would be used to transmit the sound waves.

If you mean hyper-localization, that would be a new scientific phenomenon and one worth a great deal more to the world than as a wireless charging technique. The best industrial manufacturing techniques utilizing ultra-sonic arrays can do some amazing things but they:

1) Make the environment inhospitable to humans

2) Don't actually change the "relevant characteristics" of air so much as force a specific resonant behavior to allow them to target the energy at specific locations.

What specific "relevant characteristics" of air would you be changing? How do we then leverage changing of said characteristic to achieve our desired result? It would help if you utilized the terminology from the "Gas" Wikipedia page, a cursory glance and it appears to be comprehensive (from a concept perspective) [0]

[0] https://en.wikipedia.org/wiki/Gas

[CamperBob2]

The "current constraints" being "This isn't Hogwarts."

[lordnacho]

No, it's impossible.

Engineering is not simply about having fantasies. A fair bit of what you do as a technologist is rule out things that simply are illogical. Perpetual motion machines, a way to calculate whether a program will halt, acausal filters, and so on.

For instance, it's impossible to construct a windmill that is 70% efficient. I learned that last week, so now I know not to think too much about it, other than noticing any refutation of Betz' Law.

There are many things that are hard but cannot be ruled out, like sending probes to Alpha Centauri. It's fair to spend energy thinking about those ideas, but to do that we need to stop thinking about things that are ruled out.

[dboreham]

And this viewpoint (ignore science because "progress") is exactly how people end up funding scams like this.