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Comment by gorkish | Hacker News Reader

"wireless charging" as a technology has been pretty baffling to me -- to make it even remotely efficient almost every practical consumer implementation uses some form of mechanical alignment and contact system. As long as you are resigned to do that, why not just use normal mechanical contacts instead?

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You might be willing to sacrifice efficiency for the common interface and component degradation over time from repeated physical connection mechanics.

For phones, and other small devices, it's a reasonable solution due to the current and energy transferred involved. For vehicles though, it does not make sense (imho) considering the currents involved, especially as we're approaching 4C-6C with new battery chemistries and management systems.

And the number of phone cables I've replaced, especially beside my bed is already out of control. Switching to cables that plug in at 90 degrees has helped a lot, but it's something that can still wear out quickly.

> As long as you are resigned to do that, why not just use normal mechanical contacts instead?

Maybe a bit far out there, but wouldn't you be able to make both parts (charger and chargee) water-proof easier if power can be transmitted wirelessly?

Because, at least when there are magnets involved for alignment, it's easier. I've never ripped a charger out of the wall by picking up my phone in the middle of the night and forgetting I had a short cable attached to my phone.

Kind of like saying you don't understand why we ever had early keyfobs when you still had to carry a key to start the car. It's not about it being superior in every aspect, it's about ease of use.

Can not recommend charging your phone all night wirelessly next to your head while you are sleeping.

What are your concerns?

Where is this nonsense coming from and why is it running rampant in a HN thread?

Several decades of published research that hint at correlations between EM exposure and health issues coupled with military grade cynicism about the likelihood that industry players had a hand in late breaking claims that said research was inconclusive.

Talking about phone charging in this context is like discussing airsoft pellets in a conversation about war munitions. It's patently absurd. Please do not perpetuate the idea that a low current air core transformer charging a phone is in any way invisibly harmful. It's not.

If this claim was trivially provable it would have been conclusively proven by now and yet there persists hints that chronic EM exposure, even at relatively low power, may cause problems. I vividly recall a cluster of research that blipped into the media landscape for a couple hours a few decades ago that suggested long-term exposure to cellphone broadcast antennas might be problematic and cell chargers necessarily push a hell of a lot more power. To be absolutely clear I'm not claiming to have any answers here, my areas of expertise don't cover this. I would expect any research that comprehensively dispels concerns about EM exposure to make a shitload of noise in the media landscape and to the best of my knowledge that hasn't happened.

You are exposed to greater than 1000W/m^2 of broadband EM every time you go outside; the sun shines WAY outside the visible spectrum, you know. Have you ever ridden in an electric or hybrid electric vehicle? Have you been on a train or ship? Have you walked near a power transformer or driven past a substation? These all produce field effect many many orders of magnitude stronger than we are discussing here.

You are pulling out every logical fallacy in the book in your approach to this question. EM exposure is rigorously studied and safety standards have existed almost as long as we have known about electromagnetism! About the only time that a normal person even comes close to needing to worry about them is when getting an MRI or climbing a radio tower.

Johnny Mnemonic was a work of fiction, not a documentary.

Careful there. In your haste to make your point you're dragging in proven causes of various health issues. The fields coming off of high voltage transmission equipment have been comprehensively proven to cause negative health effects. As to safety standards, MSDS standards have been around since 1983 and somehow they didn't prevent literally the entire surface of the planet from being contaminated with PFAS. You're not going to make a lot of headway here if your chosen tack is to advance coy notions that industry safety standards are rigorous.

To be absolutely clear, I'm not convinced low power EM causes problems. I'm also not convinced it doesn't. What I am absolutely certain of is that given the global scope of the industries that are implicated here, there isn't a legislative body on the planet that would so much as inconvenience them if there was a problem and it was know.

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