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Using a magnetic string to fish for a lost iPhone 12 in a Berlin canal

riedel.wtf

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Re: Using a magnetic string to fish for a lost iPhone 12 in a Berlin canal

#111

Post by zepearl »

xhrpost wrote: post #97
anfractuosity wrote: post #27

Earlier quoted context omitted.

Are different frequencies attenuated differently then out of interest in water?

Yes, generally the smaller the wavelength, the worse the attenuation. Quick googling: 4g is 600Mhz to 2.5Ghz or 0.5m to 12.5cm wavelength. For comparison, the US Navy uses 80Hz or 3750km wavelength to talk to submerged submarines.[1] [1] https://en.wikipedia.org/wiki/Ground_dipole

From https://en.wikipedia.org/wiki/Ground_dipole :

> After initially considering several larger systems (Project Sanguine), the U.S. Navy constructed two ELF transmitter facilities...

> Both transmitters were shut down in 2004. The official Navy explanation was that advances in VLF communication systems had made them unnecessary.

I then started reading about VLF https://en.wikipedia.org/wiki/Very_low_frequency and on that page I see this sentence:

> VLF waves used to communicate with submarines have created an artificial bubble around the Earth that can protect it from solar flares and coronal mass ejections; this occurred through interaction with high-energy radiation particles.

That sounds absolutely weird - how should that "...that can protect it from solar flares..." be interpreted?

EDIT: didn't notice Wikipedia's linked article - https://www.theatlantic.com/science/archive/2017/05/wow-guys...

Re: Using a magnetic string to fish for a lost iPhone 12 in a Berlin canal

#112

Post by mschuster91 »

GhostVII wrote: post #62
capableweb wrote: post #13

Earlier quoted context omitted.

> I would have just given up and bought a new iPhone If people didn't already realize that most of people hanging around on HN have the top 10% of the world's wealth, this made things clearer than ever (the phone in question costs around 1000 EUR) Makes all the conversations around finance here make so much more sense.

I suspect the vast majority of people on HN are in the top 1% globally. People don't realise how high incomes in the US are relative to the rest of the world.

> People don't realise how high incomes in the US are relative to the rest of the world.

Gross definitely, but net (after taxes, healthcare, housing and other fixed costs)... not so sure. High CoL - seriously even as someone who lives in Munich, US housing prices are utterly incomprehensible, just how the fuck do y'all even manage to survive?! -, high costs for transportation, the utter madness that is US healthcare, hundreds of dollars for cable TV, having to save for your pension or student loans.

I'd wager that even after accounting for taxes, most Europeans have more money in their pocket than Americans working in the same field.

(And obviously, all of us have it vastly better than 99% of people in Africa)

Re: Using a magnetic string to fish for a lost iPhone 12 in a Berlin canal

#113

Post by laumars »

pengaru wrote: post #85
RcouF1uZ4gsC wrote: post #51

Earlier quoted context omitted.

If you are making €200,000 per year, your time is worth around €100 per hour. Thus if this is going to take more than 10 hours, it is not worth your time.

That's very flawed and naive method for measuring value of one's time.

Why? I’m not saying you’re wrong per se but you offer a stern dismissal without any reason nor alternative.

For what it’s worth, I think the GP makes a pretty common opinion. For example people on lower incomes will do more household jobs themselves because it saves them money, whereas people on higher incomes will pay people to do things because it saves them time. The opinion might be dressed up differently when I state that but it’s still the simple act of a person putting a value on their free time. It’s why we have house cleaners, windows cleaners, gardeners, car washers, and so on and so forth. The only different is people don’t usually casually post precise numeric values against their time. But it’s still a sentiment shared by many.

Re: Using a magnetic string to fish for a lost iPhone 12 in a Berlin canal

#114

Post by pmlnr »

yosito wrote: post #2

I've gotta give them props for the persistence. I would have just given up and bought a new iPhone. It's impressive that the iPhone survived the whole ordeal, without even turning off. And the amount of stuff they found makes me wonder why people don't use magnets on strings to search for lost things in European canals more often. Could be an interesting hobby.

They do. Cambridge, UK, has regular magnet fishers.

Re: Using a magnetic string to fish for a lost iPhone 12 in a Berlin canal

#115

Post by frosted-flakes »

em_rocks wrote: post #67
magoon wrote: post #16

I’m surprised to hear that bluetooth, GPS, and cellular don’t work in water. I wonder what’s the science behind this.

Most water you’d drop a phone into has enough traces of salt to make it conductive. Therefore, the water acts like a faraday cage. Theres a calculation you can do to calculate this, its pretty standard E&M stuff. Basically you calculate the skin depth of the material and thats as far as the signal can penetrate. The derivation highlights some cool things: 1. Its frequency dependent. This is why military submarines co…

Wow, that's fascinating. I've never heard of this—I assumed it was only because the water is dense enough that it absorbs the radio signals.

Re: Using a magnetic string to fish for a lost iPhone 12 in a Berlin canal

#116

Post by frosted-flakes »

Wevah wrote: post #87
julienfr112 wrote: post #86

I'm confused. I thougt iphone where made of aluminium, that is not attracted by a magnet ...

Newer iPhone models have magnets in them to attach to various chargers and accessories.

It's also not uncommon to stick a metal disc on the back of the phone for magnetic vehicle dashboard mounts.

Re: Using a magnetic string to fish for a lost iPhone 12 in a Berlin canal

#117

Post by justusthane »

kakkan wrote: post #90
fnoof wrote: post #44

Earlier quoted context omitted.

An iPhone 12 weighs 164g [1], so, through the magic of the metric system, it needs to displace a minimum of 164ml of water to float. The iPhone has an external volume of 14.67cm * 7.15cm * 0.74cm = 77.62cm^3 = 77.62ml. So it would need to be about 2x the volume to float. [1] https://www.apple.com/iphone-12/specs/

Time to roll back this innovation and release the new iphone with 2x volume so that it'd float.

Lifeproof used to make an add-on life jacket that fit around their cases.

https://duckduckgo.com/?t=ffab&q=lifeproof+case+life+jacket&...

Re: Using a magnetic string to fish for a lost iPhone 12 in a Berlin canal

#119

Post by walrus01 »

yosito wrote: post #2

I've gotta give them props for the persistence. I would have just given up and bought a new iPhone. It's impressive that the iPhone survived the whole ordeal, without even turning off. And the amount of stuff they found makes me wonder why people don't use magnets on strings to search for lost things in European canals more often. Could be an interesting hobby.

> the iPhone survived

They had a lot better chance of success since it was fresh water, vs if it had fallen in the ocean...

Re: Using a magnetic string to fish for a lost iPhone 12 in a Berlin canal

#120

Post by thirsteh »

tj-teej wrote: post #118

Maybe this is a naive question: but I remember growing up there was a hard and fast rule that you could not have magnets anywhere near your technology, is this not the case anymore? Was it only floppy-disks and disk based tech which had issues?

Yeah, there are not many moving parts now. It messed with read heads in HDDs as well as CRT monitors.

I still get nervous if there are magnets around cause I don't know how they work.

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