I just hacked my brain (2015) • Hacker News Board

Re: I just hacked my brain (2015)

#31

Post by OkayPhysicist » Tue, Mar 23, 2021, 10:04 AM UTC

mastre_ wrote: post #29

Sanzig wrote: post #6

Earlier quoted context omitted.

Yeah... reading it in further detail, he applies current across his head between the mastoid processes. I thought it was local stimulation between two surface electrodes under the ear. A quick look at the literature shows that the targeted structures are too deep for an approach like that, so they have to go across the head. Style points for bravery, I guess, but I certainly wouldn't want to pump over a milliamp of d…

Can someone explain to this non-EE how current alone, as specified in milliamps in the absence of a specified voltage, can be used to specify a lethal condition? In other words, from here and other sources I'm inferring that 100mA can stop the heart, but does it not matter if it's from a (at?) 9V battery vs 1.5V AA battery?

Well, the resistance is a fixed variable here, so voltage and current are tied together. Can't increase the amps without increasing the volts.

Re: I just hacked my brain (2015)

#32

Post by coldtea » Tue, Mar 23, 2021, 6:15 PM UTC

99_00 wrote: post #25

tablespoon wrote: post #22

Earlier quoted context omitted.

> Your example doesn't show why a 9v battery used in this way is dangerous. So? It's part of a more general argument against assuming household items are safe when you're using them in highly unusual ways or far outside of normal parameters. But if you need a specific example of someone killing themselves with a 9V battery to get the message, a sibling comment actually linked to a Darwin award where someone did just…

No one is advocating intentionally sticking electrical probes into your body. So, again, it doesn't show that a 9 volt battery used in the way described by the article is dangerous.

>it doesn't show that a 9 volt battery used in the way described by the article is dangerous.

Then again, it doesn't have to show that - since the person in the article didn't come to use it in "that way" after serious study, research and precautions, but by assuming its harmeless in general and using it in an ad-hoc manner.

They could quite easily, with the same assumption, which is what the parent warns against, use it in a dangerous way.

Re: I just hacked my brain (2015)

#33

Post by coldtea » Tue, Mar 23, 2021, 6:18 PM UTC

99_00 wrote: post #26

FartyMcFarter wrote: post #17

Earlier quoted context omitted.

A 9V battery is enough to deliver a lethal current under the right conditions. Don't play with electricity unless you know what you are doing.

What are those conditions?

That's the question that the author of TFA should have researched very well before using it: in order to avoid those conditions.