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Scientists shine a laser through a human head

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Re: Scientists shine a laser through a human head

#31

Post by addaon »

astrobe_ wrote: post #24
ben_w wrote: post #13

Earlier quoted context omitted.

While it's almost certainly safe or it wouldn't have passed the ethics committee, what you say is an insufficiently detailed description of setup to determine if it's fine or not. 1.2 watts over your entire head is fine. 1.2 watts in a 800nm-diameter cylindrical path is "for some reason we decided to make the outer few millimetres of your skin explode, but we had to be in contact with your skin to manage that because…

What can one actually do with a 1 Watt laser? That's a good question to ask to an AI: "A 1-watt laser can be used for various applications, such as cutting materials, engraving, and even lighting cigarettes. However, it poses significant risks, including the potential to cause instant and permanent eye injuries, so safety precautions are essential". So it looks like it packs some... Power. But I guess the frequency o…

> That's a good question to ask to an AI

What makes you say that? By what metric?

Re: Scientists shine a laser through a human head

#32

Post by whatshisface »

shadowgovt wrote: post #28
HelloUsername wrote: post #4

The title made me think of Anatoli Bugorski, a Soviet scientist who in 1978 survived a high-energy proton beam from a particle accelerator passing through his head. https://en.wikipedia.org/wiki/Anatoli_Bugorski

There's a lot of pieces of the physics of that story I don't quite understand. The main one is that (IIUC) one of the reasons the damage wasn't as bad as it could have been is that at the relativistic speeds the protons were travelling at, his head was extremely space-dilated, so they were basically blasting through tissue paper. But I would expect that tissue paper to have all the mass of a human head dilated into a…

The fact that cross sections become smaller at high velocities is very intuitive: force applies its kick over time, and there is a lot of distance between the parts of an atom. If a particle is going fast enough it whizzes by without pushing on the other atoms for very long.

Re: Scientists shine a laser through a human head

#33

Post by imchillyb »

addaon wrote: post #31
astrobe_ wrote: post #24

Earlier quoted context omitted.

What can one actually do with a 1 Watt laser? That's a good question to ask to an AI: "A 1-watt laser can be used for various applications, such as cutting materials, engraving, and even lighting cigarettes. However, it poses significant risks, including the potential to cause instant and permanent eye injuries, so safety precautions are essential". So it looks like it packs some... Power. But I guess the frequency o…

> That's a good question to ask to an AI What makes you say that? By what metric?

Not OP, but…

Asking Google about one watt lasers inevitably produces junk that does not address the question at all.

Sifting and sorting through that junk is tiresome.

AI provides a succinct answer with as much depth is requested and can further clarify or expound on the original findings.

What’s not to like about such interactions? And, furthermore, how is the AI interaction in this case not objectively ‘better’ than a Google search?

Re: Scientists shine a laser through a human head

#35

Post by throwaway173738 »

short_sells_poo wrote: post #19
echelon wrote: post #9

There have to be ways of getting high space and time resolution signal capable of reconstructing people's exact thoughts, memories, and senses. Non-invasively. No "below threshold of detection". Beyond anything our scientists say is possible. We're just not advanced enough as a species to do it yet. We need to keep pushing these boundaries.

This would likely require completely new forms of physics and interacting with matter I'm afraid. It simultaneously requires extremely high resolution and high penetration (we need to see deep into the brain). You'll need to be able to measure the state of neurons and connections - probably down to the quantum level - and do this real time, and then record the data that you collected. I suppose you could flood the br…

At least there’s a theoretical path forward to super-luminal travel beyond hand-waving. Just find some exotic negative energy density matter.

Re: Scientists shine a laser through a human head

#36

Post by addaon »

imchillyb wrote: post #33
addaon wrote: post #31

Earlier quoted context omitted.

> That's a good question to ask to an AI What makes you say that? By what metric?

Not OP, but… Asking Google about one watt lasers inevitably produces junk that does not address the question at all. Sifting and sorting through that junk is tiresome. AI provides a succinct answer with as much depth is requested and can further clarify or expound on the original findings. What’s not to like about such interactions? And, furthermore, how is the AI interaction in this case not objectively ‘better’ tha…

> What’s not to like about such interactions?

The at-best-coincidental correlation with accuracy and truth.

Re: Scientists shine a laser through a human head

#37

Post by ben_w »

addaon wrote: post #36
imchillyb wrote: post #33

Earlier quoted context omitted.

Not OP, but… Asking Google about one watt lasers inevitably produces junk that does not address the question at all. Sifting and sorting through that junk is tiresome. AI provides a succinct answer with as much depth is requested and can further clarify or expound on the original findings. What’s not to like about such interactions? And, furthermore, how is the AI interaction in this case not objectively ‘better’ tha…

> What’s not to like about such interactions? The at-best-coincidental correlation with accuracy and truth.

While I agree (despite generally liking AI, I agree), this has been a shared similarity with web search results for some years already.

Re: Scientists shine a laser through a human head

#38

Post by lawlessone »

adolph wrote: post #15
davidmurdoch wrote: post #8

Earlier quoted context omitted.

You could also wear a black hole as a helmet!

The authors suggest black foamboard with cloth and a laser safety curtain is sufficient. Better safe than sorry though. To prevent light from reaching the detector from sources other than light transmitted through the head, the experiment was performed in a light-tight enclosure that surrounded the head. The enclosure was built using black foamboard and covered with two layers of black cloth and a laser safety curtai…

Not for neutrinos it isn't

Re: Scientists shine a laser through a human head

#39

Post by orbisvicis »

short_sells_poo wrote: post #19
echelon wrote: post #9

There have to be ways of getting high space and time resolution signal capable of reconstructing people's exact thoughts, memories, and senses. Non-invasively. No "below threshold of detection". Beyond anything our scientists say is possible. We're just not advanced enough as a species to do it yet. We need to keep pushing these boundaries.

This would likely require completely new forms of physics and interacting with matter I'm afraid. It simultaneously requires extremely high resolution and high penetration (we need to see deep into the brain). You'll need to be able to measure the state of neurons and connections - probably down to the quantum level - and do this real time, and then record the data that you collected. I suppose you could flood the br…

Imagine n^3 EMF-generating cubes surrounded by 6n^2 EMF-detecting cubes. Starting from an initial given state, is there any n for which over time the state of any given EMF-generating cube cannot be deduced?

Then consider a further constrained version in which the EMF-generating cubes may only generate EMF in response to external inputs, i.e. as in the game of life.

Re: Scientists shine a laser through a human head

#40

Post by shadowgovt »

whatshisface wrote: post #32
shadowgovt wrote: post #28

Earlier quoted context omitted.

There's a lot of pieces of the physics of that story I don't quite understand. The main one is that (IIUC) one of the reasons the damage wasn't as bad as it could have been is that at the relativistic speeds the protons were travelling at, his head was extremely space-dilated, so they were basically blasting through tissue paper. But I would expect that tissue paper to have all the mass of a human head dilated into a…

The fact that cross sections become smaller at high velocities is very intuitive: force applies its kick over time, and there is a lot of distance between the parts of an atom. If a particle is going fast enough it whizzes by without pushing on the other atoms for very long.

Yes, thank you, this was the intuition I was missing!

Protons almost never collide directly with a nucleus because most of an atom is empty space; a proton beam disrupts the matter it's passing through mostly by electrostatic effect, and that's a function of position and time!

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