Hacker News Reader

Let me try to clear it up. (sorry, it got a bit long)

First, the skin (and skull and clothing .. etc.) does act as a barrier, which is why the graph that is shown in the article is flawed (this is mentioned). It shows absorption of microwave radiation in the grey matter of the brain, but it doesn't account for the skin and skull that blocks it.

There are two major effects of radiation: ionization (think X-ray imaging) and heating (think microwave oven). Ionization is irrelevant for 5G, because the frequency is way too low. Heating, on the other hand, happens at many frequencies. For example, a microwave oven is at ~2.4 GHz, just like Wi-Fi (which can also operate at 5 GHz).

That said, the heating is dependent on how much power is transmitted and how well it is absorbed by the skin. For example, a low-power source (Wi-Fi antenna) doesn't fry your skin like a microwave oven because a) the power is too low and b) it mostly reflects off the surface of the skin.

The power levels that 5G needs to operate at are quite low and the reflection off the skin is quite high. This is summarized nicely in the reference I gave in another comment here [1].

To answer your specific questions:

> So am I to understand 5G causes merely skin cancer, not brain cancer? Or is non-ionizing radiation safe regardless of shielding?

The ionization effect is not present due to low frequency (see above), the heating effect should be considered, but is minimal (see reference). The authors of [1] note specifically that the skin area is safe, but the eyes may be more vulnerable if the devices operate at large power and are close-by. So, this is not dangerous for consumers but may be dangerous for workers near antennas. However, the radiation level must be very high, and the distance very short. In my reading of the paper, it is not a danger for commercial telecom applications.

> Would it be too much to ask for blasting a few thousand rats with 5G?

That is not my field of expertise..

[1] https://ieeexplore.ieee.org/abstract/document/7032050

"So am I to understand 5G causes merely skin cancer, not brain cancer?" was mostly meant as a critique of the article, since they use shielding by skin as a defense.

Otherwise yes, I'm aware that 5G is non-ionizing, and produces negligible heating, which doesn't leave many straight-forward ways it could affect biology (maybe EM fields adversely affect protein folding?). For those you pretty much need experimental studies, but looks like they've been conducted, and turned up nothing.

EM fields are not affecting protein folding. Moreover this is really just you reacting to something that feels incomprehensible and invisible while discounting something that seems normal - sunlight - even though it's orders of magnitude more powerful, causes more heating, and is directly linked to cancer in the right ranges.

But no one expresses concern about visible light causing damage from localised heating or the EM fields of it disrupting protein folding (hold a torch up to your hand - your body is quite translucent to visible light).

> EM fields are not affecting protein folding.

Why not? The energy needed to affect that is lower than ionization energy, so they could.

And I'm not "reacting" to anything. 60 GHz radiation is sufficiently different from sunlight that it might plausibly have a different effect on us (such as by interacting with some low-energy absorption peak of a protein that visible light does not interact with due to its higher energy, or by penetrating deeper into tissue than visible light can).

It turns out studies show it is not harmful. But they conducted actual studies to show that - they didn't dismiss it outright "because sunlight".

Sunlight bathes you in multiple watts in the same narrow frequency range, so it couldn't do that much.

Surely it's a different narrow frequency range? Otherwise sunlight would act as a signal jammer, a source of noise that drowned out our wireless signals?

Indeed, the radiation coming from the sun in the visible spectrum is much larger than the microwave radiation coming off it [1]. Note: the microwave spectrum ends at ~300 GHz or 1 mm wavelength, that is 1 million nanometers, so the scale on the x-axis is wayyy too short in the image. The actual value is very, very low.

[1] https://upload.wikimedia.org/wikipedia/commons/0/0d/Effectiv...

You can filter out a stable amount pretty easily but oops I just checked the blackbody math again and an exponent flipped when I changed one of the ranges while everything else stayed almost the same, I screwed up and ignore everything I said.

Hehe, happens :)

But, suppose the sun did interfere - how would you filter this out? Due to the black-body nature of the source, the amplitude would be stable, but the phase wouldn't be - you'd get entirely uncorrelated white noise, right? How can you filter that?

Good question. A good but short answer is given on Wikipedia (https://en.wikipedia.org/wiki/Matched_filter#Matched_filter_...). Any undergraduate textbook on digital signal processing should have details on this topic.

edit: to add to this, the capacity C ("throughput") of the communications channel is linear with bandwidth B (in Hertz) but only logarithmic (log_2) with noise power N. This was derived by Shannon (https://en.wikipedia.org/wiki/Shannon%E2%80%93Hartley_theore...) and in equation form:

  C = B*log_2(1+S/N)

Example: signal to noise ratio is 1 (S/N = 1). Result:

  C = B

Now we increase the bandwidth of our channel by a factor of 10, keeping the signal power equal. This will lead to a factor 10 more noise power (S/N = 1/10). Result:

  C = 10*B*log_2(1 + 1/10) = 1.38*B

So we can improve the channel capacity by increasing the bandwidth even in a noisy channel.

I've never really looked into how the encoding is typically done on those bands. You don't need a lot of bits per Hz when you have 14GHz of space, so nothing particularly elaborate with phase is strictly necessary. But yes it would definitely hurt speeds, and you have a good point in that it's something to consider as a sanity check!

Do you know anything about protein folding or just the term? Because everything you just wrote is reactionary jibberish and not based on any possible mechanism, or even a solid understanding of how protein folding works.

Regarding: "It would be nice if the Times article devoted more ink to studies showing 5G to be safe, instead of 95% focusing on how the claims that it is dangerous are shaky, and barely mentioning studies proving its safety."

There have been no studies showing 5G to be safe, because there have been no studies on 5G.

The fact that 5G is not commercially available does not mean there have been no studies. A quick Google Scholar (or whatever) search could have cleared that up for you. Here's the link to save you from typing it in: https://scholar.google.com/scholar?&q=5g+safety+radiation

Very interesting, so there are a few studies! Thank you for pointing this out, I had been under the impression that there were none whatsoever. I am not sure what conclusions can be drawn from these few studies at present (I found four or five on the Google Scholar link). It would be interesting if someone with the requisite technical background could read and assess them. (And the question of funding, as discussed in the Guardian article I linked to in another post, is also relevant, as empirically speaking, industry-funded studies on the whole do lead to significantly different results from independently-funded studies).

Non-ionizing radiation causes heating. E.g., looking into a 2.4 GHz source (microwave) of enough power cooks your eyeballs inside-out, kinda like boiling eggs. It's because they absorb a lot, but have negligible cooling due to a lack of blood circulation inside of them.

Lower powers don't seem to have significant effects, and if so, likely more of a metabolic nature than of a cancer nature. Getting an inflammation seems possible, but cancer-inducing powers cause thermal sensations/damage before you get cancer.