5g Detrimental to Insects | Hacker News Reader

5g Detrimental to Insects

nature.com

33 pointsensiferum12 comments

The title is editorialised ("5g Detrimental to Insects") which is not what the original title is, nor what the conclusion actually states - which is that at >6GHz RF energy absorption increases. The conclusion suggests that this may have effects, but didn't actually study those or figure out what they were.

Title is "Exposure of Insects to Radio-Frequency Electromagnetic Fields from 2 to 120 GHz"

Indeed, they just state that it could cause "changes" but not if those changes would be harmful or beneficial:

> This could lead to changes in insect behaviour, physiology, and morphology over time due to an increase in body temperatures, from dielectric heating.

What about other mechanisms of action? https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3780531/

A large scale study of the long-term health effects of non-ionizing RF absorption on humans is wildly overdue. The fact that we don't even have one for fruit flies is a little unsettling.

Yes. Toward the end there is an example of the kind of effect their model gives:

"As an example, for the Australian Stingless Bee (mass = 2.5 mg) a P abs of 3 × 10–8 W is estimated for an incident field strength of 1 V/m at 60 GHz. Under the assumption that the insect has a specific heat capacity equal to that of water (4179 J/K kg43), this RF-EMF exposure would result in a temperature increase of 3 × 10–6 K/s, in an isolated approximation."

Early in the article, this insect size is given:

"The scanned insect was approximately 4.5 mm long, 3.0 mm wide."

So a surface on the order of ~10 mm2. The sun provides ~100 W/m2 in winter, ~1000 W/m2 in summer. So in winter, that's about 10-4 W/mm2 or 10-3 W over the surface of this insect. The absorbed energy due to 5G per their model is several orders of magnitude below the absorbed energy coming from flying under a winter sun.

It's very good that people look at such effects. There may also be other effects besides just thermal ones as considered above. But clearly the title ("5g Detrimental to insects" at the time I write this) is undeserved and borderline trollish IMHO.

"A shift of 10% of the incident power density to frequencies above 6 GHz would lead to an increase in absorbed power between 3–370%. This could lead to changes in insect behaviour, physiology, and morphology over time due to an increase in body temperatures, from dielectric heating." which is speculative.

I agree; the paper is more measured than the HN title.

Everything has resonances:

"The most restrictive limits on whole-body exposure are in the frequency range of 30-300 MHz where the human body absorbs RF energy most efficiently when the whole body is exposed."

https://www.fcc.gov/engineering-technology/electromagnetic-c...

As a radio ham I am familiar with the 2 meter band which is at 140-144 MHz; a quarter wave antennas is pretty effective and that would be 0.5 meters which is "human scale".

Bugs are smaller so they are going to resonate at a higher frequency. You'd expect something that is a few millimeters in size to couple to millimeter waves; in that paper they flesh it out in detail.

Why was this flagged/dead? It's a valid submission and an important piece of research; we just needed a moderator to change the title.

I wonder what they mean by "insect phantoms"? Probably not what I imagine.

Usually a phantom is a real physical object, with particular properties similar to a desired subject. The phantom is experimented with instead of the actual object.

Because you made the phantom, you have "ground truth". Whereas, for example, there is no way to validate your reconstruction of a living person's brain. Because you can't measure it without xrays, which might be the thing you're trying to improve.

But if you xray a phantom, you know what you should find.

I assume it's like phantom in the medical imaging context - a kind of test object.

The OED says: A physical or computer-generated model used to calculate radiation doses, evaluate or enhance imaging techniques, etc.

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