41–50 of 171 posts
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No. All polynomials and rational functions fall off drastically slower than exponential.
We're talking about the rise in power as you get closer. 1/x² has a singularity, I doubt exp(x) can beat that...
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You may need to check your math. Inverse square does not fall off faster than exponential.
1/x² has a singularity and rises faster than exponential as you approach it. We're talking about getting closer to the source, not further.
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The manufacturer needs the phone certified in advance of shelf stocking. There is nothing stopping the FCC from confirming their test results with retail units. Plus, the risk from cheating is enormous. It’s a lot easier in the long run to just design properly working phones.
It didn't turn out to be easier to design a clean burning diesel.
Designing to the test is different than carefully selecting (or altering) a sample that passes the test.
Testing phones from 5 millimeters away from the body may seem close, but for anyone carrying their phone in a pocket, the distance is closer to 2 millimeters. Because wireless power falls off exponentially with distance, what might be a safe amount of RF exposure at 5 millimeters could be much higher at 2 millimeters. They mean to say that you should expect a power about 6 times higher, (5^2 / 2^2). This is rubbish.…
The base station also tells the phone to back-off. If the TX were running at full power, the battery will die quickly. Leave your phone in a metal, security cubby and your battery will die quickly; no power control and worse-case antenna loading.
Also the highly asymmetric data usage these days. Very little energy on the uplink.
FWIW I design antennas and amplifiers for a living. The only time I'd worry about RF exposure is to the cornea; that is a proven hazard. RF burns are a right of passage for PA designers, and are harmless as it's the outer skin layers.
Testing phones from 5 millimeters away from the body may seem close, but for anyone carrying their phone in a pocket, the distance is closer to 2 millimeters. Because wireless power falls off exponentially with distance, what might be a safe amount of RF exposure at 5 millimeters could be much higher at 2 millimeters. They mean to say that you should expect a power about 6 times higher, (5^2 / 2^2). This is rubbish.…
Why rely on a model?
20,000 phones are being sold an hour. Why not buy 200 phone's off 200 shelves and test them comprehensively at 0 mm, 1mm, 2mm, 3mm ..... The cost to volume sold is completely negligible and it is useful consumer information as 3 percent of the population is electrosensitive.
An estimated 30 million people suffer from Myalgic Encephalomyelitis (chronic fatigue) in the world and the average diagnosis takes seven years. Chronic health conditions are increasing exponentially. Healthy people aren't sensitive to environmental stimuli but unhealthy people are and the number of chronically unhealthy people grows by the day as livers strain under the stressors and weakening of modernity.
Turn your wifi off in your house at night and see if you sleep any better. Pretty simple anecdotal experiment. A house without the wifi on or excess electrical componentry on has a nicer feel. We did not evolve with this electromagnetic radiation and the cost of testing is negilible given the global population's growing exposure to it and something interesting may fall out of the research.
The risk of Apple having to make slight design modifications if research raises an issue is not a huge concern of mine. One hours phone sales should cover it and then they could further differentiate their products and raise prices.
How many electrical engineering schools are there in the world? Sounds like a great way for a university to get their staff free Iphones with a research grant.
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The manufacturer needs the phone certified in advance of shelf stocking. There is nothing stopping the FCC from confirming their test results with retail units. Plus, the risk from cheating is enormous. It’s a lot easier in the long run to just design properly working phones.
There is a German example.
I guess it could be theoretically possible for Apple to software cheat the FCC but it really does seem easier to just make a phone that meets the specifications.
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Some people do believe that non ionizing radiation has effects other than those produced by the added thermal energy (or that the thermal effects are in some way significant). The actual scientific evidence for this is minimal though.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4676010/ Essentially EM fields alternating in the low to medium frequency bands (~100khz-1mhz) can disrupt cell processes by physically jiggling the polar molecules that make up portions of miotic spindles/microtubules. Among presumably other things this effect is being investigated as a cancer fighting mechanism called 'tumor treating fields'. The carrier frequency of mob…
This is something that is already (or should be, in theory) rigorously tested for everything that's put on the consumer market (from your cheapest USB charger to your iPhone).
> The SAR limit is primarily concerned with a phone’s thermal effects—essentially, the power is limited to 1.6 W/kg to ensure that no one is burned by using their phone. I should be worried about the heat generated from my phone? I thought maybe there was some issue with RF and my cells, but this seems like a complete nonissue to me. Am I being foolish for writing this off? The only time my phone is going to burn me…
Sunlight shining on one side of a cube-shaped liter of flesh would be 10W/kg or so on average (and about 100W/kg if we consider the top 1cm). 1.6W/kg is a conservative limit.