Saturday, February 2, 2019

Panic over the airwaves

It's always been something of a miracle. From around 1920, when the development of signal amplification enabled the human voice to travel over radio waves, the thought that sounds spoken hundreds or thousands of miles away could by some mysterious process appear in our homes and cars as though the speaker were present, has been perhaps the first and greatest "miracle" of technology. Later, with the development of television, sights traveled by the same means, adding to this wonder, and shaping the baby boomer generation in a way no generation had ever been shaped before. But of course there were those who wondered: wasn't sending all this electricity, this radiation, through the air a sort of health hazard? Curiously, those who worried about that also worried about the tawdry nature of much mass entertainment, or the potential of words and sights so widely transmitted to alter or control our minds.

In a debate in the Radio Mirror back in 1934, Charles Shaw of NYU tussled with no less a figure than Nicola Tesla, the man who in many senses invented radio, long before Marconi. Shaw voiced the concern that, since radio engineers in close proximity with transmission equipment seemed to have higher body temperatures, that perhaps radio waves were going to bake us all while we slept! Not only that, but its noise and drivel "lowered our cultural standards." Tesla was left to point out that radio waves were far too weak in amplitude, and the wrong frequency, to do any cooking, and as to radio's content, wisely noted that "You can't blame lowering our culture on radio," he insisted, "blame it on yourself and myself. The type of program that comes over the air is the type you and I want to listen to."

A light pole in San Francisco
But in recent years, alas, these same two intertwined fears have arisen again about cell phone frequencies. Cell phones were "cooking" our brains, they said, or were leading to an increase in cancer. The panic has increased with the implementation of "5G" technology -- particularly since 5G will require many more antennas to give its higher frequencies coverage. Ironically, these higher frequencies are exactly the reason that 5G is harmless; it is much less able than lower frequencies to penetrate solid objects, which would include peoples' skulls and buttocks. The human body is impenetrable to frequencies above 70 megahertz, a fact which Tesla took advantage of in an experiment that demonstrated their safety. He took alternating current of a very high frequency, but a very low amplitude (power) and used it to electrify himself and others (Mark Twain among them). The high frequency prevented its penetrating the body, and the low amplitude eliminated any other risk of harm. And yet, a lightbulb in the hand of such an electrified person would glow!

Mark Twain in Tesla's lab in 1894
People today don't get much of an education in these matters, it seems. They tremble in fear of the word "radiation," not understanding that all sound and light and heat are also radiation. They confuse high-level radiation, which is known as ionizing radiation (x-rays, gamma rays, etc.) which can be lethal, with the many forms of low-level radiation (infrared waves, radio waves, etc.) which are largely harmless. They also don't understand frequency and amplitude, the two fundamental principles at stake. As noted, the higher frequencies of the radio band are in fact the weakest in terms of being able to penetrate things -- this is why, for instance, submarines use a very low frequency, so that their signals can penetrate the deep ocean, and even the earth itself. At the other end of the spectrum, so-called "short" waves are useful, since they can't penetrate the earth's ionosphere, but bounce off it instead, increasing their potential range. Getting back to cellular signals, there's the fundamental fact that, the higher the frequency, the more information they can carry, and more and more information is what's wanted. So, some years ago, the FCC moved television off the old VHF (Very High Frequency) and UHF (Ultra High Frequency) bands, and sold them off to cellular carriers. UHF peaked out at 3 GHz, and the new services will utilize the top end of UHF, and on upwards to 6 GHz. So at least a portion of this "new" frequency will be the same old frequency that once brought you midnight horror movies and Bowling for Dollars.

And then there's amplitude. The 5G signal will be far too low in energy to do any damage. With old-fashioned single transmitter systems such as radio, many watts of power were needed to give the signal a wide range, but the 5G antennas that spike these worries are in fact very very low power -- they're essentially "repeaters," picking up and rebroadcasting a very low power signal to give it range. No cell phone company would waste more electricity on these than needed to power these mini-antennas -- and even if they tried, the FCC's regulations on phones would prevent them from doing so. The current regulation for phones is for an absorption rate of 1.6 watts per kilogram of mass, which isn't enough amplitude to warm the surface of your skin more than a tiny fraction of a degree, assuming your cellphone is in direct contact with it. All phones sold in the US must meet this standard. Ultimately, these high frequencies, because they can't penetrate the body, are dissipated in the form of heat -- and if it's heat you're worried about, the electric hot pad you use for your sore neck puts out hundreds of thousands of times more.

All this leaves us with just the content of our signals to worry about. And here I would agree with Tesla -- we get what we deserve. Even when, at times, it seems we don't want it -- since now, with all our clicks tracked in one way or another, the system itself works to try to predict our desires. And yet, despite the screaming echo chambers of the 'net, it's just the sound of our own voice, really -- and we have only ourselves to blame for it if we listen.