Prius III Radiation Risk?

Hmm he seems to believe that because lawmakers picked different numbers out of a hat, some of those numbers represent better science. I personally doubt that any of them are based on fundamental Physics. (Nor is the author a Physicist)

He seems to 'confuse' a 100W to 3000W Cell phone tower, with a 100 mW Wifi antenna, for scare tactics.

 

Don't the windows block out some solar rays? Would it be safer to ride in a prius than stand out in the sun?

 

Yes far safer, here is the UV information for our windows.

 

now i know why my balls felt warm yesterday :madgrin:

 

I wouldn't worry about it. The Prius Chat store has these way cool emf signal dampener hats. I wear mine while I drive all the time ... and their cheep. In fact if I were you, I buy 2 ... one for the passenger.




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You now owe me for a new shirt as I just sprayed soda out my nose all down it! You're a loon!

 

This is the main reason for having a Moon/Sun Roof.

Tom

 

Skimmed the pdf. Note that this is not a study of any kind: It's a sort-of-quick summary of other papers. The intent of the linked document is to warn school administrators on the purported dangers of wi-fi.

Now, this is where life gets interesting. On the one hand, in my previous post, I made mention of the fact that there's particular microwave frequencies that are of some danger. Turns out that the commonly used microwave oven frequency is 2.45 GHz, and, yes, that is the resonant frequency of water molecules. While I haven't read up on this particular phenomenon, typically at a resonant frequency like this the electrons in the water molecule get bumped up to a higher energy state, then drop down in several steps, giving off (likely) either infrared at each step, or simply making the molecule bounce around with the absorbed electron momentum. Hence, the heating.

Now, the energy generating element in your typical oven is a klystron vacuum tube. They're cheap; they can generate up to the 1000 watts or so needed to heat your food; and, given that we're talking consumer goods here, they're none too accurate in frequency. Even with all that wonderful shielding that keeps microwave ovens from cooking their owners, there's always some that gets through to the ether.

Hence, no sane regulatory agency would assign any kind of communications any where near this frequency.. Which is kind of why the 2.4 GHz band is free of military, commercial, satellite, and other uses of this kidney. Also, given that this is the water resonant frequency, trying to use this frequency to send signals back and forth any distance through an atmosphere laced with water vapor would be an interesting study in futility. Of course, it would work in vacuum, but people tend not to live up there, I suppose.

Hence, the band was given over to experimenters. Cool. You can use it, you can't complain if somebody interferes with you, and the FCC and like agencies won't take action unless you do something seriously evil. Simply put, they don't want to hear about it. So, is it any surprise that baby monitors, portable telephones, and (wait for it..) wifi! are all in this band?

As a result of everything interfering with everything, various commercial interests have played nice with each other over the years, but you still get things like this (xkcd.com).

Fun with interference. But, going back to the dangers: wifi signals are in the band that makes water molecules vibrate. On the other hand, even if they are causing heating, the various safety agencies have tried to make sure that the power levels are below anything that would cause enough heating to cause damage. What you then get are tons of zany scientists running around doing epidemiological studies, trying to see if there's any effect on human health from the wifi.

The problem is, up to now, there aren't any, really. What these people are looking for are statistical correlations that show, say, that wifi is giving people acid reflux instead of, say, hot chili peppers. A correlation of zero means that there isn't any; a correlation of 1.0 means that you've got a Nobel Prize coming. But, given random numbers, the probability of actually getting zero is zero; it's much more likely that one would get 0.1, 0.2, or something low. And, if there's an error in the experimental design, the questionnaires, people who feel like giving answers for their aunt that day, or that that year's harvest had really good chilies, it might be really hard to get a definitive answer. Which is why so many of these studies call for further studies.. And, sometimes, this is the way that things are found. Really.

So, the problem, if there is one, is that the jury is always out. There's never a definitive answer, just more studies, with correlation numbers that hint that something might be there, with tremendous fame if something is found. Yep, scientists are supposed to be skeptical, and they're most skeptical of other scientists; there are those out there who keep on trying (bless their souls) to prove with F = G(m1)(m2)/r**2, that the exponent on r is not precisely 2. We need these people, they keep things honest.

But then you get people like the letter writer above, who take the "more study" caveats from the researches who found something and the (the researchers are only human) flat out errors by those who think that they have found something, and then synthesize a scare paper that sends quite the wrong message. And if the letter writer has included some results from the lunatic fringe, or is a member of the lunatic fringe themselves...

This is why, when you're looking for real results, it's a good idea to subscribe to peer-refereed journals. And reputable journals, at that. And, if one is really interested in sane results, the right thing to do is stand up, get in your Prius, and drive to the medical and EE departments of several reputable universities and interview members of the faculty who have some knowledge. (And, if you do this, publish your results. Summary papers like this get good play, believe it or not.)

So far, the answer has been: No real effects, and zero danger.

In the meantime: Be careful what you read on the internet.

And, finally: Keep an open mind.

And, really finally: This is the Prius Chat forum. Precisely who around here would actually know, and why would they? Are we MD's with radio dosimeters around our necks? (But I'd sure like two of the funny headsets, thanks!)

KBeck.

 

And again, your microwave is 1000 watts of power and your wifi is 1/10 of a watt of power, which is riskier?

 

The probable answer is neither. But (and this is where people get ulcers) I'd bet that the emissions from a microwave oven are a heck of a lot less than the wifi - and the wifi is an intentional transmitter.

Back in the day there were serious and validated dangers with the use of microwave ovens. Consumers Union did put some "Do Not Buy This Microwave" ratings on some brands and models back in the 60's and, I think, the early 70's. Since then manufacturers have gotten a lot smarter about the shielding. You may not have noticed, but I have, that there are lamda/4 self-shielding topologies all around microwave doors. And stuff like that.

In a more perfect, sane world wifi would never have been stuck in that 2.4 GHz range, but rather somewhere else with no potential health effects. But the allure of unregulated, "We don't have to pay the FCC or anybody" space is a powerful commercial (morals - we don't need no steeking morals) motivator.

Which rather explains all the people out there looking for smoke and the possible existence of fire. I'm glad they're looking, since, with money involved, it's amazing how morality can bend. But, so far, no smoke, and no fire.

As I said before, the jury is still out.. And may have gone on a trip to the Bahamas. In the meantime, we'll see if a reputable scientist comes up with his or her Nobel. I wasn't kidding about keeping an open mind. So far, with the occasional papers I've read, if there are effects, those effects appear to be buried deep in the noise. Which, if there are effects, you're probably more likely to be run over by a passing zebra then get ill from wi-fi. And a lot more likely to be crunched by a crane falling on your Prius with you in it.

That's one of the problems with Science. You'll rarely get a definitive answer. And, if there is a possible answer, that answer contains the words, "it depends." Humans want defined answers, it's part of our nature. It's just that Nature isn't that accomodating. In the meantime, getting zapped by wi-fi or your Prius is probably not worth worrying about.


KBeck.

 

Highly disagree. I don't know for you but in my case, if I organize a competition between different equipments in this around 2.4GHz spectrum, the microwave oven leaks always win. When it runs, it messes up my 802.11g connection for the nearby computer (it drops temporarily). Also, if you take an old analog AM radio and use it a simple detection device, the equipment which will generate the most noise is clearly the microwave oven.

Note: My comment does not say anything about the danger or not of these radiofrequencies.

 

So far this discussion has focused on RF exposure. Since we are discussing devices with magnetrons and motors, there is also a purely magnetic component. So far these low strength magnetic fields seem safe enough, but if we are borrowing trouble it gives us something else to worry about.

Tom

 

Fine, I stand corrected. (Gotta check around and see if I can find that old E-field meter that used to be around here..)

KBeck

 

That's simple ... a microwave is NOT a high quality transmitter. If a REAL radio transmitter is being considered, it transmits only on the part of the frequency that it is designed to transmit on ... unless it's messed up. A microwave signal will splatter over a huge part of the spectrum - thus, it affects AM radio (WAY far benieth microwave bands) as well as wifi.

 

Holy Smokes! What are you cooking in your microwave, an entire hippo? Or are you using a linear accelerator to cook meals between smashing electrons? My wimpy microwaves only have a dinky magnetron. All kidding aside, that was a pretty good post worth reading.

 

Cooking times in milliseconds!

Tom

 

I got my first ham license in '60, first-class commercial ticket in '63. I've known a passel of hams and broadcast engineers over the years. They tend to get exposed to sustained RF fields at high power levels for decades. Generally, though, we live to be tough old buzzards if we don't eat/drink ourselves to death.

Bunch of crazy coots, of course. But that's a chicken/egg conundrum.

 

Ooh, a Young's 2-slit experiment reference. I love it! Glad to see that there are other physics nerds around here.


On the related topic of damaging RF, I'm an RF engineer and all of the older guys in my group (read, working before the days of modern radiation safety requirements) have only daughters. Between the 8 guys in the group they have about 15 daughters and 0 sons.

 

from one RF geek to another ... maybe that's nature's way of self correcting

btw - we have only one child - her name is Hannah