Hot iPhone: Granite radioactivity leeched into a capacitive touch screen?
So I haven't had my brand spanking new Geiger counter for all of a week and it seems I may have already made my iphone more radioactive.
Going around the house, looking for something good and reactive, I came across a small polished dark stone with yellow-orange veins - a piece of granite that has been put into a rock tumbler I assume(?). I was getting some good clickage, hitting CPMs in the 70s and 80 right away when near it, so I set up a 10-minute average count of it, using my iPhone as a platform to get the stone at the right height. My iPhone, which I had already tested itself and used as a testing platform for other stuff that turned out to be duds, was maybe a tiny bit above my background, around 30 CPM.
The stone seemed seemed fairly hot alright (about 100 CPM on average), but then here was the weird thing... after that, I tested something else, and it was kind of hot too. Then something else. Also kind of hot. Everything was now getting CPMs in the 60 or 70s. I moved the geiger counter away from the testing stand and it immediately fell back to background, so the geiger counter itself was not contaminated. Finally I got a clue. I tested the iPhone again without anything on it. A few times. Yep, the phone itself is now testing at CPMs in the 70s. I put it aside for a day and today it's still the same, with several peaks above 100 CPM. Background is still normal.
What's going on... did I really manage to make my phone hot? Is there something special about capacitive touch screens... or just glass...that it absorbs radioactivity? (my wooden dresser, which the stone had been sitting on for much longer, shows no similar spike). What kind of radioactivity might it have absorbed...and is it going to cool over time, or do I simply have a hot phone now?
(Funny, the CAPTCHA is about mobile phones!)
iPad is radiative too
see this video "My IPad is Radioactive..."
http://www.youtube.com/watch?v=LT6qHaKFgGY&feature=player_embedded
Easily explained
As noted in a couple posts further down the thread; optical quality glass such as that found in camera lenses and high quality optical screens; has thorium in it and is therefore naturally radioactive.
Radioactivity is not "contagious". Just because someone puts some non-radioactive material next to a radioactive material that emits beta or gamma rays; the first non-radioactive material does not become radioactive.
In order to make a non-radioactive material radioactive, one has to change the composition of the nucleus; and that means adding neutrons. However, in order to do that, one needs to irradiate the substance in a nuclear reactor. One can also add alpha particles, but that requires that the alpha particles be accelerated in a cyclotron or other nuclear accelerator in order to overcome the mutual electric repulsion between the positively charged nucleus and the positively charged alpha particle.
As Professor Richard Muller of the UC-Berkeley Physics Department points out in his book, "Physics for Future Presidents", radioactivity is "contagious" in Hollywood movies, but not in the real world:
http://books.google.com/books?id=6DBnS2g-KrQC&pg=PA121&lpg=PA121&dq=%22P...
As you use your Geiger counter, you will find lots and lots of materials in your life that are naturally radioactive; and you just didn't know it.
What is your detector called?
Scosche RDTX line/ for iPad / iPhone
Question is this what you are using ?was considering purchasing , are u happy with unit?thanks tdm.
I am the OP of the thread
I am the OP of the thread with the radioactive iPhone screen (note: my other phone, which is also capacitive touch, is at background).
I'm using the Inspector Alert. It detects x-rays, gamma, beta and alpha. It has a nice big pancake mica window so it really does a good job. No complaints :))
First up was the $330 Scosche
First up was the $330 Scosche RDTX-PRO. Now Scosche has released the lower-priced and slightly less accurate RDTX version for around $270. It detects gamma radiation above 120keV within +/- 10 percent accuracy. Loosely translated from geek speak, that just means that you'll definitely know if you're in a dangerous spot.
Editing to add: - The
Editing to add:
- The phone's power is off (I let the battery run down) so it shouldn't be the screen artificially tricking the geiger through some sort of electrical interference or something.
- I just realized that it's possible that I placed items on the back of the iPhone (rather than the screen) on previous tests. In other worlds the test with the stone may have been the first time I used the front of it as the testing surface. I checked, and the back of the iPhone currently reads normal background. I have also wiped this phone down carefully with a wet wipe and I'm not getting any reduction in CPM for the front/screen. It's still hot as ever.
I guess the question becomes, CAN granite (or other radioactive rock) leach radioactivity into a glass screen over the course of abut 15 minutes?
If not, I guess my iPhone screen was radioactive all along. Which would be kind of surprising! This is a pre-Fukushima phone, as well.
NO!
I guess the question becomes, CAN granite (or other radioactive rock) leach radioactivity into a glass screen over the course of abut 15 minutes?
Contrary to the popular misconception, radioactivity is NOT "contagious". Radioactivity doesn't "leach" into glass or anything else. Not unless you actually leach material from the granite into the glass screen.
You are NOT making material that wasn't originally radioactive into material that is radioactive by exposing it to radioactivity.
Artificial radioactivity requires exposure to the output of a nuclear reactor or cyclotron.
In order to make something radioactive; you have to change the nucleus. You have to change the number of protons and/or neutrons in that nucleus.
Beta radioactivity is high energy electrons. That doesn't change the number of protons and neutrons which are 2000X as massive as the electron.
Gamma radioactivity is photons, like X-rays. There isn't any rest mass there at all.
Alpha radioactivity consists of alpha particles - two protons plus two neutrons, and is positively charged. You need to give an alpha particle enough energy to overcome the electric repulsion with the nucleus. That's where the cyclotron would come in.
You are NOT leaching radioactivity from granite to your iPhone. If your iPhone now has some component of radioactivity, it just means you missed it on the first attempt.
Your iPhone was radioactive all along, and there's nothing at all surprising about that. You are just discovering that the world has been radioactive for a long time - long before Fukushima, long before Chernobyl, and long before 1945.
The process for creating
The process for creating gorilla_glass implants potassium ions in the surface. So there should be a few K-40 ions in there too.
http://en.wikipedia.org/wiki/Gorilla_Glass
Naw, I don't think it's due
Naw, I don't think it's due to Gorilla Glass, because my other cell phone is listed as one of the products made with it, and it's basically at background. So, if it has any K-40, it must be very little. I also don't see iPhones in the product list.
Checkout a camera lens!
If you have an "SLR" type camera with a typically 50 mm lens on the front,
checkout the radioactivity of the lens.
Optical quality glass has thorium in it. Perhaps the glass on the iPhone does too.
More on radioactive lenses
More on radioactive lenses at:
http://camerapedia.wikia.com/wiki/Radioactive_lenses
http://www.orau.org/ptp/collection/consumer%20products/cameralens.htm
Wow, I bet that's it. I'm
Wow, I bet that's it.
I'm kind of thinking that's not a great material for something you spend so much time handling (I mean , it's a touch screen! and angrybirds, anyone?), carrying around on your person, and putting against your head. And here I thought EMF was the big concern with smartphones. Man, this is kind of a downer. I'd rather the rock did it =/.