thom@dewey.soe.berkeley.edu (Thom Gillespie) (06/26/89)
Don't mean to disturb anyone but I was wondering if anyone has measured any radiation coming from a Mac screen? Are there any screen sheilds for Mac screens? I'm concerned about this because I have a Mac and a couple of kids, not because I think there is more or less radiation from a Mac screen than an IBM. Thanks. --Thom Gillespie
fink@nucthy.physics.orst.edu (Paul Fink) (06/26/89)
In article <29836@ucbvax.BERKELEY.EDU> thom@dewey.soe.berkeley.edu.UUCP (Thom Gillespie) writes: >Don't mean to disturb anyone but I was wondering if anyone has measured any >radiation coming from a Mac screen? > >Are there any screen sheilds for Mac screens? > >I'm concerned about this because I have a Mac and a couple of kids, not because >I think there is more or less radiation from a Mac screen than an IBM. > >Thanks. > >--Thom Gillespie Do you let your kids watch TV? ____________________________________________________________________________ Paul J. Fink Jr. Internet: Oregon State University fink@PHYSICS.ORST.EDU Department of Physics Phone: Corvallis, Oregon 97331 (503) 737-4631
vogelei@nmtsun.nmt.edu (Todd Vogelei) (06/27/89)
In article <29836@ucbvax.BERKELEY.EDU| thom@dewey.soe.berkeley.edu.UUCP (Thom Gillespie) writes: |Don't mean to disturb anyone but I was wondering if anyone has measured any |radiation coming from a Mac screen? | |Are there any screen sheilds for Mac screens? | |I'm concerned about this because I have a Mac and a couple of kids, not because |I think there is more or less radiation from a Mac screen than an IBM. | |Thanks. | |--Thom Gillespie I would think there is definitely more radiation from a mac screen since tyhe display creates characters by *not* exciting pixels and there is much more white space that must be excited than black space that is not. The opposite is true for IBM type stuff and so more area is simply not getting bombarded by electrons than is. This is why it would be nice to reverse the screen. Right now I use a black desktop and fairly dark coloring everywhere to minimize radiation. It looks neon and I like it even if it doesn't help ;-) Todd vogelei@nmtsun
baer@Jessica.stanford.edu (Paul Baer) (06/27/89)
In article <11374@orstcs.CS.ORST.EDU> fink@nucthy.PHYSICS.ORST.EDU (Paul Fink) writes: >In article <29836@ucbvax.BERKELEY.EDU> thom@dewey.soe.berkeley.edu.UUCP (Thom Gillespie) writes: >>Don't mean to disturb anyone but I was wondering if anyone has measured any >>radiation coming from a Mac screen? >> >>I'm concerned about this because I have a Mac and a couple of kids... >>--Thom Gillespie > >Do you let your kids watch TV?> Do your kids watch TV with their faces a foot from the screen? --Paul Baer Networking and Communications Systems Stanford University PS I'd like to know if there are any such measurements, since I work with a Mac for 4-6 hours a day.
fink@nucthy.physics.orst.edu (Paul Fink) (06/27/89)
In article <3175@portia.Stanford.EDU> baer@Jessica.UUCP (Paul Baer) writes: >In article <11374@orstcs.CS.ORST.EDU> fink@nucthy.PHYSICS.ORST.EDU (Paul Fink) writes: >>In article <29836@ucbvax.BERKELEY.EDU> thom@dewey.soe.berkeley.edu.UUCP (Thom Gillespie) writes: >>>Don't mean to disturb anyone but I was wondering if anyone has measured any >>>radiation coming from a Mac screen? >>> >>>I'm concerned about this because I have a Mac and a couple of kids... >>>--Thom Gillespie >> > >PS I'd like to know if there are any such measurements, since I work >with a Mac for 4-6 hours a day. I wear a #20 sun screen. ____________________________________________________________________________ Paul J. Fink Jr. Internet: Oregon State University fink@PHYSICS.ORST.EDU Department of Physics Phone: Corvallis, Oregon 97331 (503) 737-4631
yahnke@vms.macc.wisc.edu (Ross Yahnke, MACC) (06/27/89)
In article <29836@ucbvax.BERKELEY.EDU> thom@dewey.soe.berkeley.edu.UUCP (Thom Gillespie) writes: >Don't mean to disturb anyone but I was wondering if anyone has measured any >radiation coming from a Mac screen? > >Are there any screen sheilds for Mac screens? The following company manufactures and sells anti-glare & radiation screens for the Mac: The NoRad Corporation 1549 11th St., Suite 205 Santa Monica, CA 90401 (213) 934-2101 I have no affiliation w/this company, nor have I used their products. Call them for more info or a brochure. //////////////////////////////////////////////////////////// Internet: yahnke@macc.wisc.edu Phonenet: 608.262.8626 Mailnet: 1210 W. Dayton St., Madison WI, 53706 \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
gae@gem.mps.ohio-state.edu (Gerald Edgar) (06/28/89)
It is my impression that the current opinion is that VDT ailments are caused
not by radiation, but by sitting in the same position for extended periods
of time. The news the other day reported on one of these problems, now
called "NINTENDO NECK".
--
Gerald A. Edgar
Department of Mathematics TS1871@OHSTVMA.bitnet
The Ohio State University gae@shape.mps.ohio-state.edu
Columbus, OH 43210 ...!{att,pyramid}!osu-cis!shape.mps.ohio-state.edu!gaenljg0470@uxa.cso.uiuc.edu (06/28/89)
Well, in MacUser, there's an ad for a product by NoRad which, I quote, ". . . virtually eliminates screen emitted electromagnetic- radiation." Wow, it sure sounds healthy, but doesn't that make it awfully hard to read? Last time I took a physics class (3 years) light was still considered a form of electromagnetic radiation. I guess my degree got obsolete before I even got a chance to graduate. Damn!!!! Nick Jasper University of Illinois
johnw@bucket.UUCP (John Wong) (06/28/89)
In article <29836@ucbvax.BERKELEY.EDU>, thom@dewey.soe.berkeley.edu (Thom Gillespie) writes: > Don't mean to disturb anyone but I was wondering if anyone has measured any > radiation coming from a Mac screen? > > Are there any screen sheilds for Mac screens? > There is a screen available for PC's, I believe, called Vu-Pro-Tek that blocks radiation. It's expensive (>$200). It may be adaptable for the Mac. Laptops that use LCD technology, rather than CRT, I suspect, would be safer in that there isn't a high voltage electron gun firing behind the tube. One selling point for the new Macintosh laptop... John. tektronix!tessi!bucket!johnw
cortesi@infmx.UUCP (David Cortesi) (06/29/89)
In article <29836@ucbvax.BERKELEY.EDU> thom@dewey.soe.berkeley.edu.UUCP (Thom Gillespie) writes: >Don't mean to disturb anyone but I was wondering if anyone has measured any >radiation coming from a Mac screen? > >Are there any screen sheilds for Mac screens? In the issue of New Yorker magazine now on the stands there is a long article on the general subject of hazards from video display stations. What I gathered from it was that ionizing radiation such as might be emitted when speeding electrons hit phosphor is not of much concern, but that there is very much an open question about biological effects of the pulsed 60Hz magnetic fields emitted by a typical power supply. The screen shields that purport to stop ionizing radiation would not be effective magnetic shields .. the next Maccessory may be a tastefully welded iron box...
bayes@hpislx.HP.COM (Scott Bayes) (06/30/89)
> Don't mean to disturb anyone but I was wondering if anyone has measured any > radiation coming from a Mac screen? > > Are there any screen sheilds for Mac screens? > > I'm concerned about this because I have a Mac and a couple of kids, not because > I think there is more or less radiation from a Mac screen than an IBM. > > Thanks. > > --Thom Gillespie I think I remember seeing one advertised in MacUser recently. I'm not sure I believe it's anything to worry about, but you can probably buy peace of mind fairly cheaply. Scott Bayes
landman%hanami@Sun.COM (Howard A. Landman) (07/01/89)
In article <3175@portia.Stanford.EDU> baer@Jessica.UUCP (Paul Baer) writes: >Do your kids watch TV with their faces a foot from the screen? Yes, unless I yell at them. And remember that color tubes typically produce more radiation that B&W. Howard A. Landman landman@sun.com
dooley@helios.toronto.edu (Kevin Dooley) (07/03/89)
In article <1509@bucket.UUCP> johnw@bucket.UUCP (John Wong) writes: >In article <29836@ucbvax.BERKELEY.EDU>, thom@dewey.soe.berkeley.edu (Thom Gillespie) writes: >> Don't mean to disturb anyone but I was wondering if anyone has measured any >> radiation coming from a Mac screen? >> >> Are there any screen sheilds for Mac screens? >> > >There is a screen available for PC's, I believe, called Vu-Pro-Tek that >blocks radiation. It's expensive (>$200). It may be adaptable for the Mac. > >Laptops that use LCD technology, rather than CRT, I suspect, would be >safer in that there isn't a high voltage electron gun firing behind >the tube. One selling point for the new Macintosh laptop... > >John. > >tektronix!tessi!bucket!johnw There is already an extremely effective radiation shield on your monitor. It is called the screen. The highest energy that an electron hitting the glass can possibly have is ~20keV. This means that the highest energy x-ray that can be produced is ~20keV. These x-rays have to pass through a huge chunk of glass (the screen). The radation which does make it through is very soft and its intensity is considerably less than what you would measure coming from a large chunk of cement. If somebody markets a radiation screen for computer monitors, they are running a scam. If the glass were not enough to filter out practically everything, then you would probably have to use lead (which makes reading the old screen kind of difficult). Now, having said that, let me add one caveat. There is a fair amount of radio frequency radiation (non-ionizing, very very low energy) coming from a computer monitor. Many people have claimed that prolonged exposure to rf radiation can be a health risk, although there is no evidence to support this claim. It is commonly accepted that the principle health problems associated with the use of video displays are: - back and neck pain associated with poor posture, poor positioning of the monitor and keyboard relative to the body, and uncomfortable chairs. - eyestrain resulting from improper lighting, glare and just plain staring at those tiny phophor dots to 8 hours at a crack. Common sense tells you that the best way to avoid these problems is to take frequent breaks. For more information contact the Ministry of Labour. -- Kevin Dooley UUCP - {uunet,pyramid}!utai!helios.physics!dooley Physics Dept. BITNET - dooley@utorphys U. of Toronto INTERNET - dooley@helios.physics.utoronto.ca
dooley@helios.toronto.edu (Kevin Dooley) (07/04/89)
In article <837@helios.toronto.edu> I write: > ...There is a fair >amount of radio frequency radiation (non-ionizing, very very low energy) >coming from a computer monitor. Many people have claimed that prolonged >exposure to rf radiation can be a health risk, although there is no >evidence to support this claim. I should perhaps add to this statement by saying that there is no simple device that you could attach to your monitor to filter out rf radiation (you'd have to seal the whole thing in a copper lined room and leave the building if you wanted to make any real difference). In my previous article I said that there is no significant x-ray radiation coming from a video display terminal. So let me just reiterate that anybody who wants to sell you a radiation filter that will make your monitor safer probably has some nice property in Florida for sale as well ;->. -- Kevin Dooley UUCP - {uunet,pyramid}!utai!helios.physics!dooley Physics Dept. BITNET - dooley@utorphys U. of Toronto INTERNET - dooley@helios.physics.utoronto.ca
jong@leaf.dec.com (Typo? What tpyo?) (07/06/89)
The question of possible danger from Macintosh screens unfairly singles out Macs; the danger, if there is any, originates from ANY video-display device that employs an electron gun and circuitry to manipulate it. Is there any danger from such devices, then? I call to your attention a series of three articles that ran in The New Yorker on June 12, 19, and 26, 1989, called "Annals of Radiation: The Danger of Electromagnetic Fields." The author described research that has suggested a link between extremely-low-frequency electromagnetic fields and a number of serious health problems. The studies have been conducted by a number of researchers, and the results have been repeated elsewhere. While the radiation emitted from a VDT is not known to be harmful, the circuitry that controls the electron gun, especially the vertical-retrace circuits, emits 60-hertz electric and magnetic fields. The electric field can be shielded, but the magnetic field cannot be stopped, and it reaches out from the side and back of the terminal. Fields of that strength and frequency have been implicated in health disorders by several researchers. I would urge everyone to examine the article first-hand. Unfortunately, if these scientists have actually found a problem, VDTs are the LEAST of our worries. Suffice it to say that electricity may not be our friend. -- Steve
landman%hanami@Sun.COM (Howard A. Landman) (07/07/89)
In article <837@helios.toronto.edu> dooley@helios.physics.utoronto.ca (Kevin Dooley) writes: >If the glass were not enough to >filter out practically everything, then you would probably have to use >lead (which makes reading the old screen kind of difficult). Not really. "Crystal" chandeliers and goblets are made from glass which has a high percentage of lead oxide in it, and they are quite clear. I feel nervous about drinking acid solutions containing metal-binding chelating agents (like red wine) from them, but lead crystal should make decent screen material. Howard A. Landman landman@sun.com
ra_robert@gsbacd.uchicago.edu (07/09/89)
Don't VDT screens also give off ultraviolet radiation? There's speculation that UV may contribute to cataract formation. Robert ------ ra_robert@gsbacd.uchicago.edu ------ generic disclaimer: all my opinions are mine
rose@odin.ucsd.edu (Dan Rose) (07/13/89)
In article <837@helios.toronto.edu> dooley@helios.physics.utoronto.ca (Kevin Dooley) writes: >Many people have claimed that prolonged >exposure to rf radiation can be a health risk, although there is no >evidence to support this claim. It is commonly accepted that the >principle health problems associated with the use of video displays >are: > - back and neck pain associated with poor posture . . . > - eyestrain resulting from improper lighting . . . As has been pointed out by others, the risk alluded to in the New Yorker articles was from the 60Hz-modulated magnetic field caused by the yoke doing the (vertical?) refresh of the CRT. (This of course is not Mac-specific.) I was extremely skeptical when I began reading about these hazards, since (like the poster of the enclosed messsage) I had heard that various governmental agencies had declared the risks to be confined to ergonomic problems. Having read the articles, though, I am now convinced that other hazards may exist and should be studied. I am not a conspiracy theorist, but I think that both academic and industry scientists have been ignoring or obscuring the problem. For example, the problems appear to stem from long-term, low-level exposure, while the standards applied by various protective agencies only consider short-term, high-level effects. To oversimplify, they say (in the case of microwave radiation), "if it doesn't heat you up, it must be safe" when in fact it may be altering your brain function or increasing your baby's risk of birth defects. The scariest part for me was the implication that the press has avoided reporting on the issue because they are so heavily dependent on VDTs. If you want the evidence, read the article(s) and judge for yourself. Dan Rose CSE Dept. U.C. San Diego