Is the light emmitted from a flatbed scanner dangerous?
438458
General thought about looking directly at very bright light is correct. The lens of our eyes can project a many fold brighter image on the retina. This can damage the rods and cones in your retina and can even cause permanent damage to your vision.
333807
No, none of the equipment in a PC emits any radiation. Some people believe that the electromagnetic fields around ANY electric device can cause some health issues, but no scientific proof exists and personally I believe its bogus. You may not be sleeping well due to the noise and lack of sleep can have some strange effects on your body.
317868
well for my physics project for the boards i made a photoelectronic burglar alarm- at the heart of this was an LDR( Light Dependent Resistor) when the beam of light is obstructed (think laser in the movies-lol) the LDR resistance rises and the circuit inside is set into oscillation and the alarm sounds- other good projects would be a rain alarm, a rectifier, an electroscope,..... the possiblities are endless- i suppose you could do anything involving electric circuits since thats what the cbse calss 12 physics text covers most- i doubt ud want to do anything on ray or wave optics
622757
Just what are you doing with radio active material on your screen? Inquiring minds want to know, yes, really the want to know.  Anyway, if you are talking about the emitions that eminate from your CRT monitor, check with the manufacture of the monitor. I am sure that you will find that you are safe, however, if you still believe that there's radiation will harm you coming from your monitor, then i would suggest wrapping your head in aluminum foil, don't use tin foil it only intesifies the beams, and wear sunglasses of at least 80% darkness You will find that should protect you, oh, yes, insure that you secure a radiation vest, yoiu know the kind that X-Ray techs wear when they take your x-rays (try e-bay).  Additionally, you can find like minded individuals on the web (try paranoids and conspirist dot com).  If you are still worried and scared you can always turn it off, and sell it or destroy it so that it doesn't hurt anyone eles.
1167272
You can buy a simple Radio Shack police/fire scanner. Essentially the same thing, but a much lower price.
155839
a lot of scanners are glued ...but if that is not your case try open it (there are some scues on the back)...but don;t use alcoohol
129844
A laser light as you described is not going to cause eye damage by looking at it as most are lead to believe. That is also true about having a laser pointer being pointed into one's eye. You eyes will become injured more so if you look at the sun.\n\nIf you have nothing better to do but to look at the bottom of your mouse, then you have other problems... ;=)
685111
The light is to indicate Hard drive activity. It is a meaningless today and you can safely ignore it. On systems I build I don't even bother to plug that in.\n\nBack in the days of DOS it was a usefull part of a computer. If you had HD activity but was not saving something or had no other reason to see HD activity it could mean you had a virus.  Today's multi-tasking OS's are complex beasts and even if your machine is doing nothing the system is writing/deleting cache files, defragmenting, indexing files and a host of other tasks.
786740
well on most computer the HD has its own display light. If it is messed up you can usually hear it clicking wierd or feel it and see if it is spinning. Something can often fry in a comp without any external evidence and the most likely thing to go is teh power supply. BTW dont buy another emachine. they are dangerous. My friend's caught on fire one day. it sucked anyways.
210883
wear a rainjacket. it's highly doubtful you're getting radiation from your laptop tho.
512339
Don't even question why you are having this experience. Learn to manage your margin of errors. I work with my little issues as for example a security system with motion sensors. Double deadbolts on the doors with windows disabling entree from a broken pane.Sensor lights on all corners of the house and a camera that records for 8-12hours viewable threw your t.v.set. All this combined assists me for a good nights sleep.
174710
It's a FresnelC function.  Check out the link.
1042486
MRI scans are performed in a very strong magnetic field.  There is no conclusive proof, but it is generally felt that exposure to strong magnetic fields generated by MRI scanners is harmless to humans.  That being said, however, there are some theoretical risks.  Without getting too technical, MRI images are generated by rapid variations in the magnetic field.  These variations cause the water protons within the body to behave a certain way, which in turn generate very minute signal which can be picked up by special receiver coils that make up part of the MRI scanner.  These signals are then processed by the scanner, and and image is generated.  The rapid shifts in magnetic fields can theoretically produce heat as a by-product.  This is especially true for any metallic object within the scanner that has the shape of a ring or closed loop.  In fact, this can produce enough heat in conventional MRI scanners to cause flesh burns.  This is one reason why all metal must be removed before getting an MRI scan.  The actual magnetic field itself is probably safe.\n\nAs for PET scans, the physics is entirely different.  PET scans generate an image by radioactive emissions that are produced in the body after getting injected with radioactive material.  The PET scanner itself is really nothing but a giagantic receiver device to detect these emission.  While the actual dose of radiation from a PET scan is felt to be reasonably safe, it is still radiation nonetheless.  The more PET scans you have, the more radiation you will be exposed to.  But there is no danger to just lying in the scanner itself without getting injected with the radioactive isotope because the scanner itself does not generate actual radiation.
815564
Um... What!?\n\nwhat kind of scanner are you talking about.. Radio band scanner or a Scanner for your computer that scans an image...\n\nwhat make is it ? where have you had it stored?... damp can do funny things to electronics.\n\nadd a little more info please.
462356
It probably requires a mass spec technique.  Infrared might work.  Your detection level will be the problem.
940502
Computers don't emit harmful rays, only a bit of RF noise.\n\nCRT monitors, on the other hand, emit a small amount of radiation. This is such a small amount that it is harmless, but if you want to avoid it then you should get an LED monitor instead.
325557
you could actually use the cable, you can also buy a cable tester, where you plug both ends in, run the test and some status LED's will give you the results\n\nhttp://www.maplin.co.uk/Module.aspx?ModuleNo=45778&doy=6m4&C=SEO&U=Template