When you turn to look back at the movie projector in a theater, why don't you see the beams of light anymore?
438011
Mebe cause people didnt like it
268885
cause we cant see the other side its dark
437846
Houstone we've lost visual .........over
303634
no the beams of light would bend back over the windshield of the car
38582
I realize I am out of my league as far as physics,, but the image reflects directly back to the source in front of it. For the reflection to appear upside down or vertically mirrored the light would have to be bent.\n\nok looked it up.  It is because of the predicatable behavior of light known as the law of reflection
44895
Interesting quatum phenomenon question.  The lights would come on, but they might appear strange to an observer due to the Doppler effect.  You, inside the car, would continue to see a headlight 'beam' because light's speed is a universal constant and not dependent on the speed of the source.  However, traveling beyond the speed of light in conventional space is not possible, to our knowledge.  For one, it would require infinate energy.  It would also cause macro-scale collapses in casaulity (effects happening before the cause).  To date, these bizzare effects have only been seen on quantum scales.
377296
It seems you are having some misconception about light waves.\n\nLight is energy transformation and it is not matter.\n\nConsider a ray of light. You will draw a line alone and not a wave. \n\nNow consider a point on the line.  The light intensity at this point changes periodically; starting from zero, increases to a maximum, decreases to zero again increases and again to zero. This is repeated periodically.\n\nReading the above lines many come to a conclusion that at this point some thing increases in SIZE; like a wave in water. Once again remember this is energy and is not matter.  Wave like pattern is only an analogy and nothing is displaced at the point. EVERY THING HAPPENS AT THE SINGLE POINT ALONE.\n\nIf we draw a graph, the  locus of all points will look like a wave and  this is what we say light travels in the form of wave and there is  no physical form of wave. \n\nLight possesses wave like properties and light itself is not a wave.
762620
What you see are particles of dust in the air, illuminated by the projector's beam.
115295
I believe it's the percent of light that bounces back and doesnt go through. Like a mirror reflects 95% of light. Dunno could be how much a material bends light, like water, cant remember.
1046084
TVs use cathode ray tubes to provide the picture, they need time to "warm up" before you can see the picture.  The speakers that relay the sound though are basically instantaneous.
460834
I think you are asking about the change in direction or "bending" of a light ray when it is incident to a boundary between media at a nonperpendicular angle. What seems to me to be key to understanding this is the idea that you can think of a "wavefront" of a light beam, very much like a water wave, and that wavefront motion is always perpendicular to the wavefront (ref. 1 and following pages). Also you can think of the wavefronts as wheeled axles rolling from pavement onto grass, and turning the axle as first one wheel hits the grass, then the other. Each wheel slows down on reaching the grass (ref. 2). The first to reach it turns the axle and the second straightens it out. The result is that the axle and direction of motion have turned.
1140404
The effect you speak of, really doesn't even require perfect reflection or a one-way mirror.  In our day to day experience, if you turn of the light in a closed room - it gets dark...immediately.\n\nHowever, on very short time scales, a high powered light source beamed into a cavity can result in a an internal radiation field more intense than the light source itself.\n\nIn some inertial confinement fusion experiments, scientists fire lasers into such cavities ('holraums') to achieve radiation intensities high enough to cause small capsules to implode ablatively.
931172
Because we are really close to our star, the sun.  The light from it drowns out the other lights from stars.  The same way a very small light in a room is drowned out by turning on a much larger one.  At night, we are completely turned away from it, so we can now see other lower light sources.
545742
Simple answer:\n\nA ray that does go not into your direction doesn't has a chance (unless reflected by something) to go into your eye and be "seen". If it gets reflected in a diffuse way for example by a wall and then goes into your eye you see a bright spot on the wall. If it gets non-diffuse reflected by a mirror you see an image of the bulb.\n\nWelcome to the world of geometric optics ;) ! \n\nIf follow the light ray in the other direction like a "see ray"  you get the principle of all the ray tracing computer programs that produce these nice computer images and animated movies.
436768
it is only an infinite refrexions of light. the device used to do it is called KALEIDOSCOPE
94716
One of the previous people who answered is correct in that the old-fashioned type of overhead projector is pretty much an obsolete technology.  However, with that said, many schools till use the old ones for the simple reason that they have them, and there is no money to buy the newer technology.  They also lend themselves to use by students in that they are less expensive, so less is lost if the kids cause damage. \n\nThe old projectors had a few problems in that for sure when you were in the middle of your presentation the light bulb would burn out.  The other problem was preventing the image from being "skewed" on the screen - there is a term for this but I've forgotten what it is.  Sometimes the mirror broke because of being handled roughly, but they are pretty sturdy machines.  Some of them were quite noisy because of the cooling fan - the bulbs get quite hot.  The room needed to be quite dark for them to work well, so that, combined with the continuous buzz of the fan and the stuffiness caused because the curtains were closed, tended to put the audience to sleep. \n\nThey have other advantages in that they are fairly simple to use and require no particular techincal skill.  You just write or draw your information on pieces of plastic called acetate or transparencies, using special markers made for overhead projector transparencies, and lay the plastic on the projection surface to project the image.  It was easy to get confused about the correct way to lay the acetate on the projector!!  YOu can use the acetate the same way as a chalkboard or whiteboard and write on it as you are teaching - the advantage being that you can face the class whie doing it - you don't need to turn your back to them.  Theoretically, you can use your computer to make "overheads" and print them.  However, in my experience, printing the transparencies often fouled up the printer!!\n\nThe newer projectors, no longer called "overhead projectors", are connected to a computer when in use, usually a laptop, and offer a much more sophisticated repertoire.  YOu can use Power POint to prepare presentations and have everything stored on  your laptop.  If you are using a video, Internet, or a TV segment in your presentation you can route it through the projector.  These projectors are smaller, lighter, more compact, definitely more trendy.  Today a professional presenter who showed up with the old type of overhead projector would be considered a bit behind the times.  You can incorporate the use of a laser pointer, remote control, etc. with these new projectors.   However, though they are getting cheaper, they are still much more expensive than the older models and require considerably more technical know how for operation.  When something goes wrong, it is often beyond the presenter's expertise to fix it so you often have to call in the IT person!!!\n\nThere is a device called a "palette" you can buy to sort of transform one of the older models into a model that will work like the newer ones.  I wouldn't recommend it.  If you are going to move to newer technology I would recommend skipping the half-way measure.\n\nI hope this is informative and of some help.
998287
Well, when I drive the speed of light in my car... \n\nI think the person in front of you would see that they're on, but they wouldn't illuminate anything.