How can i visualize the propogation of light ?
595536
There are two answers to this question:  one, how the waves themselves propogate and two, how the wavefront moves.  \n\nTo answer the first there are two things to remember:\n1.) a changing magnetic field creates an electric field\n2.)likewise, a changing electric field creates a magnetic field\n\nWith those two things in mind, here is how an EM wave (of which light is just one type) propogates.  A changing electric field induces a magnetic field, which induces an electric field and so on as the wave moves.  In other words one creates the other to move the disturbance along and the fields "bootstrap" themselves forward.\n\nAs to the second part, the way the wavefront moves depends on the geometry of what you're looking at.  If you imagine a source out in space, then yes you could consider the wavefront as being a sphere whose radius increases at the speed of light (for a repeated signal, then you'd have concentric spheres, one wave for each time the object sends out a pulse).  However if you restrict the wave to move in something (e.g. a waveguide, or channel)  the wave fronts would look different.\n\n\nI hope that helps
1079883
Red Light:\n        a violet rectangle with red stars in the top left corner of a big red rectangle. \nBlue Light:\n         a blue rectangle in the top left corner of a big rectangle having violet and blue stripes alternately.
1135193
See a magic square in\nhttp://en.wikipedia.org/wiki/Magic_square
928848
What's not clear is whether the image is a virtual or real one.\n\nFirst, consider a quick graphical, geometrical ray trace of a focusing \nmirror (let's assume it's spherical so that the analysis is simple).  I \nusually do this by drawing the reflector and locating its center of \ncurvature and focal point (which is just half the distance from the middle \nof the sphere to the center of curvature).  To look at image formation, I \ndraw a large number "1" where the object should be -- in this case, \noutside the focal point.  I then draw two rays from the top of the "1" -- \none parallel to the line from the center of the sphere throught the radius \nof curvature and one through the radius of curvature.  The first ray must, \nafter reflection, go through the focal point (because it acts as a \nparallel ray from infinity, which are all focused at the focal distance \nfrom any optic).  The second must just come back upon itself, because it \nis perpendicular to the reflector surface.  The intersection of the two \nrays is where the head of the image "1" is located.  In this case, it's \noutside the focal point.  I then do the same thing from the bottom of \nthe "1", and then draw the orientation of the imaged "1"...  It's clearly \ninverted and reduced in size and more than 1 focal length away from the \nmirror.  This is clearly the real image you referred to in your question.  \n\nWhere's the virtual image?  It's not there!  What you're observing is the \nreal image.\n\nTo understand this, consider what a virtual image is and how it's formed \nby an example.  A virtual image does NOT result from the convergence of \nray bundles at any real point in space... A virtual image is observed when \na situation arises rays from a single point appear to emerge from a point \nin space, but which doesn't correspond to any real point.  A good way to \nsee this is to turn the spoon around and look at the convex surface.  You \nsee yourself right side up!  If you do the ray trace using the method I \noutline above, you find an apparent convergence of rays behind the mirror \nwhich produces an upright image, which is just what you see in this case.  \nBut, since the spoon is silver, it's pretty apparent that there can't be \nany rays actually focused behind it -- so it's a virtual image.\n\nAn interesting thing occurs, however, when you flip the spoon back to the \noriginal configuration and move the object inside the focal point.  The \nimage you see is no longer inverted! And it's big!  If you do the ray \ntrace you find that the convergence of the rays which form the image is \nnow in back of the spoon, so that the image has shifted to an upright \nvirtual image which is magnified.  Try it with one of your spoons -- it \nreally works!\n\nAnd even more interestingly, if the object were placed exactly at the \nfocal point, all hell would break loose and what you would see would be a \ngiant blob filling the spoon that looks like nothing but a big source of \nlight.  In this case, there is neither a virtual nor a real image formed \nand the mirror/spoon is acting like a collimator -- turning all rays from \nthe object into parallel light streaming to infinity (roughly).\n\nI hope this helps!
759217
Burn it in a sprectrophotometer.  Look at the emitted light.
547532
Your nearest rainbow? Just kidding!\nTry this site: http://physics.nist.gov/PhysRefData/Elements/legend.html
422475
Angle at which light is totally reflected. \n\nThis website has a good diagram.\n\nhttp://www.physicsclassroom.com/Class/refrn/U14L3c.html
774228
Try Infranview http://www.irfanview.com/ its free
489404
yes...but u must know the angle of incidence and angle of refraction...light up a candle and place a mirror opposite to it in a room at an angle so tat u can see the candle.then keep other mirror at a place where u can see the first mirror and the candle... continue the process till u get sufficient light. try to place mirrors in the ceiling to get better light.
545100
As no one else has had a crack at this, I'll have a go with my best guess. Have you access to a reflectance spectrophotometer? Instead of shining light through a sample, it measures light reflected from a sample. At a pinch, you might be able to modify a uv/vis spectrophotometer to measure this.\n\nI hope this helps.
627144
Try these links:\n\nhttp://cse.ssl.berkeley.edu/segwayed/lessons/light/emspectrum.html\n\nhttp://search.yahoo.com/bin/search?fr=ybr_sbc&p=electromagnetic%20visible%20graph
451850
it hepls us see in an abstract light everything around us
575076
Tricky....\nI assume that it will be impossible to see the light inside the ball. When you "see" things is because the light bounces on the surface of objects into your eyes... As the light in this hypothetical ball cannot get out of the ball and towards your eyes, you'll see just a dark shiny ball... (i guess)
321224
http://illusionsetc.blogspot.com/\n\nhttp://www.panoptikum.net/optischetaeuschungen/opticalillusions.htm\n\nhttp://images.search.yahoo.com/search/images?p=optical%20illusions&fr=FP-tab-web-t&toggle=1&cop=&ei=UTF-8\n\nhttp://search.yahoo.com/search?p=optical+illusions&fr=FP-tab-web-t&toggle=1&cop=&ei=UTF-8
86659
You cant. What you are seeing is an illusion. You are the only think that is real in the universe.\n\nJust kidding.\n\nThe above concept, by the way, is called Solipsism, i believe, that you are the only thing that is real, and all else is an illusion.\n\nBut seriously, the only way you can believe anything is to test out the theory that it is true. So, test out the theory that what you see is truly there. If you can touch it, taste it, experience it, then even if it is not there objectively, it is there subjectively, which is all that is important.
48695
Don't forget that your samples must be small and THIN (flat). If the sample is too big/thick then no light will pass through to the lenses.\nMost things are best viewed after mounting them in a drop of water under a cover slip.\n\n1. Crystals of salt, icing sugar, etc.\n2. Fibres of cotton, wool, synthetics, string, etc.\n3. The torn edges of paper.\n4. The individual dots of colour from non-glossy pictures. You will probably have to add a bit more illumination from above the sample for this by shining a light onto it (e.g. desk light).\n5. Leaf 'skeletons'.\n6. Living leaves - from a potted plant (e.g. a 'spider plant') bend the leaf and clip it between two slides. (Additional top illumination needed.)\n7. The thin 'skin' from between the 'leaves' of an onion (onion epidermis).\n8. The edge of a razor blade or sharp knife (with top illumination).\n9. Strands of spider webs.\n10. Dust.\n11. By gently using a potato peeler you can make thin sections of all sorts of plant parts. Usually only the very edges of these sections are suitable for viewing. You might like to stain plant samples with a drop of iodine (use instead of water) under the cover slip.\n12. If you have a wood-plane then make thin samples of different types of wood.\n\n(P.S. Forgive my UK spelling)
245658
Yes, from a physics perspective there are an infinite number of colors.\n\nBut from the perspective of your retina, there are a finite number that you can perceive, in the thousands as I recall.