I know that it results from light falling on non-transperant object, but what does exactly happen in that object (Or light) that gives this shadow?
131465
A shadow is a patch which has a lower intensity of light as compared to its surroundings.\nSo when light cannot go through an opaque object there has to be a lower/nill intensity of light behind the object, thus a shadow is formed.\nAnd as far as the light hitting the opaque object is concerned, it is reflected and/or absorbed to be converted to heat energy.
128031
It's the way the molecules are formed in any particular "color" item and the light that gets absorbed by those molecules.  The light that doesn't light absorbed is the color you see.
449013
there is an optical effect like this ( it is just a refraction at an interface - like water and air ) and sorry i can't remember either ( i will search tho )\n\ncool i searched the term ATMOSPHERIC REFRACTION and guess what LOL( go to Wikipedia )
139969
Plasma does not cast a shadow. Plasma is the extreme for of matter. Its the core of the sun but Plasma cannot cast a shadow.
502324
We only see the light reflected off of an object.  Google the invisibility cloak that scientists have comeup with.  It works by refracting and redirecting light .
562428
moving from a higher to a lower energy level releases energy, producing light, but;\nit only produces light in the visible light spectrum when it moves down to level n=2.  if it ends up at another energy level, the light released will be infared, ultraviolet, etc... depending on where it ends up.
647943
A "sundial" casts a single shadow from its gnomon (the point that comes out of the top). \n\nAn "armillary sphere" however is a different device altogether. It helped in the understanding of the earth and stars. Many armillary sheres were created with the sun in the middle, therefore casting numerous shadows depending on which point in space you were.\n\nWhile on earth at 1:38pm a sundial will cast one shadow.\n\nCheck out these links for more information:
433797
well what happens when you shine a light of a specific colour onto a white wall?\n\nOnly the colour that you shined will be reflected back because that is all the wall has to work with!
173887
That's not the earth's shadow.  That only happens during a lunar eclipse.  What you are seeing is the different phases of the moon.
229036
no it's not cos of the earth's shadow on the moon. its cos of the position of the sun and the angle at which the sun's rays hit the moon. the moon moves around the earth. if it moves further from the sun, less light will be reflected and you see a half-moon or quarter-moon.\n\nas u know, the light hte moon 'projects' is actually the reflection of light. the moon isnt a source of light. \n\nwhen the sun is directly behind the moon, and it shines on the 'back' of the moon, this causes an eclipse cos ppl on earth can only see a dark circle (the moon - as it does not reflect light in this case) and a whitish circle around the moon (the sun's rays)\n\nhope this helps!! :D
81306
You are on the right track. It's quite simple:\n\nGenerally, wet things look darker because they refract less light. Light, which is made of photons, refracts against an object and lands on your retina and your brain can register some amount of darkness or brightness. Now when that object is wet (assuming it is hydrophilic or "wettable") more light is absorbed by the water so less light lands in your eyes and the object appears darker.\n\nGreat question!
596248
First of all how do you know that it is?\nNewton's ring is a ring within a ring within a ring. It is a question of resolution so get a bigger looking glass to see some rings within the ring that seems like a dark circle. \n\nWell actually the dark center is caused by interference or the place where waves cancel each other.
91360
The maximum velocity of light is in air (strictly in vacuum).\n\nThe velocity is less in other medium.\n\nThe change in velocity from medium to medium is refraction.\n\nWhen light enters from medium 1 to medium 2, a potion of light is bounced back into the medium 1 and the remaining passes into medium 2 (Refracted). The bouncing back is reflection.\n\nThe proportion of reflection or refraction depends on the angle the \nray makes at the point of incidence on the boundary.\n\nWhen light enters from glass (a medium of less velocity; optically denser medium) into air (a medium of more velocity; optically rarer medium) no portion of light is refracted (do not enter into air) at certain angles of incidences. The whole portion of light is bounced back into glass\n\nThey are TOTALLY AND INTERNALLY reflected.\n\nThere is no change in velocity and therefore total ilnternal reflection is not refraction,
188694
the effect is called Gradient!\n\nUse the help menu to figure it out, i dont have the menus memorized to talk you through it
119597
That's because light reflects in the mirror just as if it's coming from the same distance the real object is but behind the mirror.  You are nor looking an image that is at the mirror distance, but really at the real object distance.
108760
Shadow means no light. So id light is cut-off or changed shadow will be formed or changed at the speed of light.\n\nCoclusion:\n========================================\nspeed of shadow = speed of light = 3x10^8 m/s\n\nor 186,000 miles/s
589482
B - the reason you can see an object is because light bounces off of it. if light bounced off of an object evenly, then you would have to be in a specific location to see it (think of a mirror reflecting a laser. you can't see the laser beam in the mirror, ideally, if you are shining it at an angle). if the light is reflected unevenly, then you can see it at pretty much any angle.