When an opaque object is placed between a candle and a wall, why will there be a shadow?
Because the opaque object prevents the rays of light from falling on the wall.
Why will the shadow be larger, the nearer the object is to the candle?
Because the rays of light diverge, in every direction from the candle, in straight lines, and the nearer the object, the more rays will it intercept, as is represented in [Fig. 9].
Fig. 9.
In [Fig. 9], let L represent the flame of a candle. When the object is placed at A, the shadow on the wall will extend from C to D; but when the object is moved nearer, as at B, the shadow will extend from E to F.
Why does an object seem to be smaller, the farther it is from us?
Because the angle at which the light from it strikes the eye, is less when at a distance, than when near to the eye.
