Shadows are areas where direct light from a light source cannot reach due to obstruction by an object. A shadow occupies all of the space behind an opaque object with light in front of it. The cross section of a shadow is a two-dimensional silhouette, or reverse projection of the object blocking the light. The sun causes many objects to have shadows and at certain times of the day, when the sun is at certain heights, the length of shadows change.
Hoyt's New Cyclopedia Of Practical Quotations 
- Quotes reported in Hoyt's New Cyclopedia Of Practical Quotations (1922), p. 699-700.
- The worthy gentleman [Mr. Coombe], who has been snatched from us at the moment of the election, and in the middle of the contest, while his desires were as warm, and his hopes as eager as ours, has feelingly told us, what shadows we are, and what shadows we pursue.
- Edmund Burke, speech at Bristol on Declining the Poll.
- Thus shadow owes its birth to light.
- John Gay, The Persian, Sun, and Cloud, line 10.
- (Orion) A hunter of shadows, himself a shade.
- Homer, Odyssey, II. 572.
- Follow a shadow, it still flies you;
Seem to fly it, it will pursue.
- Ben Jonson, song, That Women are but Men's Shadows.
- The picture of a shadow is a positive thing.
- John Locke, Essay concerning Human Understanding, Book II, Chapter VIII. Par. 5.
- Alas! must it ever be so?
Do we stand in our own light, wherever we go,
And fight our own shadows forever?
- Owen Meredith (Lord Lytton), Lucile (1860), Part II, Canto II, Stanza 5.
- Shadows are in reality, when the sun is shining, the most conspicuous thing in a landscape, next to the highest lights.
- John Ruskin, Painting.
- Some there be that shadows kiss;
Such have but a shadow's bliss.
- Shadows to-night
Have struck more terror to the soul of Richard
Than can the substance of ten thousand soldiers
Armed in proof, and led by shallow Richmond.
- Like Hezekiah's, backward runs
The shadow of my days.
- Alfred Tennyson, Will Waterproof's Lyrical Monologue. (Ed. 1842). Changed in 1853 ed. to "Against its fountain upward runs / The current of my days".
- Majoresque cadunt altis de montibus umbræ.
- And the greater shadows fall from the lofty mountains.
- Virgil, Eclogue, I. 84.