World Lines As A Tool To Describe Events
A one-dimensional line or curve can be represented by the coordinates as a function of one parameter. Each value of the parameter corresponds to a point in spacetime and varying the parameter traces out a line. So in mathematical terms a curve is defined by four coordinate functions (where usually denotes the time coordinate) depending on one parameter . A coordinate grid in spacetime is the set of curves one obtains if three out of four coordinate functions are set to a constant.
Sometimes, the term world line is loosely used for any curve in spacetime. This terminology causes confusions. More properly, a world line is a curve in spacetime which traces out the (time) history of a particle, observer or small object. One usually takes the proper time of an object or an observer as the curve parameter along the world line.
Read more about this topic: World Line
Famous quotes containing the words world, lines, tool, describe and/or events:
“Until the day when, your endurance gone, in this world for you without arms, you catch up in yours the first mangy cur you meet, carry it for the time needed for it to love it and you it, then throw it away.”
—Samuel Beckett (1906–1989)
“Was seiz’d by the spirit that trails in the lines underfoot,
The rim, the sediment that stands for all the water and all the land
of the globe.
Fascinated, my eyes reverting from the south, dropt, to follow those slender windrows,
Chaff, straw, splinters of wood, weeds, and the sea-gluten,
Scum, scales from shining rocks, leaves of salt-lettuce, left by the tide,”
—Walt Whitman (1819–1892)
“A broken altar, Lord, thy servant rears,
Made of a heart, and cemented with tears:
Whose parts are as thy hand did frame;
No workman’s tool hath touched the same.”
—George Herbert (1593–1633)
“If you describe things as better than they are, you are considered to be a romantic; if you describe things as worse than they are, you will be called a realist; and if you describe things exactly as they are, you will be thought of as a satirist.”
—Quentin Crisp (b. 1908)
“If I have renounced the search of truth, if I have come into the port of some pretending dogmatism, some new church, some Schelling or Cousin, I have died to all use of these new events that are born out of prolific time into multitude of life every hour. I am as bankrupt to whom brilliant opportunities offer in vain. He has just foreclosed his freedom, tied his hands, locked himself up and given the key to another to keep.”
—Ralph Waldo Emerson (1803–1882)