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:
““If she belongs to any besides the present, it is to the next world which artists want to see, when paganism will come again and we can give a divinity to every waterfall.””
—Henry Brooks Adams (1838–1918)
“Who will in fairest book of Nature know
How virtue may best lodged in beauty be,
Let him but learn of love to read in thee,
Stella, those fair lines which true goodness show.
There shall he find all vices’ overthrow,
Not by rude force, but sweetest sovereignty
Of reason,”
—Sir Philip Sidney (1554–1586)
“One of the great reasons for the popularity of strikes is that they give the suppressed self a sense of power. For once the human tool knows itself a man, able to stand up and speak a word or strike a blow.”
—Charles Horton Cooley (1864–1929)
“Living in cities is an art, and we need the vocabulary of art, of style, to describe the peculiar relationship between man and material that exists in the continual creative play of urban living. The city as we imagine it, then, soft city of illusion, myth, aspiration, and nightmare, is as real, maybe more real, than the hard city one can locate on maps in statistics, in monographs on urban sociology and demography and architecture.”
—Jonathan Raban (b. 1942)
“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)