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.
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Famous quotes containing the words world, lines, tool, describe and/or events:
“Raising a daughter is an extremely political act in this culture. Mothers have been placed in a no-win situation with their daughters: if they teach their daughters simply how to get along in a world that has been shaped by men and male desires, then they betray their daughters’ potential But, if they do not, they leave their daughters adrift in a hostile world without survival strategies.”
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I will abroad!
What? shall I ever sigh and pine?
My lines and life are free, free as the road,
Loose as the wind, as large as store.
Shall I be still in suit?”
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—Bible: New Testament, Luke 24:11.
Response to women who describe the empty tomb of Jesus.
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