The Feynman Lectures on Physics Website. Space-Time Diagrams. Any discussion of cosmology requires a careful consideration of what we can see and when we can see it. A good way to keep track of these concepts is the space-time diagram. A space-time diagram is nothing more than a graph showing the position of objects as a function of time. The usual convention is that time runs up the diagram, so the bottom is the past, or early times, and the top is the future, or late times. A point on this graph describes both a position (the horizontal or x coordinate) and a time (the vertical or t coordinate). A "point" in space-time is called an event. The picture above shows a space-time diagram of the Earth going around the Sun.
The line representing the position of the Earth as a function of time is called a worldline. The space-time diagram above shows particles with different velocities. Back to the Cosmology Tutorial. Concerts, tour dates, and festivals for your favorite artists. The Oh-My-God Particle. By John Walker January 4, 1994 Fly's Eye The University of Utah operates a cosmic ray detector called the Fly's Eye II, situated at the Dugway Proving Ground about an hour's drive from Salt Lake City. The Fly's Eye consists of an array of telescopes which stare into the night sky and record the blue flashes which result when very high energy cosmic rays slam into the atmosphere. From the height and intensity of the flash, one can calculate the nature of the particle and its energy.
On the night of October 15, 1991, the Fly's Eye detected a proton with an energy of 3.2±0.9×1020 electron volts.[1,2] By comparison, the recently-canceled Superconducting Super Collider (SSC) would have accelerated protons to an energy of 20 TeV, or 2×1013 electron volts—ten million times less. All evidence points to these extremely high energy particles being protons—the nuclei of hydrogen atoms. Microbial Mass How Fast? How fast was it going? And thus, approximately: v = 0.9999999999999999999999951 c Quicktime. Moving slabs [This Dynamic Earth, USGS] The layer of the Earth we live on is broken into a dozen or so rigid slabs (called tectonic plates by geologists) that are moving relative to one another.
"Historical perspective" College Physics.