Is it true that in college, there are usually fire drills that take place in the middle of the night causing the whole building to evacuate. Also, what do alarms usually sound like in a residence hall. Also, are the alarms (I'm not talking about smoke detectors) usually just in the hallways, or in the dorm rooms too. Because this is a pretty broad question, share your personal experiences, if you've had any.
The rubber sheet image is only an analogy and not an actual representation of space-time. However, embedding diagrams show only 2 or 3 of the 4 space dimensions to give an illustration of paths in space-time. 1) What is meant by space-time distortion is that the shortest-path distance an object travels is not a straight line. So by analogy, the shortest distance in flat space is like a straight line on a plane. But the shortest distance on a curved surface is a curved line. So shortest distance lines that are curved are visualized as lines in a curved space. (The distance referred to here is the space-time interval, s √[x? + y? + z? - (c*t)?].) 2) Free-falling objects (according to General Relativity) follow shortest-path trajectories. In empty space, that is a straight line. In space time, a straight line is constant velocity. In the presence of mass, the line is curved, which means non-constant velocity or acceleration, and the curvature is such that the acceleration is directed toward the mass that is curving the spacetime. That is why you fall to earth. 3) Far from masses spacetime is flat and free falling objects move at constant velocity (which could be zero, but only has meaning relative to an observer). 4) Matter and energy cause distortion of spacetime. That is the theory. 5) I don't know what that means
For what purpose? If you wish to get a parking ticket, then right at the hydrant is a good place. If you don't want that ticket, then in New York city, you need to leave a clear space around the hydrant of 15 feet (unless there is a sign with a different distance).
