Why didn’t they know space and time were combined together in astronomy almost forever? If “it is a theory not only of curved space, but of curved or warped time as well”, how did this theory measure the time for different kinds of time, for examples, True Solar Time, Mean Solar Time, and Sidereal Time?
According to Einstein, as special theory of relativity showed, space and time separately are relative quantities which vary with individual observers. Einstein take this idea from Minkovski, who developed the mathematics of the space-time continuum. Minkovski’s spacetime (4 D) is a mathematical construction.
But for Einstein, the space-time continuum is not simply a mathematical construction. Einstein viewed the world is a space-time continuum.
“To describe any physical event involving motion, however, it is not enough simply to indicate position in space. It is necessary to state also how position changes in time. Thus to give an accurate picture of the operation of New York — Chicago express, one must mention not only that is goes from New York to Albany to Siracuse to Cleveland to Toledo to Chicago, but also the times at which it touches each of those points. his can be done either by means of a timetable or a visual chart.”
“In same way the flight of an aeroplane from New York to Los Angeles can best be pictured in a four-dimensional space-time continuum. The fact that the plane is at latitude x, longitude y, and altitude z, means nothing to the traffic manager of the airplane unless the time co-ordinate is also given. So time is fourth dimensional. And if one wishes to envisage the flight as a whole, as a physical reality, it can not be broken down into a series of disconnected take-offs, climbs, glides, and landing. Instead it must be thought of as continuum curve in a four-dimensional space-time continuum.
Since time is an impalpable quantity it is no possible to draw a picture or construct a model of a four-dimensional space-time continuum. But it can be imagined and it can be represented mathematically.
Obviously the astronomers has to think of the Universe as space-time continuum” (Lincoln Barnett, The Universe and Dr.Einstein, page 58–61)
Stop here. Because Einstein did not continued his fantasies to space in the events of the movement of the Sun, Moon, Stars and Planets. His fantasies limited in the movement of Chicago express and the flight of an aeroplane. For the layman, it is really an ordinary and for a long time ago is widely known.In fact, the time used by trains, planes, and ships were all determined based on astronomy. Our clocks is a Local Mean Time, and it is calculated from the Greenwich Mean Time.
It seems Einstein had no idea on the fantasies of the movement of celestial bodies. He had not realized that the locations of stars in the sky can be pictured as an aeroplane at latitude x, longitude y, and altitude z.
Einstein’s statement is incorrect: “Since time is an impalpable quantity it is no possible to draw a picture or construct a model of a four-dimensional space-time continuum. But it can be imagined and it can be represented mathematically.”
Time as a dimensional, actually is a direction of three-dimensional space. It is not a four-dimensional space-time (4 D), but a three-dimensional of space and one-direction (3 D + 1 D). A model of a four-dimensional space-time (4 D) should be have one-direction: 4 D + 1 D, but it is no possible to draw a picture of 4 D + 1 D.
In astronomy is known a model of a three-dimensional space and one-direction, that is 3 D + 1 D Space And Time, to be more precisely, 3 D + 1 D Celestial Sphere Coordinates System. Thus, since time is an impalpable quantity it is possible to draw a picture or construct a model of a three-dimensional space and one-direction (time).
3 D + 1 D Celestial Sphere Coordinates System
It seems Einstein had no idea in the “elementary” basic of fundamental concept of astronomy.
Astronomers has to think of the Universe as space-time continuum
But, that it is, something weird that have happened: Obviously the astronomers has to think of the Universe as space-time continuum. Einstein advises to the astronomers of the need to take into account the time, because time can not be separated by space.
Let us note how could it be happened? Perhaps it is because Einstein was a genius!
Stephen Hawking also explained in the background of the Space and Time Warps:
“General Relativity was a major intellectual revolution that has transformed the way we think about the universe. It is a theory not only of curved space, but of curved or warped time as well.
Einstein had realized in 1905, that space and time, are intimately connected with each other. One can describe the location of an event by four numbers. Three numbers describe the position of the event. They could be miles north and east of Oxford circus, and height above sea level. On a larger scale, they could be galactic latitude and longitude, and distance from the center of the galaxy. The fourth number, is the time of the event. Thus one can think of space and time together, as a four-dimensional entity, called space-time. Each point of space-time is labeled by four numbers, that specify its position in space, and in time. Combining space and time into space-time in this way would be rather trivial, if one could disentangle them in a unique way.
That is to say, if there was a unique way of defining the time and position of each event. However, in a remarkable paper written in 1905, when he was a clerk in the Swiss patent office, Einstein showed that the time and position at which one thought an event occurred, depended on how one was moving. This meant that time and space, were inextricably bound up with each other.”(Stephen Hawking, hawking.org.uk).
As Stephen Hawking said that time and space were inextricably bound up with each other, for the layman it might be something new, but for astronomers it’s nothing new. Space and time were combined together in astronomy almost forever. Actually, time is one of the basic concepts in astronomy.
In astronomy, knowing the time is very important. That is why, before the invention of the atomic clock, the clock used on ships is made specifically called Chronometer.
Earth’s orbit around the Sun, it about 900 miles per hour. it means our position at the Earth or geographic position is moving about 900 miles per hour. We can make calculation that 4 seconds of time is the same with 1 mile, or 1 minute of time (60 seconds) is the same with 15 miles. Obviously, we must know the time quite exactly in order to get the accuracy of calculation, for example, when measuring the altitude of star in the sky.
That is the reason the calculations in astronomy applied immediately or instant.
Three kinds of time in Astronomy.
One is local time, the other is Greenwich Mean Time (GMT), and Sidereal Time. Local time, is the time we already used to, it comes in 24 different varieties or zones.
Greenwich Mean Time (GMT) is the standard time in the astronomy, when someone make calculation in connection with apparent altitude of celestial bodies and the deviation of rays, by using the sextant and Nautical Almanac. GMT doesn’t vary according to location.
Some interesting questions arise
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