TW Viewpoint | Satellites and the Age of Instant CommunicationsMarch 18, 2022 | Lorne Ketch
In 1687, Isaac Newton published his seminal book, Mathematical Principles of Natural Philosophy. It laid the foundation for the modern era of the physical sciences. His equations gave a mathematical framework for planetary motion, which aided in predicting satellite orbits.
Let's jump ahead a few centuries. Rockets emerged as a weapon during World War II and technical advances came fast after the war. The Soviet Union successfully orbited Sputnik in 1957 and galvanized the world. Many of us can remember watching that bright Sputnik racing across the night sky. The space race then began in earnest. Vast numbers of satellites have since been placed in orbit by many countries. There were a number of driving forces for this, but the military requirement was certainly a primary one. Satellite-based communications was another.
A satellite can orbit the earth's centre of mass at any orientation to the earth: the orbit can be over the poles, around the equator or any angle in between. The velocity of a stable orbit depends upon altitude. Low orbits require high velocity. Sputnik was a low-altitude satellite which is why it seemed to speed across the sky.
All orbits can be used to advantage for a particular purpose. For instance, the American GPS satellite system consists of a swarm of 24 satellites placed in strategic orbits. The orbits are precisely calculated such that any GPS receiver on earth can see at least four satellites at any time. Four are required to calculate the observer position and altitude. GPS has become ubiquitous and is found on most smart phones today.
One of the most useful of all satellite orbits is directly above the equator. Newton's equations revealed that if one could place a satellite at 35,786 km (22,236 mi) above the equator, the speed (11,300 km/h / 7,000 mph) for the satellite to maintain a stable orbit would exactly match the earth spinning below it. From the perspective of a person on the earth, a satellite orbiting over the equator at that altitude appears stationary in the sky. No other orbit can achieve this as the satellite will always appear to be moving across the sky from the perspective of an earth viewer. That's a result of the movement of the satellite and the rotation of the earth under it.
This "sweet spot" over the equator is called a geostationary or geosynchronous orbit. It can be referred to as "parking" a satellite over a position on the equator. The concept of a geostationary orbit was popularised by Arthur C. Clarke in some of his writings. The orbit is also referred to as the Clarke Belt. That real estate is much sought after. As of April 2020, there were 534 satellites in geostationary orbits. They are owned by many countries.
These satellites provide a range of benefits. One is earth environmental monitoring. We are accustomed to seeing beautiful satellite pictures of hurricanes and other weather features. A "stationary" satellite can take continuous pictures of the same location. American GOES (Geostationary Operational Environmental Satellite) imagery is available online in 5-minute time steps. Advancing optics and computer technology has given high resolution pictures that can be corrected for high latitude distortion. (The further the satellite looks towards the poles, over the curve of the earth, the more distortion there is. Only the point directly below the satellite is relatively distortion free.)
The communication benefit of such an orbit was not lost to scientists and engineers. One could send a radio or television signal from a point on earth to the satellite which could then bounce it to another distant point on the earth—any point in view of the satellite. However, one could send the signal even further. That just required more satellites. Send the signal up to one, which sends it to another visible geostationary satellite, which could send it to another satellite, and so on. One can bounce that signal clear around the earth then send it down to a receiving station. The age of instant communications was launched.
For decades now, we have watched world events unfold on our television sets and now on the internet. We see natural disasters, wars, sports and other big news items in "real-time", as they happen. Satellites parked over the equator are a big part of modern instant communications. It is interesting that ancient writings from 2500 years ago predicted impressive technical achievements and global communications ability. This was long before Isaac Newton opened the door to a modern technical age.
For example, about 536 BC, a Jewish prince named Daniel, who was soon to become a senior government minister in the Persian Empire, was told to write of a time far in the future:
…seal the book until the time of the end; many shall run to and fro and knowledge shall increase (Daniel 12:4).
This predicted increase in knowledge foresaw global, real-time communications at the end of the age. The prophetic book entitled Revelation speaks of two men who will possess great supernatural power from God. They are referred to as the two witnesses. The text says they will eventually be killed and rise from the dead three days later. It then predicts that people all over the world will see this event simultaneously.
And their dead bodies will lie in the street of the great city which spiritually is called Sodom and Egypt, where also our Lord was crucified. Then those from the peoples, tribes, tongues, and nations will see their dead bodies three and-a-half days…(Revelation 11:8–9).
The prediction of people around the world viewing such an event in real-time could not have come to pass until our day and the days ahead of us. How could a man living 2500 years ago have foreseen such an occurrence?
If this ancient text, known as the Bible, could foresee this singular technical ability, perhaps other things it predicts should be taken more seriously. In reality, this ancient information source is very much still a book for our day and for tomorrow.
To learn more of what it says about the immediate future watch Gerald Weston's insightful video on this very topic, called "Future Shocks."