Why? It's just two competing effects.InquiringMind said:
In that case the gravitational effect wins over the kinematic effectInquiringMind said:
Just to be sure you are clear, neither one of these statements is true as an absolute statement. What you have left out is "relative to <something>". That is, your time ALWAYS moves at one second per second no matter where you are in a gravity well or how fast you are moving relative to something else.InquiringMind said:
If you eat too much food, you put on weight. If you exercise a lot, you lose weight. If you eat a lot and exercise a lot you should put on weight and you should lose weight. Is that a paradox too?InquiringMind said:
Free-fall orbital speed decreases with altitude.InquiringMind said:
Time dilation refers to the difference in the elapsed time measured by two observers, due to a relative difference in velocity or gravitational field strength. In the context of geosynchronous satellites, which orbit the Earth at an altitude of approximately 35,786 kilometers, time dilation occurs because these satellites are moving at high speeds relative to observers on the Earth's surface and are also in a weaker gravitational field. This results in the satellites experiencing time at a slightly different rate than clocks on Earth.
The speed of a geosynchronous satellite, which travels at about 3.07 kilometers per second, causes it to experience time dilation due to its velocity. According to Einstein's theory of relativity, the faster an object moves relative to an observer, the slower time passes for that object from the observer's perspective. Therefore, clocks on satellites tick slightly slower compared to those on Earth, leading to a measurable difference in time over extended periods.
Gravity also plays a significant role in time dilation. According to general relativity, time passes more slowly in stronger gravitational fields. Since geosynchronous satellites are located farther from the Earth's center than clocks on the surface, they are in a weaker gravitational field. This means that time actually passes faster for the satellites compared to clocks on Earth. The combined effects of gravitational time dilation and velocity time dilation must be taken into account when considering the overall time experienced by the satellites compared to Earth.
The net effect of time dilation results in satellite clocks running faster than Earth clocks when both gravitational and velocity effects are considered. The gravitational time dilation causes satellite clocks to gain time, while the velocity time dilation causes them to lose time. However, the gravitational effect is stronger, leading to an overall gain of about 38 microseconds per day for the satellite clocks. This means that satellite clocks must be adjusted periodically to remain synchronized with Earth-based clocks.
Accounting for time dilation is crucial for the accuracy of satellite-based technologies, such as GPS. If time dilation effects were not corrected, GPS calculations would lead to significant errors in positioning, potentially resulting in navigational inaccuracies of several kilometers over the course of a day. Therefore, engineers and scientists must incorporate relativistic corrections to ensure that satellite systems provide precise timing and location information for users on Earth.