The time at the Earth's core is slightly slower than the time at the Earth's surface due to the effect of time dilation. This is a consequence of general relativity, which predicts that the rate of time depends on the strength of the gravitational field. The stronger the gravity, the slower the time. Since the Earth's core is closer to the center of mass and experiences stronger gravity than the surface, the time at the core ticks slower than the time at the surface. It is calculated that every second at the Earth's center ticks about 3 x 10^-10 slower than it does on the surface. This means that over the course of Earth's history, the core has become about 2.5 years younger than the crust. That's a fascinating fact!

Dr Lyudmil Antonov thank you for your contribution to the discussion

Gravitational force is inversely proportional to the distance between the two bodies. Earth's gravity depends on the distance between the centre of the earth and the object on the surface of the earth. As the altitude increases, the distance from the centre of the earth increases. The most effective geometry for gravity is a sphere. Mountain top is farther from center of earth and the density of basalt or granite is less than the mantle or the earth core. Gravity anomalies are often due to unusual concentrations of mass in a region. For example, the presence of mountain ranges will usually cause the gravitational force to be more than it would be on a featureless planet positive gravity anomaly Gravitational pull will also change subtly as you move around the surface of the Earth, varying with latitude and local topology, as the Earth is not a perfect sphere. But generally speaking, gravitational pull, and therefore weight, is lower on a mountain than at sea level, says Bell. Gravity is significantly less on high mountains or tall buildings and increases as we lose height gravity is caused by the Earth spinning. Gravity affects things while they are falling but stops when they reach the ground. It does not operate on things that are moving upwards. As we go up the surface of the earth, the distance from the centre of the earth increases and hence the value of g decreases, so the value of g decreases with height. Due to this reason, the value of acceleration due to gravity is less in the mountains than in the plains. This is because acceleration due to gravity decreases (-ve) when we move upward from the earth and increases (+) when we move towards the earth that's why it's less at the top of mountains than plains or atmospheric pressure is also a reason behind this decrease. The acceleration due to gravity decreases with increase in altitude from the surface of the earth. The gravitational acceleration decreases with altitude, g is equal to 9.5 m/s2 at 100 km altitude, which is 9% larger than 8.7 m/s2. However, at 500 km altitude, g is close to 8.45 m/s2, which is close to 3% smaller than 8.7 m/s2. We all know that gravity decreases the farther one gets from Earth. For example, the gravity on the top of Mount Everest is slightly lower than the gravity at sea level, because the mountain is farther from the center of Earth. In fact, a 150-pound person would weigh only 149.58 pounds at the top of Mount Everest.