# The Earth’s Core is Actually 2.5 Years Younger than Its Surface

Thursday, 26 May 2016 - 8:47PM
Thursday, 26 May 2016 - 8:47PM
Ever since Einstein developed the theory of relativity, scientists have known that time can be dilated dependent on how close to the speed of light an object is traveling or its location in relation to a massive object. Yes, that means that time travel, especially time travel to the future, is theoretically possible, and it can be proven that this phenomenon does indeed occur. For instance, GPS satellites have to take time dilation into account to correct their onboard clocks, as they are obviously much further away from the Earth and thus experience time dilation due to gravity to a differing degree than objects on the surface of the planet.

Recently, a team of physicists set out to find the time differential that would exist between the surface of the Earth and the center of the Earth due to time dilation. They did this to fact check one of the points that the famous Richard Feynman would use in his lectures - that the time differential between the center and the surface and the Earth would be about 100 days. What they found was that Feynman's calculations were actually off by some amount.

The physicists found that the center of the Earth experiences a slower time than the surface, but only by about 0.0000000003 seconds. Of course, that may not seem like much of a difference, but when one considers the fact that the Earth is believed to have been formed 4.5 billion years ago, it begins to add up.

In the end, the math comes up to about 1.5 years. However, when the variations in density between the center and the surface are accounted for, the total comes out to be about 2.5 years. It's still not that much in the grand scheme of things, but it's still a bit weird to think that something that formed at the exact same time has two different ages.

Of course, this big reveal isn't just true for the Earth, but is also true for any massive body. The thing is, the more massive the object, the greater the time differential. For instance, the team also found that the sun's core is actually 40,000 years younger than its surface thanks to gravitational time dilation.

While as of now these may seem like somewhat insignificant factoids, it does demonstrate the credibility of Einstein's relativity. Likewise, they also serve as a reminder that time dilation is a real thing, and will likely one day be used by mankind to accomplish time travel.