When you look inside the Earth, it is like an onion: it has layers. But not all of these layers are equally young, due to the relativity
The Earth, our planet, is made up of several layers that are mainly grouped into crust, mantle and core. Due to the difference in mass between the interior and the exterior of the Earth, the Earth’s core is younger than the crust, despite the fact that both layers were created practically at the same time. It looks like magic, but no, it’s science.
The secret lies in the properties of space-time that Einstein explains in his theory of general relativity. According to this treatise (and as evidenced by the evidence we have) the more intense the gravitational field, the slower time passes at that point in space; and that’s why the Earth’s core is technically the youngest part of the blue planet.
The Earth core, a young man with a lot of antiquity
According to the most accepted theories at the moment the Earth was formed by the agglomeration of matter that revolved around the Sun. Once a large ball of molten rock was created, it began to cool, starting from the outside, until it could harbor intelligent life. This outer crust also serves as thermal protection for the Earth’s mantle and core, which remain even at high temperatures. As one descends towards the center of the Earth gravity varies and we find large currents of magma.
This mixture of speed and (above all) variation in gravity, make time passes differently on the surface than it does at the Earth’s core. This transforms into a terrestrial core that is younger than the crust, despite both being created at the same time. A fact at least curious that reminds us that things are not really what they seem to us. Specifically, in this case, the age difference is two years less for the nucleus terrestrial than for the crust, which is not too much on the time scale of the Universe.
The earth’s mantle is younger, but this does not affect us
This means that if two clocks had been placed from the start on the Earth’s core and crust, today there would be a difference of exactly 2.49 years between the two; a real and measurable difference. The reality is that since there was no one to place the clock, we cannot even get to the Earth core, this difference does not affect us at all. Even from a geological point of view, 2.5 years is a negligible difference compared to the age of Earth, but the data is more than curious.
This same effect is what affects satellites (such as GPS) that orbit outside the Earth’s atmosphere and that they need relativistic corrections to avoid losing their precision. This type of data that is published in scientific journals even (such as the specific case of the Earth’s core) helps us to realize that the theory of relativity is more than a theory and that nature is so rare that two things, Although they start and end at the same time, they can be of different ages.