It also helps them learn more about the Earth’s mysterious depths by studying spots on the planet that exhibit higher- or lower-than-average gravity, researchers can investigate the mass-shifting processes unfolding there. Studying the geoid helps scientists measure the loss of ice in polar regions as a result of climate change, the geodesy experts told me, and better understand what happens when our planet becomes a baked potato. Monitoring those changes has real scientific value. Other changes occur over shorter periods, such as during floods and droughts. Some shifts unfold over millennia parts of Earth are still rising after the previous ice age ended, like a sofa puffing back up after its occupant stands, he said. “Any mass has its own gravity, so if you move mass, you move gravity,” Santos said. That’s because Earth itself is always churning through volcanism and plate tectonics, shifting mass around. Potato Earth is not a static model, Marcelo Santos, a geodesy professor at the University of New Brunswick, in Canada, told me. For example, taking the geoid into account ensures that every floor of your brand-new skyscraper is level, Shum said-if it were built today, with the power of the potato, the Tower of Pisa would probably be closer to upright. The geoid has applications on the ground as we know it according to the geodesy experts, an imaginary ocean at rest is a fantastic reference for infrastructure planning. The Potsdam potato may not be what Earth really looks like, but it’s also not entirely imaginary. The geodesy community calls it the Potsdam potato. A widely known visualization of the geoid, constructed from tens of thousands of space-based measurements of Earth’s gravitational field, comes from the institute where Ince works, in Potsdam, Germany. “We can only collect gravitational data and model it approximately.” The idea originated in the early 19th century with the German mathematician Carl Friedrich Gauss, but it wasn’t until satellite technology came along, in the 20th century, that geodesists could outline the potato with real precision.
Sinem Ince, a scientist at the GFZ German Research Center for Geosciences, told me. After all, it’s not a shape we can see naturally. The geoid is a complicated concept, especially if you’re not one of the several experts I begged to explain it. Behold our imperfect potato planet! It’s weird, but it’s ours. But the geoid is a reminder that Earth is wonkier than we might have realized-delightfully so. Really, our planet’s surface isn’t anywhere near so tuberish. Potato Earth has popped up on the internet over the years, each time confounding some people who mistakenly believe that this is what Earth looks like stripped of water. In this view, Earth looks ready to be drizzled with some olive oil and sprinkled with herbs, and then thrown into the oven. The differences in Earth’s gravity are actually quite small, so most visual representations of the geoid are exaggerated to highlight the bumpiness, Shum told me. Protrusions correspond to the denser parts of the planet, which exert more gravity the indentations indicate the less dense bits, which wield less gravity. Imagine that the shape of Earth is subject only to the influence of its own gravity-no tides, no winds, no currents-and that water is distributed accordingly over the whole planet. He works in geodesy, which involves the study of Earth’s gravity field, and he sees the planet through a different lens than the rest of us. Shum, a professor at Ohio State University, is one such person.
And then you have the geoid people-the ones who think of Earth less as an imperfect sphere and more as a lumpy potato.Ĭ. Earth, in fact, is an ellipsoid, a little bit squashed at the poles and fat around the equator, not to mention speckled with mountain ranges. Earth scientists know that’s not exactly true. Earth, in most renderings, is a smooth sphere with a glossy complexion- a blue marble, as pictures snapped from space have shown us.
0 kommentar(er)
