Truth Of Nature

Scientists made an unexpected discovery several years ago that Mercury has a small magnetic field.
This discovery by the Mariner 10 spacecraft puzzled them, who believed that because of its small size the planet's core had long ago solidified. But the most common explanation for a magnetic field is a molten interior, such as on Earth. The Moon and Mars, for example, show evidence only of ancient magnetic fields.
The Messenger spacecraft is on its way to Mercury and is expected to arrive next year, but in the meantime researchers led by Jean-Luc Margot, an assistant professor of astronomy at Cornell University, launched their own attempt to learn about the planet's core. Researchers have cracked a mystery at the core of Mercury — and say there's molten fluid inside the tiny planet. They did it by using the same trick as cooks who want to know if an egg is raw or hard-boiled. Spin the egg. A hard-boiled egg with a solid interior will spin smoothly, a raw one with a liquid center will wobble.
Material nature keeps the nature of an egg true, hard boiled or not,- and can be used to understand nature of another material object because of its material consistency. In short Truth of Nature.
Principle of similitudes
This principle is based on the truth of nature: a grain of sand will prove to be the key for understanding a mountain and a flower for a rain forest for an example.
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