1312 questions and answers in this section
Explain why can the length of days vary depending on the year?

Explain why can the length of days vary depending on the year?

The Earth moves through space with a slightly tilted axis (about 23.5 degrees relative to its orbit). This detail is not trivial; it is even...

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Explain why is the lava from Hawaiian volcanoes so fluid?

Explain why is the lava from Hawaiian volcanoes so fluid?

Hawaiian lavas are primarily composed of basalt, a volcanic rock rich in iron and magnesium, but very low in silica. The key point is this...

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Explain why a vacuum-sealed jar resists opening even when twisting the lid?

Explain why a vacuum-sealed jar resists opening even when twisting the lid?

In a vacuum jar, a large part of the air inside was removed just before sealing it. Air is made up of many small molecules...

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Explain why a rubber band loses its tension if it remains stretched for too long?

Explain why a rubber band loses its tension if it remains stretched for too long?

An elastic band is typically made of a material called an elastomer polymer. A polymer is a long chain formed of small repeated chemical units...

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Explain why the mirror in the bathroom becomes foggy after a hot shower?

Explain why the mirror in the bathroom becomes foggy after a hot shower?

Fogging is simply water in the form of tiny droplets, which appear when the water vapor present in the air cools down quickly. This phenomenon...

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Explain why the ink of a ballpoint pen sometimes smudges?

Explain why the ink of a ballpoint pen sometimes smudges?

Ballpoint pen ink is a mixture mainly composed of dyes or pigments, mixed with an oily or viscous solvent. This viscosity, in other words the...

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Explain why do stars twinkle more in winter than in summer?

Explain why do stars twinkle more in winter than in summer?

In winter, the marked contrast between the very cold air near the ground and the warmer layers of air higher up enhances atmospheric turbulence. The...

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Explain why certain species of ferns grow on tree trunks?

Explain why certain species of ferns grow on tree trunks?

These ferns exhibit clever adaptations to grow directly on trees. They often develop aerial roots capable of capturing moisture present in the air or water...

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Explain why is the city of Houtouwan (in China) invaded by vegetation after its abandonment?

Explain why is the city of Houtouwan (in China) invaded by vegetation after its abandonment?

In the 1980s, Houtouwan was a small fishing village on Shengshan Island in China. The inhabitants primarily lived off fishing, in a place bordered by...

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Explain why do some aquatic plants float on the surface of the water?

Explain why do some aquatic plants float on the surface of the water?

Aquatic plants float due to the principle of Archimedes: they experience an upward buoyant force equal to the weight of water they displace. In other...

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