A celestial object refers to a single, cohesive structure that is bound together by gravity and sometimes by electromagnetism.
The world’s oceans contain 20 million tons of gold.
The speed of light in water is about three-quarters of that in vacuum.
Magical thinking is the attribution of causal relationships between actions and events, which cannot be justified by reason and observation.
Trillions of neutrinos or ghost particles are passing through you at this very moment. The vast majority are passing through the ground, through the earth’s core, and flying back into space. Some neutrinos that reach the earth have emanated from the cores of exploding stars or the edge of black holes.
No one has been on the Moon since December 14th 1972.
The speed of sound in water is nearly five times faster than the speed of sound in air.
The boundary of the region from which no escape is possible is called the event horizon. Although crossing the event horizon has enormous effect on the fate of the object crossing it, it appears to have no locally detectable features.
The part of the ocean farthest from land lies in the South Pacific and is known as the oceanic pole of inaccessibility.
Dark matter is a kind of matter to account for gravitational effects that appear to be the result of invisible mass.
To become invisible an object must do two things: it has to be able to bend light around itself so that it casts no shadow, and it must produce no reflection.
Unlike visible light, infrared shows through the dust clouds in the Galaxy.
Ultra violet radiation comes from hotter objects, including bright young stars, white dwarfs, and binary stars, which are two stars orbiting around one another.