Top 10 physics factsPhysics quiz
What was offered to Albert Einstein in 1952?
Presidency of Israel. In 1952, Prime Minister David Ben-Gurion offered Einstein the position of President of Israel to Albert Einstein, after the death of Israel's first president, Chaim Weizmann. Einstein, then aged 73, refused: "I lack both the natural aptitude and the experience to deal properly with people". He died three years later.
How do baby birds get oxygen inside their eggs?
Oxygen comes in through pores in the shell. Directly under the shell, there is a small pocket of air. The microscopic pores on the egg surface allow the CO2 to escape and fresh air to get in, so a developing bird can breathe.
This is the aurora of Jupiter. What are the visible bright spots caused by?
Jupiter moons. Jupiter's moons, especially Io (spot on the left), are powerful sources of auroras on Jupiter. These arise from electric currents along field lines, generated by a dynamo mechanism due to the relative motion between the rotating planet and the moving moon.
At what temperature does water boil at the top of Mt Everest?
68°C (154.4°F). The boiling point of water depends on the pressure. On top of Mount Everest, the pressure is about 260 mbar (26.39 kPa) and the boiling point of water is 69 °C. (156.2 °F). In contrast, water can still remain liquid near deep hydrothermal vents, even if the temperature is very high.
What is the only physical difference between heavy water and pure water?
Heavy water has greater density. Heavy water contains deuterium instead of common hydrogen-1. In its pure form it has a density about 11% greater than water, but otherwise, it is physically and chemically similar. It is not radioactive. Because of greater density and stronger hydrogen-oxygen bonds, its behaviour is slightly different in some biochemical reactions. It may be toxic, but only when a large fraction of water (> 50%) in higher organisms is replaced by heavy water.
What is the densest substance in the universe?
Neutron star. A neutron star is a stellar remnant of a supernova. Neutron stars are very small, but extremely dense - with a radius of only about 12–13 km (7 mi), they can have a mass of about two Suns.
Does the candle burn more or less violently in zero gravity?
Less violently. In zero gravity, no convection occurs, that normally shapes the flame, disperses CO2 and brings fresh air to the wick. Without convection, CO2 from combustion does not disperse as readily and tends to smother the flame
Why do cats have vertical pupils?
To better see in the dark. The sharpest image is produced by round pupils, and if cats weren’t nocturnal, they probably would have round pupils like us. But the vertical pupil, in combination with horizontal eyelids, gives the cat greater and more accurate control in different types of lighting. A cat may adjust the amount of light by moving eyelids only.
What is the main reason to have dimples on the golf ball?
Improvement of aerodynamics. Since the 17th century, the best golf balls were made of stitched feathers. The stitches mimicked the effects of dimples, therefore, the need for a layer of turbulence around the ball was not discovered until much later.