How many colors are in the spectrum of visible light?

How many colors are in the spectrum of visible light?

Newton divided the spectrum into seven named colors: red, orange, yellow, green, blue, indigo, and violet.

When did the astronauts walk on the moon?

They also had to come back to Earth safely. Apollo 11 blasted off on July 16, 1969. Neil Armstrong, Edwin “Buzz” Aldrin and Michael Collins were the astronauts on Apollo 11. Four days later, Armstrong and Aldrin landed on the moon.

Which planet has the fastest rotation?

Jupiter is the fastest spinning planet in our Solar System rotating on average once in just under 10 hours. That is very fast especially considering how large Jupiter is. This means that Jupiter has the shortest days of all the planets in the Solar System.

Who was the first Postmaster General of the US?

In 1775, the Continental Congress appointed Benjamin Franklin Postmaster General (PMG). Franklin had previously served in that post under the Crown. He was followed by his son-in-law, Richard Bache, and Ebenezer Hazard. The first Postmaster General of the new United States of America was Samuel Osgood.

How many times has the host country won the World Cup?

In the 19 FIFA World Cups so far, six host countries have been crowned champions: Uruguay (1930), Italy (1934), England (1966), Germany FR (1974), Argentina (1978) and France (1998), much to the delight of their home fans.

When were license plates invented?

In 1901, New York became the first state to register automobiles; by 1918 all states required license plates. States were slower to require licenses for drivers. Only 39 states issued them by 1935 and few required a test, despite widespread concern about incompetent drivers.

Why do my ears pop on a plane?

Your ears pop in airplanes because the air high above the surface of Earth is less dense than air near the surface, because air near the surface has all the air above it pushing down. Your inner ear has air trapped in it and as the atmospheric pressure changes, it causes pressure on your ear drum.

Where did the word dad come from?

Even the Oxford English Dictionary throws its hands up and admits “of the actual origin we have no evidence.” But, the OED continues, “the forms dada and tata, meaning ‘father,’ originating in infantile or childish speech, occur independently in many languages.” In other words, “dad” might come from baby babble and entered adult vocabulary from there as “dad,” but it’s not a sure thing.