"To know that we know what we know, and to know that we do not know what we do not know, that is true knowledge." - Nicolaus Copernicus (born on this date in 1473)

"A dream you dream alone is only a dream. A dream you dream together is reality." - Yoko Ono (born on this date in 1933)

"Possibly because I've lived so much of my life in difficult circumstances, I think I have a more profound understanding of life." - Mo Yan (born on this date in 1955)

"The older I get, the better I used to be." - John McEnroe (born on this date in 1959)

"A little learning, indeed, may be a dangerous thing, but the want of learning is a calamity to any people." - Frederick Douglass (born on this date in 1818)

"If you take a bale of hay and tie it to the tail of a mule and then strike a match and set the bale of hay on fire, and if you then compare the energy expended shortly thereafter by the mule with the energy expended by yourself in the striking of the match, you will understand the concept of amplification." - William Shockley (born on this date in 1910)

Extraterrestrials might be thinking twice about visiting Earth, based on this view from space of the latest winter storm that is pummeling the southeastern United States. 

We will have a better and freer society when we have a greater understanding of math.

"In the end, it's not the years in your life that count. It's the life in your years." -Abraham Lincoln (born on this date in 1809)

Galileo's way of thinking was a much more revolutionary instrument for science than even the telescope. 

"I do not feel obliged to believe that the same God who has endowed us with sense, reason, and intellect has intended us to forgo their use." - Galileo Galilei (born on this date in 1564)

"The sun, with all those planets revolving around it and dependent on it, can still ripen a bunch of grapes as if it had nothing else in the universe to do." - Galileo Galilei (born on this date in 1564)

While President Putin has released some political prisoners, the act itself was a kind of de facto acknowledgement of the corruption and the repressiveness of Russia's political and justice system. 

A new study states that it took 60,000 years to kill more than 90 percent of all life on Earth. 

"Our greatest weakness lies in giving up. The most certain way to succeed is always to try just one more time." - Thomas A. Edison (born on this date in 1847)

Although we live in an information age, we don’t really know what information even means.

A newly released video captures Felix Baumgartner's world record-setting free fall back to Earth from the edge of space, from his perspective. 

"I don't like people who have never fallen or stumbled. Their virtue is lifeless and it isn't of much value. Life hasn't revealed its beauty to them." - Boris Pasternak (born on this date in 1890)

"If all you do is mock the people who disagree with you, you miss your chance to honestly engage with them, learn about where they come from, and — just maybe — teach them a little piece of something that they might not have known before."

Ethan Nadelmann describes the War on Drugs as a prime example of the risk perception gap becoming a risk in and of itself.