Neil deGrasse Tyson hardly needs any kind of introduction these days. We already know his work very well through books, radio, television, and the Internet, and on his own merit he has become one of the best science communicators in the world. His talks are very popular, but it's in that space where he usually moves away a bit from astrophysics and explores other aspects. One of them was Bill Gates' fortune. Basically, what Tyson wonders is how much money would be enough for the billionaire to make the effort of picking it up from the floor, taking his wealth as a reference...
The first thing that comes to mind for many when we mention Neil deGrasse Tyson is probably a meme. Our story takes us back to June 2011, when Dr. Tyson described in a video the impressive achievements of Isaac Newton, and the Web was quick to immortalize his gestures. But that was the "explosion" in the astrophysicist's popularity. With a couple of web searches, we can find material that predates the meme effect by far. In fact, his book "Death by Black Hole: And Other Cosmic Quandaries" is from 2007, and if my memory doesn't fail me, he published eight or nine more books before that. But what brings us here is one of his videos, and instead of melting minds with black holes or astronomical phenomena, he leaned toward Bill Gates' fortune:
https://www.youtube.com/embed/GXWvCYPnUKEThe Fortune of Bill Gates and a Coin on the Floor
Taking into account the quality of the video and the detail that Gates' fortune amounts to $50 billion, it's possible to calculate that the talk took place at some point in 2008 or 2009. After playing a bit with the word "billion" (our thousand million), Tyson describes his financial situation (I have a job, I own my house, etc.), and presents the hypothetical case of a coin on the floor. How big would its denomination need to be for him to take the trouble of picking it up, thinking at the same time about his general financial security? Right off the bat, he admits he would ignore 1- and 5-cent coins, while the 10-cent coin would be a candidate "if he's not in a hurry". The 25-cent coin, the famous "quarter", is useful in parking meters and washing machines, so it would end up in his pocket. In other words, the value of a coin that justifies picking it up from the ground for the doctor lies between 10 and 25 cents. However...
When we move that same exercise over to Bill Gates and his fortune, Tyson's conclusion is that the philanthropist would only bother to pick up the equivalent of $45,000. Now, two details: The first is that Forbes currently assigns Bill Gates a fortune of $90.2 billion, so those $45,000 would be about $80,000 today (without introducing inflation). The second is that the Web calculated Tyson's net worth at that time, and it came to about $280,000. Needless to say, that number has grown.
