Risk.

Hey, Vsauce. Michael here. When will you die? I don't mean you specifically, I mean the mean of you all - the average Vsauce viewer. By combining World Health Organization life tables with YouTube analytics for Vsauce viewers, we can calculate that the average date everyone over the age of 15 watching this video right now will die on is 8:42 in the morning, November 28th, 2059. The mode is in 2073. Morbidly, but mathematically, about 340 of the people who watch this video this week will not be around at this time next year.

These statistics are based on averages but interestingly the average person considers him or herself anything but average. Studies have consistently shown that the average person believes he or she will live a longer and healthier life than the average person. We overestimate the likelihood that bad things will happen to other people and underestimate the likelihood that they will happen to us. It's a natural part of our psychology, but, yeah, we miscalculate risk in many fascinating ways.

K.C. Cole points out that we are often more responsive to threats that are personal, exotic, erratic, and dramatic than we are to threats that are well more likely. I love one of her examples - imagine a world where cigarettes are harmless, but one cigarette pack out of every eighteen thousand seven hundred and fifty contains a single cigarette laced with dynamite that, when lit, violently explodes, blowing the user's head off. People would be loudly and messily losing their heads every day all over the world but in that imaginary universe the same number of people would die every day because of smoking that already do. The results would just be more shocking, more immediate and probably more likely to affect our decisions.

Last month, I and some of my favourite YouTube creators met with President Obama about the decisions Americans make when it comes to protecting themselves from the cost of staying healthy. The issue with health care is mired in conflict and debate matched only by the turmoil of risk assessment going on in our own minds. Our myelinated machines use more biases and shortcuts to evaluate probabilities than can fit in a single video, but a particularly strong example is the availability heuristic. Our tendency to think that something is more likely because it happened recently or there are more examples of it happening available in our memories, not because it actually is more likely.

We also over-exaggerate risks we don't have control over while being comparatively fearless in the face of equal risks we nonetheless can control. Chianti Stars' famous 1969 study on risk found that people were willing to accept risks 1,000 times greater if they could control them, for instance, driving a car than if they didn't have control, for instance, a nuclear disaster.

Let's talk about Abraham Wald. Only so much extra armour can be added to an airplane before it becomes too heavy to fly. Now, during World War 2 the US military noticed the planes returning from enemy territory were usually damaged around the wings, the body, and the tail gunners. So, they put more armour on those areas. But it didn't make a difference. The same number of planes continued to be lost. So the military hired Wald for his mathematical superpowers. He told them to put what little armour they could on the parts of the planes that weren't being hit. Why? Well, because returning planes were survivors. They took damage in areas where a plane can take damage and survive. Damage to other areas caused the plane to not return. Wald was protecting them against survivorship bias - only paying attention to successes.

A similar phenomenon is partly responsible for why music feels like it was just better back in the day than it is now. Is that really true, or are we just remembering the good stuff? Wald's work saved thousands of lives and made flying safer for many more. Tragically, a few years later Wald and his wife died in an airplane crash. You can't predict how and when you will die, it's not that easy. But a few risk scoring systems have been created to make the discussion and comparison of hazardous behaviors clearer.

The micromort was conceived by Ronald A. Howard and is an amount of risk equal to a one in 1,000,000 probability of dying. John Green discussed Micromorts in a fantastic mental floss video you should watch if you haven't already. He points out that a single skydive temporarily increases your death risk by seven micromorts - a seven in 1,000,000 chance of dying. That's the same as smoking 5 cigarettes. It's been estimated that you gain one micromort for every half litre of wine you drink.

Every year you spend drinking Miami tap water, every 1,000 miles you fly in a jet plane, every 230 miles you travel by car, every 20 miles you travel by bicycle, and every 6 miles you travel by motorcycle or canoe. There is a happier unit of risk - the microlife. Proposed by David Spiegelhalter and Alejandro Leiva, a microlife is gained by doing helpful things. In small quantities, their benefits are roughly linear and one microlife is the equivalent of 30 extra minutes of life.

Twenty minutes of moderate exercise gives you two more microlives. Two hours of sedentary behavior -1 microlives. Plenty of non-scientific websites exist that allow you to calculate when you will die based on your life expectancy and habits. PokeMyBirthday.com is the kind of goofy site that takes a nonetheless interesting look at not your death, but your birth. Enter your birthday and see when you were conceived, when your mother probably first realized she was pregnant with you, and the dates your parents created or moved into position the two cells that eventually became the thirty trillion cells that are now watching this video.

Every single person who ever died, died right here on planet Earth. Except for three. The crew of Soyuz 11. On June 30th, 1979, their cabin depressurized while returning to Earth, before they crossed the agreed-upon boundary between Earth and outer space. Far from any populated area, a three-sided metallic column sits where their craft landed in Kazakhstan. It's a remote memorial to humankind's remotest deaths. We haven't all died here on Earth, but so far we have all been born here. Thanks for being here. Stay safe, and as always, thanks for watching.