If you have ever tried to catch a bill as it falls through your fingers, you know just how hard it is unless to anticipate the drop and react before it falls. There's actually a mathematical reason why this task is so difficult, and due to a number of variables, it is actually impossible. Many won't believe it at first, but if you try the trick out with a friend, you will soon find that it cannot be done. The video below will explain a little bit more about why you can't catch a falling dollar bill with your fingers, check it out.
This trick is commonly surrounded by a bet between friends, or maybe even strangers, with the terms often being if you can catch it, you keep the money. This trick all has to do with the average human reaction time, which is actually around .2 seconds. There are many reaction apps out there if you want to test yourself, but unless you have fine-tuned your skills, it will likely be around this number. When you work out the math, the money will fall 20 cm before the brain is even able to react in time.
Now, if you want to hustle your friends, there are a few constraints you need to set up in the experiment. The catching fingers should be the index and middle finger as these move much slower than if you were to try to catch the banknote with your thumb and index finger. The participant also needs to spread their fingers as far apart as possible.
It is important to note that some people may get lucky and catch the note, so this won't work 100 percent of the time. However, based on average reaction time, this trick is physically impossible to pull off. If you're up for the challenge, try it out with a friend and see if you have the skills.