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  • Hi this is David from MinuteEarth.

  • And these are my fingerprints.

  • Each one has a particular pattern on it: a whorl, a loop, an arch, or in the case of

  • my left thumb, a somewhat rarer double loop whorl.

  • But even if your left thumbprint has one of the boring patterns, your print is unique

  • to you.

  • In fact, there's no one in the world - past, present, or future - who has a fingerprint

  • that matches any one of yours.

  • To understand why, we first need to know how they form.

  • Early on in fetal development, lumps of stem cell tissues - called volar pads - grow under

  • the skin on each finger.

  • Whether the volar pad is small or big or off to the side or grows unevenly determines the

  • main pattern of the fingerprint - an arch, whorl, loop, or even a very interesting and

  • exciting double loop whorl.

  • Because your volar pad size and orientation is somewhat genetic, many relatives, and most

  • identical twins, have the same main patterns on each finger, and so DNA alone isn't where

  • the uniqueness of fingerprints comes from.

  • Instead, it comes from the chaotic way in which the fingerprints grow.

  • On top of the volar pads, the embryonic skin has several layers of cells, all growing at

  • different rates.

  • And as the inner layer grows, the middle layer buckles, causing ridges to form in the upper

  • layer.

  • The ridges first form parallel to the three areas of greatest stress on a growing finger:

  • near the fingernail, near the crease at the first joint, and on top of the volar pads.

  • As the ridge lines grow, they sometimes run into one another, resulting in either a block

  • or a split.

  • The details of precisely where on the finger those ridge lines meet up and whether each

  • one get turned into a dead end or a fork is determined by a bunch of different factors,

  • like how nerves and capillaries grow in the layer below the skin, fluid pressure changes

  • in the womb, and even which direction the finger is oriented relative to gravity.

  • And because there are chaotic and unpredictable differences in each of these, whether a given

  • ridge becomes a dead-end or a fork is essentially random, even for babies that develop in the

  • same womb.

  • The average person has around 50 forks or dead ends at different places on each fingerprint.

  • Even if you oversimplify things - ignoring position and so on - and just think of each

  • of these points as an independent coinflip between fork and dead end, there are more

  • than a quadrillion different possibilities for fingerprints.

  • To get a sense of how many possibilities that is, there are 80 billion fingerprints in the

  • world, which are represented by this black dot.

  • A quadrillion is 10,000 times larger.

  • And, remember, this is a simplification, because the number of potential unique fingerprints

  • gets way, way bigger when you take into account the relative positions of these points.

  • So my left thumbprint - and all my fingerprints and all your fingerprints - are each pretty

  • much mathematically guaranteed to be unique - to be the only ones in the whorl.

  • Each of your fingerprints is one of a kind, and each of your passwords should be, too.

  • That's why I use Dashlane, who sponsored this video.

  • Dashlane randomly generates a unique strong password whenever I sign up for a new account,

  • and instantly logs me back in whenever I return to the site.

  • It also securely autofills my personal information whenever I need to fill out online forms and

  • lets me know if there's been a data breach at any of my regular haunts.

  • The basic service is free, but with Dashlane Premium I can access Dashlane on all my devices

  • and store unlimited passwords.

  • And you know the best part?

  • I can use my own unique fingerprint to open my Dashlane password vault on my phone!

  • To download your own free 30-day trial of Dashlane Premium, go to

  • The first 200 viewers can also get 10% off a yearly Dashlane Premium membership using

  • the code MINUTEEARTH at checkout.

Hi this is David from MinuteEarth.

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B1 US dashlane minuteearth fingerprint finger unique loop

Why Are Your Fingerprints Unique?

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    April Lu posted on 2019/03/27
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