The Number Illusion You Won't Believe

Vsauce2 February 26, 2020
Video Thumbnail
Vsauce2 Logo

Vsauce2

@vsauce2

About

Welcome to the official Vsauce2 YouTube channel! Hosted by Kevin Lieber, Vsauce2 explores recreational mathematics including, paradoxes, math games, riddles and more to uncover the surprising complexity beneath seemingly simple concepts. Vsauce2 launched in December 2010 and is run by Kevin Lieber. Vsauce is... Michael Stevens: Producer/Host of Vsauce1 Kevin Lieber: Producer/Host of Vsauce2 Jake Roper: Producer/Host of Vsauce3 Matthew Tabor: Writer for Vsauce2

Video Description

Sometimes math is so beautifully tricky, and presented in such a subtle way, that it’s virtually indistinguishable from magic. Welcome to The Kruskal Count. David Copperfield is probably the most famous living magician/illusionist, and he’s made use of the Kruskal Count to convince millions of people worldwide that he harbors amazing predictive powers. Does he? Well… yes and no. At the core of his mathematical mind reading is physicist Martin Kruskal’s discovery that certain counting games are really a sequence of chains that can intersect and eventually become one single chain. Using that knowledge of well-concealed probability, it’s easy to perform a mind-blowing demonstration that appears to be pure magic. But it doesn’t *always* work, because that’s the way probability goes. Sometimes it’s perfect, sometimes it isn’t. By examining the Kruskal Count as a magic trick and also through its original card-based format, we’ll see that magic can be math… and math can be magic. Play “The Kruskal Count Card Trick” simulator by Alex Frieden and Ravi Montenegro: http://faculty.uml.edu/rmontenegro/research/kruskal_count/kruskal.html *** SOURCES *** David Copperfield Vacation Destination Trick: https://youtu.be/RZmS_BTwPEU “The Kruskal Count,” Lavarius, Rains, Vanderbei, October 2001. https://arxiv.org/pdf/math/0110143.pdf Mathematical Card Tricks: “It’s probably magic,” American Mathematical Society: http://www.ams.org/publicoutreach/feature-column/fcarc-mulcahy6 “How Long Does It Take To Catch A Wild Kangaroo?” by Ravi Montenegro and Prasad Tetali: https://arxiv.org/pdf/0812.0789.pdf *** LINKS *** Vsauce2: Twitter: https://twitter.com/VsauceTwo Facebook: https://www.facebook.com/VsauceTwo Talk Vsauce2 in the TCU Discord: https://discord.gg/tyh7AVm Hosted and Produced by Kevin Lieber Instagram: http://instagram.com/kevlieber Twitter: https://twitter.com/kevinlieber Podcast: https://www.youtube.com/thecreateunknown Research And Writing by Matthew Tabor https://twitter.com/TaborTCU Editing by John Swan https://www.youtube.com/channel/UCJuSltoYKrAUKnbYO5EMZ2A Huge Thanks To Paula Lieber https://www.etsy.com/shop/Craftality Select Music By Jake Chudnow: http://www.youtube.com/user/JakeChudnow Get Vsauce's favorite science and math toys delivered to your door! https://www.curiositybox.com/ #learning #education #vsauce2

Upgrade Your Tech Today

AI-recommended products based on this video

Loading...
2Pack 10ft iPhone Charger 90 Degree Lightning Cable Right Angle Long USB Charging Cord Compatible with Apple iPhone 14 13 12 11 Pro Max XS XR X 8 7 6 5 Plus iPad iPod

2Pack 10ft iPhone Charger 90 Degree Lightning Cable Right Angle Long USB Charging Cord Compatible with Apple iPhone 14 13 12 11 Pro Max XS XR X 8 7 6 5 Plus iPad iPod

(2,193)
$14.24
FREE delivery Sat, Jun 14 on your first order
400+ bought in past month
Loading...
Magnetic Wireless Charger for iPhone: Fodable 3 in 1 Charging Station for Multiple Apple Devices - Travel Charging Pad Dock for Apple Watch iPhone 16 15 14 13 12 Pro Max Plus & Airpod Global Recycled Standard

Magnetic Wireless Charger for iPhone: Fodable 3 in 1 Charging Station for Multiple Apple Devices - Travel Charging Pad Dock for Apple Watch iPhone 16 15 14 13 12 Pro Max Plus & Airpod Global Recycled Standard

(656)
$49.99
PrimeFREE delivery Sat, Jun 14
100+ bought in past month
Loading...
Magnetic Wireless Charger for iPhone - 3 in 1 Mag-Safe Charging Station for Multiple Devices Apple - Charger Stand Dock for Apple Watch iPhone 16 15 14 13 12 Pro Max Plus Airpods

Magnetic Wireless Charger for iPhone - 3 in 1 Mag-Safe Charging Station for Multiple Devices Apple - Charger Stand Dock for Apple Watch iPhone 16 15 14 13 12 Pro Max Plus Airpods

(750)
$59.99
PrimeFREE delivery Sat, Jun 14
Loading...
iPhone Charger [Apple MFi Certified] 3FT, 3Pack USB A to Lightning Cable Braided Fast Charging Apple Cord Compatible with iPhone 14 13 12 11 Pro Max XS XR X 8 7 6 5 Plus iPad/iPod/AirPods

iPhone Charger [Apple MFi Certified] 3FT, 3Pack USB A to Lightning Cable Braided Fast Charging Apple Cord Compatible with iPhone 14 13 12 11 Pro Max XS XR X 8 7 6 5 Plus iPad/iPod/AirPods

(5,626)
$17.99
FREE delivery Sat, Jun 14 on your first order
50+ bought in past month
Loading...
2Pack 10ft iPhone Charger 90 Degree Lightning Cable Right Angle Long USB Charging Cord Compatible with Apple iPhone 14 13 12 11 Pro Max XS XR X 8 7 6 5 Plus iPad iPod

2Pack 10ft iPhone Charger 90 Degree Lightning Cable Right Angle Long USB Charging Cord Compatible with Apple iPhone 14 13 12 11 Pro Max XS XR X 8 7 6 5 Plus iPad iPod

(2,193)
$14.24
FREE delivery Sat, Jun 14 on your first order
400+ bought in past month
Loading...
Magnetic Wireless Charger for iPhone: Fodable 3 in 1 Charging Station for Multiple Apple Devices - Travel Charging Pad Dock for Apple Watch iPhone 16 15 14 13 12 Pro Max Plus & Airpod Global Recycled Standard

Magnetic Wireless Charger for iPhone: Fodable 3 in 1 Charging Station for Multiple Apple Devices - Travel Charging Pad Dock for Apple Watch iPhone 16 15 14 13 12 Pro Max Plus & Airpod Global Recycled Standard

(656)
$49.99
PrimeFREE delivery Sat, Jun 14
100+ bought in past month
Loading...
Magnetic Wireless Charger for iPhone - 3 in 1 Mag-Safe Charging Station for Multiple Devices Apple - Charger Stand Dock for Apple Watch iPhone 16 15 14 13 12 Pro Max Plus Airpods

Magnetic Wireless Charger for iPhone - 3 in 1 Mag-Safe Charging Station for Multiple Devices Apple - Charger Stand Dock for Apple Watch iPhone 16 15 14 13 12 Pro Max Plus Airpods

(750)
$59.99
PrimeFREE delivery Sat, Jun 14
Loading...
iPhone Charger [Apple MFi Certified] 3FT, 3Pack USB A to Lightning Cable Braided Fast Charging Apple Cord Compatible with iPhone 14 13 12 11 Pro Max XS XR X 8 7 6 5 Plus iPad/iPod/AirPods

iPhone Charger [Apple MFi Certified] 3FT, 3Pack USB A to Lightning Cable Braided Fast Charging Apple Cord Compatible with iPhone 14 13 12 11 Pro Max XS XR X 8 7 6 5 Plus iPad/iPod/AirPods

(5,626)
$17.99
FREE delivery Sat, Jun 14 on your first order
50+ bought in past month
Loading...
Apple AirPods Pro 2 Wireless Earbuds, Bluetooth Headphones, Active Noise Cancellation, Transparency, Personalized Spatial Audio, High-Fidelity Sound, H2 Chip, USB-C Charging

Apple AirPods Pro 2 Wireless Earbuds, Bluetooth Headphones, Active Noise Cancellation, Transparency, Personalized Spatial Audio, High-Fidelity Sound, H2 Chip, USB-C Charging

(26,678)
$259.99$194.99
FREE delivery Wed, Aug 20
5K+ bought in past month
Loading...
3 in 1 Charging Station for iPhone, Wireless Charger for iPhone 16 15 14 13 12 11 X Pro Max & Apple Watch - Charging Stand Dock for AirPods Global Recycled Standard

3 in 1 Charging Station for iPhone, Wireless Charger for iPhone 16 15 14 13 12 11 X Pro Max & Apple Watch - Charging Stand Dock for AirPods Global Recycled Standard

(30,415)
$30.39
Prime
1K+ bought in past month
Loading...
3 in 1 Charging Station for iPhone, Wireless Charger for iPhone 16 15 14 13 12 11 X Pro Max & Apple Watch - Charging Stand Dock for AirPods (Blue) Global Recycled Standard

3 in 1 Charging Station for iPhone, Wireless Charger for iPhone 16 15 14 13 12 11 X Pro Max & Apple Watch - Charging Stand Dock for AirPods (Blue) Global Recycled Standard

(27,328)
$39.99
PrimeFREE delivery Sat, Jun 14
100+ bought in past month
Loading...
Wireless Charger for iPhone- 3 in 1 Charging Station for iPhone 16/15/14/13/12/Pro Max/Pro/Mini/Plus, Apple Watch 10/9/8/7/SE/6/5/4/3/2/1/Ultra2/Ultra, AirPods pro/2/3/4

Wireless Charger for iPhone- 3 in 1 Charging Station for iPhone 16/15/14/13/12/Pro Max/Pro/Mini/Plus, Apple Watch 10/9/8/7/SE/6/5/4/3/2/1/Ultra2/Ultra, AirPods pro/2/3/4

(27)
$27.99
FREE delivery Sat, Jun 14 on your first order
Loading...
Anker USB C Charger Cable (6ft 100W, 2Pack), USB 2.0 Type C Fast Charging Cable for iPhone 15 / 15Pro / 15Plus / 15ProMax MacBook Pro 2020, iPad Pro 2020, iPad Air 4, Samsung Galaxy S23+/S23 Ultra ClimatePartner certified

Anker USB C Charger Cable (6ft 100W, 2Pack), USB 2.0 Type C Fast Charging Cable for iPhone 15 / 15Pro / 15Plus / 15ProMax MacBook Pro 2020, iPad Pro 2020, iPad Air 4, Samsung Galaxy S23+/S23 Ultra ClimatePartner certified

(44,904)
$17.99
FREE delivery Wed, Aug 20 on your first order
6K+ bought in past month
Loading...
Anker USB C Cable, [2-Pack, 6 ft] Type C Charger Premium Nylon USB Cable, USB A to Type C Charging Cable Fast Charge for Samsung Galaxy S10 S10+ / Note 8, LG V20 and Other USB C Charger (Black)

Anker USB C Cable, [2-Pack, 6 ft] Type C Charger Premium Nylon USB Cable, USB A to Type C Charging Cable Fast Charge for Samsung Galaxy S10 S10+ / Note 8, LG V20 and Other USB C Charger (Black)

(103,365)
$13.49
5K+ bought in past month
Loading...
Anker Nano USB C Wall Charger,45W Fast Charging Smart Display Charger,with 180°Foldable Plug,Smart Recognition,Built-in Care Mode,for iPhone17/16/15 (Non-Battery,One USB-C Port,No Cable Included) ClimatePartner certified

Anker Nano USB C Wall Charger,45W Fast Charging Smart Display Charger,with 180°Foldable Plug,Smart Recognition,Built-in Care Mode,for iPhone17/16/15 (Non-Battery,One USB-C Port,No Cable Included) ClimatePartner certified

(698)
$39.99
FREE delivery Wed, Mar 4
1K+ bought in past month
Loading...
Anker Nano USB C Wall Charger,45W Fast Charging Smart Display Charger,with 180°Foldable Plug,Smart Recognition,Built-in Care Mode,for iPhone17/16/15 (Non-Battery,One USB-C Port,No Cable Included) ClimatePartner certified

Anker Nano USB C Wall Charger,45W Fast Charging Smart Display Charger,with 180°Foldable Plug,Smart Recognition,Built-in Care Mode,for iPhone17/16/15 (Non-Battery,One USB-C Port,No Cable Included) ClimatePartner certified

(698)
$39.99
FREE delivery Wed, Mar 4
1K+ bought in past month
Loading...
MRGLAS 2025 Upgraded Magsafe Car Mount Vacuum Suction Magnetic Phone Holder Car, 360° Foldable Adjustable Suction Cup Phone Stand [89+LBS Suction & 2800gf Magnetic] for Car Accessories iPhone17/16

MRGLAS 2025 Upgraded Magsafe Car Mount Vacuum Suction Magnetic Phone Holder Car, 360° Foldable Adjustable Suction Cup Phone Stand [89+LBS Suction & 2800gf Magnetic] for Car Accessories iPhone17/16

(1,124)
$27.19
1K+ bought in past month
Loading...
OHLPRO Tablet Car Mount Universal Tablet Holder for Car Windshield Dash Dashboard, 360 Degree Rotation,TPU Suction Gel Stick, for iPad Mini 4/3/2/1Samsung Galaxy Size 7"- 10.5" Tablet Mount

OHLPRO Tablet Car Mount Universal Tablet Holder for Car Windshield Dash Dashboard, 360 Degree Rotation,TPU Suction Gel Stick, for iPad Mini 4/3/2/1Samsung Galaxy Size 7"- 10.5" Tablet Mount

(1,515)
$18.99
FREE delivery Tue, Jun 17 on your first order
Loading...
Magnetic Car Mount Air Vent Cell Phone Holder, Universal Vehicle Dash Dashboard Ac Airvent Cellphone Magic Stand with Clip Hook, for iPhone 16 15 Samsung Lenovo Google etc

Magnetic Car Mount Air Vent Cell Phone Holder, Universal Vehicle Dash Dashboard Ac Airvent Cellphone Magic Stand with Clip Hook, for iPhone 16 15 Samsung Lenovo Google etc

(128)
$21.99
FREE delivery Tue, Jun 17 on your first order
Loading...
AINOPE Phone Holder for Car Vent 2025 Gravity Air Vent Car Phone Holder Mount for iPhone 17 Pro Max Vent Clip Hand Free Cell Phone Car Mount for iPhone Air 17 16 Pro Max Samsung S25 Car Accesorries

AINOPE Phone Holder for Car Vent 2025 Gravity Air Vent Car Phone Holder Mount for iPhone 17 Pro Max Vent Clip Hand Free Cell Phone Car Mount for iPhone Air 17 16 Pro Max Samsung S25 Car Accesorries

(30,765)
$18.98
FREE delivery Sat, Jan 3 on your first order
2K+ bought in past month
Loading...
Spigen Spigen Tempered Glass Screen Protector [GlasTR EZ FIT] designed for Nintendo Switch 2 (2025) - 2 Pack

Spigen Spigen Tempered Glass Screen Protector [GlasTR EZ FIT] designed for Nintendo Switch 2 (2025) - 2 Pack

(0)
$29.99
Loading...
SanDisk 256GB Ultra microSDXC UHS-I Memory Card with Adapter - Up to 150MB/s, C10, U1, Full HD, A1, MicroSD Card - SDSQUAC-256G-GN6MA

SanDisk 256GB Ultra microSDXC UHS-I Memory Card with Adapter - Up to 150MB/s, C10, U1, Full HD, A1, MicroSD Card - SDSQUAC-256G-GN6MA

(217,850)
$24.63$19.70
FREE delivery Wed, Aug 20 on your first order
5K+ bought in past month
Loading...
SanDisk Ultra Flair USB 3.0 64GB Flash Drive High Performance up to 150MB/s (SDCZ73-064G-G46)

SanDisk Ultra Flair USB 3.0 64GB Flash Drive High Performance up to 150MB/s (SDCZ73-064G-G46)

(191,288)
$12.53$11.33
FREE delivery Sun, Aug 10 on your first order
1K+ bought in past month
Loading...
SanDisk Ultra 3D NAND 4TB Internal SSD - SATA III 6 Gb/s, 2.5 Inch /7 mm, Up to 560 MB/s - ‎SDSSDH3-4T00-G26

SanDisk Ultra 3D NAND 4TB Internal SSD - SATA III 6 Gb/s, 2.5 Inch /7 mm, Up to 560 MB/s - ‎SDSSDH3-4T00-G26

(35,424)
$359.99
FREE delivery Tue, Jun 17
Loading...
SanDisk Ultra Dual Drive Luxe USB 3.1 Type-C 32GB Flash Drive for Acer Convertible 2-in-1 Laptops Aspire 1, Chromebook Spin 713 (SDDDC4-032G-G46) Gen1 Bundle with (1) Everything But Stromboli Lanyard

SanDisk Ultra Dual Drive Luxe USB 3.1 Type-C 32GB Flash Drive for Acer Convertible 2-in-1 Laptops Aspire 1, Chromebook Spin 713 (SDDDC4-032G-G46) Gen1 Bundle with (1) Everything But Stromboli Lanyard

(9)
$79.11
Loading...
Anker USB C Cable, [2-Pack, 6 ft] Type C Charger Premium Nylon USB Cable, USB A to Type C Charging Cable Fast Charge for Samsung Galaxy S10 S10+ / Note 8, LG V20 and Other USB C Charger (Black)

Anker USB C Cable, [2-Pack, 6 ft] Type C Charger Premium Nylon USB Cable, USB A to Type C Charging Cable Fast Charge for Samsung Galaxy S10 S10+ / Note 8, LG V20 and Other USB C Charger (Black)

(103,365)
$13.49
5K+ bought in past month
Loading...
Magnetic Wireless Charger for iPhone - 3 in 1 Mag-Safe Charging Station for Multiple Devices Apple - Charger Stand Dock for Apple Watch iPhone 16 15 14 13 12 Pro Max Plus Airpods

Magnetic Wireless Charger for iPhone - 3 in 1 Mag-Safe Charging Station for Multiple Devices Apple - Charger Stand Dock for Apple Watch iPhone 16 15 14 13 12 Pro Max Plus Airpods

(750)
$59.99
PrimeFREE delivery Sat, Jun 14
Loading...
4-in-1 Wireless Magnetic Power Bank 10800mAh Portable Charger with iWatch Charger, QC4.0+20W PD Fast Charging USB C Battery Pack for Magsafe, iPhone 16/15/14/13/12 Series, Apple Watch etc. (White)

4-in-1 Wireless Magnetic Power Bank 10800mAh Portable Charger with iWatch Charger, QC4.0+20W PD Fast Charging USB C Battery Pack for Magsafe, iPhone 16/15/14/13/12 Series, Apple Watch etc. (White)

(581)
$42.95
PrimeFREE delivery Sat, Jun 14
Loading...
eazpower for Magsafe Power Bank 10000mAh, Magnetic Battery Pack Wireless, 20W PD Fast Charging, Compact Portable Charger with Built-in Cables and Stand for iPhone 16/15/14/13/12/ Apple Watch/Airpods

eazpower for Magsafe Power Bank 10000mAh, Magnetic Battery Pack Wireless, 20W PD Fast Charging, Compact Portable Charger with Built-in Cables and Stand for iPhone 16/15/14/13/12/ Apple Watch/Airpods

(330)
$39.99
PrimeFREE delivery Sat, Jun 14
200+ bought in past month