All the large-scale structure in the universe may owe its existence to nothing.
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Thanks to Patreon supporters:
Bryan Baker, Donal Botkin, Tony Fadell, Saeed Alghamdi

Let's see how clearly I can explain this. We think of empty space as, well... empty, the epitome of nothingness. But as our understanding of physics has evolved we have realized that it's not truly empty. Space is filled with fields. There is a field for every subatomic particle. One for electrons, up quarks, down quarks, neutrinos and so on. In empty space these fields are basically zero, flat, nil. But it's impossible to make them perfectly zero so there are always some quantum fluctuations in the fields, even in a perfect vacuum. These are sometimes called virtual particles but they should really just be thought of as little disturbances in the field. Vacuum fluctuation play a role mediating the interactions of subatomic particles but they don't really have an impact on the large-scale structure of the universe, EXCEPT during inflation, right after the big bang when the universe increased in size 10^26 times. Due to this rapid expansion, those tiny fluctuations were blown up to the scale of the observable universe. And we know this by looking at the cosmic microwave background radiation where we can see slightly hotter and cooler parts of the early universe that correspond to density fluctuations. And it is these density fluctuations that allowed matter to clump together into large structures like the gigantic gas clouds that would go on to contain stars and planets. In case the video isn't clear, this is what I've been trying to say.

Animations by Gustavo Rosa

This video was sponsored in part by Dyson #ad

These are the molecular machines inside your body that make cell division possible. Animation by Drew Berry at the Walter and Eliza Hall Institute of Medical Research. http://wehi.tv

Special thanks to Patreon supporters:
Joshua Abenir, Tony Fadell, Donal Botkin, Jeff Straathof, Zach Mueller, Ron Neal, Nathan Hansen

Support Veritasium on Patreon: http://ve42.co/patreon

Every day in an adult human roughly 50-70 billion of your cells die. They may be damaged, stressed, or just plain old - this is normal, in fact it’s called programmed cell death.

To make up for that loss, right now, inside your body, billions of cells are dividing, creating new cells.

And cell division, also called mitosis, requires an army of tiny molecular machines.DNA is a good place to start - the double helix molecule that we always talk about.

This is a scientifically accurate depiction of DNA. If you unwind the two strands you can see that each has a sugar phosphate backbone connected to the sequence of nucleic acid base pairs, known by the letters A,T,G, and C.

Now the strands run in opposite directions, which is important when you go to copy DNA. Copying DNA is one of the first steps in cell division. Here the two strands of DNA are being unwound and separated by the tiny blue molecular machine called helicase.
It literally spins as fast as a jet engine! The strand of DNA on the right has its complimentary strand assembled continuously but the other strand is more complicated because it runs in the opposite direction.
So it must be looped out with its compliment strand assembled in reverse, section by section. At the end of this process you have two identical DNA molecules, each one a few centimeters long but just a couple nanometers wide.

To prevent the DNA from becoming a tangled mess, it is wrapped around proteins called a histones, forming a nucleosome.
These nucleosomes are bundled together into a fiber known as chromatin, which is further looped and coiled to form a chromosome, one of the largest molecular structures in your body.
You can actually see chromosomes under a microscope in dividing cells - only then do they take on their characteristic shape.

The process of dividing the cell takes around an hour in mammals. This footage is from a time lapse. You can see how the chromosomes line up on the equator of the cell. When everything is right they are pulled apart into the two new daughter cells, each one containing an identical copy of DNA.
As simple as it looks, this process is incredibly complicated and requires even more fascinating molecular machines to accomplish it. Let’s look at a single chromosome. One chromosome consists of two sausage-shaped chromatids - containing the identical copies of DNA made earlier. Each chromatid is attached to microtubule fibers, which guide and help align them in the correct position. The microtubules are connected to the chromatid at the kinetochore, here colored red.
The kinetochore consists of hundreds of proteins working together to achieve multiple objectives - it’s one of the most sophisticated molecular mechanisms inside your body. The kinetochore is central to the successful separation of the chromatids. It creates a dynamic connection between the chromosome and the microtubules. For a reason no one’s yet been able to figure out, the microtubules are constantly being built at one end and deconstructed at the other.
While the chromosome is still getting ready, the kinetochore sends out a chemical stop signal to the rest of the cell, shown here by the red molecules, basically saying this chromosome is not yet ready to divide
The kinetochore also mechanically senses tension. When the tension is just right and the position and attachment are correct all the proteins get ready, shown here by turning green.
At this point the stop signal broadcasting system is not switched off. Instead it is literally carried away from the kinetochore down the microtubules by a dynein motor. This is really what it looks like. It has long ‘legs’ so it can avoid obstacles and step over the kinesins, molecular motors walking the other direction.

Studio filming by Raquel Nuno

Why do spikes form on ice cubes? Without them the world would be vastly different.
Awesome Jingle by Accent: http://bit.ly/AccentVe
Thanks to Prof. Stephen Morris from UofT: http://bit.ly/1GFANBE

Filmed in part by Martin Marek in Olomouc, Czech Republic

Time lapse of a growing ice spike by Lesley Hill, Russ Sampson and Edward Lozowski, with technical help by Kenny Lozowski.

Ice spike image by Dan and Lynn Wolaver: http://wolaver.org/log/09.11.29.htm

Concerned ice spike video by rocknut420: https://www.youtube.com/watch?v=GwM0we_t94c

Earth footage courtesy of NASA: https://www.youtube.com/watch?v=G4BPOEmugtM

Ice vase image by PgunnG: http://www.reddit.com/r/pics/c....omments/1voeqk/so_i_

Second ice vase image by A K Haart: http://akhaart.blogspot.com/20....15_01_01_archive.htm

Scientists are being inspired by nature to design the next generation of security devices. Arrays of nanoscale holes create beautiful reflected colours that are almost impossible to forge. This video was supported by TechNyou - check out their series on logical fallacies: http://bit.ly/WBsD31

Soon these nanoscale security devices could replace holograms. They are many times more reflective than holograms, and although the structures are smaller scale, they are lower aspect ratio and therefore easy to manufacture in bulk.

The electron wiggle simulation is from PhET, the best physics simulations ever: http://phet.colorado.edu

Special thanks to Thomas from Copenhagen who showed me around the city including the science museum where he assisted with the soap bubble demonstration.

Clint Landrock is the Chief Technology Officer for Nanotech Securities: http://www.nanosecurity.ca

Music is "Firefly in a Fairytale" by Gareth Coker

SEE THE SETUP FIRST: http://bit.ly/bulletblock
Click here for the explanation: http://bit.ly/1dHPk2K
Spinning Tube: http://bit.ly/Va43Z6
Spinning Disk: http://bit.ly/14MSKsT
Chain Drop: http://bit.ly/1713VQO
Spool: http://bit.ly/14wkxfn

Special Thanks to:
Henry (MinutePhysics): http://www.youtube.com/minutephysics
Destin (Smarter Every Day): http://www.youtube.com/smartereveryday
Greg and Mitch (ASAP Science): http://youtube.com/asapscience
Elise Andrew (I F***ing Love Science): http://youtube.com/iflscience

Thanks to everyone at RIT and Dickinson College who helped with the making of this video:
Rochester Institute of Technology
Robert Teese, Katelyn Wilkerson, Andrew Gillie, Andrew Stidwill

Dickinson College
This experiment was the brainchild of David Jackson based on a demo at Princeton.
Priscilla Laws, Catrina Hamilton-Drager, Maxine Willis

High-speed camera support:
Charles Zwemer and Bria Antoine

Music Licensed from CueSongs.com: The Temper Trap "Love Lost"
Lights Motion "Epilogue"

Lucía interpreta "Somebody to love" de Queen en la semifinal de la cuarta edición de La Voz Kids.

Si estás en España:
- Puedes ver este vídeo en http://www.telecinco.es/lavozkids/ y el programa completo en http://www.mitele.es/programas....-tv/la-voz-kids/0000

- Descárgate la app de La Voz Kids para no perderte nada del programa http://mdia.st/1i8iNqu

Si estás fuera de España:
- Suscripción/Suscription: http://bit.ly/2mqAtky

Lyka interpreta "Photograph" de Ed Sheeran en las cuartas audiciones a ciegas de la cuarta edición de La Voz Kids.

Si estás en España:
- Puedes ver este vídeo en http://www.telecinco.es/lavozkids/ y el programa completo en http://www.mitele.es/programas....-tv/la-voz-kids/0000

- Descárgate la app de La Voz Kids para no perderte nada del programa http://mdia.st/1i8iNqu

Si estás fuera de España:
- Suscripción/Suscription: http://bit.ly/2mqAtky

What is the specious present? And how do our brains perceive time?
Get a 30-day free trial on Audible: http://bit.ly/AudibleVe
More info about this topic: http://wke.lt/w/s/z8TeR

For a report on ABC's Catalyst program (http://www.abc.net.au/catalyst/), I visited the Large Hadron Collider in Switzerland to find out what is being done now that the Higgs Boson has been discovered.

Although its mass has been measured around 125-126 GeV most of the other properties of the particle remain unknown. Its spin appears to be 0 or 2 but more results are required to nail this down. If it is the standard model Higgs, the spin should be 0, resulting in a fairly symmetric distribution of decay products in the detectors.

We may know this year if it's not the standard model Higgs - this would be the case if it doesn't decay into specific particles with the expected frequency. However if it is the standard model Higgs, it may take many more years to be certain. The large hadron collider will be shut down in 2013 for upgrades so that higher energies up to 14 TeV can be tested. Right now the LHC is operating at 8 TeV. The next announcement is expected in December.

The nutrient content of food is declining. Is it because of soil depletion, selective breeding, or... something else?
Watch my new documentary, VITAMANIA: http://ve42.co/vita

I came across this story as I was making the film Vitamania. When you ask sellers of vitamins why you should take vitamin supplements even if you eat a healthy diet, they will say because our food doesn't contain all the nutrients it once did. This is supposedly due to soil depletion, cold storage, food ripening off the vine, and global transport of out-of-season foods. And to an extent this is true. Foods contain the greatest amount of nutrients if they are eaten soon after they are harvested. An unexpected source of nutrient decline is the increasing amount of carbon dioxide in the atmosphere. It causes plants to grow faster and bulk up on carbs but at the expense of other nutrients, so in percentage terms the amount of nutrients are actually declining. For now this decline is modest so supplementing with vitamin pills is probably unnecessary for most people with a healthy diet but it may be a concern in future.

Thanks to Kate Pappas & Chris Kamen for writing, producing and filming this video with me
Edited by Lucy McCallum
Sound mix by Wayne Hyett
Fact Checking by Calvin Lee and Claire Smith
Thanks to the Collingwood Children’s Farm and Glenn Fitzgerald from the University of Melbourne & Agriculture Victoria

Further Reading:

https://www.sciencedirect.com/....science/article/pii/
https://www.ncbi.nlm.nih.gov/p....ubmed/15637215/?ncbi
http://soils.wisc.edu/facstaff..../barak/poster_galler
https://www.politico.com/agend....a/story/2017/09/13/f
http://www.abc.net.au/news/201....8-05-24/scientists-w

Do negative air ions improve mood, anxiety, depression, alertness?
Part of this video was sponsored by LastPass, click here to find out more: http://bit.ly/2RZZTZk

Special thanks to Prof. Jack Beauchamp and Dr. Nathan Dalleska from Caltech for all their help running these experiments and discussing the research. For more, check out the links below:
http://www.cce.caltech.edu/peo....ple/jesse-l-jack-bea
http://beckmaninstitute.caltech.edu/eac.shtml

If you want to dig into the research on negative ions yourself, I suggest starting with the review studies:

Air ions and mood outcomes: a review and meta-analysis.
Perez V, Alexander DD, Bailey WH.
BMC Psychiatry. 2013 Jan 15;13:29.
https://www.ncbi.nlm.nih.gov/pubmed/23320516

Air ions and respiratory function outcomes: a comprehensive review
Dominik D Alexander, William H Bailey, Vanessa Perez, Meghan E Mitchell, and Steave Su
J Negat Results Biomed. 2013; 12: 14.
https://www.ncbi.nlm.nih.gov/p....mc/articles/PMC38485

Exposure of laboratory animals to small air ions: a systematic review of biological and behavioral studies.
Bailey WH, Williams AL, Leonhard MJ.
Biomed Eng Online. 2018 Jun 5; 17(1):72.
https://www.ncbi.nlm.nih.gov/pubmed/29866122

Thumbnail photography by Raquel Nuno

VFX by Alan Chamberlain

Sound recording by Whitney Clavin

Motion Graphics by Charlie Kilman

Music from Epidemic Sound: http://epidemicsound.com "Capture a Picture 1" and "Seaweed"

Higher: http://bit.ly/blockhigher
Same height: http://bit.ly/SameHeight
Lower: http://bit.ly/BlockLower

Special Thanks to:
Henry (MinutePhysics): http://www.youtube.com/minutephysics
Destin (Smarter Every Day): http://www.youtube.com/smartereveryday
Greg and Mitch (ASAP Science): http://youtube.com/asapscience
Elise Andrew (I F***ing Love Science): http://youtube.com/iflscience

Thanks to everyone at RIT and Dickinson College who helped with the making of this video:
Rochester Institute of Technology
Robert Teese, Katelyn Wilkerson, Andrew Gillie, Andrew Stidwill

Dickinson College
This experiment was the brainchild of David Jackson based on a demo at Princeton.
Priscilla Laws, Catrina Hamilton-Drager, Maxine Willis

High-speed camera support:
Charles Zwemer and Bria Antoine

When a tube spins with an X and an O labelled at either end, why do we see only one letter during the rotation?

Carlos, Antonio y Paco y Kely interpretan "Toda Una Vida" de Antonio Machín en las primeras batallas de la tercera edición de La Voz Kids.

Si estás en España:
- Puedes ver este vídeo en http://www.telecinco.es/lavozkids/ y el programa completo en http://www.mitele.es/programas....-tv/la-voz-kids/0000

- Descárgate la app de La Voz Kids para no perderte nada del programa http://mdia.st/1i8iNqu

Si estás fuera de España:
- Suscripción/Suscription: http://bit.ly/2mqAtky

I've created an educational product to help people learn chemistry!
You can buy it here: http://www.snatoms.com

The sun has been producing light for about five billion years but where does all its energy come from? The most common idea is that the sun is burning gas - like a giant fireball in the sky. If this were true, the sun would have gone out long ago. So how is the sun actually fuelling itself? It is converting its own mass into energy. By combining protons (the nucleus of hydrogen) into helium, it squeezes some mass into energy - 4.3 billion kg per second. It is Einstein's famous E=mc^2 which gives us the quantitative relationship between mass and energy, where c is the speed of light.

Physics of contraptions meant to go faster than light.
Audible: http://bit.ly/AudibleVe
My video about the problem with Facebook: http://bit.ly/PwFB

Special thanks to MinutePhysics for visual effects and Prof. Geraint Lewis for revisions to earlier drafts of this video.

Panem finds power in the radiance of the sun, and the water which rains down upon us! District 5’s Chief Energy Researcher Derek Muller takes CapitolTV on a tour of our nation's cutting edge renewable technologies, and demonstrates one of the largest ‘Kelvin’s Thunderstorm’ experiments ever built to date… all for a brighter and more efficient Panem.

Sanctioned by the Capitol Ministry of Information, DISTRICT VOICES was made with friends from Google - http://artcopycode.com/campaign/lionsgate

For more of Panem’s finest programming, and to register for updates, visit http://CapitolTV.pn
#CapitolTV - #DistrictVoices

The Hunger Games: Mockingjay Part 1 – In theaters November 21
http://TheHungerGamesExplorer.com
#Mockingjay

The truth, with photons.
I hope I've articulated everything clearly in this video. If not, I'll clarify in comments. Thanks to everyone who appears in this video and thanks to everyone who watches this video!

Veritasium is of course a combination of the latin 'veritas' meaning truth, and the common element ending 'ium'. I guess this is my version of the 'draw my life' craze that rolled through YouTube many years ago. Except I wanted to tell my story with the actual moments, the photons, the stored magnetic states. There's something about that which is so important to me (because I think the alternative involves fooling yourself) which is why I'm so fascinated by film and video.

One of my inspirations for the name Veritasium came from the end of the poem Ode on a Grecian Urn by John Keats, in which he writes:
"Beauty is truth, truth beauty,—that is all
Ye know on earth, and all ye need to know."

Special thanks to Patreon supporters:
Tony Fadell, Donal Botkin, Michael Krugman, Jeff Straathof, Zach Mueller, Ron Neal, Nathan Hansen, Yildiz Kabaran,
Terrance Snow, Stan Presolski

Music from http://epidemicsound.com
Magnified X1 - Gunnar Johnsen
Fluorescent Lights - Martin Gauffin
Dissolving Patterns - Ebb & Flod
Luna - Ebb & Flod

Additional music by Kevin MacLeod: http://incompetech.com
Sneaky Snitch

When air is compressed very quickly, it can reach high temperatures. In this demonstration we show how cotton wool can reach the point of auto-ignition by quick compression of air in the fire syringe.