Trees Are Freaking Awesome!

Hope this was worth the wait! So many people helped with this video: Prof John Sperry, Hank Green, Henry Reich, CGP Grey, Prof Poliakoff, my mum filmed for me in beautiful Stanley Park and Jen S helped with the fourth version of the script. Prof John Sperry Hank Green (SciShow) Henry Reich (minutephysics) CGP Grey Prof Poliakoff (Periodic Videos) Also thanks to the Palais de la Decouverte – they helped me with the whole vacuum pump setup in Paris. No, I could not actually suck water up 10m – I did about 4m, but the vacuum pump was easily able to do it and I saw spontaneous boiling on all of our various trials. Footage from this may end up on 2Veritasium. Trees create immense negative pressures of 10’s of atmospheres by evaporating water from nanoscale pores, sucking water up 100m in a state where it should be boiling but can’t because the perfect xylem tubes contain no air bubbles, just so that most of it can evaporate in the process of absorbing a couple molecules of carbon dioxide. Now I didn’t mention the cohesion of water (that it sticks to itself well) but this is implicit in the description of negative pressure, strong surface tension etc.

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Comments ( 25 )
  1. PtOrangEstudios
    November 4, 2012 at 11:07 pm

    No offence but you aren’t really giving a good explanation of why god doesn’t exist to this person. Just because you criticize his resources doesn’t make you right. Submit evidence that shows without a doubt why they are incorrect (I don’t believe in god in the classical sense but if you can’t argue properly it’s embarrassing for people who share your opinion)

  2. PtOrangEstudios
    November 4, 2012 at 11:29 pm

    I know this was a while ago but ummmm yeah. The earth was formed from a variety of random crap that was floating about (and yes I could explain how dieing stars create heavier elements and how these become compounds but I’m not going to) When it formed the earth was more than ROCK, Not only that but during this period thousands of meteorites pummelled the earth they had amino acids and proteins the building blocks for cells. They also carried water, everything has an explanation without a god

  3. DivergentMind
    November 5, 2012 at 12:26 am


  4. Loomr
    November 5, 2012 at 12:27 am

    Hey I just want to say a big thank you for existing and doing what you are doing 🙂 , I love to see smart, young (and old), positive people doing something worthwhile in their lives and sharing it through videos. You know there’re many things that you can do as a young person, many different lifestyle options from partying, listening to certain music, sports and what not, but I don’t think there are too many examples of the kind of joy that shines through these videos. Love you all.

  5. elishasaul
    November 5, 2012 at 12:36 am

    Secrecy is the nature of corruption. We’re not gonna see Catholic priests, or Protestant ministers, or televangelists running through the streets shouting gleefully that they’re stealing people’s money. But yet we know that’s what they’re doing, don’t we? The identical weakness towards corruption that exists in religious men, also exists in men who decide to study science instead (or anything else). And the people who love science don’t wanna see it anymore than the people who love religion.

  6. satanicmouse98
    November 5, 2012 at 1:00 am

    Great video

  7. quiro1001
    November 5, 2012 at 1:26 am

    stupid vegans 

  8. sumdedgie
    November 5, 2012 at 2:26 am

    Could the evaporation also be used for a cooling effect to prevent the top of the tree from scorching? Just a thought, and interested if it is viable at all… If it does or doesn’t make sense just let me know 🙂

  9. SormaNo4
    November 5, 2012 at 3:10 am

    Biology is Amazing. To think I used to hate it…

  10. Sarahminitann
    November 5, 2012 at 3:27 am

    Why do I find arguments of religion and science on every video I watch? I am religious but I never go and argue if someone say that it is no God or something like that, I say ”we belive what we want to but I dont want to argue of our thoughts”. Can’t everybody just enjoy the freaking video and stop argue? Seriously

    – 13 year old girl

  11. lethalrumble1
    November 5, 2012 at 4:27 am

    Hydrogen bonding.

  12. chrsrumbaugh
    November 5, 2012 at 4:52 am

    Thats the words I couldn’t think of, the molecules pulling on each other and their container, now it makes total sense! Thank you.

  13. kleinlui
    November 5, 2012 at 5:17 am

    What keeps water from seperating so that there is such a space without molecules? The same effects that create surface tension?

  14. Denuhm
    November 5, 2012 at 6:12 am

    I’m a botanist, thank you for saving me SO MUCH TIME. People always argue with me about this >_>

  15. alin116
    November 5, 2012 at 6:21 am

    oh, look ViHart is there, too 😀

  16. BananaaRAWR
    November 5, 2012 at 6:46 am

    I almost peed myself in excitement when I saw Hank 😀

  17. jawbone2000
    November 5, 2012 at 6:46 am

    Sorry but there is something that i don’t quite understand. is the 10 meter limit calculated for a specific thickness of tube, does this not mean that the narrower the tube, the higher is the limit? can the limit be calculated mathematicaly? maybe there is no need for the negative pressure (regarding the fact that with 1 meter capilary rise, the force needed for sucking watter may be smaller) thanks 😀

  18. Mandy Lou
    November 5, 2012 at 7:04 am

    Wow, I was way off in my own guesses… I would have never thought of this one… XD The more you know!!

  19. umjackd
    November 5, 2012 at 7:50 am

    Yep, that’s Hank Green. He does a lot of other stuff too!

  20. umjackd
    November 5, 2012 at 8:02 am

    At 7:02 aaaaand at 7:21, Vihart is chilling off to the side. 🙂

  21. umjackd
    November 5, 2012 at 8:40 am

    It’s fine for people to have a religious opinion about religion, spirituality, ethics, whatever. But not when it comes to science.

  22. Entraya Korsbakke
    November 5, 2012 at 9:04 am

    The only corruption i know of in the scientific community are those who send out bad, incorrect, or overblown data. Religion sometimes makes use of this bad science to support their claims. Other than that, science itself is neither good nor bad, and that is usually true about the scientists studying it

  23. robeshko
    November 5, 2012 at 9:58 am

    Great example!

  24. robeshko
    November 5, 2012 at 10:26 am

    Sounds like the ego and the id by sigmund freud lol, now that was a hard book to follow but any who you’re not wrong. I wonder if the media has stumbled on such great knowledge…

  25. Ignacio Visus
    November 5, 2012 at 11:24 am

    Thank you so much for these awesome videos!

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