How Plants Tell Time

[@Sciencerely]

As a scientist I was highly fascinated when I firstly heard about these oscillations in nature. Of course not only plants but also humans have a lot of so called circadian rythms (meaning that we have highly regulated protein oscillations over a day). A great example here are circadian rythms which regulate our sleep patterns (they "make" us tired in the evening). Since these rythms are partially controlled by our own body (and not only daylight) we experience difficulties in falling asleep when we travel long distances by plane (jet lag). Intriguingly, newborns do not have these proper rythms and therefore they wake up at random times in the middle of the night (parents will relate). Although I have a small channel, I am planning to make a video about this topic since there are also interesting disorders associated with it!

[@VariantAEC]

Going to talk about cryptochromes? Neat stuff to be sure. Maybe you discussions will be different than Sci-Show's older videos on mammalian circadian rhythms?

[@Byunnlby]

For a scientist, you really don't know how to construct a sentence.

[@tiffyw92]

Plants were the OG sundials before it was cool.

[@ooooneeee]

There are even cyanobacteria with circadian rhythms. Nature is amazing.

[@raychang8648]

Interesting. Can you explain why evening primrose and dragonfruit flowers open big after dark? You'd think that there wouldn't be any active insects to pollinate those flowers at that time. Here in Taiwan, those dragonfruit flowers can be huge!

[@aaron1232006]

I usually have a clock in my back garden for the flowers know what time it is

[@desp8161]

Most gardeners don't do this but it's really important. Thank you.

[@aaron1232006]

@@stevenutter3614 somebody doesn't like jokes

[@helgrind8493]

@I like Green Unless they have the cape! Then they can make the wooooooosh noises

[@cherryRedStilettos]

i found mine really respond to a cukoo clock best. might be it reminds them of birds? hmm. ponderances. :)

[@ssatva]

5:00 "...able to keep track of time, and react appropriately..." So more sophisticated than my teenage self... *sigh* okay, current adult self, is what you're saying here?

[@TrekkieBrie]

You guys should talk about C3 & C4 plants and temperature! Also, this reminded me that I don't miss my botany courses.

[@elizabethebloem249]

Plant development and Average Daily Temperature would be cool to learn more about!

[@TrekkieBrie]

@@existenceisillusion6528 I was a physics major till I swapped to natural science. I can promise your high level maths will likely be easier than botany lol. I've never in my life struggled so hard in a class.

[@TrekkieBrie]

@@existenceisillusion6528 yeha no, my professor is only hanging onto his job via tenure. He gives us about 200 PowerPoint slides a test and just says okay study this. Then when the exam rolls around it's written in a way to purposefully confuse you. I like my University, and I love 90% of my professors, there are exceptions though lol.

[@TrekkieBrie]

@@existenceisillusion6528 haha I'll just say that rarely does a "rate my professor" score get that low. Only 13% would take him again.

[@Hidemyname78]

I wish you would have gone deeper into this I am so fascinated by this subject i live in florida and have come across a few plants thay move when touched it looks like a fern i dont know but i can sit and watch it for hours i love it

[@TitanUranusOfficial]

Finally a video explaining the plant equivalent of the circadian. It's about time.....

[@sooskca]

What's up? Just pumping my pulvinus.

[@Beutimus]

I'm glad I'm not the only one who giggled at 'Pulvinus'

[@Yngdady]

If I did nothing but photosynthesize every day for millions of years, I'd be aware of the time of day, too

[@nolanwestrich2602]

I see that you're hypothetically a plant _species_ here, not just an individual plant.

[@VariantAEC]

The distinct lack of complicated sciency naming conventions used for some plant functions just indicates that no one knows what the heck they do!

[@abbieq11]

Telling time usually requires a mouth, Hank.

[@medokn99]

I see what you did there

[@uplink-on-yt]

Sunflower growth is a bit shady, isn't it?

[@grannysvids]

That was bloody interesting, thanks SciShow. 👏

[@scifitoilet]

im growing a single sunflower and its pretty cool to watch it go back and forth annd now i know why!

[@Demnus]

Some space civilization with neutron-quantum brains eventually stumbles upon our little planet: "Fascinating! This primitive meatsacks seams don't have a brains, tough they some how figured out some interesting tricks."

[@toamastar]

Fascinating! Thanks guys!

[@LususxNaturae]

Last time I was this early I saw my Mimosa plants open

[@edwardatkinson5272]

Plants! Plants! Plants! Plants!

[@robertoarmstrong7317]

I appreciate the depth of the research associated with this.. but my brain is still bamboozled..

[@olive4naito]

Plants some seeds 😊 A lot of seedlings close their leaves at night and open again in the morning. Tomato seedlings and adult plants do this. I'm not sure about drought tolerant plants though.

[@Yora21]

When I trained as a gardener, one of the masters said that trees will drop their leaves in fall, even if you keep them in a heated greeenhouse and give them artificial lighting to simulate summer conditions. Apparently, there is some kind of internal timer that tells the tree that summer has ended, regardless of environmental conditions.

[@naturegirl1999]

Yora I remember that last year, some trees that normally dropped their leaves kept them anyway since winter was warmer than usual and there wasn’t a lot of snow for most of it, this was in Council Bluffs, Iowa. So they actually do rely on the environment. Question, did you and your master place a tree in a greenhouse for a year and test this?

[@loganl3746]

I was actually just wondering about this. The other evening, I thought my bean plants needed extra water during this heat wave cuz they were drooping, but when I went to water them the next morning, they were fine again. Mystery solved!

[@schifoso]

"Leaf-opening and leaf-closing substances". How scientific!

[@cjohnson7180]

Hank is the best ❤️

[@19lamborghini92]

Hank looking spiffy today! 10 out of 10 hair trim. Really strutting!

[@dreyhawk]

Having spent years working with plants and seeing how they can respond to different stimuli I think of it as they don't have what we recognize as a brain. We know they can often communicate with others of their species in the same vicinity and those plants can respond to it. We know they can develop defenses to new pests. There is so much still to learn about them. Maybe there is something there that we just don't recognize yet.

[@PikaRaichupikapika]

1970s: "Oh boy I bet we'll have flying cars in the future" 2019: "How plants tell time"

[@jorjahlanay]

Maybe, just maybe, plants that curl up at night are just trying to save energy. If you think abt it, they follow the sun all day, using energy to produce pollen and absorb sunlight, after the sunlight is gone, there’s no need to use energy, maybe they just curl up and slowly use photosynthesis to have just enough nutrients so by the next morning they can repeat the process again. Also, my science teacher Mrs. Fix has me addicted to SciShow. Much love to you guys ❤️

[@JeremyWS]

Yay, more weird botany. Yay, science.

[@Nhoj31neirbo47]

Science is only beginning to understand the complexity of flora.

[@lankarddkl8722]

4:48 I get what you meant, but brains and muscles are nothing more that really complex chemistry.

[@TT-RR]

This something that frustrates me about the science community. there so stuck in thinking that intelligence requires a brain and other human like characteristics. I think that plants have intelligence. flora intelligence just evolved differently then the majority of living creatures on earth.

[@richardoteri356]

Than*

[@Movie.Hammer]

Brains allow us to reason, not function. Reasoning really is the awareness of our functions and the ability to adapt it quickly if needed.

[@Dell-ol6hb]

TempTorm yeah all the proof you need of this is how people can lose huge portions of there brain and yet they can still function and survive, just at a more limited capacity than people with their whole brains. Like most of your basest deepest and most necessary functions are at the base of your brain at the stem, that should tell that you really don’t need a brain to survive.

[@humzahkhan6299]

Or really really complex physics

[@aleesabarker8352]

. I’m so glad that you’re covering plants! This is my favorite subject, Biology!

[@Nhoj31neirbo47]

Botany ftw!

[@ollieanntan4478]

Me too!

[@lanatherana157]

I swear this is the coolest thing I've ever heard!

[@OneironauticalOne]

This reminds me I need to turn my succulent in my office so it doesn't end up a hunchback echeveria before I trim it.

[@jno805]

It sounds like it needs more sun, Echeveria etiolate and stretch out when they need more. In the northern hemisphere they basically need a southern facing window or a grow light to keep growth compact

[@OneironauticalOne]

@@jno805 Thanks! I do have a north facing window I may trim its stalk if it gets longer and start placing it in more direct sun.

[@ThrottleKitty]

"How do plants act like they are alive when they are not alive???" Maybe they are actually just... alive? Like all other life?

[@JIMPONYD]

Last night I told my wife my nyctinasty was kicking in, and she slapped me. That’s what I get for trying to expand my lexicon.

[@ooooneeee]

😂😂😂

[@st3wham1]

What's forest's favourite time? 'Three' o'clock Don't worry, I'll leaf.

[@brendanotoole5871]

Barking up the wrong tree dude, you should branch out into other areas of comedy, find your roots, and go against the grain.

[@st3wham1]

@@brendanotoole5871 I don't think that wood be a good idea, I think I'd pre-fir to stay with my orginal form of comedy, regardless these saps love it.

[@osotanuki3359]

Nyctinasty: when a plant goes “Ewww the night is NASTY” and pulls its leaves in to get as far away from it as possible”

[@redwolfjoy]

I always wondered why sunflowers faced east. Now I know! Thanks!

[@ollieanntan4478]

This was awesome 🌱

[@ayylmao2710]

In dutch, those "plant elbows" are basically called "plant armpits"

[@sourceeee]

*plants dont have brains* i reject your reality and substitute my own

[@317Ly]

what a savage statement 😉

[@jameswallace9906]

I’m taking a test in bio2 on this today Thanks Hank

[@maxwellvandenberg2977]

Could you do an episode on Calcium signalling or gliotransmitters? They are neat.

[@paramchauhan382]

MITOCHONDRIA IS THE POWER HOUSE OF THE CELL!!!!

[@a_blind_sniper]

4:45 That delivery was perfect. I had to stop myself from spitting out my drink

[@stuarthenry7716]

Yo! Scishow the advert preceding this episode was for a psychic might want to ask for a bit more control of advertising.

[@davefoc]

I have some cactus that open their flowers as the sun comes up and close them as the sun goes down. I did some experiments to try to figure out what controlled the opening and closing of the flowers. In the case of my cactus no time telling was required, the flowers opened no matter what time it was when light was applied and they closed when the light was removed. I tried to understand the mechanism a bit but I didn't find much on that. If anybody's interested I made a video of my experiments. Look for Dave Kirkeby Cactus Flower Experiments.

[@redlove108]

"the plant pumps water" --- Hold up. How? What tells it to? And is this a reaction or... ya know.. a choice... o.O

[@nobrains9]

I'm going to hazard a guess and say its via osmosis. The higher concentration of the Pfr probably acts a bit like salt, pulling water out of the surrounding tissues and making the cells swell up, causing the leaf to move. Could be wrong though, don't hold me to that...

[@TheStarBlack]

It's definitely not a choice. Plants are just running a program encoded in their DNA.

[@Master_Therion]

Oh, would you look at the thyme, I need to leaf.

[@apple54345]

ayyyy, there he is.

[@gravijta936]

@@apple54345 Sage Therion has really grown on us all.

[@TitanUranusOfficial]

Your jokes are timeless....

[@Master_Therion]

@@TitanUranusOfficial Thanks. Is that a new profile pic?

[@TitanUranusOfficial]

Yes, thanks to recent debate on another channel about sex-robots, I am a sexy robot.

[@micaelcarestiato]

I love plants, very interesting video!!

[@kenxclout]

One of my friends gets paid minimum wage for watering plants. *Pour guy.*

[@revmaillet]

hehe you made my boyfriend and daughter groan...lol

[@zorrokitty5666]

That used to be me, my first job was working at a plant nursery for 7.25 an hour

[@freedapeeple4049]

If he likes working with plants, he could hire himself out as a plant rental/maintenance guy. Provide plants for restaurants, building lobbies, etc. It's possible to make pretty decent money that way...

[@furryz666]

Freeda Peeple or just grow and sell weed

[@Movie.Hammer]

Fascinating! I did a video essay on this during 10th grade, and this still taught me a lot!

[@lorenasbarros]

How do they do it? - Aliens

[@nicesponge123]

Plants sneezing

[@AnastasiaPlantlegs]

i genuinely think plants are a lot more similar to us than we think

[@TheStarBlack]

Ah this takes me back to A Level biology!

[@NathanMichalik]

Pre-video comment: I would guess it has to do with chemical changes since they rely on photosynthesis. Might be pretty easy to tell when the sun goes down when photosynthesis slows down/stops Post video comment: ya but how does my blind cat know to wake me up at 6:55am every single day even though my alarm goes off at 7am?

[@farhanahmed2508]

Hah! We're doing this chapter in our class these days 😀 'Control & Coordination'

[@dontwatchmyvideosyouwillre6997]

That awkward moment when a plant is literally better at counting and timing than you

[@coolbeans9617]

“Plants can tell time” *vegans shaking* jk I respect your diet decisions

[@dotsdot5608]

Just dont eat dogs; thats bad :p

[@thomas5975]

@@dotsdot5608 very nice with spice

[@coolbeans9617]

KanadianSpaceProgram omg air is my favorite breakfast too

[@dotsdot5608]

@@thomas5975 OOF!

[@woopygoman]

Veganism & vegetarianism are irrational. You need to end one life to sustain another. It's the circle of life. They just happen to limit their murdering to plants but plants are just as alive as animals. Enjoy your life fully and eat meat.

[@TomClarke1995]

As a navigator/explorer in real life, I always love learning new ways to Rainer myself with natural cardinal direction indicators. Fun fact: Moss at the base of trees tend to grow on the shady side. Also, look up how to know true south from a wrist watch

[@kraneiathedancingdryad6333]

I'm a plant nerd, and I approve this message 😁👉🌻

[@GeneralDurandal]

The short answer is "magic".

[@MediocreMachining]

“Pulvinus”

[@RamArt9091]

Now i wonder how "walking palms" work.

[@Deppie_____]

Before i watch: its going to be something with photosynthesis

[@srpenguinbr]

Why are some plants sensible to the touch? In Brazil, there is a plant know as "dorme dorme" ("sleep-sleep") which has leaves that sort of shrink and coil if you touch one of them

[@rickharold69]

Awesome

[@airrival66]

How do plants sense altitude (above sea level)? In places with high relief, you can sometimes see a point where some plants stop growing. So, can plants detect barometric altitude?

[@nbgreen02]

It happens in constant temperature also. So non factor

[@theCidisIn]

Some fungi have psilocybin and psilocyn, the latter of which is close enough to serotonin to bind to those receptors. Making it a sort of Neuro transmitter. It's also like one atom off, I may be wrong on how many atoms, one atom off of another Neurotransmitter we produce called NN-DMT. So the mycelium is just a bundle of fibrous tissue with some Neuro transmitters in it. Is that a brain? The little mushroom fruits that grow up from it and release spores to effectively reproduce also contain the psilocybin and psilocyn. Which makes sense because it's all effectively the same material... But those mushrooms and psilocyn are how their brains connect with ours maybe? I know mycelium doesn't have synapses and electrical signals stimulating different Neuro transmitters and muscle spasms, but they don't need it. Just the one neurotransmitter and a bunch of fibrous tissue too have it in. Primitive or super advanced brain... Or just some trippy fungi. You decide.

[@theCidisIn]

Pulvinus is a dirty sounding plant elbow, like a wenis is a dirty sounding human elbow part.

[@theCidisIn]

My cactus will bend like crazy towards the sun, and it happens FAST.

[@theCidisIn]

It's a really sharp bend.

[@theCidisIn]

In the Adventure Time episode "Food Chain", I feel like they did an excellent job explaining how plans experience time. It's super trippy, but also super viable. At least to me.

[@DeagleBeagle]

isn't the reason why plants shrink at night obvious? There is no sun in the night and shrinking probably decreases evaporation

[@VariantAEC]

This wasn't about the why (which isn't to say your observations are invalid), but the how (which is to say your observations are irrelevant in this instance).

[@helgrind8493]

@@VariantAEC He means it as a why. The hypothesis is that the leaves lose water due to evaporation proportionate to the surface area of the leaf. Whereas during the day it makes sense to make this area as big as possible (more surface area=more sunlight=more photosynthesis), during the night it makes sense to decrease the surface area of the leaf to keep loss of water by the plant to a minimum.

[@lewiscorden6537]

sun up = time day

[@ryanvess6162]

The sun, the sun, the sun, the sun

[@gibranhenriquedesouza2843]

Now tell us how plants measure temperature.

[@thomas5975]

Nice

[@Kitsudote]

Just a guess, but maybe plants close at night because the flowers (or the like) have a greater surface area and the plant would get too cold this way.

[@littleratblue]

What is it about a flower petal that makes it soft feeling?

[@kjell159]

My leaf also droops after nasty movements.

[@ADDeeJay]

Good. Now tell me how all the bamboo flower at the same time?

[@allhumansarejusthuman.5776]

Wait. I'm early. 15 comments. What? Do you always upload in early to mid afternoon? Or are you just getting jealous of plants time keeping ability?

[@SunriseFireberry]

What would we do without plants?

[@helgrind8493]

Die horribly due to asphyxiation?

[@HuyLy94]

Huh I always wondered why my calathea plants seemed to move through the day

[@selfdiscardedkingofruin7291]

My plants always say it's 4:20

[@cob571]

69.

[@JonahPleatherbooth]

What're your thoughts on recent experiments suggesting plants can learn and form memories?

[@Nhoj31neirbo47]

It’s very cool. You might enjoy checking out my channel’s playlist titled Plant Consciousness.

[@freedapeeple4049]

Check this out: kzbin.info/www/bejne/eaPVhHSZYtudfZY

[@naturegirl1999]

I remember there was an experiment involving a plant growing towards a light that would only get turned on after a fan got turned on, until eventually the experimenter stopped turning on the light and the plant still grew toward the fan

[@ttrdf]

oversimplified, science is very important, but alone is not enough

[@erincutright7020]

So then what happens during cloudy days? Do plants still act like it's nighttime?

[@TylerPKegger]

PLANT GANG HERE!!!!!

[@patar3323]

Oof, right in the pulvinas

[@Pylotis_]

Please explain Mimosa Pudica.

[@ToxicTerrance]

I vow on this day to never eat another plant in my life!

[@TeeTee-bz3pv]

It's plants sleeping.....

[@cheeseburgermonkey7104]

106th so close top 100!!!

[@sneeringimperialist6667]

Turgid pulvinus...

[@georgytodorov7947]

Mimosa pudica. Explain! :)

[@helgrind8493]

Same explanations as Hank provides, only that these mechanisms also respond to touch, not only to light....

[@Malfunct1onM1ke]

I support the nastic movement

[@TheRealGuywithoutaMustache]

Plants are so in tune with their bodies, that they simply use their biological clocks, compared to us, who use digital clocks instead.

[@KarlHerzog]

Woah, too deep bruh

[@horrorkesh]

Did it have a snoot droop

[@AidanRatnage]

Do fully grown sunflowers face West in the southern hemisphere?

[@Je.rone_]

I hope not cause i sure can't 😀

[@goblincleric4130]

but how do they know what season it is?