HackerLangs
TopNewTrendsCommentsPastAskShowJobs

Giant trees have no trouble pumping water to top branches: new research(news.exeter.ac.uk)

268 points·by hhs·7 วันที่ผ่านมา·123 comments
news.exeter.ac.uk
Giant trees have no trouble pumping water to top branches: new research

https://news.exeter.ac.uk/faculty-of-environment-science-and-economy/giant-trees-have-no-trouble-pumping-water-to-top-branches/

121 comments

karim79·7 วันที่ผ่านมา
I grow marijuana and chillies from time to time. I got good at it. I will say that plants are malleable in untold ways and so I find this article to be unsurprising.

Plants will do what they need to do in the end. I've done stuff like co2 bombing, and increasing nutrients to the point to where I get a whole new ecosystem of insects and an entirely new situation.

It is such fascinating stuff that it's actually the life I want to live. I'm a computer scientist but now I yearn for the botanical sciences.

I highly recommend checking out defoliation strategies and low-stress training methods for anyone interested. Plants are not dumb creatures. The results you can get from them are astonishing and the science of what plants actually are becomes more profound by the day.
kuerbel·7 วันที่ผ่านมา
I'm studying for a bachelor's degree in horticulture part-time through a distance-learning university. If you're more interested in growing plants, I'd say horticulture is a better fit than botany. If you're more interested in understanding how plants work, botany is probably the better choice. That said, you'll still learn a lot of botany in a horticulture degree as well obviously
karim79·7 วันที่ผ่านมา
Thank you sir. I actually got my CS from distance learning and somehow the combination of growing things and monitoring everything using CS just grabs me. I would work on any farm anywhere with appropriate agency.
whacked_new·7 วันที่ผ่านมา
this is low key one of the few things that I think of doing for the rest of my life, though my bias is towards seaweed farming and related ecosystems
tryagainian·7 วันที่ผ่านมา
Oooo, I get a bit excited about interdisciplinary techno-plant-and-livestock

Another area that might be easier to break in to as far as work goes is labouring for an irrigation business, kinda agricultural plumbing.

You’ve probably seen pivots[1] and side-roll irrigation systems.

This would put you in more direct contact with the farm operators, expose you to a wide range of agricultural crops, and also tie neatly in to your existing CS skill set with regard to agricultural SCADA (Supervisory Control and Data Acquisition), or Industrial Arduino as I like to call it.

Working for seed processes / distributors and fertiliser and pest & weed control industries could also be another foot-in-the-door move.

https://en.wikipedia.org/wiki/Center-pivot_irrigation
karim79·6 วันที่ผ่านมา
(2)
pvaldes·7 วันที่ผ่านมา
Botany comprises all, but most people see it as a synonym of plant classification.

Horticulture is about growing plants and multiplying it, often with flower power overtones and moon myths that vastly underestimate its importance.

Veganism is often mistaken as a synonym of "botany loving people", but is just a religious movement started by a priest, and centered around the random ideas that:

1) Plants occupy a lower rank of importance among life beings because they lack a single particular type of sensor that only the cool animals have, and...

2) Plants are safe to eat, because they were designed by god for us

None of those ideas are validated by real facts. As people grows in the cozy comfort of their religious group they lose the capability to see the whole picture and turn into food zombies that move and hate just by inertia. You can show science here for weeks and weeks without finding a sign of intelligent life.

---------------

Many people stop here and will never heard about:

Geobotany. Be afraid, very afraid. This is what a cabal of Da Vincy code linguists would do in the dark to bring pain to the world.

Most people will be put off by it in seconds, by the strange words and tedious lists, but there is an unexpected reward at the end when all pieces fall in place. You will never see the wildlife in the same way.

And plant physiology, that is like a really good sci-fi book.

Very complicated, defiant, dealing with really futuristic problems, and with more "hit the coin" moments that Mario. Who would imagine that the future of the humanity is linked with the capability to huge organisms to do physical work that makes the stronger animal look like crap
mountainriver·7 วันที่ผ่านมา
With a lot of software getting eaten up I’m increasingly interested in biology. Seems like one of the later frontiers that could have massive benefits, and AI is really well suited to help us understand it.
karim79·7 วันที่ผ่านมา
True and also, the actual physical contact and results are absolute magic. Maybe we need to create a "computer scientists for botony" forum. I think that has legs.

Botany is great because the results are basically what I'd call magic. It's such beauty (and horror on occasion).

The marriage of CS and botany seems like a match made in heaven and just from writing these comments I've convinced myself that it's probably the most practical way to go forward in life.
grantith·7 วันที่ผ่านมา
Just about everything we experience in our lives is a constant distraction from the fact that biology and its mechanisms are the most interesting thing in our existence.
karim79·7 วันที่ผ่านมา
Absolutely this.
nntwozz·7 วันที่ผ่านมา
But but… physics—space and time etc?

— Carl Sagan
card_zero·7 วันที่ผ่านมา
There is apparently such a thing as "Computational Botany", where you model virtual plants.
globular-toast·7 วันที่ผ่านมา
Have you considered computational biology? They are always looking for people. Knuth said a while back that biology has tons of open and useful problems left to be solved.
itomato·7 วันที่ผ่านมา
one time, while communing with Nature, I looked up at the transpiring coastal tree line flexing in the wind and I uttered, "pumps."

My hunch is that torsion, flex and their effect on the capillary structures are at play, but I haven't been able to step away from CS myself.
aaron695·7 วันที่ผ่านมา
stymaar·7 วันที่ผ่านมา
> These vessels have evolved intricate adaptations that can maintain the water in liquid form, even under the extreme low pressures

This sentence undersells the phenomenon quite a bit: the “extreme low pressure” is in fact several bars of negative pressure and the challenge of maintaining water in liquid form is avoiding cavitation.

I was exposed to the physics of trees though the entrance exam to École Polytechnique (France's best University) and it's been carved in my mind since then: http://alainrobichon.free.fr/Concours/X_PC_PH1_01.pdf

AFAIK students are still being given this masterpiece for practice even though it's now 25 years old.
nomel·7 วันที่ผ่านมา
This goes against all previous research/measurements for actually tall trees (looks like they only considered up to 80m) and the fact that there are exactly zeros trees in the world taller than 130 meters [1]. Wide capillaries at the base, like stated in the article, don't seem to be related.

[1] https://www.sfgate.com/science/article/REDWOODS-How-tall-can...
fc417fc802·7 วันที่ผ่านมา
I agree it doesn't pass the sniff test (where are the 500 meter trees in the rainforests?) but I think it would make an excellent goal for molecularbiological and genetic engineering. We (our civilization) need to become much more skilled at that before we start editing the human germline, and we will inevitably want to edit the human germline eventually (or rather we are currently exhibiting great restraint in not doing so but I'm not sure how much longer that will last), and anyway thousand meter trees just sound like they would be really cool.
oersted·7 วันที่ผ่านมา
Sounds cool but for such experimentation you would want relatively fast experimental iterations to get anywhere, and this would take literal ages. You can play around with growth speed of course but that’s a different question and might be in some ways opposed to achieving height.
fc417fc802·7 วันที่ผ่านมา
I don't think so. You don't have to reach the height limit just to iteratively develop the initial implementation of the pump system. A system that actively moves water would push it out the top so you've got an observable phenomenon to work with.
oersted·7 วันที่ผ่านมา
I’m sure there will be a ton of unexpected complexities that arise only when you are trying to push the limits, like in all engineering domains. And it’s all a highly interconnected system, you cannot expect to dramatically change the water flow without impacting others aspects.

I know it is quite distant, but from my experience in large-scale data engineering, 90% of the time goes in addressing subtle issues that can only be observed hours into a job, the rest of the issues are quickly resolved earlier. I am assuming that such complexities will be so much harder in physical systems, and even more so in biological systems.
Sharlin·7 วันที่ผ่านมา
There are obviously other factors limiting tree growth, like compressive strength.
ghaff·7 วันที่ผ่านมา
I seem to recall for some long-ago course that the 8,000m peaks are up around the compresssive limit so yoou couldn't really have a taller mountain.
Sharlin·7 วันที่ผ่านมา
In theory you can always have taller mountains if you just have a (exponentially!) wider base. But given all sorts of practical constraints, Earth mountains are pretty much limited to <10 km.
Jweb_Guru·7 วันที่ผ่านมา
Mostly true on Earth, but not on other planets with lower gravity, and AFAIK it depends on the rock type. Hence why you have Olympus Mons on Mars (or insanely tall ice mountains on Pluto, when that material couldn't form such a steep talus angle on Earth).
ghaff·7 วันที่ผ่านมา
Well, yes, I'm talking about ~1g on earth. And, also yes, rock type makes a difference but I assume there is some commonality with the tallest peaks.
fc417fc802·7 วันที่ผ่านมา
Which would also serve as reasonable challenges for genetic and molecularbiological engineering so ... what's your point?

Or do you mean to suggest that the failure of any accepted tree height records to surpass the maximum capillary distance can be explained by some other factor? (Based on your other comment it seems safe to assume that isn't what you meant but anyhow.) That seems far too convenient given that the observed cutoff is within the expected range.
Sharlin·7 วันที่ผ่านมา
I was referring to your "500m trees" which would be over 3x taller than the tallest trees ever seen.
raducu·4 วันที่ผ่านมา
> where are the 500 meter trees in the rainforests.

There could be structural reason as to why it's not possible, not pumping water *
gre·7 วันที่ผ่านมา
> 500m

500ft is taller than the max ever, not 1640 ft
cortesoft·7 วันที่ผ่านมา
Couldn't both things be true? Water transport is not the limiting factor, but some other thing is?
[deleted]·7 วันที่ผ่านมา
chasil·7 วันที่ผ่านมา
Kurzgesagt has two videos on trees addressing this and other questions.

https://m.youtube.com/watch?v=ZSch_NgZpQs

https://m.youtube.com/watch?v=pHJIhxZEoxg
calibas·7 วันที่ผ่านมา
The largest tree on record is rejected in part because it's over the theoretical limit: https://en.wikipedia.org/wiki/Nooksack_Giant

Too bad we cut it down, along with almost every other giant Douglas-fir.
Alien1Being·7 วันที่ผ่านมา
Human barbarism is not new...

"The placard recorded that the Nooksack tree produced 96,345 board feet (227.348 cubic meters) of the "finest quality" lumber.

The New York Times regarded the tree in a March 7, 1897 issue as the "most magnificent fir tree ever beheld by human eyes" and called its destruction a "truly pitiable tale" and a "crime".

The Morning Times of February 28, 1897 claimed that the wood, sawed into one-inch strips, would reach from "Whatcom [the tree's location] to China"."
fsckboy·7 วันที่ผ่านมา
>Human barbarism is not new...

to be fair, without humans there would be nobody to declare "barbarism". At one time, all humans were barbarians, it took a certain level of cultural development before the word "barbarism" was necessary, so at that point it was "new". It remains be be shown whether cultures that call other cultures "barbaric" are actually "better".
mattgrice·7 วันที่ผ่านมา
Yeah man if a barbarian fells a tree in the forest but nobody is around to hear it, is it still barbaric?
vlovich123·7 วันที่ผ่านมา
Barbarism was just the ethnic slang Greeks had for non Greeks that Romans then adopted for non Romans. But cultures playing “I’m the best” is not new nor did it require cultural development; othering is a natural part of game theory to make sure your tribe has tighter cohesion against intruders.
card_zero·7 วันที่ผ่านมา
Yeah, they were called barbarians because they talked funny. Bar bar barbar bar, they went.
inigyou·7 วันที่ผ่านมา
Maybe they were talking about https://en.wikipedia.org/wiki/Barbara%27s_Rhubarb_Bar
alchemism·7 วันที่ผ่านมา
...and if you aren't pronouncing it "Var" you might be one ;-)
GroksBarnacles·7 วันที่ผ่านมา
This is such a useless comment. What even is your point?
hinkley·7 วันที่ผ่านมา
There are stories that the moss on trees in temperate rainforests allow the tree to pull water from their branches instead of the ground, increasing their max height.

For a while there were people poaching the moss that facilitated this, which is a problem because it grows only inches per year.
ryanmcbride·7 วันที่ผ่านมา
God that's sad. We really can't have anything nice.
hinkley·7 วันที่ผ่านมา
It’s harder to remove the moss from high up in the tree and there are more risks in doing so. I was never clear on how prevalent this shittery was.
card_zero·7 วันที่ผ่านมา
Who wants moss!? Is it luxury moss?
hinkley·7 วันที่ผ่านมา
When peeled off the trunk it comes off in sheets, which is a bit harder to accomplish than just creating tufts and blobs of moss.
lazide·7 วันที่ผ่านมา
Yes, for terrariums
seabrookmx·7 วันที่ผ่านมา
I just visited this beauty[1] a few weeks ago. Not 400ft tall, but over half that and over 13ft round at the base!

We're lucky to have a handful of big Doug Firs, Sitka Spruce, and Western Red Cedars left on Vancouver Island.

[1]: https://en.wikipedia.org/wiki/Big_Lonely_Doug
nullorempty·7 วันที่ผ่านมา
>Giant trees have no trouble pumping water to top branches

Hm, may be because they are not really "pumping" the water?
leni536·7 วันที่ผ่านมา
What would you call it?
cj·7 วันที่ผ่านมา
Not that it really matters, but the article also refers to it as “drawing water to the top”. That seems more representative of reality than “pumping water from the bottom”.
chowells·7 วันที่ผ่านมา
If you think of it that way, you have a real problem. It only takes about 10 meters for the weight of a column of water to create enough downward force that it starts vaporizing, at which point no pumping action works. This is why any deep well has a submerged pump. You simply can't pull water upward further than that with negative pressure in the Earth's atmosphere. It must be pushed with positive pressure instead.

This is why the question is interesting. You can't just suck water to the top of a 60 meter tree. There must be some kind of positive-pressure pumping involved.
pulvinar·7 วันที่ผ่านมา
The trick for trees is capillaries, which change the equation. The 10 meter limit only applies to larger columns. With capillaries there's a high negative tension that allows evaporation from leaves to pull the xylem sap up 100 meters or more.

There's no free lunch here. The Sun drives the evaporation, and if the tree were in a closed system with no solar input, the humidity would eventually get high enough to stop it.
hinkley·7 วันที่ผ่านมา
One of the things Susan Simard proved was that deep rooted trees that had found subterranean water continue pulling that water at full speed at night when transpiration is low, and that water finds its way into the fungal networks in the soil and into nearby plants.

Simard attributes intention to this, but osmosis is “fair”. It seeks to move water to where sugars are and sugars to where water is. So a plant giving up sugars will receive water, and one low on water will give up sugars in the process of equalization.

Do fungi contain pumps to maintain disequilibrium in this work? I could not say. But even when they first learned the trick of tapping roots the basic premise would have worked in a rudimentary fashion woth no further optimization.
fc417fc802·7 วันที่ผ่านมา
I don't understand how osmosis enters into this? Capillary action is sufficient to explain water traveling up the roots to a point where it was removed. Evaporation from leaves is sufficient to explain removal during the day. You'd need some other explanation for extraction by fungi or etc at night.

As a largely unrelated aside, there will still be a chemical potential across a membrane that doesn't permit a solute to cross. So water can diffuse into a concentrated solution without the solute flowing backwards into the reservoir. Alternatively, small solutes can leave while larger solutes are retained. This is the basis of dialysis.
hinkley·4 วันที่ผ่านมา
In retrospect what I wrote became a bit more of a non sequitur than I meant.

Trees aren't even accessing water at ground level most times but pulling it up from 5-30 feet down. Fungal distribution is also a capillary action network (with asterisks) and ends up making some of that pumping more horizontal, but at the expense that if a tree's root sap is high in sugar due to dehydration, then the fungal network both introduces water to those roots but also exports sugar at the same time. Simard tries to anthropomorphize this process. It's my only real complaint with her work.

The asterisks are that fungal networks can react to information faster than the documented transport mechanisms work so we don't really know how the heck they do their thing yet. So it's possible that they're also maintaining nutrient gradients to feed themselves beyond the straight arbitrage that osmosis represents.
left-struck·7 วันที่ผ่านมา
The 10 metre thing assumes you have a suction side which is 10 metres lower than the pump, or at least a suction that is long/low enough that it can’t meet the pump’s NPSHr (Net Positive Suction Head required).

In a tree the inlet to the “pump” is at the base of the tree. It’s not like there’s a pump sitting in the tree at 80 metres trying to suck water up from the ground, that would obviously fail. It’s more like a very long pump.
tenuousemphasis·7 วันที่ผ่านมา
>if the tree were in a closed system with no solar input

... that would be the least of the tree's problems.
theendisney·7 วันที่ผ่านมา
This line of reasoning has always cracked me up. The internal dialog acidentally out loud at the least flattering moment. I believe the correct response to be:

The tree is a perpetual motion machine hooked up directly to the wheelworks of nature! It PUMPS 500 liters per day usibg Wind, solar, capilar action and evaporation! How do i charge my car with this?
lazide·7 วันที่ผ่านมา
Well, if you chop it down and burn it to boil water, then Use it to spin up a turbine…
taneq·7 วันที่ผ่านมา
It’s like the pop sci fact that if you took all your blood vessels and laid them end to end… you would die.
hinkley·4 วันที่ผ่านมา
This is still one of my all time favorites, although alveoli work the same way and are more fun to say.

The other day my friend said they wanted a new nervous system and my brain went down this route of pulling out the old one and putting in the new one.
[deleted]·7 วันที่ผ่านมา
kijin·7 วันที่ผ่านมา
Yeah, that "extreme low pressure" part of the article had me scratching my head. Even a complete vacuum at the top will not suck water up more than 10 meters! The author was probably oversimplifying for a lay audience.
[deleted]·7 วันที่ผ่านมา
fc417fc802·7 วันที่ผ่านมา
That analysis only applies to a single discreet pump. A line of pumps in series does not suffer from that problem and that is roughly what a biological system would be expected to consist of.
Sharlin·7 วันที่ผ่านมา
There are no pumps in a tree, in series or not. There’s nothing between the roots and leaves that actively drives water upward in any way. The xylem is literally dead tissue.
fc417fc802·7 วันที่ผ่านมา
Please notice that the comment I was responding to there made claims of physical infeasibility that I was responding to. I was not expressing any claims regarding actual concrete trees that you could go and visit.

More generally you seem to be dismissing out of hand the primary topic of discussion which is neither constructive nor enlightening.
margalabargala·7 วันที่ผ่านมา
Yeah it's the difference between creating low vs high pressure.
card_zero·7 วันที่ผ่านมา
The low pressure is up there already, for free.

Or the high pressure is down here, whichever way you want to look at it.
rolph·7 วันที่ผ่านมา
more like capillary action.

https://en.wikipedia.org/wiki/Xylem#Cohesion-tension_theory
leni536·7 วันที่ผ่านมา
Capillary action is subject to the same limits as suction at the top. Capillary action can't increase the water pressure at the bottom of the tree.

If you put a straight thin capillary tube upright in water so it sucks up water from the bottom, no matter how thin, it can't draw water up above ~10m of water level.
card_zero·7 วันที่ผ่านมา
Oh, so we don't really know how it works. Fun.
rolph·7 วันที่ผ่านมา
the research is relevant to the issue of transpiration column hieght as a postulated limitation to overall hieght of any tree.

a column of water is pulled by hydrogen bonding between molecules in a tug of war fashion, the top of the column is where water is dissociated from the column at such a rate as to maintain low pressure with respect to the column[xylem]

in summary water moves from bottom to top in a transpiration stream, that ultimately ejects water vapour from the leaves, resulting in a low efficiency mechanism, that loses a lot of the water but occurs at such a rate that the low efficiency is "good enough" for whats needed.
fc417fc802·7 วันที่ผ่านมา
> a transpiration stream, that ultimately ejects water vapour from the leaves

I don't believe this is correct, or rather is not a required component of the system but rather incidental. The chemical system within the leaf removes water via chemical reaction. There is a respiration process to dispose of waste gasses. Water vapor happens to be lost to this process not of necessity but rather because keeping it separate is quite difficult (ie requires significant complexity and additional energy expenditure). I expect that many desert adapted species approach perfection (but have not bothered to verify).
oneshtein·7 วันที่ผ่านมา
Capillary action and mechanical pumping by wind.
HarHarVeryFunny·7 วันที่ผ่านมา
There seems to be a lot of things that come together to make it work, but it's basically sucking not pumping. The term to google is Transpiration.

It's a bit like a siphon effect with water evaporating from the leaves creating low pressure internally which draws more water up, and the reason it's able to pull a whole column of water up is because water molecules stick together to some extent via hydrogen bonds.

Given that evaporation is what is driving it, I wonder how that works with evergreens with low evaporation - I guess it's basically a replacement system, so you only need to pull what you evaporate.
cwmoore·7 วันที่ผ่านมา
They do wave in the wind, and evolution is likely capturing some of that motion for work.
hetspookjee·7 วันที่ผ่านมา
Not sure if you’ve ever visited the groves in California where these huge trees grow but they seem to find the place where the wind doesn’t really seem to bother them, among other reasons (fog staying and little creeks terminating are others). And when the wind comes along it’s surprising how little they actually wave. Such tiny radii change I reckon cannot move much water like you’d need for a pumping notion. So I’d say it has barely if any an influence
cwmoore·7 วันที่ผ่านมา
I have seen trees before too, anecdotally, my random naysayer.
gitaarik·7 วันที่ผ่านมา
“Trees contain lots of thin, hollow vessels and they suck water upwards by creating low pressure at the top,”

So sucking / pulling?
IsTom·7 วันที่ผ่านมา
So a suction pump?
card_zero·7 วันที่ผ่านมา
Same principle as chimneys. But I also noticed this line:

> leaves which have adapted to withstand greater water stress before wilting.

That must be one of the "adjustments to water transport" mentioned. So I suggest that they do, in fact, have trouble pumping water to top branches.
DANmode·7 วันที่ผ่านมา
Or, it’s simply a rate to variably adjust to, so the tree is neither flooding nor parching the leaf.
gitaarik·7 วันที่ผ่านมา
Maybe it's not more trouble pumping, eh, sucking water up. But that the top branches are the last ones to get water in periods of draught, and have therefore more resilience?
hinkley·7 วันที่ผ่านมา
My recollection is that capillary action is a little from column a and a little from column b.
m463·7 วันที่ผ่านมา
on the other hand, many giant trees get the water out of the air via fog:

Coalescence of coastal fog accounts for a considerable part of the trees' water needs.[23]

https://en.wikipedia.org/wiki/Sequoia_sempervirens#Fog_and_f...

https://en.wikipedia.org/wiki/Sequoia_sempervirens
efskap·7 วันที่ผ่านมา
Similarly, it blows my mind that all trees are made of air, specifically the carbon in it. I used to think that the biomass must come from the soil, but reality is more interesting.
c22·7 วันที่ผ่านมา
Kind of like how the vast majority of weight loss in animals happens via exhaling.

Weirder still is the realization that all the air is just trapped light.
kijin·7 วันที่ผ่านมา
Actually, all matter is just trapped energy.
theendisney·7 วันที่ผ่านมา
There is no such thing as energy.
lazide·7 วันที่ผ่านมา
Rather, no such thing as matter. Energy is pervasive.
kulahan·7 วันที่ผ่านมา
It's also kind of weird to think that soil, really, is just ground up "stuff" that used to be trees, plants, rocks, etc.
[deleted]·7 วันที่ผ่านมา
nomel·7 วันที่ผ่านมา
Sequoia are still limited in height by gravity, probably due to capillary pressures. [1] If they evolved to be segmented, they could probably do it.

[1] https://www.sfgate.com/science/article/REDWOODS-How-tall-can...
hinkley·7 วันที่ผ่านมา
There’s also a theory that the moss on these trees is mutualism instead of simply epiphytic. The moss holds moisture, which can be accessed by the tree.
pkghost·7 วันที่ผ่านมา
Folks still sleeping on structured water.

While admittedly contested and only reproduced by a few labs outside Gerald Pollack's at University of Washington, there is a solid case that it could play a role in transporting water and sap to the tops of trees. At least, it's involved in the motion induced in hydrophilic tubes when there is sufficient ambient radiant energy (uv/infrared).

Relevant papers:

"Exclusion-zone water inside and outside of plant xylem vessels." 2024 Scientific Reports. https://www.nature.com/articles/s41598-024-62983-3

"Surface-induced flow: a natural microscopic engine using infrared energy as fuel." 202 Science Advances. https://www.science.org/doi/10.1126/sciadv.aba0941

"Long-range forces extending from polymer-gel surfaces." 2003 Phys. Rev. E. https://link.aps.org/doi/10.1103/PhysRevE.68.031408

Pollack's site: https://www.pollacklab.org/

Some critiques of Pollack's theory:

Schurr, J.M. (2013). Phenomena associated with gel–water interfaces: analyses and alternatives to the long-range ordered water hypothesis. J. Phys. Chem. B, 117(25), 7653–7674. https://doi.org/10.1021/jp302589y Elton, D.C., Spencer, P.D., Riches, J.D. & Williams, E.D. (2020). Exclusion zone phenomena in water — a critical review of experimental findings and theories. Int. J. Mol. Sci., 21(14), 5041. https://doi.org/10.3390/ijms21145041 (open access; the most thorough critical review) Elton, D.C. & Spencer, P.D. (2021). Pathological water science — four examples and what they have in common. In Water in Biomechanical and Related Systems (Biologically-Inspired Systems, vol. 17), pp. 155–170. Springer. https://doi.org/10.1007/978-3-030-67227-0_8 (preprint: https://arxiv.org/abs/2010.07287)
theendisney·7 วันที่ผ่านมา
I regretably didnt save it but there was a truly hilarious topic on usenet sci.physics long long ago. If we've gathered enough evidence against something or if the thing goes against accepted consensus you are forbidden from doing further research and new evidence is no longer allowed. The topic then invited others to list such topics. The list grew to hundreds of entries and people couldnt resist getting angry reading their personal trigger words despite there being many more silly things on it.

Yours shall be filed under homeopathy :)
fc417fc802·7 วันที่ผ่านมา
Be careful with that dismissal. The concept of an exclusion zone itself appears to be legitimate. More generally, there's lots of strange and surprising effects that crop up on the molecular level at interfaces in solution. However not all mechanistic explanations for such behavior are shall we say "widely accepted".

And then there's homeopathy which is a largely unrelated and entirely nonsensical thing.
pkghost·5 วันที่ผ่านมา
> And then there's homeopathy which is a largely unrelated and entirely nonsensical thing.

And be careful with that dismissal! Not that I'm helping my case, here, but Pollack doesn't think it's baloney (see related chapter in his book "The Fourth Phase of Water").
fc417fc802·5 วันที่ผ่านมา
While there is plenty of evidence of strange molecular phenomena occurring at interfaces in solution, there is to the best of my knowledge absolutely no evidence to support the claims made by homeopathy. Moreover the latter appear patently unreasonable at a glance (and only become increasingly so when examined with a critical eye) while the former fall well within the bounds of established chemistry and physics.
theendisney·23 ชั่วโมงที่ผ่านมา
I didnt believe any of it but when conventional methods failed the homeopathy worked incredibly well. So, i dont get to mock it. The same guy also gave me other alternative medication. I had to pull it out of him as he innitally refused for legal reasons.

So, i make of it that alternative medicine and homeopathy doesnt work because you may not talk about it(!?)

Or as Brian Josephson put it, The idea that water can have a memory can be readily disproved by any one of a number of easily understood, invalid arguments
accidentallfact·7 วันที่ผ่านมา
I don't get why it is believed that trees can't pump water above a certain limit, all it should take is a system of valves, something that plants already have for other purposes. It certainly isn't lumuted by trees literally sucking water up as that would limit them to a height that can be easily exceeded by the majority of trees.

It seems that trees just don't grow that tall anymore. Even common trees such as the spruce seem to be able to reach 100m, they just kind of don't.

One possibility is the depletion of nutrients. But what I think is to blame is the lack of elephants. They constantly ruined young trees and the lucky few that survived then grew huge. Perhaps the redwoods were actually created by the natives, who removed young trees, and kept the old trees standing.
bnegreve·7 วันที่ผ่านมา
> all it should take is a system of valves,

That would work, but it's not how to works apparently. According to this veritasium video, it's because of "negative pressure" aka tension.

https://www.youtube.com/watch?v=BickMFHAZR0

I recommend watching, I think it's one of the best veritasium Dereck has ever produced.
tryagainian·7 วันที่ผ่านมา
Also, wasn’t the 250 ppm atmospheric CO2 concentration prior to the start of the Industrial Revolution a historic low as far a geological-time goes?

I suppose that’s not particularly relevant for more recent old growth tall trees that seem to have got by fine in a colder Earth.

But it’s easy to imagine a warmer, wetter, Earth with higher atmospheric CO2 concentrations being more conducive to taller tree growth.

On the other hand, I probably don’t really know what I’m talking about, not my area of expertise.
cwmoore·7 วันที่ผ่านมา
“The root cause is nailed down (not a theory anymore)…” —Claude
luxuryballs·7 วันที่ผ่านมา
I’m glad to find the trees are doing well, even the big ones, that managed to grow big... ???
jzer0cool·7 วันที่ผ่านมา
Any truth to whether water pumped by tree (branches) is potable?
huijzer·7 วันที่ผ่านมา
Another paper for the “Obviously” category. Otherwise the leafs at the top would be brown. But I did a PhD myself and our papers were exactly the same. Noone wants to rock the boat. Professors just want to get to their pension without problems. And people will cite things that are in line with their own stuff. So there you have it. Just proving the obvious time and time and time again.
kank0de·7 วันที่ผ่านมา
plants are very brave, both metaphorically and physically.
yubblegum·7 วันที่ผ่านมา
Rather tenacious and unrelenting than brave. Many of them wear war paint, employ chemical warfare, and dress up in scary getups to scare away potential enemies/predators. Effective for sure, but "brave"?
alldayhaterdude·7 วันที่ผ่านมา
Happy for them.
lukeholder·7 วันที่ผ่านมา
This made me laugh out loud. Thanks.
arghandugh·7 วันที่ผ่านมา
pinchydev·7 วันที่ผ่านมา