Blood Pumping Mechanism of the Hoof (2020)

Also, in upright posture, the soleus is responsible for pumping venous blood back into the heart from the periphery each time it contracts and is hence often called the skeletal muscle pump, peripheral heart or the sural (tricipital) pump.

Soleus Pushup - https://stories.uh.edu/2022-soleus-pushup/index.html and https://www.physio-pedia.com/Soleus_Push_Up

This is the science behind the Baithak aka Hindu Squat.

signalbright• 2 months ago

Posts like this one are the reason we read Hacker News

9dev3• 2 months ago

Random knowledge about fringe subjects that I can infuriate my wife with at 1am in the morning?

rramadass6• 2 months ago

Try this - https://news.ycombinator.com/item?id=48247031 ;-)

Paracompact4• 2 months ago

I've been pondering for a while a question that is exceedingly unlikely to ever be answered within my lifetime, because as a prerequisite it assumes a framework strong enough to answer several very hard questions in philosophy, neuroscience, and information theory. And that question is: Is it possible even in principle for a conscious entity to have an instinctual understanding and awareness of every low-level detail comprising its design?

An extensive network of veins called a venous plexus are located on both sides of each of the lateral cartilages and in the sensitive structures of the hoof. The compression of these veins by the plantar cushion against the lateral cartilages or the coffin bone against the hoof acts as a “pump” to force the blood up the leg and back to the heart.

A horse is an extremely sophisticated biological machine, but it has no idea what makes itself tick. It has some limited mental model of the world around it and that's about it. Humans fare little better, but at least can make inch-by-inch progress through scientific study.

Such a creature that knew and felt itself perfectly, could at any point inquire the status of its own glycogen stores in its liver, could diagnose and micromanage its immune responses, could introspect accurately and with infinite recursion upon its own thoughts, seems hard to imagine, because if one were to set out to design such a creature, naturally its complexity would have to scale with the complexity it is attempting to self-model. Perhaps there is some sort of upper limit to the consciousness:complexity ratio that makes closing this gap impossible. (Or perhaps there isn't, and that would be just as fascinating.)

If nothing else, I would like to read a Borges story on the subject. Such a creature might inevitably be doomed to the same fate as Funes the Memorious.

Animats2• 2 months ago

Is it possible even in principle for a conscious entity to have an instinctual understanding and awareness of every low-level detail comprising its design?

Access is possible, complexity limits what you can do with it.

It's like having a JTAG port on a chip with a lot of test access. You can read the state of most of the gates, but now you're overwhelmed with data. Processing that data takes more resources than the system being monitored.

At a larger scale, though, this starts to work. Modern industrial plants and cars have sensors all over the place, more than are really needed to operate the system. They're there to diagnose it.

QuercusMax• 2 months ago

Kinda like we have sensors all over the place, but the info a lot of them deliver (pain) is pretty vague. And because of how it gets aggregated and delivered to the brain, sometimes you have funny glitches like how I can scratch the inside of my left ear and it makes me cough.

Animats2• 2 months ago

Or, in a more modern sense, it would be easy to give an LLM access to its own weights. But it would not be useful.

Shitty-kitty2• 2 months ago

Many of the systems that complex biological systems rely on, evolved long before the brain, some of them go back to before there were nervous systems at all. Truth is that it's all a hodge-podge of layers of complexity built on-top and sideways. In tech terms we would call it enormous technical debt.

literalAardvark• 2 months ago

We're all vibe coded :(

UltraSane• 2 months ago

Humans are kept alive by quadrillions of closed control loops. Being aware of them all would be very distracting.

colbyn• 2 months ago

I’ve thought about this. Or at least something like that.

When reading dune there’s a class of women who can control their biochemistry in such a way that they can eg prolong lifespan, or anything else within the realm of feasible biochemistry.

Here I was like: how does the nervous system function in that way? How could signals from the mind control the behavior of molecules?

The mind cannot itself feel pain, similarly the mind has sensory limits within the body. As argued in a book called the body a guide for occupants: cancer is a very good example of a disease that our nervous system should be able to detect but for whatever reason we don’t, probably because cancer is something we can only now treat.

Not all of the body can be made legible to the mind.

Although maybe a better question: why don’t we have a dedicated organ that can sample blood with laboratory like precision and make anomalies available to the conscious mind beyond whatever faculties we currently have?

One thing that definitely should be within the realm of conscious control: body fat. There are ways of forcing the body to metabolize more fat for energy and the biggest problem is managing excess heart (easily becomes lethal). But this could be super useful in cold climates. Imagine being able to literally burn body fat to stay warm? The amount of heat that can be released is enormous. Nowadays most of us could probably afford the otherwise superfluous expenditure of body fat (beyond essential functions).

Paracompact4• 2 months ago

why don’t we have a dedicated organ that can sample blood with laboratory like precision and make anomalies available to the conscious mind beyond whatever faculties we currently have?

"My triglycerides are at 220 mg/dL" is not a useful signal to a hominid banging rocks together.

Instead, what we got was the budget version, keyed for resolution rather than understanding: thirst (osmolality of plasma fluid), suffocation (blood acidity induced by excess CO2), and when all else fails, at least vague malaise as a catch-all "something's off, let's maybe sit down."

One thing that definitely should be within the realm of conscious control: body fat. There are ways of forcing the body to metabolize fat for energy and the biggest problem is managing excess heart (easily becomes lethal). But this could be super useful in cold climates.

Non-shivering thermogenesis is primarily mediated by brown fat. It's how babies keep warm. Adults still retain some brown fat, and it appears spending time in the cold can stimulate its production. https://stagetestdomain3.nih.gov/news-events/nih-research-ma...

Imagine being able to literally burn body fat for heat? Nowadays most of us could probably afford the otherwise superfluous expenditure of body fat.

Brown fat is burned in the body by a protein called thermogenin (UCP1). The same process can be stimulated by the drug 2,4-Dinitrophenol (DNP), albeit to lethal consequences if you're not careful. I suppose the reason we can't do this at will is because our body can do it unconsciously for us better and more safely than our frontal cortex ever could.

nkrisc• 2 months ago

Although maybe a better question: why don’t we have a dedicated organ that can sample blood with laboratory like precision and make anomalies available to the conscious mind beyond whatever faculties we currently have?

Because random mutations and selective pressure has never lead to such a trait that persists in a population.

rendall• 2 months ago

"A horse is an extremely sophisticated biological machine, but it has no idea what makes itself tick."

To my ears, a lot of detail is hidden in "knowing what makes itself tick". The limit of human Umwelt, cognitive closure, is an arena I find fascinating.

Modern people tend to identify understanding with mechanistic explanations. Veins, glycogen, immune states, hoof pumps. These are interesting and satisfying to us. But does that kind of explanation satisfy only because we are apes with ape language and interests, leaving aside even that we live in a society that values those explanations?

If a horse-level intelligence existed, perhaps its most satisfying explanations would not be "I can inspect the venous plexus in my hoof," but something else. Maybe more proprioceptive: pressure, load, gait. Or maybe that's just still my primate prejudice poking through.

What would satisfy a horse scientists might seem opaque or insufficient to us, but maybe our biochemical account would seem equally beside the point to it?

Maybe there is no species-neutral answer to what counts as understanding what one is.

On a deeper level, I suspect that a "complete understanding" in an absolute or divine sense is infinite. Our perceptions are necessarily limited, only a model of reality. In order to understand in a way that helps us survive, we must filter out a lot of information that is not absolutely irrelevant, but is irrelevant to us. Even Funes remembered only that which is relevant to a human, that which he could perceive in the first place. He could not remember changes in magnetic fields, background radiation, subtle shifts in gravity.

Paracompact4• 2 months ago

Indeed, specification of what "understanding" even is is one of the hard problems that would have to be solved before answering such a question! Nobody disagrees, for instance, that an LLM has no understanding, awareness, or even access to the underlying numerical weights of its neural network, but still there is much debate whether it understands anything at all, even subjects that it is clearly superhuman at performing in. Perhaps "understanding" will only have a meaningful definition to us if it is tied with conscious awareness, but that's hardly better.

Another very relevant Borges story is "On Exactitude in Science." If we could precisely model every physical law and even the precise distribution of matter in the universe, but this model conveyed to us no intuition or usefulness on a human level, can it even be called understanding? Instead we seek teleological anthropomorphic explanations in everything, and it's baked into how we discuss things. "Big cats developed powerful muscles to run fast and catch prey," "our immune system exists to keep us from getting sick," "rooks are worth more than knights," "the universe favors states with the highest possible entropy," "de Rham cohomology detects topological holes."

shiandow• 2 months ago

If you try to understand by knowing every little detail it is bound to fail because that attempt only increases the number of things you need to understand.

I think the Buddhist had it right in this instance, if you want to understand yourself completely stop trying to know every little thing and just be aware.

LargoLasskhyfv• 2 months ago

There is a Sci-Fi novel about fancy forest frogs, which possess that ability down to the biomolecular level. And a human researcher stranded on their world, being modifyied by them, to help her survive and adapt to the toxic environment.

https://en.wikipedia.org/wiki/The_Color_of_Distance

(QVACK! °oO0°·.)

9dev3• 2 months ago

I think considering yourself as a consciousness inhabiting a body, maybe in a way similar to the aliens in The War of the Worlds, is a false premise. Consciousness is one control system, but there are many, and your mind relies not just on the brain but the entire body.

So when you say being aware of every detail of your design, that hinges on awareness in the realm of critical thinking - but all the while, parts of your body are absolutely aware and in control of every little detail. I'd even say, these "subsystems" send a notification to your consciousness if anything is outside normal operational parameters, which makes total sense: Surfacing only details that require immediate attention is a good strategy to control complex systems, and one that we apply to many superficial constructions as well.

Another fun aspect of this is that when you try to suffocate yourself by holding your breath for too long, you'll pass out. Why does that happen? Because your body switches off your rogue consciousness in an attempt to stay alive - because staying alive overrules your subjective experience.

986aignan• 2 months ago

It's difficult to say anything about experiential/first-person consciousness as we don't know what it is. Some say it doesn't exist and everybody is a p-zombie. That aside...

As you mention, there's a problem where if you want to know yourself fully - including observability of your mind - you need to be aware of the thing that is aware, and aware of the thing that is aware of the thing that is aware, etc, down to infinite regress.

But that doesn't necessarily mean that it's impossible. It would suggest that such a being works by moving along a set of fixed point. Suppose x is the state of the physical mind (whether that's a brain, a set of chips, or something else). Suppose f(x) returns the updated state after this mind takes into account what it knows (i.e. f(first-order aware) = first- and second-order aware). Then if the mind-state always changes so that x is a fixed point of f, then the mind already knows all there is to know about itself.

So the question, on the mind side, is whether there exists a sufficiently generally intelligent type of mind for which moving along fixed points is computationally easy. I don't know. It could be possible, it could be impossible. Finding fixed points is hard in general, though.

There's also the problem of sensors, which may seem simpler but hides a similar difficulty. What happens if whatever thing that measures blood sugar fails? Or if the immune system goes auto-immune due to an immune cell defect that makes it report benign cells as foreign? Then you need an integrity sensor for the sensors - then you need an integrity sensor for the integrity sensor... At least this fixed-point problem for sensors should be easier than the one for general minds.

The consciousness:complexity ratio would probably express itself in that a mind of a certain complexity with the fixed-point-of-f constraint would be less intelligent on average than a mind of the same complexity without such a constraint.

card_zero• 2 months ago

Speaking as a horse, I wonder why you think we have any ideas at all. But anyway, ideas are less complex than the systems that they explain, that's the whole point of ideas. We're always progressing to simpler explanations while at the same time discovering that the world has new complexities. (The simplification is winning.)

I'd go into more detail, but I've seen a white gatepost and have to stop now.

qsera2• 2 months ago

naturally its complexity would have to scale with the complexity it is attempting to self-model...

And yet, in order to understand how a recursive function work, one only have to understand the base case, and the relation between the function's input and output, and not everything that it does in its recursive steps.

So the point is, if an organism/consciousness is a recursive algorithm, it is feasible that it could be understood by itself.

not_kurt_godel• 2 months ago

Not strictly possible per https://en.wikipedia.org/wiki/G%C3%B6del%27s_incompleteness_...

jimmaswell• 2 months ago

It makes me tangentially think of the speech in Virtue's Last Reward about how it takes a higher intelligence to understand the intricate structures that termites build, ending with a question of what it is that humans are building to be understood by a higher intelligence.

rramadass6• 2 months ago

Far more interesting but relevant fact;

Giraffes are at the very edge of physical adaption. In the fantastic Channel-4 TV series Inside Nature's Giants (https://en.wikipedia.org/wiki/Inside_Nature%27s_Giants) they dissect a giraffe and show how their anatomy/physiology is adapted to handle extreme blood pressure (because their heart needs to pump blood to the brain through the long neck against gravity). But that same pressure when sent down to the legs will burst their blood vessels. So how does cardiovascular adaptation work in this case?

Read these to find out;

1) How giraffes deal with sky-high blood pressure - https://www.bbc.com/future/article/20210803-how-giraffes-dea...

2) The Remarkable Cardiovascular System of Giraffes - https://www.annualreviews.org/content/journals/10.1146/annur...

3) How long limbs reduce the energetic burden on the heart of the giraffe - https://journals.biologists.com/jeb/article/228/20/jeb251092...

4) Giraffe dissection episode (must watch!) - https://www.youtube.com/watch?v=pkhztOqKYIc

PS: Inside Nature's Giants is one of the best scientific series which everybody should watch, particularly students. This is how evolution should be taught; all episodes on Youtube - https://www.youtube.com/results?search_query=inside+nature%2...

rramadass6• 2 months ago

Inside Nature's Giants: Racehorse dissection episode - https://www.youtube.com/watch?v=feAj2aspkIE

beefandcheese• 2 months ago

And then we nail metal shoes on them.

adiabatichottub• 2 months ago

A good friend of mine is a ferrier, or as he likes to say, "equine podiatrist". There's actually quite a lot to it. They are responsible for shaping the hoof and shoe in a way that corrects problems with the horse's gait. Each shoe is custom made and fitted to the horse, fashioned from a plain bar of steel. It takes years to become truly proficient at the craft.

Blood Pumping Mechanism of the Hoof (2020)

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