Consider that even on this planet, where the conditions are so ideal for life, as far as we know, life has only occurred once. There are not multiple trees of life. Everything alive here is related and has a common ancestor. You would think that if life had a strong tendency to occur where conditions favor it, we'd see another line. — petrichor

I don't think this reasoning provides strong evidence for how probable abiogenesis is. Any protolife that developed today is apt to be seen as food by existing life forms which have had billions of years to improve their effectiveness as an eating machines. Perhaps abiogenesis occurs on earth every million years on average, but the resulting life form is no competition for existing life forms with an evolutionary head start.

Edit: Did you recognize this and edit?

I think what I'm wanting to settle, for myself, is whether or not the circuits are in turn being interpreted by us, or if they are performing logical operations. — Moliere

I'm not clear on what you want clarification of, but let my respond to the rest of your post and then let me know what might still be unaddressed.

What makes Q and ~Q different other than one is on the left side, and the other on the right side? Do we just arbitrarily choose one side to be zero and the other side to be 1? Or do the logical circuits which have a threshhold for counting do it differently?

To my mind the circuit still doesn't really have a logical structure anymore than a stop light has the logical structure of Stop/Go without an interpretation to say "red means stop, green means go". So are we saying "Q means 1, and ~Q means 0"? — Moliere

The SR f!ip-flop circuit is symmetrical, so it is somewhat arbitrary which output is chosen to be Q and ~Q. However, the Set pin is defined as the input that can cause Q to produce a 1 (5V) output. So one could swap Q and ~Q, but to be consistent with the conventions for SR flip-flops one would also need to swap which input is labeled S and which R. So like the stoplight it is a matter of convention.

Also, flip-flops themselves don't perform logical operations. They just serve as memories that can be used to provide inputs to logic gates (or combinations thereof), and store outputs from logic gates.

Delete

Based on the website I linked it looks like Q and ~Q are out of phase with one another. So the memory comes from being able to output an electrical current at inverse phases of one another? How do we get from these circuits to a logic? And the phase shift is perhaps caused by subtle manipulations of the transistor? — Moliere

Phase isn't a particularly useful concept for thinking about the relationships between Q and ~Q. In the case where both Set and Reset are grounded, both Q and ~Q will be at 5 Volts rather than one being at 5V and the other being at 0.2 Volts. Also, when considering the transitions from one state to another things get messy for a time and thinking of Q and ~Q as having a phase relationship breaks down.

As for, "How do we get from these circuits to a logic?"...

So with a flip-flop we can use as a one bit memory, we have what we can think of as a logical variable. Additional circuitry can take the Q output of multiple flip-flops and perform logical operations. The result of the logical operation can then be stored in another flip-flop, for use at a later time.

At this point it is pragmatic to jump up a level in abstraction and think in terms of logic gates instead of transistor circuits. So we can have an AND gate and brush consideration of transistors, resistors, and power supplies under the rug. We can simply think of an AND gate as a device with two inputs which treat voltages above 2.5 Volts as a logical 1 (true), voltages below 2.5 Volts as a logical 0 (false), and output the logically appropriate voltage level on the output.

The following image shows schematic symbols for logic gates of various kinds and their truth tables:



Such logic gates can be strung together to yield whatever logical function is needed. For example a one bit adder:



A and B could be the outputs of two flip flops representing the two bits to be summed. Cin represents "carry in" and can be connected to the "carry out" of another adder. S will have an output logic level representing the sum of A and B given the state of Cin. Cout will have an output level which can be connected to the Cin of a different adder.

By connecting such logical blocks together we can create something useful. For example we could have three 32 bit registers. (With each register just being a collection of 32 flip-flops.) Two of those registers could have 32 bit binary numbers that we want to add together. The third register could have its flip-flop inputs connected to the S outputs of a 32 bit adder chain and thus we would have the ability to take two stored 32 bit numbers and add them and store the sum in the output register.

Now so far I've glossed over the dynamics of changing states. That is much too complicated to try to cover in any detail. With digital logic, typically a 'clock' is used in order to be able to ignore the short term dynamic transitions of flip flops and logic gates from one stable state to the next.

The SR flip-flop schematic I showed is about as bare bones as a flip-flop can get. The flip-flops in a microprocessor are typically more complex D flip-flops which have a D(ata) input terminal and a CLOCK input. D flip-flops work by changing their output state (Q) to match the D input state when the clock signal transitions from a logic 0 to a logic 1. So with all of the flip-flops tied to the same clock signal, all of the transitioning can be synchronized. As long as the clock frequency is slow enough, all of the dynamic transitioning that occurs after the last clock edge has time to settle to a stable state before the next clock edge.

That helps me understand the feedback part very well -- so thank you again for taking the time. When Set is grounded the voltage from R3 no longer gives the voltage necessary for the transistor to be in the "on" state, but the parallel circuit through R2 does so the circuit flips over to Tr2. Since Tr1 is now off that means 5V goes to Q as the path of least resistance. The same holds for reset and the blue state. — Moliere

Very good! :up:

I'll respond to the rest of your previous post later today.

Sure. "constant speed" was a bad use of terms, But "approximate", and "average" do not imply that the speed was anything other than constant. You have provided no representation of the movement of the object during that time period. — Metaphysician Undercover

Everyone else who has been involved in this discussions understands that the ball is accelerating continuously in the scenario under consideration. Your lack of comprehension is not caused by the other people in the discussion.

Maybe Wonoto is 'stuck'. — BC

And there, but for the fortuity of my circumstances, go I.

The story of a hole in a state of flow with an innumerable number of other holes towards ~Q: We start at 5 V and move through R1 to TR1 because the voltage at Q is lower than the voltage at ~Q (assuming we're already in a steady state), then we go through the unmarked resistor on the other side of the transistor, up through R3 and out ~Q. If you touch "Set" to the zero volts line than you ground the flow causing the voltage to switch over to R4-T2-R2-Q. — Moliere

To keep the explanation relatively simple it is easier to mostly ignore current flows and look at voltage levels in various places. However, I think it will help if I go into more detail about the type of transistor depicted in the flip-flop schematic, and the way current flows through the transistor. So to that end, let's looks at the left half of this image:



This image also helps introduce the names for the terminals of the transistor which are symbolized with B(ase) E(mitter) and C(ollector). The purple arrows indicate the way current can flow through the transistor with the width of the arrow illustrating that the current flowing into the collector is larger than the current flowing into the base. All of the current must exit out of the emitter. Typically the base current is around one hundredth of the emitter current. However, current can only flow into the collector when there is current flowing into the base. Therefore a small base current acts as an input controlling the larger collector current.

Another factor having to do with the physics of the semiconductor device that the transistor supervenes on, is the fact that the base voltage needs to get up to ~0.7 volts before current will flow into the base, and therefore before current will be able to flow through the emitter.

So to get back to simplistically modelling things in terms of the voltage levels on different wires. We can think of the transistor as a device where, when the voltage at the base of the transistor is 0.7 volts or higher, a switch is closed between the collector and the emitter, allowing current to flow through the transistor from collector to emitter.

[tl;dr]More accurately than looking at it as a switch, we might look at the path from collector to emitter as a resistor with a resistance of about 42 Ohms when the transistor is in the 'on state', and as an open circuit when the transistor is in the 'off state'. In that case, if we suppose the resistance of R1 and R4 to be 1000 Ohms, then we have an explanation for why the flip-flop schematic shows a voltage at Q of 0.2 volts for the blue state. In the blue state the 5 volts of the flip-flop power supply gets divided between the 1000 Ohm resistance of R1 and the 42 Ohm resistance of the 'on stated' TR1. In the red state the voltage at Q simply is the +5 Volts of the power supply. (Ignoring for the sake of simplicity, the the relatively low base currents flowing through R3 and R4. The ambitious reader who is into that sort of thing can assume that R3 and R4 have a resistance of 100000 Ohms, and look up linear circuit analysis, and calculate voltages out to more decimal places. However, for pragmatic purposes we can ignore current through R3 and R4, and just consider whether the voltage at the transistor bases are above or below 0.7 Volts to know whether a transistor is off or on.)

And for this discussion we can ignore the resistance of the unlabeled resistors altogether and treat them as open circuits. They are for practical details engineers need to worry about but, not of any help in looking at things in the simple voltage focused model of the flip-flop schematic.[/tl;dr]

Getting back to the flip-flop schematic...


The schematic is marked up in accordance with modelling things in terms of static voltage states where we don't need to be concerned with current flows and what happens on a dynamic basis. For now at least, we just want to look at how the circuit acts as a one bit memory. That can be understood by recognizing the fact that when the Set input is grounded to 0 Volts the red markups indicate the voltages on the wires they are near. When the Reset input is grounded the blue markups apply.

There are two other states that are of interest, which are not detailed on that schematic. These two states are the different memory states that the circuit can be in when both Set and Reset are disconnected from ground. What the voltage state of the flip-flop is, when both Set and Reset are disconnected, depends on whether Set or Reset was last tied to ground. In other words, the voltage at Q reflects the flip-flop's memory of whether Set or Reset was last connected to ground.

I'm going to have to leave off there for now. I'll respond to more of what you wrote later

Also, there is another scenario to consider, which is what happens when both Set and Reset are connected to ground yielding Q=~Q, and how Set and Reset being disconnected from ground simultaneously is like flipping a coin. But as Q=~Q might suggest, that's a state that is best avoided for sound logic.

I didn't mean feedback necessarily, just the view that process might be seen as fundemental, not substance. — Count Timothy von Icarus

Yeah. Your point was recently hammered home for me on another forum by someone who wants to dichotomize everything into either physical things or abstractions, and can't understand physical processes as a category different from either.

I guess for me, feedback is important in making a system interesting, so I'm biased towards focussing on systems with feedback.

I'm sure I don't understand how a circuit has a memory, still. — Moliere

I'll take a stab at trying to convey it without going into too much detail.

Frequently memories are implemented in subcircuits which have a designed in bistability. An example of a bistable system would be a coin on a table. Assuming the coin can't be stood on edge, the coin on a table will have a stable state of either showing (outputting) heads or tails, true or false, 1 or 0.

Some sort of work (flipping the coin) will need to be done in order to get the coin/table system to represent the state opposite of what it is currently representing.

The flip-flop circuit shown below is loosely analogous:



Unfortunately, the image creators were a bit sloppy in the way they used text colors (and I'm too lazy to look for a better image) so imagine the text which says "+5 Volts" and "Zero Volts" to be black. (Those parts of the circuit are 'part of the table' and stay constant. The remaining red and blue text details the two different stable conditions the subcircuit can be in - red state or blue state.

The circuit shown has two inputs S(et) and R(eset) and two outputs Q and ~Q. (Typically only one of the two outputs might be used, since as long as the system has had time to reach stability the ~Q output state is the logical inverse of the Q output state.)

The two three-terminal devices (TR1 and TR2) are transistors. The terminals that exit the transistors horizontally (to the left or right) are the control inputs to the transistors. When a control input is at 0.7 volts or greater that transistor will be on and allow current to flow in the top terminal and out the bottom terminal resulting in the output to which the transistor is connected (Q or ~Q) being pulled towards 0V (captioned as 0.2V).

Two other particularly important elements for having a flip-flop are R2 and R3. R2 and R3 represent resistors. Note that R2 connects the Q output to the input of TR2 while R3 connects the ~Q output to the input of TR1. So each output has some control of the other transistor's input. As long as S and R are not connected to anything the transistor that is turned on will keep the other transistor turned off. Simultaneously a transistor being turned off (in combination with the resistor network) causes the other transistor to be turned on. So like a coin on a table the circuit will just sit in one of the two stable states, red or blue.

The S and R inputs can be be momentarily connected to 0 Volts in order to force a change from red state to blue state and after the input which was connected to 0 Volts is disconnected the flip-flop will stay in the state it was forced into.

I'm going to leave it there for now. Let me know if that helps, or what needs more explanation.

We are not entirely out of touch with the world when we sleep. Our brains are busy doing something (???) 24/7. Your brain "puts you to sleep" and it "wakes you up". They can keep track of time well enough to wake you before your alarm goes off (unless it has decided to sleep through the alarm). — BC

Yes. It was striking the first time I underwent anesthesia - the difference in time sense between waking up from sleep and coming out of anesthesia.

I believe it has already happened in some enclaves. — Janus

:rofl:

Apparently, knowing "the truth" doesn't involve having very good reading comprehension. I didn't say anything about the Buddha or Lao Tzu
— wonderer1

Pardon me but yes you did. You claimed that the mystics are naive, grandiose and by implication untrustworthy. I can't imagine how you arrived at this idea. — FrancisRay

I did not claim to know the truth, What I would claim is that the nondual doctrine, for which it is possible to know the truth, is the only theory that makes sense in metaphysics. I can know this because it's just a matter of doing the sums — FrancisRay

It is quite easy to quote what I actually said. I'll repeat it below with emphasis.

Not a liar, just naive, and in too many cases grandiose. — wonderer1

Can you see that that I wasn't referring to "the mystics", but instead to a subset of mystics? I try to refrain from looking at things in black and white ways. So I would appreciate it if you would be so charitable as to try to avoid jumping to conclusions that I've said something is black and white when I haven't done so.

I did not claim to know the truth, What I would claim is that the nondual doctrine, for which it is possible to know the truth, is the only theory that makes sense in metaphysics. I can know this because it's just a matter of doing the sums. . . . — FrancisRay

Bzzzt! The way that can be summed is not the true way. That's Mystic 101.

Both metaphysics and mysticism study the nature of all extended objects, so it makes no difference whether it is this or that object. As the Upanishads state:

“The understanding of one single thing means the understanding of all;
the voidness of one thing is the voidness of all.”

Aryaveda
Catuhsataka
v. 191 — FrancisRay

That's some grade A bullshit, in addition to being grandiose. Seriously? "The understanding of one single thing means the understanding of all"? Look around. Have you have seen many of your fellow social primates who seem like they understand all? If so, I don't think you are paying very close attention.

And of course the Buddha and Lao Tzu were naive. They didn't have the benefit of the tremendous growth in human knowledge that has occurred since their day. Why would they be anymore likely to understand all, than the people you see around you?

Not to say that people don't pick up some beneficial perspectives and skills from the Buddha, Lao Tzu, et. al.

Can you enlighten me? — Gnomon

No. The paper is too far over my head to grasp, without reading a lot more than the paper itself, and life is short.

Or you're just immune to science. — flannel jesus

MU has as much as said that his mind is closed to the extent that he can keep it so:

I, am an impenetrable fortress. Nothing, I repeat nothing, from that "external world" can infiltrate my defenses, and move me. All which exists within my mind comes from the inside. Thus is my reality.

There is however, a sense in which ideas come to my mind from somewhere other than my mind. Since they cannot penetrate through my fortress, and enter from the external, and "ghostly phenomena" is silly talk, I conclude that they enter my mind through "inner space". And since the ideas which enter my mind through inner space seem to be very similar to the ideas which enter your mind through inner space, I can conclude that we are very well connected through inner space. — Metaphysician Undercover

And, a misleading map gets people lost. — Metaphysician Undercover

Ah, the irony.

There are none so blind...

You posted your opinion implying that the common Yin Yang symbol was used as input... — Gnomon

Have you looked at the original paper? (Which T Clark linked early in the thread.)

I just took a look and the caption under the only picture of the Yin-Yang symbol says:

a, Coincidence image of interference between a reference SPDC state and a state obtained by a pump beam with the shape of a Ying and Yang symbol (shown in the inset). The inset scale is the same as in the main plot. b, Reconstructed amplitude and phase structure of the image imprinted on the unknown pump.

Ok, can you explain it to me ? My amazement is that this all rather predates solid state transistors. — unenlightened

It doesn't predate computers built from relays as the 'bug link' I posted shows. I would think Spencer-Brown would have been well aware of this, and wouldn't have believed himself to be presenting anything particularly novel in pointing out the possibility of memory implemented in switches.

As far as explaining... I'm not sure what you are asking me to explain. I haven't been reading along.(although I am curious about Spencer-Brown's thoughts on implementing complex math in Boolean logic) So I'm not in a position to explain much about what Spencer-Brown has to say. I could explain the workings of the flip-flop in the image I posted, but I don't have a good sense of how much background knowledge I'd need to provide, in order for you to find my explanation comprehensible.

Yeah, tempting but stupid. Computer memory is not made of switches. But kudos for bothering to read the thread at all. — unenlightened

Well computer memory is implemented in a variety of ways these days, but any modern computer is going to have some memory elements implemented as flip-flops. A simple schematic of a flip-flop is illustrated below.



Note that the symbols labeled TR1 and TR2 represent transistors, which for practical purposes are switches.

Older (pre-solid-state) computers used electromagnetically controlled switches with contacts that opened and closed. (relays) This allowed a literal bug to crash a computer. Solid-state switches (transistors) are a big improvement.

Did you interpret the symbolic image as an error of judgment, or a deliberate hoax? — Gnomon

Isn't that a false dichotomy?
Maybe a stunt to get a lot of attention to their paper? Maybe one of the researchers is into Taoism? Maybe a target that was handy and interesting enough?

This is extraordinary! A circuit made entirely of switches that has a memory! — unenlightened

Wow, if someone implemented something like that we could have computers and an internet!

Sorry, couldn't resist.

Humans can move the plants that they want to move. This solves the problem for plants that can't move themselves. All of our food crops etc will be easy to shift. — Agree-to-Disagree

Things are not that simple.

The Canadian Shield (French: Bouclier canadien [buklje kanadjɛ̃]), also called the Laurentian Plateau, is a geologic shield, a large area of exposed Precambrian igneous and high-grade metamorphic rocks. It forms the North American Craton (or Laurentia), the ancient geologic core of the North American continent. Glaciation has left the area with only a thin layer of soil, through which exposures of igneous bedrock resulting from its long volcanic history are frequently visible.

https://en.m.wikipedia.org/wiki/Canadian_Shield

And life goes on, and on, and on. For million, billion of years, etc etc etc. — niki wonoto

Hoping for that gives purpose to some of us.

Anyone who benefits better have a nuclear arsenal ready to defend themselves from invasion. :grin: — frank

O Canada! Our home and native land!
True patriot love in all thy sons command.
With glowing hearts we see thee rise,
The True North strong and free!
From far and wide, O Canada,
We stand on guard for thee.
God keep our land, glorious and free!
O Canada, we stand on guard for thee;
O Canada, we stand on guard for thee

:up:

What math? It's a philosophical problem, one which mathematics has not resolved. Look, there's a point in time, when a body at rest becomes a body accelerating. The body changes from being at rest, to being in motion at some point in time. Since the rate of increase of velocity (acceleration) is expressed as over a period of time, at this point in time, when the body changes from being at rest to being in motion, the rate of increase must be infinite because it's a number expressed over zero, x/0. — Metaphysician Undercover

That's what I'm asking you, "What math?"

You keep bringing up mathematical issues, such as infinity and division by zero, as if they are magic words meant to distract from your inability to explain why they are of relevance.

It's starting to appear as if you don't know how to apply math to the situation. (Not that there is anything wrong with that.)

Re your version of [1]: Can processes per se account for anything? I agree with Hume that causation is essentially epistemic. We can have a useful account (ie a symbolic representation) positing that A causes B. But causation is a not necessary concept. In a block universe where time is represented, A and B are part of a single spatio-temporal 'thread'. — Christopher Burke

I agree. There is much we can't be certain about regarding the nature of reality. Still, we are talking about the way a physicalist sees things.

Re your version of [2]:
'Practical purposes' do indicate something important about how we interact with extramental reality. I don't think they can be dismissed so easily as irrelevant to our understanding. You say "we need to resort to simplistic non-physical psychical representations", but most psychologists would dispute that pejorative classification as simplistic ... as would I. — Christopher Burke

It wasn't meant as a pejorative. Just a statement about what the situation is. Hopefully scientific psychologists would recognize, along with Einstein:

The scientific theorist is not to be envied. For Nature, or more precisely experiment, is an inexorable and not very friendly judge of his work. It never says "Yes" to a theory. In the most favorable cases it says "Maybe", and in the great majority of cases simply "No". If an experiment agrees with a theory it means for the latter "Maybe", and if it does not agree it means "No". Probably every theory will someday experience its "No"—most theories, soon after conception.

Psychologists are considering what is going on, in systems much more complex than Einstein considered. Simplistic psychological theories are the most we can reasonably hope for at this point in human history. I'm not saying that psychologists are not doing a great job at improving our understanding of our minds. It's just the nature of the situation humanity is in.

Even if we had a complete model based on all possible data from observation, would we know what it is like to be that bit of reality? — Christopher Burke

Not comprehensively. We aren't capable of fully knowing what it is like to be each other. But that's a limitation that comes with having a physical mind.

“The last dollop in the theory [of Physicalism] – that it subjectively feels like something to be such [neural] circuitry – may have to be stipulated as a fact about reality where explanation stops.”
Steven Pinker, 2018, Enlightenment Now: the Case for Reason, Science, Humanism and Progress — Christopher Burke

I think Pinker is overly pessimistic. There is much understanding to be gained beyond where Pinker suggests explanation might stop.

I fear you've built up this very narrow idea of what materialists think, that isn't actually what materialists think. — flannel jesus

:up:

[1] Physicalism claims that physical representations can account for everything.
[2] We need non-physical psychical representations to account for some things.
[3] Ergo physicalism is a false claim.
...
Where is my error? — Christopher Burke

I would correct your first two premises as follows:

[1]Physicalism claims that physical representations processes occuring in nature can account for everything.
[2]For practical purposes we need to resort to simplistic non-physical psychical representations to account for some things, because we don't have detailed data about what is going on in our brains, nor do we have brains capable of processing such a mountain of data in an expeditious way.

So you would at least need to add some additional premises to reach your conclusion.

These ideas are very definitely testable. To state otherwise would be to say that every mystic who has ever claimed to know the truth is or was a liar. — FrancisRay

Not a liar, just naive, and in too many cases grandiose.
— wonderer1

Oh boy,.. You're calling the Buddha and Lao Tu naive and grandiose? But not yourself? — FrancisRay

Apparently, knowing "the truth" doesn't involve having very good reading comprehension. I didn't say anything about the Buddha or Lao Tzu.

Let's talk about your grandiosity instead. Why would anyone take seriously your claim to know "the truth". Lots of people know all sorts of truths that you don't know. So other than as a naive grandiose claim, how is your claim to know "the truth" to be interpreted?

To make things more concrete... There is an object sitting on the computer case on the right side of my desk. What is "the truth" about the nature of that object. Give as much detail as you can.

These ideas are very definitely testable. To state otherwise would be to say that every mystic who has ever claimed to know the truth is or was a liar. — FrancisRay

Not a liar, just naive, and in too many cases grandiose.

Scientists are not infallible, they are human like everyone else. And the human urge to go along with the popular trend is quite strong, especially when doing so would help in furthering one's career. Hence, to think that scientists at large would orient their scientific labor in support of an official narrative is not at all unreasonable to consider. — Merkwurdichliebe

Not ureasonable I suppose, for someone with a lack of experience with science and scientists. However, regardless of how reasonably understood it might be, that you hold that view (being as ignorant as you demonstrate yourself to be) ignorant conspiracy theory rationalization is what it is.

The concept of "acceleration" involves a fundamental philosophical problem. Acceleration is the rate of increase of velocity. So if an object goes from being at rest, to moving, there is a brief period of time where its "acceleration" is necessarily infinite. — Metaphysician Undercover

Show your math.

NYTimes article:

The university lab which did the testing “disassociates itself from any use, interpretation, or subsequent misrepresentation of the results it provides,” the institute said. “In no case do we draw conclusions about the origin of these samples.”

Similarly, Antígona Segura, one of Mexico’s top astrobiologists, questioned Mr. Maussan’s contentions. “These conclusions are simply not backed up by evidence,” said Dr. Segura, who collaborates with the Nexus for Exoplanet System Science, a NASA initiative to search for life on distant worlds. “The whole thing is very shameful.”

What does "sec**2" even mean? — Metaphysician Undercover

https://www.quora.com/What-does-per-second-squared-mean

In addition, what's interesting about the genes of life on earth is that a lot of it is junk. A lot of it doesn't do anything. It's vestigial. If we share 70% of DNA with this alien, that means we share a hell of a lot of vestigal DNA - that's actually a pretty big problem. — flannel jesus

Good point, although I'm assuming that if there was DNA testing, it wasn't a whole genome sequencing of whatever DNA there was to test. A test that only looked for 100 genes might find 70 matches, while ignoring non-coding DNA.

I'm guessing the 'researchers' won't be releasing any details of any DNA testing.

Do you think the genes for wings in bats is similar to those for birds, is similar to those for flying insects?

They're not. — flannel jesus

That's a bit simplistic. True, insects are quite distant and the genetic distance is going to be relatively large for them. However the four animals in Frank's picture are all tetrapods:

Tetrapods (/ˈtɛtrəˌpɒdz/;[5] from Ancient Greek τετρα- (tetra-) 'four', and πούς (poús) 'foot') are four-limbed vertebrate animals constituting the superclass Tetrapoda (/tɛˈtræpədə/).[6] It includes all extant and extinct amphibians, and the amniotes which in turn evolved into the sauropsids (reptiles, including dinosaurs and therefore birds) and synapsids (extinct pelycosaurs, therapsids and all extant mammals). Some tetrapods such as snakes, legless lizards and caecilians had evolved to become limbless via mutations of the Hox gene,[7] although some do still have a pair of vestigial spurs that are remnants of the hindlimbs.

Note the mention of Hox genes. All of the tetrapod species in Frank's picture have Hox genes playing a strong role in determing much about the body plan, and constraining the course that tetrapod evolution could take.

I do wonder why it is that it has taken so long for the process view to take over. Is it necessarily less intuitive, or is the problem that we drill a sort of naive corpuscularism, a substance metaphysics, into kids for the first 14-18 years of their education? It certainly seems less intuitive. I sort of buy into Donald Hoffman's argument that we evolved to want to focus on concrete objects (thus excluding the "nothing"). — Count Timothy von Icarus

Off the top of my head I can't think of many easily observable examples of feedback outside of social interactions, so I think it is pretty natural that people don't tend to have intuitions that are informed by observing feedback systems. (I suppose the notion of karma suggests somewhat the idea of a feedback sysyem.) I don't see it as so much a matter of our educational systems, as a matter of our lacking the perceptual and cognitive systems to see the feedback occurring in things around us.

I look into some types of feedback systems routinely, and have intuitions conducive to understanding feedback systems to a greater degree than most, but it takes expensive instrumentation for me to be able to observe the relevant processes. I'd have to think about how better intuitions about feedback systems could be cost effectively instilled during K-12 education.

Relativity theory was created for pragmatic purposes, and is fundamentally not truth-apt. — Metaphysician Undercover

Black holes, gravitational lensing, and gravitational waves have all been observed and were predicted on GR. What do you mean by relativity theory not being truth-apt?

:up: