Why evolution by natural selection didn't make use of RF? - Page 1
Forum section: electronics / general

author: RoGeorge
author_rank: Super Contributor
timestamp: August 27, 2023, 01:12:23 pm
content: Life evolved many ways of sensing and signaling, from chemical, to sound, to light in the IR to UV spectrum, but no RF.How so?

author: Gyro
author_rank: Super Contributor
timestamp: August 27, 2023, 03:03:46 pm
content: Derrr, because there is no known way of biologically generating RF and there was nothing to listen to on the radio while they were evolving?

author: Kim Christensen
author_rank: Super Contributor
timestamp: August 27, 2023, 04:01:46 pm
content: Also, there was no need. Sound and light work "good enough" to eat, excrete, breed, avoid predators, etc...

author: DavidAlfa
author_rank: Super Contributor
timestamp: August 27, 2023, 04:04:44 pm
content: Because probably there's no chemical reaction capable of generating low frequency RF.Edit: Damn, Gyro had already said exactly this

author: TimFox
author_rank: Super Contributor
timestamp: August 27, 2023, 04:07:20 pm
content: Natural selection is just that: selecting which of already available options leads to success in breeding future progeny with that option selected.Feathers evolved as a useful insulation mechanism before they were used in flight.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 27, 2023, 04:33:30 pm
content: Quote from: Gyro on August 27, 2023, 03:03:46 pmReally? An electric eel discharging is probably generating some RF. Nervous systems generate RF and some animals apparently use that to hunt.https://en.wikipedia.org/wiki/Ampullae_of_LorenziniElectric, magnetic, whatever...

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 27, 2023, 04:34:26 pm
content: Fireflies make light, that's THz RF, right?

author: IanB
author_rank: Super Contributor
timestamp: August 27, 2023, 04:46:31 pm
content: As I understand it, creatures like electric eels can sense disturbances in the electric field they generate using receptors along the side of their body. So they can detect the presence of other things nearby. Not RF, but certainly electricity.

author: RoGeorge
author_rank: Super Contributor
timestamp: August 27, 2023, 05:10:43 pm
content: Quote from: Gyro on August 27, 2023, 03:03:46 pmNot only RF is missing, but also the much lower spectrum, e.g. VLF, which would be easier to produce biologically.There are high voltage electric eels, and sharks can sense incredibly small electric currents from a nearby swimmer. From there, one animal might leave the sea and use such organs for radio. The frequency doesn't has to be stable, could be just a current spike at first, similar with the spark gap transmitters.While writing these, I thought maybe there was too little RF "illumination" underwater, where life evolved first. Maybe the life on land is just too young for bio-radio.By looking at this timeline of life evolution,https://en.wikipedia.org/wiki/Timeline_of_the_evolutionary_history_of_lifeonly the last 1/10 of it has land life. Maybe that's why we are nothing but "walking bags of sea water", indeed, because 90% of the evolution was in the sea water.I guess life on land should eventually evolve some form of bio-radio.

author: Infraviolet
author_rank: Super Contributor
timestamp: August 27, 2023, 06:14:21 pm
content: The only reason RF is useful to us in because some portions of the spectrum are quiet and don't have lots of natural phenomena producing radio waves at those frequencies. If life had started to evolve RF capabilities then the whole spectrum would have been very busy, not only would it have been useless for mankind to hope to make long range communications with RF (if man had evolved under such a scenario), but all the species using the spectrum would make it useless to each other for any ranges which would be longer those which could already be sensed with visible light, IR and sound.As for creatures evolving passive RF sensors to look for reflections off objects, well the spectrum is fairly quiet naturally so there wouldn't be enough RF background radiation present to be worth listening to in the hope of being able to detect such reflections.That all said, this is an argument for why it would be a bad idea in the end for life to evolve RF transmitters, that doesn't mean evolution doesn't sometimes pursue adaptions which are great when the first creature has them but become useless when more get in on the game. Evolution doesn't plan ahead.

author: Gyro
author_rank: Super Contributor
timestamp: August 27, 2023, 06:18:21 pm
content: Quote from: Alex Eisenhut on August 27, 2023, 04:33:30 pmYes, there's a lot of electric field sensing used in water, even including sharks. The Electric Eel is a bit of an odd one - I still don't know how it doesn't fry its own head and tail, it must sting a bit! I doubt if its output rise time is fast enough to count as RF though, it must still be triggered by the normal biological processes and speeds, but maybe there's some sort of avalanche process that occurs.I think the OP could maybe have clarified the frequency range that he was thinking of.Quote from: Alex Eisenhut on August 27, 2023, 04:34:26 pmHa, yes. optical frequencies are possible, but those come down to chemical mixing. I guess you could argue that the Bombardier beetle can generate pulses of slightly lower frequency when it ejects hot steam from its ass by the same means!https://en.wikipedia.org/wiki/Bombardier_beetle

author: jpanhalt
author_rank: Super Contributor
timestamp: August 27, 2023, 06:52:34 pm
content: 1) Evolution did produce it. We are proof of that.2) Electric eels produce very low frequency AC at up to 500 Hz. Our muscle action potentials might be considered another example and brain eeg is another example. There are biological processes to produce alternating electric currents.

author: djsb
author_rank: Super Contributor
timestamp: August 27, 2023, 08:19:52 pm
content: Maybe some animals can detect the low frequencies of volcanic activity. Maybe this is why they scarper quickly in the movies. Or is this just Holywood fiction?

author: TimFox
author_rank: Super Contributor
timestamp: August 27, 2023, 11:10:23 pm
content: Volcanic activity can make low-frequency mechanical/acoustic vibrations, which could be detected by a sensitive animal.Electric eels generate high-voltage pulses, but I assume there is a strong DC component.

author: coppercone2
author_rank: Super Contributor
timestamp: August 27, 2023, 11:41:01 pm
content: because the matter that is available here for biolgoical functions is most likely to make the systems that evolved. Who is to say what can happen if say uranium was a essential micronutrient for left handed triple helix life?I assume its kind of like what you can put together with the junk box that you have.How about instead of lightning the catalyst is some kind of weird triboelectric crystals under water arcing away?

author: Brumby
author_rank: Unknown
timestamp: August 27, 2023, 11:52:40 pm
content: I am wondering about this aspect:How would the use of RF provide an evolutionary advantage?Indeed .... the question begs: What, exactly, do you mean by "RF"?

author: coppercone2
author_rank: Super Contributor
timestamp: August 28, 2023, 12:05:57 am
content: uh like a radar bat

author: vk6zgo
author_rank: Super Contributor
timestamp: August 28, 2023, 12:26:41 am
content: Quote from: RoGeorge on August 27, 2023, 01:12:23 pmThe only consistently proven natural producer of RF is lightning.Unfortunately, it doesn't happen continuously, so wouldn't be much use to lifeforms, which require their senses to work at all times.Some creatures can detect electrostatic fields, but not RF fields.

author: jpanhalt
author_rank: Super Contributor
timestamp: August 28, 2023, 12:27:18 am
content: Maybe the premiss of this thread is out of date? It seems the answer may be that we haven't looked for RF emissions?https://today.ucsd.edu/story/can-organisms-sense-via_radio-frequency#:~:text=%E2%80%9CResearchers%20in%20Europe%20were%20able,Deheyn%2C%20the%20project's%20lead%20investigator.I am a little familiar with bioluminescence. Fireflies have been known for ages. As we developed techniques to search deeper, we found that the ability to produce electronically excited states, regardless of whether light was emitted from the entity, is pretty widespread in the animal/protista kingdoms. That was an observation of Prof. William D. McElroy, who I was privileged to have as a professor many years ago. Coincidentally, he later became Chancellor at UCSD.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 28, 2023, 02:31:25 am
content: When and where would it evolve, and why?To be "RF", we must mean frequencies far above the cutoff due to ionic diffusion. This isn't a neural thing, this isn't a muscle contraction thing. Eels are scrunchy batteries, not spark gaps.It has to be pretty fundamental, an early-ish discovery; most mechanisms I can think of involve some kind of mechanical interaction, piezoelectricity of a specific crystal for example,combined withsome highly nonlinear process for harmonic generation (e.g. spark breakdown, but less destructive and more consistent).I mean, that's not even that far out, hydroxyapatite (the mineral of vertebrate bones) is piezoelectric, at least a little bit. But it would have to be applied in some way to get a transient into it, and have a spark gap or avalanche breakdown effect around it, with enough electrical insulation not to spoil the effect while also maintaining adequate structure and perfusion to, you know, be a useful otherwise-ordinary part of the organism.And then there has to be a simultaneous mutation that effects some kind of receiver.And these structures will be small, like, multicellular organisms, whether invertebrate or otherwise. So any relevant frequencies will be very high, or very close in.And the most dramatic evolution all took place underwater, where there was plenty of optical transparency, but RF is wholly shorted out.But even this is very unrealistic, very mechanistic, conventional minded; it's probably more likely that protein structures might evolve to create organic semiconductors already, and perhaps diodes (of various types, including the potential for negative resistance) and transistors could be created. Powered by muscle contractions, piezoelectricity, proton pumps (or other ions, but protons are fastest of course), etc., perhaps signals could be created idiomatically -- by random chance, and with similar junctions between individuals, perhaps enough reciprocity could be present that the transceiver problem is solved.But this still assumes that there is an environment conducive to RF transmission (so, basically terrestrial only), that such structures evolve despite (or at best in parallel with) competing solutions that are easier to develop; like small-molecule emission and reception (smell!), but also optics have the advantage that quantum effects like chemiluminescence can be discovered by random chance, and, light sensors have been a staple of most/all epipelagic and terrestrial life forms, probably since before predation evolved, even?I guess there's kind of an interesting angle (and, equally well I suppose: reason to be skeptical of any such proposed story's potential accuracy, and space to be creative with what kinds of ideas might be possible) to "alternative history" evolution, that kind of parallels a lot of mythologies, like: there once was an age of fantastic beasts of all sorts, but things get more familiar, less miraculous, more banal, more standardized, as you approach the present. Why don't you see elves and goblins anymore? Same reason you don't see trilobites, or Dickensonia, anymore: they all "moved into the west". Why don't they evolve again now? Simple: there's no pressure to; there's no mechanism to make such radical changes, under pressure of everything else in the environment they have to fit in with. The basic vertebrate body plan hasn't changed in over 300 million years or so, and it's just so foundational there's essentially no way for mutations to occur in those lowest-level genes without succumbing to miscarriage (or the oviparous equivalent). In fact it's far easier to severely deform those structures to new uses, than to redo the fundamentals of the body plan (see horse legs and hooves for example, the wrist and hand being largely resorbed or fused in favor of the middle-finger bones for weight bearing).Well, along such a timeline, I would suppose such a special structure would've had to evolve quite early, but there explicitly weren't the conditions necessary to permit its evolutionary testing/exploration.Also worth mentioning, electron/ion exchange in bacterial mats, whether through biofilaments, or inorganic (ferrous?) or hybrid structures; but this is basically DC, and I'm not aware of any that are particularly conductive, nowhere what you'd need to make a resonant structure as such. Alternately, evolution would have a field (ha!) day with resonant cavities and lenses and antennas, that would be quite cool to see across species -- but again, without a way to harness microwaves, nor a medium to carry them, such ideas will remain confined to ones' imagination.Tim

author: coppercone2
author_rank: Super Contributor
timestamp: August 28, 2023, 03:10:21 am
content: also I think the planet would need to have massive amounts of metal, mountains or carbon fiber trees or something because right now RF is too easy to locate if something is emitting it. It seems not favorable to stealth on the planet we are on. and perhaps near some radio noisy star.

author: retiredfeline
author_rank: Frequent Contributor
timestamp: August 28, 2023, 03:21:37 am
content: Unlike light and sound which are pervasive, there is little RF in the natural world and not conveying useful everyday information, so radio waves from space don't count, so organisms would have no impetus to develop for it.

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 28, 2023, 03:47:30 am
content: A better question to ask would be why biology hasn't evolved to be able to detect radioactivity at levels well below that which would cause significant damage. My guess is that there simply weren't enough cases where it would have improved survival for evolution to design that in.

author: Brumby
author_rank: Unknown
timestamp: August 28, 2023, 05:05:01 am
content: Quote from: NiHaoMike on August 28, 2023, 03:47:30 amMy thought is that detection isn't necessary. Simply let radioactivity affect biology and see which mutations better cope with it. Same goes for any other potentially malevolent environmental factor.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 28, 2023, 05:47:24 am
content: Detect in what way? DNA damage from diverse sources is repaired by several mechanisms. Upregulation of those might correlate with radiation, but also environmental factors like high heat and dehydration; D. radiodurans is just a soil microbe, by coincidence also a radiation extremeophile. Or tardigrades, etc. Whether any of these effects are worth raising from biochemical to conscious* level, probably not?*In the sense of whatever counts for behavior, mobility, etc.Regional radioactivity, of hazardous levels, that would be meaningful to avoid via sensory input, is largely a modern industrial creation; simpler life like bacteria or mold can adapt, and complex life can just roll the dice.Tim

author: tggzzz
author_rank: Super Contributor
timestamp: August 28, 2023, 10:12:34 am
content: Quote from: RoGeorge on August 27, 2023, 01:12:23 pmIt has evolved.The many people that "are" sensitive to WiFi etc are indicating that their genes should be removed from the gene pool. Or maybe I'm too optimistic.

author: jpanhalt
author_rank: Super Contributor
timestamp: August 28, 2023, 10:45:21 am
content: Quote from: T3sl4co1l on August 28, 2023, 05:47:24 amRadiobacter durans (aka Micrococcus radiodurans) , a very old name (https://en.wikipedia.org/wiki/Deinococcus_radiodurans), is quite resistant to radiation.One of the things I have wondered about (albeit very briefly) is why organisms do not take advantage of heavier elements like lead, which can be very useful in organic synthesis. Perhaps, it wasn't prevalent in early planets in sufficient quantity to be used as life evolved? See:https://science.nasa.gov/origin-elements(chart attached). [/coppercone_moment)John

author: coppercone2
author_rank: Super Contributor
timestamp: August 28, 2023, 11:20:47 am
content: I don't think its dispersed too well, it tended to sink down deep during planetary formation I imagine.merging neutron stars make quite a big RF field. and also spritz some weird elements around. maybe that is where you find that kind of lifetry something like erroding uranium mountains that constantly sprinkle uranium dust into shallow pools of life creating water, so its like raining uranium or whatever there. what a terrible planet that would be.

author: snarkysparky
author_rank: Frequent Contributor
timestamp: August 28, 2023, 12:26:00 pm
content: RF is to quick for biological processes to do phase detection on RF signals. It becomes a scaler, hot or not. which nearly all biology already uses.

author: SiliconWizard
author_rank: Super Contributor
timestamp: August 28, 2023, 07:39:07 pm
content: Quote from: Brumby on August 28, 2023, 05:05:01 amWell, yes. It's hard to tell wether natural radioactivity on Earth hasn't actually triggered some very useful mutations along the way, but it probably has.

author: vad
author_rank: Frequent Contributor
timestamp: August 29, 2023, 01:17:48 am
content: Here is my dilettante’s perspective on this matter:The typical process of evolution involves genetic mutations that randomly alter the genome, occasionally introducing new physiological capabilities that confer an evolutionary advantage to the genome. These changes usually occur on a small scale and can progress over numerous generations. For example, hundreds of millions of years ago, multicellular organisms developed rudimentary neural systems that aided in controlled movement. Subsequently, certain mutations led to the emergence of photosensitive receptors, which added optical sensors to these neural systems. Initially, these receptors and neural networks were minute and quite primitive, but after millions of generations, they evolved into the complex eyes and visual cortex we see today.The pivotal term I wish to emphasize is "minute". Radiofrequency (RF) necessitates sensors that are many orders of magnitude larger, ideally around half a wavelength. The likelihood of substantial structures spanning meters emerging from random mutations in small, primitive organisms is significantly lower, presumably by many orders of magnitude, than the likelihood of sensors for UV, visible light, and microwave frequencies developing.To rephrase, this concerns the relationship between wavelength and cell dimensions. The greater the length, the more intricate the mutation that must take place to generate a sensor suitable for that particular wavelength.

author: Tomorokoshi
author_rank: Super Contributor
timestamp: August 29, 2023, 04:23:43 am
content: Obviously, because it's just too expensive to get certified to the RED.

author: Circlotron
author_rank: Super Contributor
timestamp: August 29, 2023, 05:31:21 am
content: Quote from: vad on August 29, 2023, 01:17:48 amThat line of reasoning would seem to indicate that we should be more likely to have sensors for UV and X-ray and so on. But we don't.

author: IdahoMan
author_rank: Regular Contributor
timestamp: August 29, 2023, 05:55:27 am
content: A: Because life didn't evolve.

author: EPAIII
author_rank: Super Contributor
timestamp: August 29, 2023, 09:59:07 am
content: Not the best answer. We have eyes, but we do not generate light. In fact very few species do. No, we use the light that is provided by the sun. And there also is RF being provided by the sun, other stars, and other celestial objects. So no, our inability to generate RF is not the reason.Perhaps it has more to do with the size of RF receiving devices vs those which can receive light. Light is electromagnetic waves, just like the RF we are talking about. But the wavelength is a lot shorter so the receiving equipment can be a lot smaller. And, according to Einstein, photons of light are more energetic than those of RF so a single photon of light can produce a larger signal.Why not UV or X-rays? Well, again look to the sun. Sure it produces those wavelengths. But It produces far more visible light. The planet was bathed in visible light and that is what we evolved to utilize. And I wouldn't be all that surprised if some life forms could or even still can "see" UV. I don't know about X-rays.Just a quick search; apparently some people CAN see UV light.https://www.google.com/search?channel=fen&client=firefox-b-1-d&q=seeing+uv+lightOK, another quick search and you can add X-rays to the list of viewable radiation:https://www.google.com/search?q=can+any+animals+see+x+rays&client=firefox-b-1-d&sca_esv=560955759&channel=fen&sxsrf=AB5stBjxPRN8OFpt83zQnbUuEf7s8ErpMg%3A1693303662255&ei=bsPtZKmVD-axqtsPu6uIgAw&oq=can+any+amimals+see+x-rays&gs_lp=Egxnd3Mtd2l6LXNlcnAiGmNhbiBhbnkgYW1pbWFscyBzZWUgeC1yYXlzKgIIADIGEAAYHhgNMggQABiKBRiGAzIIEAAYigUYhgNImoUBULAKWNBhcAJ4AZABAJgB6wGgAcISqgEGNi4xMy4xuAEByAEA-AEBwgIKEAAYRxjWBBiwA8ICBRAAGKIEwgIIEAAYiQUYogTCAggQABgFGB4YDcICChAAGAUYHhgNGA_CAggQABgIGB4YDcICBhAAGAcYHsICBBAAGB7CAggQABgHGB4YD8ICCBAAGAgYBxgewgIIECEYoAEYwwTiAwQYACBBiAYBkAYI&sclient=gws-wiz-serpYes, it seems to me that the reason must be at the receiving end, not the generating end. And human beings and their eyes are not the be-all and end-all of existence.Quote from: Gyro on August 27, 2023, 03:03:46 pm

author: tom66
author_rank: Super Contributor
timestamp: August 29, 2023, 10:29:48 am
content: It's interesting to postulate a world in which animals did use RF. Say the electric eel could create a small arc, this would potentially be useful as a wideband transmitter, and could summon other eels if they had some capability to receive the signal. That could perhaps be an accidental evolution, as a diode-like response is possible with dissimilar metals in some cases. In terms of more complicated means of communication like voice, I don't see how that could be practical. It would require modulation of a carrier frequency, and I can't think of any biological process that would be capable of evolving that, it's essentially a biological transistor. Nerve cells aren't capable of analogue modulation AFAIK.Another question I heard once was why the wheel doesn't appear in nature given its almost superior nature in every way to the leg for locomotion. Well, a true bearing is not possible in biology because there is no way to supply oxygen to the tissue through the bearing. All you see in biology are ball joints which allow only partial rotation. It could possibly develop as a component that later separates from its oxygen supply (like a nail breaking off) but it would be quite a leap to be able to then use that for locomotion, given there's no intermediately step that is apparent that conveys a selection advantage. Also, any such tissue would be liable to needing replacement from time to time, as it wore down. It is not clear how that would be possible with an independent component.

author: tszaboo
author_rank: Super Contributor
timestamp: August 29, 2023, 11:28:09 am
content: Light is RF, it's just a specific spectrum. In a parallel world we could have eyes that work in the gamma rays spectrum, and think about how weird it would be to see in the light spectrum."Imagine it, you wouldn't be able to see through things, it would be so strange." said the giant talking squid while driving to his work in the factory, making squid pants.

author: vad
author_rank: Frequent Contributor
timestamp: August 29, 2023, 11:28:41 am
content: Quote from: Circlotron on August 29, 2023, 05:31:21 amThere are animals with UV vision.

author: Circlotron
author_rank: Super Contributor
timestamp: August 29, 2023, 11:40:10 am
content: Quote from: tom66 on August 29, 2023, 10:29:48 amFlagella have a bearing of sorts. Good enough to support 6000-17000 rpm.https://en.wikipedia.org/wiki/Flagellum

author: vad
author_rank: Frequent Contributor
timestamp: August 29, 2023, 11:41:46 am
content: Quote from: Circlotron on August 29, 2023, 05:31:21 am… Also, it is a logical fallacy. If two arguments, A and B, are false for different reasons, explaining why A is false might not give you a clue about the reasoning for argument B.For example, bears cannot both breathe underwater and fly. Explaining why bears cannot live underwater will not explain why they cannot fly.

author: Psi
author_rank: Super Contributor
timestamp: August 29, 2023, 11:45:59 am
content: Quote from: vad on August 29, 2023, 11:28:41 amHumans too. Within people that have tetrachromacy (4 cones in the eye instead of 3) there's a sub type where they can see into the UV.

author: jonovid
author_rank: Super Contributor
timestamp: August 29, 2023, 05:11:52 pm
content: evolution by natural selection is scientific theory, not a fact.we was made by the creator of the universe.science struggles with increasing the odds of natural selection in a lab.the best scientists can do is cut and paste bits of biology with frankenstein like results.the kinds are the limit of selective breeding. dog genetics are different from cat genetics so incompatible. so are two different biological kinds.experiments adding metal to a biological organism is the stuff of alchemy. cyborgs are an unnatural freak show.

author: coppercone2
author_rank: Super Contributor
timestamp: August 29, 2023, 08:16:59 pm
content: also this thread fails to acknowledge the mognolian death worm. i read some where they generate lightning

author: Bud
author_rank: Super Contributor
timestamp: August 29, 2023, 08:44:06 pm
content: And who created the creator?

author: tom66
author_rank: Super Contributor
timestamp: August 29, 2023, 09:47:57 pm
content: Quote from: jonovid on August 29, 2023, 05:11:52 pmIn science, "theory" is as good as fact. You are confusing the common vernacular "theory" with the scientific term. A theory in science is a set of well-supported hypotheses which can be rigorously tested, and importantly, are independently falsifiable. Natural selection by evolution has been observed in the wild, can be simulated with computers and robustly explains the history of life we observe via the fossil record.No one can say for certain whether there is a god or not, by the very nature, god is untestable and is not falsifiable, at least in the many forms taken in religious belief. However, we can say with certainty, that no scientific field has ever uncovered specific evidence pointing to a god or gods creating life on Earth.It's fine to have a personal belief in a deity if it makes you feel better, but please don't claim that natural selection is not a robust theory because it is one of the most robust theories in all of biology.

author: TimFox
author_rank: Super Contributor
timestamp: August 29, 2023, 10:13:17 pm
content: "Just a theory" is a common, yet mistaken, misunderstanding of scientific processes.Similarly, in common English there is not much difference between "force", "power", and "energy", yet scientists and engineers must use the words carefully.(Punctuation and grammar help, as well.)

author: jpanhalt
author_rank: Super Contributor
timestamp: August 29, 2023, 10:15:11 pm
content: Something to think about:Source:https://www.smithsonianmag.com/science-nature/what-does-it-mean-be-species-genetics-changing-answer-180963380/#:~:text=Based%20on%20a%201980%20book,DNA%20to%20be%20considered%20separate.QuoteSource:https://www.amnh.org/exhibitions/permanent/human-origins/understanding-our-past/dna-comparing-humans-and-chimps#:~:text=If%20human%20and%20chimp%20DNA,equals%20about%2035%20million%20differences.QuoteI am not an atheist, but there is nothing in believing in a power we cannot understand that conflicts with evolution. Those who say so are relying on texts written by humans. Much was deleted and not included from ancient texts in modern Christian texts. (Disclosure: I am not familiar with non-Abrahamic religions)

author: Circlotron
author_rank: Super Contributor
timestamp: August 29, 2023, 10:35:38 pm
content: Quote from: Bud on August 29, 2023, 08:44:06 pmThis is beyond my understanding. That proves it didn’t happen.

author: xrunner
author_rank: Super Contributor
timestamp: August 29, 2023, 10:45:43 pm
content: Quote from: jonovid on August 29, 2023, 05:11:52 pmUh no ... evolution is a fact.This is factually shown in the geological record. It happened. But theories and facts are two different things and one does not become the other. Theories do not become facts over time because they get "better". Facts are what we find in the real world, such as evolution, gravity, elements, electromagnetic forces, and so on. Theories are what scientists use to explain various properties of the facts that we find.I see people making this mistake my whole life.

author: Kim Christensen
author_rank: Super Contributor
timestamp: August 29, 2023, 11:48:32 pm
content: Quote from: Circlotron on August 29, 2023, 10:35:38 pmThe old argument that "there must be a creator" because "something cannot come from nothing" is circular reasoning. ie: A non-answer that may as well be discarded.

author: coppercone2
author_rank: Super Contributor
timestamp: August 30, 2023, 12:23:44 am
content: please stay on topic about spark snakes

author: BrianHG
author_rank: Super Contributor
timestamp: August 30, 2023, 01:48:45 am
content: I thought that electric eels could make some signals which were detected from a pond to a pond after a flooded rain storm which may have isolated individuals. I don't remember how, (it was a National Geographic or David Attenborough docu) but a particular signal they sent was designed to attract mates and one pond within the right size could trigger a sexual response of an electric eel of opposite sex in the next pond of similar size.This means the charge they sent out had a tuned amplitude and frequency and the mate was attuned to that pattern for searching for sexual mates. It was also said that other signals, like defensive electrical attacks would not trigger the sexual response in other eels. So, by close definition, we have a signal with selective amplitude and frequency characteristics developed by natural selection. Perhaps with a few million years of guided evolution, this effect can be further attuned to something like a radio transceiver we are accustomed to.Maybe the OP's title is wrong...

author: TimFox
author_rank: Super Contributor
timestamp: August 30, 2023, 02:26:15 am
content: Since the electric eel's discharges are pulsed, it is more likely that pulse patterns and rates form the code, rather than carrier frequency.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 30, 2023, 02:28:54 am
content: Yeah, nothing wrong with signaling at low frequencies, likely well under 1kHz given the depolarization rate of neurons. Also well serves predators, like sharks sensitive to myoelectric fields. E-fields don't go far in water (sea or otherwise), but that's enough when it's very dark (abyssal) or murky (several river species) -- eyes offer no improvement!Tim

author: Tomorokoshi
author_rank: Super Contributor
timestamp: August 30, 2023, 04:18:23 am
content: And then there are these things. Keywords: quarter-wave plates, Stokes parameters:https://en.wikipedia.org/wiki/Mantis_shrimp

author: tggzzz
author_rank: Super Contributor
timestamp: August 30, 2023, 08:41:02 am
content: Quote from: karpouzi9 on August 30, 2023, 02:45:51 amDoesn't everybody?Oh, wait.... given some of the earlier posts in this thread, that is probably beyond some posters

author: JPortici
author_rank: Super Contributor
timestamp: August 30, 2023, 12:55:12 pm
content: I've read some articles that suggest that bird flocks could use magnetic fields to coordinate and to decide which direction they need to go

author: SiliconWizard
author_rank: Super Contributor
timestamp: August 30, 2023, 08:30:29 pm
content: Quote from: tggzzz on August 30, 2023, 08:41:02 amIf we get that kind of "lunacies" on an engineering forum, imagine what it's like in the general population.

author: tggzzz
author_rank: Super Contributor
timestamp: August 30, 2023, 08:36:09 pm
content: Quote from: SiliconWizard on August 30, 2023, 08:30:29 pmUnfortunately we don't have to imagine.All we have to do is look at the news and see how people are being persuaded that something that looks blue is actually red because a random crackpot says that <insert conspiracy here>.

author: BrianHG
author_rank: Super Contributor
timestamp: August 30, 2023, 08:48:59 pm
content: Quote from: JPortici on August 30, 2023, 12:55:12 pmNot just birds. Even some forms of bacteria have magnetic navigation.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 31, 2023, 02:47:59 am
content: Static fields are easy: electric fields make your hairs stand on end, or other things; magnetic fields by magnetite crystals usually, I think. Anything faster than nerve response rate though, good luck. Actual "RF", in the MHz to say 10s of THz, far harder to do.Also arguably in the 10s-100s THz, there's thermal radiation, but this is getting into the quantum range, in this case by way of phonons; heat. Bolometry works for anything, of course, I mean, you can certainly feel various wavelengths if they're strong enough (from diathermy to direct microwaves, to the warmth of the sun), and the sensor isn't too thin for the wavelength. Not very sensitive though.Tim

author: RoGeorge
author_rank: Super Contributor
timestamp: August 31, 2023, 04:47:32 pm
content: Quote from: tggzzz on August 30, 2023, 08:41:02 amThat's far from obvious, nor trivial. The continuous sinusoids calculated with Fourier are not really there. The sinusoids areas ifit were to be a bunch of added together sinusoids instead of the given shape of a signal, but they are not really there. One can see with an oscilloscope that there is some other wiggly form and no sinusoid in an arbitrary signal.A given shape can be decomposed many ways. One way is to write our shape as a sum of sin and cos functions, thus the Fourier spectrum. But the same signal can be decomposed, for example, in a series of wavelets. Or, maybe with some other kernel function instead of either sin/cos or wavelets.Now, is our arbitrary signal a sum of wavelets? Or a sum of sinusoids? Or some other sum of some other kernel functions?I think the correct answer is neither, our arbitrary signal is just the shape we see on the oscilloscope, not a sum of sinusoids, not a sum of wavelets, or any other sum.It's a happy coincidence that Fourier is particularly useful in engineering, somehow overlaps with the idea of superposition (which only holds for linear systems). Then we are all trained to apply Fourier only where it holds, and we turn a blind eye to what doesn't match, or we learn how to minimize Furrier side effects like the Gibbs artifacts, the need of windowing, the lost of causality.We do that all the time and only consider what we need out of it, up to the point where we start to believe a square wave is made of odd harmonics in a certain ratio, which is not really so. I consider that's just a form of gaslighting, though this time the gaslighting is just an innocent side effect with no malicious intent behind. I consider the sinusoidal components aren't really there, and that can be proved in practice.(An example of causality artifact can be seen in any digital oscilloscope, when sinx/x compensation is on, and the level of a constant 0 or 1 voltage starts to wiggle on the screenbeforean edge, as if the signal will somehow have premonitions and knows in advance when an edge will come - that's just a Fourier artifact, the logic level can not know the future.)I think it can be proved in practice that the sinusoids from the Fourier spectrum are not really there.For example, if we take a square wave of 1kHz, such a signal is supposed to have plenty of sinusoidal 3kHz in it, according to Fourier. However, one can make a filter that will only respond to asinusoidalshape of 3kHz, and no other shape than sinusoidal.Such a 3kHz filter won't respond to a square wave of 1kHz, which indicates there is no sinusoidal 3kHz in our 1kHz square. I'll say that's a proof Fourier spectrum is not really there.Now, the funny thing is that what we casually call a 3kHz filter in EE will respond to a 1 kHz square, how so!?!But then, what's a filter? And how/why does it work?That's another simple yet difficult question to answer.

author: tggzzz
author_rank: Super Contributor
timestamp: August 31, 2023, 06:57:17 pm
content: Quote from: RoGeorge on August 31, 2023, 04:47:32 pmThat last sentence is wrong, pure and simple. The earlier ones make no sense.For similar reasons I suppose you would claim that the individual colours in white light are not really there.QuoteObserving something on one type of instrument (e.g. a scope) is irrelevant. Why not choose a spectrum analyser instead?Fourier analysis is a mathematical concept. Ditto wavelet analysis. The validity of one does not invalidate the other.You can also decompose a 2D shape into a set of triangles. Or squares. Or hexagons.QuoteSigh. You are missing many important concepts there, and I don't have time to attempt to enlighten you. I just refer you to textbooks.The rest of your post isn't even wrong.

author: RoGeorge
author_rank: Super Contributor
timestamp: August 31, 2023, 07:44:55 pm
content: Quote from: tggzzz on August 31, 2023, 06:57:17 pmWe are here to talk about ideas, not to disconsider each other. Well, again, you start with ad hominem innuendos, assuming how you are smart and the others are not. That attitude never made anybody look smart, quite contrary but arrogant. I don't have the time to enlighten you either.

author: TimFox
author_rank: Super Contributor
timestamp: August 31, 2023, 11:16:48 pm
content: Quote from: RoGeorge on August 31, 2023, 04:47:32 pmIn the real world, to see if there be 3rd harmonic power in a square wave, do the following simple experiment with real equipment.I'm not aware of any realizable (in the technical sense) filter that would discriminate against non-sinusoidal waveforms in the way you suggest.Experiment: start with good square-wave generator, with reasonable rise and fall times, but with stable frequency (from a good clock oscillator); set frequency to 1.00 MHz.Connect directly to modern spectrum analyzer, with synthesized local oscillators and selectable filter bandwidth ("RBW").Set RBW to minimum value available in the SA, and let the sweep width be set by the default manufacturer's value for that RBW.1. Set center frequency to 1.00 MHz and observe signal level at 1 MHz.2. Set center frequency to 3.00 MHz and observe signal level at 3 MHz.Will the ratio between those levels agree with the Fourier series of a 1 MHz square wave?

author: coppercone2
author_rank: Super Contributor
timestamp: August 31, 2023, 11:29:55 pm
content: some how derailing this thread to yell about harmonics is just not cool

author: Bud
author_rank: Super Contributor
timestamp: September 01, 2023, 03:29:31 am
content: Quote from: RoGeorge on August 31, 2023, 04:47:32 pmNo, one cannot

author: tggzzz
author_rank: Super Contributor
timestamp: September 01, 2023, 07:48:19 am
content: Quote from: Bud on September 01, 2023, 03:29:31 amHow about capturing the signal, doing an FFT, and seeing if there is any frequency other than 3kHzOops; that contains the "invalid" word "Fourier".Or an analogue variant: a bandstop filter centered on 3kHz, plus a switch. If the filter's output is non-zero, the switch is opened. Oops; that depends on the concept of the equivalence of time and frequency domains, as defined by Fourier.

author: Bud
author_rank: Super Contributor
timestamp: September 01, 2023, 12:45:13 pm
content: Quote from: RoGeorge on August 31, 2023, 04:47:32 pmThat is exactly what a 3kHz filter WILL DO, you just have not tried or have not measured properly.

author: coppice
author_rank: Super Contributor
timestamp: September 01, 2023, 01:46:16 pm
content: Its sad how many of the messages in this thread come down to "that can't happen. because I've never seen it happen", rather than "here is a physics road blocker which means that can't happen".

author: Kim Christensen
author_rank: Super Contributor
timestamp: September 01, 2023, 03:44:48 pm
content: Can't think of a "filter" that only passes a 3Khz sine while ignoring the 3Khz harmonic from a 1Khz squarewave. But I can imagine a "detector" for a pure 3Khz sinewave. Basically a 3Khz filter, x2 RMS detectors, and comparators to compare the energy at 3Khz vs everything else.But on the topic of organic RF, I don't think there's any creature that outputs electrical pulses with sufficient rise time to emit enoughRFenergy to be useful for anything.

author: TimFox
author_rank: Super Contributor
timestamp: September 01, 2023, 04:09:42 pm
content: "RF" is a definition of a subset of electromagnetic radiation frequencies, not a physical definition such as "alpha particle radiation".Different sources define "RF" starting somewhere between 3 to 10 kHz and ending somewhere between 1010and 1011Hz.The FCC defines radio-frequency "RF" as between 3 kHz and 300 GHz and "microwave" as between 1 and 30 GHz.Traditional subsets of RF use "3", since they were originally defined in terms of wavelength (in meters).3 to 30 kHz is "VLF"30 to 300 kHz is "LF"0.3 to 3 MHz is "MF", where the broadcast band lies3 to 30 MHz is "HF", called short wave30 to 300 MHz is "VHF"0.3 to 3 GHZ is "UHF"until we reach 30 to 300 GHz, which is "extremely high frequency" EHF.There are names for the decades below 3 kHz and above 300 GHZ.The IEEE, NATO, and other agencies have other nomenclature, including the confusing radar bands (X, Ku, etc.).

author: Kim Christensen
author_rank: Super Contributor
timestamp: September 01, 2023, 05:32:28 pm
content: Sure that's fine... But how would a creature effectively radiate or receive "RF" in the VLF, LF, or even MF bands? Giant organic loopstick? It would have to be a very big animal.

author: TimFox
author_rank: Super Contributor
timestamp: September 01, 2023, 06:48:20 pm
content: I was just pointing out what "RF" is: many postings above were about other electromagnetic fields or frequencies, such as visible light or the Earth's magnetic field.Nobody mentioned how modern man, with metal fillings in his teeth,supposedlycan demodulate and hear MF broadcast radio fields.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: September 01, 2023, 06:55:30 pm
content: It seems to me possible that RF detection capability could have developed, but it is highly unlikely. And full blown RADAR even less likely. For a whole series of reasons.Any capability that is retained by evolution has to provide some benefit (or at least do no significant harm) to survival. So any systems which randomly occur must either be biologically nearly free, or provide significant benefit.In my limited understanding all of the extant sensing systems started with a sensing capability, and then in some cases a transmitting capability came along later. The oldest appear to be chemical, temperature and light sensing systems which began providing very simple approach or avoid data. Quite useful to mobile organisms looking for food or avoiding hostile environments.In the entire spectrum from VLF through X-rays the highest power level on earth occurs in the visible spectrum and also has a very simple signal correlated to some biological survival (daily on-off). So it is easiest of all to detect and is useful. For reasons explained in several other posts detecting other bands is generally more difficult, and the immediate survival benefit is less obvious. All subsequent development of vision systems are just riffs on this theme, with transmitters (various luminescence schemes) and modulators (colors and color changing capability) developing long after vision systems had become quite complex.This theme occurs in all other sensing systems I am aware of. Something simple with a strong available signal to detect that is survivability related happens and then gets elaborated over tens of thousands of generations.RF has at least three strikes against it. Low ambient power. Difficult detection. And little obvious survivability benefit.Radioactive detection similar. The strongest strike against it is that natural radioactivity strong enough to effect breeding success is extraordinarily rare.

author: RJSV
author_rank: Super Contributor
timestamp: September 01, 2023, 09:50:50 pm
content: Humourous thought is an electric EEL trying to fight a ball of aluminum foil....(I'll let readers conjure that up).The body's neurological basis is, interestingly, pulse based, and certainly sounds interesting on a speaker.I believe it's the firing rate that 'encodes' your intensity. Had an interesting routine nerve test that the tech had turned up the speaker for a minute. Seemed like pulses, maybe 10 to 15 per second type in audio play. Much like short little noisey pulses, 20 mSec est.

author: EPAIII
author_rank: Super Contributor
timestamp: September 02, 2023, 03:49:58 am
content: You don't seem to understand the scientific method. Or you are just trying to poke at it.ALL science is theory. Some theories are better than others, but all are theories. Scientists develop theories to try to explain observations. And then they or other scientists develop ways of testing the theories to see how well they agree with more observations. Those additional observations always ultimately show that any given theory is inaccurate in some respects. The earth is flat. No, it is round. No, it has a somewhat irregular shape. Etc.And sooner or later all theories are replaced by more accurate theories. No theories ever actually become total fact. They remain theories.Some theories may be established well enough that some people start to call them laws. But that should not be thought to be true. Even laws of science are ultimately shown to be inaccurate in one way or another. So, even the so-called laws of science are still just theories.There is no such thing as "scientific fact".The failure to understand this is the cause of much consternation by the general public and by many of our national and world figures.Quote from: jonovid on August 29, 2023, 05:11:52 pm

author: EPAIII
author_rank: Super Contributor
timestamp: September 02, 2023, 04:00:59 am
content: You say those sine waves are not really there.And yet, they cause interference or noise all across the RF bands. It seems like something is really there.Quote from: RoGeorge on August 31, 2023, 04:47:32 pm

author: TimFox
author_rank: Super Contributor
timestamp: September 02, 2023, 02:03:11 pm
content: Quote from: EPAIII on September 02, 2023, 03:49:58 amScience and religion are different: religion has myths and science has theories.Those who oppose one or the other think that myths and theories are a bad thing: both of those groups are wrong.Myths attempt to explain things, especially their origins, such as creation myths, but they do not have predictive power.Theories do not explain the purpose of things, but have predictive power; when a theory's predictions do not agree with experimental evidence, they are to be modified or replaced.This is a technical forum: theories are useful.