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  1. #61

  2. #62
    Quote Originally Posted by Endus View Post
    The universe, and the energy it contains, is finite.



    And? I never said energy was being destroyed. Converted to mass, or used mechanically, like literally any engine; this one just reduces waste to zero and is powered by a star.
    [/SIZE]


    Congrats, you've noticed Dyson contributed more than just ideas like his Dyson Sphere. That paper isn't talking about Dyson Spheres in particular, just advanced species in general, and not even every possible species, hes just proposing one particular avenue of investigation.

    I'm not the one making basic errors, here.
    The problem is there can be no such thing as zero waste. If it takes in any energy and uses it, it has to output at least a small fraction as waste. Otherwise you are talking about a 100% efficiency engine which, unless some alien race figured out how to get around entropy, cannot exist in the universe. Now, that doesn't mean the energy is pointed our way just that there is no such thing as zero emission engines. There will ALWAYS be a by product of it.

  3. #63
    I Don't Work Here Endus's Avatar
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    Quote Originally Posted by gondrin View Post
    The problem is there can be no such thing as zero waste. If it takes in any energy and uses it, it has to output at least a small fraction as waste. Otherwise you are talking about a 100% efficiency engine which, unless some alien race figured out how to get around entropy, cannot exist in the universe. Now, that doesn't mean the energy is pointed our way just that there is no such thing as zero emission engines. There will ALWAYS be a by product of it.
    There can still be waste, and it doesn't need to be 100% efficient; the concept of a Dyson shell is that it takes in and makes use of 100% of a star's output, not that it does so at 100% efficiency. If it's dumping the slag/waste/whatever onto its outside shell as additional armor, that's fine.

    To avoid being detected, it has to cut radiative emissions to near-zero (not much above cosmic background radiation, at least), but that's a very particular kind of "waste" that you could absolutely manage to avoid putting out. Just, in theory mind you, hypothetically, if you can encase a star in a sphere of metal with enough tech to absorb and process the star's emitted energy, the radiation emitted by the star isn't escaping that cage. You might be producing a lot of other wastes, maybe the contents of the shell are a little warmer than the background vacuum, due to waste heat absorption, say, but not something that could be seen from light-years away.


  4. #64
    Quote Originally Posted by Endus View Post
    You might notice that wasn't responding to you.


    That doesn't debunk anything. The first link was what percentage of global population have smartphones. As you've now successfully confirmed, it's not just using the number of plan subscriptions or phones per capita, it's actually looking at the percentage of people that actually have a smartphone.

    You've just backed me up.
    Did you not really read? First link is total number of mobile subscriptions. second link has 67% as unique mobile users which was lower than your original number and given the fact that over 25% of the population can't legally sign up for a cellphone on their own and businesses can sign up for mobile phones I'm guessing that 67% doesn't actually mean individual people who own a cell phone as it would require nearly the entire adult population of the world to own a phone.

  5. #65
    Quote Originally Posted by Endus View Post
    You might notice that wasn't responding to you.
    But similarly as when responding to me the statements were exaggeration without any basis.

    Quote Originally Posted by Endus View Post
    Energy conversion doesn't mean there's electromagnetic radiation of some wavelength that necessarily results. Converting a star's energy output into electrical, mechanical energies, converting it directly into mass, these are all "using energy" to accomplish something. If I use a lever to lift a weight, I am using mechanical energy to lift that weight. And that weight can often be lowered back down, returning energy to the lever or some other system.
    There are two problems with your statements:
    Within a closed system (such as Dyson sphere) you cannot keep lifting it higher and higher; and apart from that it isn't meaingful.
    What people discuss when harvesting the energy of a star are things like thinking or computers - the system does something useful, but it doesn't store energy when working. It's not like a computer stores energy by converting zeros to ones and we want to power a gigantic computer to slowly convert all the zeros to ones.

    And even without doing anything just the normal temperature of the huge Dyson sphere would be a huge ball radiating in infrared. If it magically didn't, then it would increase in temperature and reach the temperature of the star and become vaporized and then plasma.

    Quote Originally Posted by Endus View Post
    "Using" energy is converting it from its current state/form/vector to a useful state/form/vector.
    No, "using" energy is primarily to convert something from one state to another - and most of the energy isn't stored in the new form.
    You know that people use petrol to fuel cars to go from A to B and then back to A?

    Quote Originally Posted by Endus View Post
    And Dyson introduced the concept, hence why it's named for him.
    He introduced/popularized it in the 1960 science article titled "Search for Artificial Stellar Sources of Infrared Radiation", since he understood the energy concept above - which you don't. You incorrectly claimed the paper was about something else.

    Quote Originally Posted by Endus View Post
    "The variant of the Dyson sphere most often depicted in fiction is the "Dyson shell": a uniform solid shell of matter around the star.[20] Such a structure would completely alter the emissions of the central star, and would intercept 100% of the star's energy output."

    And I was pretty clear, I thought, in describing such a shell, so there shouldn't have been any confusion.
    It is described that way in fiction, but it isn't realistic - and that's why Dyson dismissed that. Note that the wikipedia article uses the term "intercept" and "harvest" energy to indicate that they would use it to do meaningful work - but all of the energy will still radiate away.

    Do you also think that archeologist should search for horned Viking helmets, since they are common in fiction?

  6. #66
    Void Lord Doctor Amadeus's Avatar
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    Yes, yes, the government has finally released evidence that we don't know what something moving around in the air on terrible film is, obviously aliens! /s
    #ANTIFA "Intellect alone is useless in a fight...you can't even break a rule, how can you be expected to break bone" Khan Singh

  7. #67
    Herald of the Titans Vorkreist's Avatar
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    Same triangle light drone videos. Why are they still pretending its unidentified when there were reports the chinese have projects similar to that thing and drones that submerge ( as reference to other videos of ufo's going under water or popping out ) ?

  8. #68
    I Don't Work Here Endus's Avatar
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    Quote Originally Posted by Forogil View Post
    But similarly as when responding to me the statements were exaggeration without any basis.
    Not really.

    The universe is finite. Baffling huge, but that's not the same as "infinite".

    There are two problems with your statements:
    Within a closed system (such as Dyson sphere) you cannot keep lifting it higher and higher; and apart from that it isn't meaingful.
    What people discuss when harvesting the energy of a star are things like thinking or computers - the system does something useful, but it doesn't store energy when working. It's not like a computer stores energy by converting zeros to ones and we want to power a gigantic computer to slowly convert all the zeros to ones.

    And even without doing anything just the normal temperature of the huge Dyson sphere would be a huge ball radiating in infrared. If it magically didn't, then it would increase in temperature and reach the temperature of the star and become vaporized and then plasma.
    I'm not sure why you're pretending that energy can't be converted from one form to another after just incorrectly lambasting me about the laws of thermodynamics.

    First, the Dyson shell (I'm gonna use this term because you got unreasonably pedantic) isn't a closed system. The shell plus the star form a closed system, but the shell itself is constantly seeing a massive energy input from the star, through the star's lifespan. So yeah; that allows for consistent energy use for functional work by the shell.

    Hell, look at the Earth. The Earth's entire ecosystem is largely powered by the Sun, a star. That's a constant influx of energy. The Earth is not a closed system, at all; that influx of solar energy clearly demonstrates that.

    No, "using" energy is primarily to convert something from one state to another - and most of the energy isn't stored in the new form.
    That's just incorrect. And contradicts the very law of thermodynamics you tried to quote at me. All the energy is "stored" in the new form because the energy was converted, and energy cannot be created nor destroyed.

    Also, referring to "state" is confusing, since that's usually a reference to matter and whether it's solid/liquid/gas/plasma. Which, sure, energy could be converted into any of those, or out of those, but there's all kinds of energy that don't function as a state of matter.

    You know that people use petrol to fuel cars to go from A to B and then back to A?
    How is that an example of anything? Also, the fuel use for vehicles is mostly down to overcoming things like friction; if the vehicle were in a hypothetical gravity-free vacuum and you boosted it to its travel speed, it'll cover the same A to B distance on the same amount of fuel it took to accelerate to that travel speed and no more; it coasts the rest of the way and uses zero additional fuel.

    But regardless, you used energy to move the vehicle from A to B. And then from B to A. But what you're skipping out on is that the car functions by releasing the energy contained in the fuel. So there goes your complain that "energy isn't stored in the new form", I guess. The concept of fuel (or batteries) contradicts that, and that's before we even get to the first law of thermodynamics again, which says that the energy absolutely is stored in the new form, because there's no other alternative.

    He introduced/popularized it in the 1960 science article titled "Search for Artificial Stellar Sources of Infrared Radiation", since he understood the energy concept above - which you don't. You incorrectly claimed the paper was about something else.
    The paper's about detecting alien life, and using infrared radiation to do so.
    The concept of a Dyson sphere was one idea he tossed off in the paper, but it wasn't the focus of the paper.

    And again; Dyson originated the idea, he isn't the sum total of all development of the concept.

    It is described that way in fiction, but it isn't realistic - and that's why Dyson dismissed that.
    Not in that paper, no. Because it hadn't been described that way in fiction, because Dyson was the first to describe the idea, in that paper.

    Note that the wikipedia article uses the term "intercept" and "harvest" energy to indicate that they would use it to do meaningful work - but all of the energy will still radiate away.
    I really don't know why you keep making arguments that violate the First Law of Thermodynamics after big-text quoting it at me.

    Energy conversion is a thing; you cited that yourself. Stop pretending energy can't be converted into matter.


  9. #69
    Quote Originally Posted by Endus View Post
    Evolution is a biological characteristic, and there's no reason to presume an artificial life form would experience such a thing. There's little reason to expect that any adjustments made would not be fully intentional and deliberate; "body" modification to achieve an intended purpose.
    I studied a lot in college, from engineering to english. I ended up at evolution (which is why I could supply you with the terms 'dispersal ability' and 'range shift' in the climate change thread, one of my labs included doing data analysis on range shifts in the sky islands of the sonoran desert) with a focus on genetics. There's nothing about evolution that should lead someone to believe that it's a characteristic that exists solely in biological entities. We first observed it in biological creatures, but it's by no means solely a biological characteristic. Machine learning is real, non-biological evolution. As long as a thing replicates (which AI would have to do to be able to control a system in the first place), isn't perfect at doing so, and faces selection bias, evolution occurs. There's no such thing as a perfect copy. There's no such thing as an absence of selection bias.

    The fact that there's no such thing as a perfect copy is the reason you can expect that not all changes are going to be fully intentional and deliberate. Arguing arguendo, even if all changes were fully intentional and deliberate, that's still a part of evolution, just changing how the template being tested is generated.

    BTW, your dyson sphere idea being the best defense, via obscurity, essentially assumes the dark forest exists. Otherwise, why the obscurity? As far as I can tell, your argument was that the dark forest doesn't exist, because an AI would act like it does exist.

    Quote Originally Posted by Forogil View Post
    Your errors regarding evolution are minor, misunderstanding thermodynamics is fundamental for any understanding.
    Na, those weren't minor either. Those mistakes were about as fundamental to evolution as entropy is to physics.

    Quote Originally Posted by Endus View Post
    I'm not the one making basic errors, here.
    Yeah, you are. There's no conversion of energy from one form to another without entropy. That's what forogil is talking about. Thermal radiation. The entropy you experienced when converting energy produces heat, heat that has to be radiated outward. You're not going to contain that thermal energy within the sphere without making the entire sphere unusable. There's no getting around that. You can convert whatever energy you want to mass, you're still going to end up with more thermal energy than you started with. That's what the 'time arrow' is. You can't radiate less thermal energy than the star produces without the buildup of thermal energy. Again, time arrow (the fact that the linked paper takes this as given ["Such a dark object would be radiating as copiously as the star hidden inside it, but the radiation would be in the far infrared..."], and doesn't even bother referencing anything else should clue you in to how fundamental the error you're making is). That mismatch in expected spectra of stars is how you'd find spheres. It's why forogil linked that paper. Radiating the same amount of energy from an object with a larger radius means the surface of that object is colder.
    Quote Originally Posted by Rudol Von Stroheim View Post
    I do not need to play the role of "holier than thou". I'm above that..

  10. #70
    Quote Originally Posted by Ihavewaffles View Post
    That is...a bit confusing..he says two things, that universe is either two things, everything or universe + nothing (what I call the infinite void) it can't be everything cuz that would require infinite energy, makes you wonder if there's a limit to big bangs n big crunches, how much is scooped up for each event and eventually it all just fizzles out...and everything becomes the void, but then how did it all start?
    2nd thing he says, universe n nothing, well I wouldn't call it that, since there's something in the void that does pushback otherwise there would be no big crunch..
    the 1st thing can't be right cuz the universe was the size of a pebble at one point, then expanded into a space and has currently expanded 92 billion light years into it, that is just mind boggling and since the void is infinite one can never ever expand to any percentage of it...its so weird..



    think i have seen a video or two, some time past, can't remember any..

    Oh, I see now which one I have watched, the one about the three body problem...yeah, nobody can give an answer that...

    There well not likely to be a big crunch(in the sense where the expansion stops then reverses) current consensus based on observations of the universe is that its expansion rate is increasing, but will never be so extreme as to cause a big rip. There are 2 possible events (PBS space time and one of Science asylums other videos) go into detail. Quantum fluctuations in spacetime has a "chance" to cause a big bang type event. The random chance for that to occur is something on the order of 10^10^10^76 years. To give an example of how large that number is, if you were to replace every atom in our observable universe with another observable universe, you would have to repeat that process 40+ times. Then put a 0 on every one of those atoms to get enough to fill that number.

    There is the other thing that "could" occur with quantum tunneling. Since a particle wave function has a non-0 chance to be anywhere on that wavefunction, and since they could be anywhere in the observable universe, there is a non-0 chance that a sudden decrease in entropy due to all particles (by this point being photons, positrons, electrons due to how long this would take) converge into a single point and causing another big bang. It would be like, all the air in your room through random motion all ends up in one corner of the room. Is it possible? Yes it is! Are you likely to ever witness it in the course of the life span of our solar system, even if its just a place the size of your bedroom? Probably not.

    I am VASTLY oversimplifying the explanations, because the theories and equations would take me forever to type out, and I most likely would write something wrong.


    https://www.youtube.com/watch?v=Qg4vb-KH5F4 - PBS Space time
    https://www.youtube.com/watch?v=PC2JOQ7z5L0 - 2nd video since they are tied.. like I said its complicated :P

    https://www.youtube.com/watch?v=nwfFdbNskYs - Science Asylum

    Science Asylum like before is less mathy and easier to understand the initial concepts.


    -edit-

    I did make a small mistake, when describing how large the number I posted was. In reality, that number is far.. far bigger.

    40+ universe thing was how long it takes for all matter in the universe to convert to Iron (10^3200 years).
    Last edited by Nilinor; 2022-05-18 at 03:12 PM.

  11. #71
    I Don't Work Here Endus's Avatar
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    Quote Originally Posted by Ripster42 View Post
    I studied a lot in college, from engineering to english. I ended up at evolution (which is why I could supply you with the terms 'dispersal ability' and 'range shift' in the climate change thread, one of my labs included doing data analysis on range shifts in the sky islands of the sonoran desert) with a focus on genetics. There's nothing about evolution that should lead someone to believe that it's a characteristic that exists solely in biological entities. We first observed it in biological creatures, but it's by no means solely a biological characteristic. Machine learning is real, non-biological evolution. As long as a thing replicates (which AI would have to do to be able to control a system in the first place), isn't perfect at doing so, and faces selection bias, evolution occurs. There's no such thing as a perfect copy. There's no such thing as an absence of selection bias.

    The fact that there's no such thing as a perfect copy is the reason you can expect that not all changes are going to be fully intentional and deliberate. Arguing arguendo, even if all changes were fully intentional and deliberate, that's still a part of evolution, just changing how the template being tested is generated.
    I would disagree that describing any system with selection bias as "evolution" is reasonable. It may share mechanics with some of those in biological evolution, but that doesn't make it the same thing, obviously.

    Just as a hypothetical, a self-replicating machine may create versions that have errors, but the selection bias in play may be the machine itself, which aggressively destroys any such variations when detected, comparing them against itself. Especially if it's taking action before the new version is complete, the moment the aberration is detected. That's not a system that will see any meaningful (or, arguably, even identifiable) change over time, as the selection bias is unrelenting and excludes any such variation.

    That's grossly inefficient, of course; I'm not arguing for effectiveness, here.

    I also don't see how an AI need to replicate. That's a strange tenet and seems to come completely out of nowhere. While it may need to expand, that's not the same thing at all.

    BTW, your dyson sphere idea being the best defense, via obscurity, essentially assumes the dark forest exists. Otherwise, why the obscurity? As far as I can tell, your argument was that the dark forest doesn't exist, because an AI would act like it does exist.
    Technically, it just requires the Dyson shell builder to believe that there's a dark forest, no that the belief is accurate. It was just a hypothetical I tossed off.

    Yeah, you are. There's no conversion of energy from one form to another without entropy. That's what forogil is talking about. Thermal radiation. The entropy you experienced when converting energy produces heat, heat that has to be radiated outward. You're not going to contain that thermal energy within the sphere without making the entire sphere unusable. There's no getting around that. You can convert whatever energy you want to mass, you're still going to end up with more thermal energy than you started with. That's what the 'time arrow' is. You can't radiate less thermal energy than the star produces without the buildup of thermal energy. Again, time arrow (the fact that the linked paper takes this as given ["Such a dark object would be radiating as copiously as the star hidden inside it, but the radiation would be in the far infrared..."], and doesn't even bother referencing anything else should clue you in to how fundamental the error you're making is). That mismatch in expected spectra of stars is how you'd find spheres. It's why forogil linked that paper. Radiating the same amount of energy from an object with a larger radius means the surface of that object is colder.
    Thermal radiation is, itself, energy, and thus can be converted. Hell, that's how steam engines work; thermal energy is converted into shifting water from liquid to gas, whose expansion is then converted into mechanical energy. Not at full efficiency, so it's not going to be full conversion and there's still waste heat, yes, but that's a question of how advanced the technology is.

    If we're talking a Type II Civilization which can capture the entire energy capacity of a star, then its technological level is bafflingly superior to our own, as we're not even a Type I civilization. The existence of the Dyson shell means we should assume certain functions have been developed, such as direct conversion of energy into matter; there could easily just not be enough structural matter in the planetary system to construct such a sphere, just in terms of mass, and thus new matter would need to be created to complete such a construction.

    The paper doesn't consider a Dyson shell; the sphere Dyson conceived of was more of a skeletal chassis or cloud of orbitals, and the fact that it's detectable through infrared radiation means it's not capturing all the energy of that star (and thus isn't a Type II civilization). And I was talking about a hypothetical where that was the case. Sure, the technical requirements may be vastly higher, but that's still the hypothetical I was addressing. And I'm not the guy who came up with that idea; I didn't invent the idea of a Dyson shell nor the idea of a Type II civilization (that'd be Kardashev).


  12. #72
    Scarab Lord Ihavewaffles's Avatar
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    Quote Originally Posted by Nilinor View Post
    There well not likely to be a big crunch(in the sense where the expansion stops then reverses) current consensus based on observations of the universe is that its expansion rate is increasing, but will never be so extreme as to cause a big rip. There are 2 possible events (PBS space time and one of Science asylums other videos) go into detail. Quantum fluctuations in spacetime has a "chance" to cause a big bang type event. The random chance for that to occur is something on the order of 10^10^10^76 years. To give an example of how large that number is, if you were to replace every atom in our observable universe with another observable universe, you would have to repeat that process 40+ times. Then put a 0 on every one of those atoms to get enough to fill that number.

    There is the other thing that "could" occur with quantum tunneling. Since a particle wave function has a non-0 chance to be anywhere on that wavefunction, and since they could be anywhere in the observable universe, there is a non-0 chance that a sudden decrease in entropy due to all particles (by this point being photons, positrons, electrons due to how long this would take) converge into a single point and causing another big bang. It would be like, all the air in your room through random motion all ends up in one corner of the room. Is it possible? Yes it is! Are you likely to ever witness it in the course of the life span of our solar system, even if its just a place the size of your bedroom? Probably not.

    I am VASTLY oversimplifying the explanations, because the theories and equations would take me forever to type out, and I most likely would write something wrong.


    https://www.youtube.com/watch?v=Qg4vb-KH5F4 - PBS Space time
    https://www.youtube.com/watch?v=PC2JOQ7z5L0 - 2nd video since they are tied.. like I said its complicated :P

    https://www.youtube.com/watch?v=nwfFdbNskYs - Science Asylum

    Science Asylum like before is less mathy and easier to understand the initial concepts.


    -edit-

    I did make a small mistake, when describing how large the number I posted was. In reality, that number is far.. far bigger.

    40+ universe thing was how long it takes for all matter in the universe to convert to Iron (10^3200 years).
    I'll watch those videos, that was a very complicated post you made, like the average page of three body problem book, lol, I don't mean this as criticism (oh god, now I probably scared away most people from giving that book a try...).

    I dunno dude, without a big crunch, to accumulate enough pressure n energy there into a single point, how could you possibly have enough 'stuff' to cause the next big bang?

  13. #73
    Quote Originally Posted by Endus View Post
    I would disagree that describing any system with selection bias as "evolution" is reasonable. It may share mechanics with some of those in biological evolution, but that doesn't make it the same thing, obviously.

    Just as a hypothetical, a self-replicating machine may create versions that have errors, but the selection bias in play may be the machine itself, which aggressively destroys any such variations when detected, comparing them against itself. Especially if it's taking action before the new version is complete, the moment the aberration is detected. That's not a system that will see any meaningful (or, arguably, even identifiable) change over time, as the selection bias is unrelenting and excludes any such variation.
    That's basically what already happens at the genetic level. There are a lot of different polymerases involved in doing exactly that. The systems aren't perfect because, as I said, there's no such thing as a perfect copy. The errors you get when copying DNA are biased in favor of DNA if you go by info stored compared to enterprise quality SSDs. About 1 error per 10^11 base pairs with 4 options per base (which I think is the same as 1 error per 10^22 bits as far as encoded data goes, correct me if I'm wrong), compared to 1 error per 10^17 bits, with 2 options per base. All you do by narrowing the difference between generations is slowing evolution. It's still evolution. I'll agree with you on one point though, it's not biological evolution. You even list all the component parts:

    1) replicating machine
    2) change over time
    3) selection bias

    The fact that you don't understand what you're saying in that paragraph, is why your problems with understanding evolution are as bad as your understanding of entropy.


    Thermal radiation is, itself, energy, and thus can be converted.
    This is you not understanding what entropy, heat, or the time arrow is. One of these, and I don't know which. There will always be the same or more thermal energy as a % of total energy in a closed system as time goes on. There's no way around this. "The second law of thermodynamics states that processes that involve the transfer or conversion of heat energy are irreversible and always move toward more disorder". Irreversible. Always. Not things you here often in chemistry/physics.

    Hell, that's how steam engines work; thermal energy is converted into shifting water from liquid to gas, whose expansion is then converted into mechanical energy.
    In the steam engine analogy, the thermal energy being radiated by the sphere is just like the steam: it has to be released from the container, or the added heat keeps building up until it explodes (in your sphere case, until everything inside becomes so hot their electrons can no longer maintain orbit around the nucleus).
    Quote Originally Posted by Rudol Von Stroheim View Post
    I do not need to play the role of "holier than thou". I'm above that..

  14. #74
    Quote Originally Posted by Ihavewaffles View Post
    I'll watch those videos, that was a very complicated post you made, like the average page of three body problem book, lol, I don't mean this as criticism (oh god, now I probably scared away most people from giving that book a try...).

    I dunno dude, without a big crunch, to accumulate enough pressure n energy there into a single point, how could you possibly have enough 'stuff' to cause the next big bang?
    Quantum stuff is.. complicated. Richard Feynman said "If you think you understand quantum mechanics, you don't understand quantum mechanics." Like, so much is possible on the scale its insane, entanglement, tunneling. Its the reason that hawking radiation is a thing as well, and how Black holes lose mass, even though anything that enters a black hole can't escape.

    It also doesnt help that terms that are used for physics stuff, make people have general assumptions as to what particles, waves etc are, when in fact its nothing like it. It took me a long time to understand. Like a good example is "spin" how can something have a 1/2 spin or 2/3 spin etc. Its not spin as we know it, its just a term to describe a property of a particle.

  15. #75
    I Don't Work Here Endus's Avatar
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    Quote Originally Posted by Ripster42 View Post
    This is you not understanding what entropy, heat, or the time arrow is. One of these, and I don't know which. There will always be the same or more thermal energy as a % of total energy in a closed system as time goes on. There's no way around this. "The second law of thermodynamics states that processes that involve the transfer or conversion of heat energy are irreversible and always move toward more disorder". Irreversible. Always. Not things you here often in chemistry/physics.
    I'm not arguing against the concept of entropy, at all. I have no idea where you're even getting that. I never argued for 100% efficiency, just near-100%. There's always a small portion that won't be recoverable, yes, but that doesn't mean that portion is significant, on the observable level. A Dyson shell generating enough waste heat that its outer surface is 0.2 Kelvin above the ambient temperature is suffering the effects of entropy, there's a small amount of waste heat being produced that is not being recovered.

    That doesn't make it detectable at any appreciable interstellar distance. That's my point; I was never arguing for 100% efficiency, just that efficiency is a scale that can approach 100%.

    In the steam engine analogy, the thermal energy being radiated by the sphere is just like the steam: it has to be released from the container, or the added heat keeps building up until it explodes (in your sphere case, until everything inside becomes so hot their electrons can no longer maintain orbit around the nucleus).
    Some steam engines don't release the steam, bud. They collect it and let it re-condense to be fed back into the boiler, so you don't need much additional supply of liquid (and what you do is down to leakage). Real-world engines don't aim for 100% efficiency because we've got a lot of environment to vent oversupply into, so sure, a hypothetical Dyson shell would need far more advanced and refined tech, but that was presupposed.


  16. #76
    Let us list the errors and exaggerations:
    Quote Originally Posted by Endus View Post
    Not really.

    The universe is finite. Baffling huge, but that's not the same as "infinite".
    1. We don't know that. The observable universe is growing (although things are passing beyond its horizon), but currently finite. Beyond that we don't know, but it is clear that it doesn't just end at the "edge".

    Quote Originally Posted by Endus View Post
    I'm not sure why you're pretending that energy can't be converted from one form to another after just incorrectly lambasting me about the laws of thermodynamics.
    2. I'm not arguing that it cannot be converted, only that it cannot be converted with 100% efficiency.

    Quote Originally Posted by Endus View Post
    First, the Dyson shell (I'm gonna use this term because you got unreasonably pedantic) isn't a closed system. The shell plus the star form a closed system, but the shell itself is constantly seeing a massive energy input from the star, through the star's lifespan. So yeah; that allows for consistent energy use for functional work by the shell.
    3. It needs to dissipate that energy as well; or it heats up. And Entropy.

    Quote Originally Posted by Endus View Post
    Hell, look at the Earth. The Earth's entire ecosystem is largely powered by the Sun, a star. That's a constant influx of energy. The Earth is not a closed system, at all; that influx of solar energy clearly demonstrates that.
    4. And Earth - like a Dyson sphere - radiates about about the same energy in infrared (primarily) as it receives from the Sun (I believe it radiates a bit more due to primordial heat). That's how you use energy to do meaningful work, instead of converting it to something else.

    Quote Originally Posted by Endus View Post
    That's just incorrect. And contradicts the very law of thermodynamics you tried to quote at me. All the energy is "stored" in the new form because the energy was converted, and energy cannot be created nor destroyed.
    5. Wrong again. Almost all of the energy that goes into a system isn't stored in the new form - it is lost to the environment.
    Look at a computer or a human brain - the energy enters and is used to do useful work, but it isn't stored in the system, instead it is radiated away as heat.

    Additionally you cannot use all of the incoming energy to do meaningful work. For solar radiation at Earth we could in theory use about 93% - the remaining 7% cannot be used to do any work here.

    Quote Originally Posted by Endus View Post
    The paper's about detecting alien life, and using infrared radiation to do so.
    The concept of a Dyson sphere was one idea he tossed off in the paper, but it wasn't the focus of the paper.
    6. Previously you claimed that the paper wasn't about the Dyson sphere...
    And the point is that it can be detected based on the infrared radiation - while you claimed that they couldn't be detected.

    Quote Originally Posted by Endus View Post
    Not in that paper, no. Because it hadn't been described that way in fiction, because Dyson was the first to describe the idea, in that paper.
    7. The point was that when looking for Dyson spheres we should look for realistic ones, and not base our search on the fictional ones. You totally missed that.
    8. A similar concept had been described in fiction in Olaf Stapledon's Star Maker, at least in the end of the "Vision of the Galaxy" chapter (I really should re-read it).


    Quote Originally Posted by Endus View Post
    Energy conversion is a thing; you cited that yourself. Stop pretending energy can't be converted into matter.
    Yes, energy conversion is a thing - but that's insignificant when using a star as energy source for a sustained period.

    9. Energy can be converted to matter. However, we have no indication that it can be used to convert energy back into bulk matter in significant quantities. Creating an electron-positron pair that is then annihilated is spectacular, but afterwards you don't have more matter. Obviously one could "store" the output of the star by converting carbon to hydrogen (or less efficiently iron to lead). I doubt that it can be done efficiently, and are you seriously suggesting that civilizations will harnesses the output of a star to sort of undo the fusion in the star?
    Last edited by Forogil; 2022-05-18 at 05:40 PM.

  17. #77
    I Don't Work Here Endus's Avatar
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    Quote Originally Posted by Forogil View Post
    Let us list the errors and exaggerations:

    1. We don't know that. The observable universe is growing (although things are passing beyond its horizon), but currently finite. Beyond that we don't know, but it is clear that it doesn't just end at the "edge".
    The positions that argue for an infinite universe don't mesh with the Big Bang theory. Arguments that the Big Bang exists within a greater universe outside it don't really have much support, since that greater universe would be beyond space-time, so we're talking about something pretty strange.

    In terms of what expanded out from the Big Bang, that's finite. Can't be otherwise, or it could never have been a singularity

    2. I'm not arguing that it cannot be converted, only that it cannot be converted with 100% efficiency.
    Well, I literally never made an argument that you could, so that was a straw man.

    3. It needs to dissipate that energy as well; or it heats up. And Entropy.
    "Dissipate" is what you do with energy you can't make use of. Why are you presuming such an advanced system can't make use of that energy?

    And to repeat the prior point; at no stage did I ever deny entropy. Entropy doesn't lead to a Dyson shell emitting the same infrared radiation as the star inside it, however.


    4. And Earth - like a Dyson sphere - radiates about about the same energy in infrared (primarily) as it receives from the Sun (I believe it radiates a bit more due to primordial heat). That's how you use energy to do meaningful work, instead of converting it to something else.
    Earth isn't anything like a Dyson sphere.

    And again; infrared radiation is recoverable and useable; https://www.pnas.org/doi/10.1073/pnas.1402036111

    Also, the phrase "that's how you use energy to do meaningful work, instead of converting it to something else" is nonsensical, since the only way to get energy to do meaningful work is to convert it to something else. Usually, some other form of energy. Electrical energy transformed into mechanical energy, for instance, to power an engine. Hell "work" is literally the physics term for energy transferred to or from an object by an application of force. https://en.wikipedia.org/wiki/Work_(physics)

    5. Wrong again. Almost all of the energy that goes into a system isn't stored in the new form - it is lost to the environment.
    Look at a computer or a human brain - the energy enters and is used to do useful work, but it isn't stored in the system, instead it is radiated away as heat.
    This is a factor of the inefficiency of current technology or biology, not a law of physics.

    Additionally you cannot use all of the incoming energy to do meaningful work. For solar radiation at Earth we could in theory use about 93% - the remaining 7% cannot be used to do any work here.
    Again, this is about current technological limits, not physics.

    6. Previously you claimed that the paper wasn't about the Dyson sphere...
    And the point is that it can be detected based on the infrared radiation - while you claimed that they couldn't be detected.
    It isn't "about" the Dyson sphere, though it mentions the concept offhandedly. The subject's right there in the title.
    As for the second bit, I repeat; Dyson came up with the idea, but he is not the one who's expanded upon that idea to the greatest extent. The Dyson shell I originally described was not Dyson's idea, but a further iteration on that idea, expanding it into new territory and beyond Dyson's original scope. Hell, Dyson isn't even the first guy to conceive of this; he was inspired by Olaf Stapledon, a sci-fi writer. As you noted yourself.

    7. The point was that when looking for Dyson spheres we should look for realistic ones, and not base our search on the fictional ones. You totally missed that.
    There's nothing "unrealistic" about a Dyson shell. It carries some challenges, but most of those wouldn't matter to an AI, which was the explicit example I was hypothesizing.

    Yes, energy conversion is a thing - but that's insignificant when using a star as energy source for a sustained period.

    9. Energy can be converted to matter. However, we have no indication that it can be used to convert energy back into bulk matter in significant quantities. Creating an electron-positron pair that is then annihilated is spectacular, but afterwards you don't have more matter. Obviously one could "store" the output of the star by converting carbon to hydrogen (or less efficiently iron to lead). I doubt that it can be done efficiently, and are you seriously suggesting that civilizations will harnesses the output of a star to sort of undo the fusion in the star?
    Again, you're describing a technological limitation, not a physics limitation.

    We know bulk matter conversion is possible, because it happened, in the aftermath of the Big Bang. That burst initially started out as pure energy, and all the matter in the universe coalesced from that point. Energy, to matter, pulling together gravitationally to form a new star, which converts said matter back into energy, and so on.

    I'm not arguing this is particularly feasible; it's a requirement of a Type II civilization on the Kardashev scale, however. We're not even a Type I civilization, here on Earth. And Kardashev went further, to Type III, and others have expanded to Type IV and V from there. These aren't fathomable from our perspective; their actions would be indistinguishable from natural forces (in that we'd describe their actions as "natural" and be unable to determine otherwise, not that they'd be aping "real" natural forces); we're essentially talking about Gods, in the "can create universes and control their function" sense.

    It was a hypothetical. I wasn't arguing that there's a bunch of these shells out there, somewhere. My personal opinion is that we're likely alone, at least effectively (within the Milky Way, say).


  18. #78
    Quote Originally Posted by Endus View Post
    In terms of what expanded out from the Big Bang, that's finite. Can't be otherwise, or it could never have been a singularity
    We don't know any of that. We don't even know if there were a singularity, only that it was pretty close to one, as we don't have theories that work in those conditions.

    Quote Originally Posted by Endus View Post
    "Dissipate" is what you do with energy you can't make use of. Why are you presuming such an advanced system can't make use of that energy?
    Because of thermodynamics, and understanding how exergy is actually used up.

    Quote Originally Posted by Endus View Post
    And to repeat the prior point; at no stage did I ever deny entropy. Entropy doesn't lead to a Dyson shell emitting the same infrared radiation as the star inside it, however.
    Either it magically doesn't radiate it away and thus heats up until it has the same temperature as the star, and cooks everyone inside, or it radiates it away.

    Quote Originally Posted by Endus View Post
    Earth isn't anything like a Dyson sphere.
    Making lots of (smaller) earths wouldn't be too far from Dyson's actual idea.

    Quote Originally Posted by Endus View Post
    And again; infrared radiation is recoverable and useable; https://www.pnas.org/doi/10.1073/pnas.1402036111
    We may define the EEH percentage efficiency as Pengine max/f(Thot), in which case the Carnot-limited EEH efficiency in the above example is 1–2%.
    This is also consistent with their graphs having a Carnot-limited Power not even reaching 4W/m2.

    Quote Originally Posted by Endus View Post
    Also, the phrase "that's how you use energy to do meaningful work, instead of converting it to something else"
    Make perfect sense. The key phrase is meaningful. The goal isn't to convert energy to some other energy.

    When a perfectly normal brain works the goal isn't to convert sugar and oxygen to carbon dioxide and waste product, but to think. That is the meaningful work. The fact that energy is converted from one chemical form to another isn't the goal.

    Quote Originally Posted by Endus View Post
    This is a factor of the inefficiency of current technology or biology, not a law of physics.
    Nope. That's the simplified application of laws of physics - entropy lowers it, to quote from the paper you linked.

    A calculation similar to Eq. 3 gives a Carnot-limited solar-cell efficiency of ∼87% (under highly concentrated sunlight), which is lower than the “Landsberg limit” of (1 – Tambient/Tsun) ∼ 93%, because entropy is generated in the light absorption process (7).

    Quote Originally Posted by Endus View Post
    Again, this is about current technological limits, not physics.
    Physics is that we have no indication that it is physically possible to convert energy to bulk mass. Obviously if we invoke magic or technobabble like star trek's replicator we can convert energy into pure mass, but might as well have hyper-drive, white holes, or what-ever.

    Seriously, give it up. You are wrong on every count, and the following two quotes just shows you for what you are:

    Quote Originally Posted by Endus View Post
    Not in that paper, no. Because it hadn't been described that way in fiction, because Dyson was the first to describe the idea, in that paper.
    Then I show that it is false, and you reply:
    Quote Originally Posted by Endus View Post
    Hell, Dyson isn't even the first guy to conceive of this; he was inspired by Olaf Stapledon, a sci-fi writer. As you noted yourself.
    Doesn't the 180s hurt you?
    Last edited by Forogil; 2022-05-18 at 09:29 PM.

  19. #79
    Quote Originally Posted by Endus View Post
    I'm not arguing against the concept of entropy, at all. I have no idea where you're even getting that.
    You are, and you don't even realize it. That's the problem. Again, the concept is so basic, people don't even bother making a reference about it in academic papers. What are you going to do? Cite the 2nd law of thermodynamics? People are going to think you're an asshole.

    Quote Originally Posted by Endus View Post
    Some steam engines don't release the steam, bud. They collect it and let it re-condense to be fed back into the boiler, so you don't need much additional supply of liquid (and what you do is down to leakage). Real-world engines don't aim for 100% efficiency because we've got a lot of environment to vent oversupply into, so sure, a hypothetical Dyson shell would need far more advanced and refined tech, but that was presupposed.
    And they still get rid of heat somehow. It's not the water I'm talking about in the steam engine. It's the thermal energy contained in the steam. Whatever steam engine you're talking about, it gets rid of the heat in some manner. They're using a heat exchanger or some type, which radiates heat somewhere else. What you're trying to suggest violates the 2nd law of thermodynamics. That you don't understand is your problem.

    This, right here, is you arguing against entropy:
    Quote Originally Posted by Endus View Post
    "Dissipate" is what you do with energy you can't make use of. Why are you presuming such an advanced system can't make use of that energy?
    There comes a point where you literally can't use the energy anymore, because there's no gradient to move it along. That energy is heat. Without dissipating that heat at the same rate the sun is producing energy, you're going to continue to build up heat. Dissipating that heat is also known as thermal radiation, which is, again, exactly why forogil linked that paper.

    Edit: I should say, dissipating that heat in a vacuum is thermal radiation. Convection works if you've got some medium to use.
    Last edited by Ripster42; 2022-05-18 at 10:30 PM.
    Quote Originally Posted by Rudol Von Stroheim View Post
    I do not need to play the role of "holier than thou". I'm above that..

  20. #80
    I Don't Work Here Endus's Avatar
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    Quote Originally Posted by Ripster42 View Post
    You are, and you don't even realize it. That's the problem. Again, the concept is so basic, people don't even bother making a reference about it in academic papers. What are you going to do? Cite the 2nd law of thermodynamics? People are going to think you're an asshole.
    Is your argument that it is simply not possible to use thermal energy for any kind of work and that it can only accumulate or be radiated?

    Because if not, it's a resource that can be used for some purpose.

    That seems to be the fundamental issue you folks have, here; I offered a hypothetical about a Type II civilization on the Kardashev scale, and the argument I'm getting back is that heat can't be used for any useful purpose and would either accumulate or must be radiated outward.

    And there just isn't an argument for that. The arguments provided are that it's beyond our technological capacity, but so is a Type II civilization. Bafflingly far. It's a bigger stretch by orders and orders of magnitude than our current stage of technological development is from the era when Homo Habilis knapped stone tools and huddled around a fire. We know energy can be converted directly into matter, because that's where matter comes from. So it's a question of mechanics, not possibility. There's a whole hell of a lot of things we can observe happening that we have no technological capacity to effect, but that doesn't mean it can't ever be technologically achieved.

    I didn't develop these concepts. Dyson shells and the Kardashev Scale predate me by a hell of a lot.
    Last edited by Endus; 2022-05-19 at 12:23 AM.


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