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Everything posted by Delta1212
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The smallest self-contained component of life from which all living things are built is the cell.
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What detector would you be using for this? Anything capable of detecting and providing you with information about a photon is going to affect that photon.
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0.1666666666666666666666666...That string of numbers goes on to infinity. The digit 1 occurred once, therefore it must occur again because it is an infinite series.
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Constancy of light speed without relative time.
Delta1212 replied to DimaMazin's topic in Speculations
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Except that the black hole does have enough money to pay back the loan, it just needs to be taken out of its savings instead of out of the loan. The universe doesn't really care how it gets paid back as long as it can balance the books at the end of the day.
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But when you bump into your car, will I measure the amount of force you apply to each other as being different if I am moving with respect to you than if I am not?
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Um...Cc+cc=Cc, Cc, cc, cc So yeah, 50%
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Correct, as far as I'm aware. It's just important to note, as I explained above, that energy doesn't accelerate objects in a linear way. It accelerates objects as a fraction of the speed of light (which is why it would take infinite energy to accelerate a massive object to the speed of light, preventing anything from moving that fast). When dealing with the incredibly small range of motion that we normally do, this difference is effectively imperceptible. It only becomes relevant at very high speeds.
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You mean speed/velocity/movement. Accelerated reference frames are different from inertial reference frames. It's impossible to tell who is moving and who is at rest, but it's fairly easy to tell who is accelerating.
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Ah, ok. (Note: I don't have a strong enough handle on the math in relativity to give accurate numbers, so I'm going to basically make some up that roughly correspond to the general idea. If someone wants to go through and apply accurate math to the examples for better illustration, feel free to do so). Let's say superman throws a ball so hard that it flies off at half the speed of light. Now let's say he's on a spaceship flying past you at half the speed of light. When he throws the ball, he sees it fly away at half the speed of light. However, since he's in a different reference frame than you, you see him moving in slow motion, let's say half speed. This means you see the ball moving away from him at only 25% the speed of light. Since it was already moving at half the speed of light, you see it moving at 75% the speed of light. How can superman apply a specific amount of energy to the ball and have it change speeds by different amount in different reference frames? Doesn't this create an inconsistency that means the laws of physics work differently at different speeds? The answer is no, and here's why. Objects don't have a linear relationship between the amount of energy applied to them and their change in speed. The faster an object is moving, the more energy it takes to accelerate it by the same amount. It might tale the same amount of energy to accelerate something to half the speed of light from rest as it does to accelerate it from half the speed of light to three quarters of the speed of light. We're experiencing motion in such a narrow range of speeds that this isn't really noticeable. 100 mph is approximately 0.0000015% of the speed of light. The energy required to accelerate something from 0 to 100 mph would then accelerate something from 100 mph to 199.9999985 mph. To put that in prospective, if you traveled for 100 years at that speed, you'd have traveled to the sun and back and be less than a mile and a half behind where you'd be at 200 mph. So from an Earthly perspective, twice the energy = twice the acceleration. That's not 100% accurate, but it only becomes noticeable at extremely high speeds.
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I'm having a little trouble following what you're trying to say. I sort of see the point you're making, but not well enough to address it well. Could you try rephrasing your point or giving a more detailed example of where you see the problem so I can fully understand the issue?
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If I was Osama bin Laden and the USA had just faked my death, I'd be taping myself mooning the camera next to a picture of today's paper and sending it to every major media outlet in the world. The damage to US creditability would be devastating. So, for a start, if I was in charge of the US, I wouldn't give someone who hates us that much power to hurt us solely for the sake of, let's face it, spawning a bunch of massive college parties for about a week. It's been a dozen years. Most of the population of the US had already stopped thinking about it on more than an extremely occasional basis and the assassination really didn't accomplish much of anything domestically. Hell, abroad it strained relations with Pakistan. If they were going to fake an assassination they really should have stuck him in a cave in Afghanistan. Nobody would have been surprised and the amount of outrage from anyone not actually in AQ would have been effectively zero. I understand that you find a lot of facts suspicious, the issue is that I can understand how things could have happened in reality that lead to all those things, but I don't understand why someone would stage it to appear the way that it happened. There were significantly more advantageous ways to go about doing it, and it only makes sense if they already knew that Osama bin Laden was dead or in custody, in which case why not just say that because it realistically wouldn't be much different in its effect. Literally the only thing I think you could even stretch an argument for is that they actually captured him in the raid without killing him and are keeping it a secret in order to minimize retaliation (e.g. From people trying to free him) and/or ensure any intelligence they get from him stays usable for longer. Note that I think this is significantly less likely than that he is just dead, but "everything except for the actually killing him part actually happened" is literally the only way you can get a narrative where the government secretly didn't kill Osama that isn't just a lot fucking weirder than the supposed inconsistencies in the story.
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It might help conceptually to think of velocity not as a property that objects have but a sort of location or space that they occupy. Every velocity space has its own timeline, and the further you get from your own velocity space, the slower time will appear to move and the less in sync the timelines are. When you accelerate, you aren't gaining or losing speed so much as shifting to an adjacent velocity space with its own timeline. The "real" timeline will always be the one you are currently occupying. So if you see a train go by at close to the speed of light, you will really see the people on board moving in slow motion. In your timeline, they are moving in slow motion. The train is in a different velocity space, however, with its own timeline. The people on the train see you moving in slow motion, and in that timeline, you really are moving in slow motion. This means that you won't agree on the order in which some things happen, but that's ok because you can only intersect once. You'll both agree on what was happening in each others timelines at the exact moment that the train passes you, but you won't agree on the order or duration of events before or after. The reason this works without fundamentally breaking things like causality is that you can't pass each other a second time to compare notes without one or both of you shifting into a new velocity space in order to turn around and head back in the other direction. Once you move to a new velocity space, the timeline for that velocity becomes the real one. If the train comes around and goes past you again, it will have to shift through a velocity space with a timeline that will prevent the disagreement on the order of events that it has with you from breaking causality (i.e. Prevent it from reaching you before something happens for you that already happened for it or vice versa). If the train slows to a stop next to you, it will wind accept your timeline and the people on board, having been moving in slow motion, will find that they have aged less than the rest of the world. If, on the other hand, you were to jump on another train, catch up to the other one and board it, you would be moving into their velocity space, accepting their timeline, and find that you had actually aged less than all the people on the train because you were the one moving in slow motion. The reason people are having a hard time when you ask what really, physically happened is because what really physically happens may really, physically not be the same thing from one timeline to the next. This is hard to grasp and not intuitive because we evolved and have spent our entire lives in one single timeline, or at least a very small subset of timelines that were so close together the difference is effectively imperceptible to anyone that isn't trying extremely hard to measure it. There was never any need to understand how things worked when dealing with multiple, parallel timelines and so that can be much harder to internalize, almost like trying to imagine what life what be like if we could move around in four spacial dimensions instead of three. As a note, I used the term velocity space in order to evoke a certain conceptual understanding, but that is actually what a reference frame is. It's not a completely perfect analogy, but I'm hoping it might help you internalize what is actually going on, even if it seems a little surreal to think of overlapping alternate timelines based on speed. Just to extend it a bit, in this way units of speed like mph are actually units of distance between timelines. If something is moving 10mph faster than you, it would be equally accurate to say that your timelines are 10mph apart. It just happens that this is ridiculously close and you need to get as "far apart" as a significant fraction of the speed of light before the timelines are really noticeably out of sync.
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I think the confusion is arising from the fact that when people are saying there is no effect on the human body, they mean that it does not change in operation in any way *except* that from the frame of someone who isn't moving at the same speed, it is operating more slowly. This slowing has no *additional* impact on the body, which is what everyone is talking about when they say the body isn't affected. If your heart beats 50 times a minute according to the clock next to you, when you speed up and it takes twice as long for a minute to pass, it'll take twice as long for your heart to beat 50 times. From your perspective, your heart is still beating 50 times per minute. From Earth's, your clock takes two minutes to register a minute and your heart takes two minutes to beat 50 times.
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Ah, it's because no chunk of time is being removed. The length of a "moment" is simply different. Your body functions in the way it does, and at the rate it does, because it takes a certain amount of time to go through the complex chemical processes that keep you alive. Your bodies various functions need to stay in sync with each other and in sync with these processes or stuff starts to break. When you have time dilation, everything takes longer but stays in sync. You may breathe half as often, but that's ok, because your heart is beating half as often and your cells are using up oxygen half as fast. Because everything in your body takes twice as long to accomplish the same thing, you effectively age half as quickly. And since your brain is also operating at half speed and everything around you is going half as fast, you can't tell the difference between that and normal speed. From the perspective of Earth, you are in effect moving in slow motion. Now here's the rub, the astronaut looks back at Earth and sees everything there moving in slow motion in comparison to him! Who is correct? Well, since in the twin paradox, the astronaut returns to Earth younger, he was obviously moving in slow motion, not the Earth, correct? Well, let's look at this from another perspective. The Earth is hurtling through space at a very high speed around the galactic center. If the astronaut blasts off in the opposite direction, you could say he is actually slowing down to a stop while the Earth continues flying along at close to light speed. So the spaceship is now at rest watching Earth fly off at the speed of light. This spaceship doesn't have a twin on it, it has two triplets, with the third remaining on Earth. These two see the third triplet age slower than them. Now, one of the triplets decides to take the escape pod and return to Earth. The triplet remaining on the spaceship sees him take off and speed off at a rate that is even faster than Earth is moving. After all, he had to catch up with Earth. This means the triplet on the escape pod is not only moving in slow motion to the twin on the spaceship, he is moving in slower motion than Earth. To the triplet on the spaceship, the triplet on Earth is younger than the triplet on the escape pod, but is now aging faster. By the time the escape pod reaches Earth, the triplet on board will actually be younger than the triplet who remained on Earth. From Earth's perspective, the two triplets took off, approached light speed, aged slower and then one returned younger than the triplet who stayed. From the spaceship's perspective, it slowed to a stop, Earth moved away at lightspeed, the people there aged slower, then one twin took off and aged even slower so that he'd be younger by the time he reached Earth. There's really no way to determine which of these two perspectives is actually correct, so effectively we must treat both as equally true. Edit to respond to your previous post: If the two triplets then left Earth and came back to the spaceship, the triplet on board would find them both arriving younger than him. So the ages on the spaceship would go, from oldest to youngest: Triplet on Spaceship, Triplet on Earth, Triplet on Escape Pod.
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Took me about 25 minutes, but I wasted 10 of those trying to find a way to avoid working it out more than one or two steps ahead before giving in and then solving it a few minutes later.
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Usefulness of the theory of evolution
Delta1212 replied to MonDie's topic in Evolution, Morphology and Exobiology
By physicist, I mean someone with an advanced education in physics. The choice isn't between a guy in a lab coat with a chalkboard and a guy working as a mechanic. It's between a guy who learned to fix cars working out of his garage and a guy with a mechanical engineering degree. I realize, and should have taken into account so my mistake, that when someone says physicist, people automatically assume it gets preceded by something like "experimental" or "theoretical" but for all practical purposes, an engineer is just a type of physicist. That's how they knew how to design the car in the first place. I may not have been clear in the point I was trying to make. I was attempting to clarify why the umbrella of evolutionary theory is useful above and beyond the fields that are heavily reliant upon it for a theoretical base. You don't need to understand evolution to discover DNA or figure out what it does and how it works. Studying it will, of course, be a hell of a lot harder without that foundation, but that was my point. I realize that, as has been said, nothing in biology makes sense except in light of evolution, but you don't need something to make sense to use it. Considering how the conversation had been going previously, I was attempting to explain how evolution would be useful even if we somehow had managed to achieve all of our current knowledge of biology other than evolution (and no, I don't know how we would have managed that). What I was trying to say was that without the theory of evolution to act as that foundation of all of our knowledge of biology, advancing that knowledge becomes next to impossible. Evolution frames our knowledge of biology and makes it easier for us to figure out how things work. Obviously, all of that knowledge can then be attributed to knowledge of evolutionary theory, but I was shooting for a good reason why evolution all by itself is useful knowledge rather than "only" being a foundation for useful knowledge. -
Think of atoms like coins. Heads is decayed. Tails is undecayed. You have 100 of these coin atoms. Every ten minutes, you flip all of the coins and remove any that come up heads (decayed). The first coin flip, you expect about half to come up heads, so you have fifty left. The second flip, you have half of those come up heads, leaving you with 25, and so on. Because decay is a binary position, either the atom is decayed or it is not in the same way that a coin is either heads or tails but never 1/3 tails and 2/3 heads. There is no process of decaying, merely a probability of decay occurring at any given moment. Or thinking of it another way, the atoms don't "know" how big of a chunk of material it is in, and that will have no impact on when the atom decays. An atom in one pound of a substance will not decay any sooner or later than an atom in a ton of the same substance. So, if you start with a gram and a half a gram of atoms. After the half life has elapsed, you will have a half of a gram and a quarter of a gram. The half a gram doesn't know it started out as a gram, so it's like starting that exact moment with half a gram, which will take just as long to halve itself as the original half a gram did. This only seems weird to us intuitively because we are used to dealing with more mechanical processes that have lots of in between steps. For instance, if it takes me half an hour to ear half a tub of ice cream, then, barring changes like brain freeze or feeling sick, it should take me an hour to eat the entire thing. However, there is not a set probability that any random bit of ice cream will be eaten at any given moment. I am far more likely to eat a bit of ice cream that is exposed on the surface than one buried at the bottom of the tub. Additionally, every bit I eat brings bits of ice cream farther down closer to the surface by lower where that surface is, this changes their probability of being eaten over time. With decay, it is not being induced by something else (usually), the placement of the atom in the material does not impact the likelihood of the atom decaying and other atoms decaying elsewhere in the substance do not change the probability of the atom decaying.
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Also, keep in mind, saying that both GR and QM cannot be correct doesn't mean that one or both are necessarily wrong. They are both highly accurate at predicting experimentally verifiable results. The most likely scenario is that one or both are incomplete. For example, take Newtonian gravity. If Newton's conception of gravity was correct, Mercury's orbit would not behave the way that it does. Newton's theory was therefore wrong. However, that doesn't mean that gravity doesn't exist, only that Newton was missing some rather important properties of gravity (such as the fact that its effects propagate at the speed of light rather than instantaneously) which Einstein added to formulate GR. It is likely that either General Relativity or Quantum Mechanics will eventually be replaced, not with something completely new, but with a slightly different formulation of basically the same theory that is more accurate to reality. The level of precision that each theory achieves at predicting reality means that it is exceedingly unlikely that either is simply wrong and must be chucked out in its entirety.
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Regarding a dog becoming a non-dog: Let's use the definition of species that states two populations are separate species when they cannot interbreed. To simplify things, we'll use individual dogs that represent ideal members of their populations because narratively I think it's easier to wrap your mind around individuals than populations. Each dog referenced in this example will be considered capable of reproducing with any healthy member of their concurrent population, and anything a member of their population can successfully reproduce with, they can, too. Basically, every dog will be representative of a whole generation of dogs. So, we start with Fido. Fido will be our original generation. Fido has a puppy named Fido 2, who is a lot like Fido, but not exactly since children are never exactly like their parents. Many generations pass, various small genetic mutations build up in the population, and eventually Fido 10,000 would no longer be capable of breeding with Fido if he were still alive. Well, they must be separate species! But wait, Fido 10,000 is the first dog incapable of reproducing with Fido because of genetic incompatibility. That means that Fido 9,999 could still have viable children with Fido, so Fido 9,999 must still be a dog. Hey, hold on, Fido 10,000 is almost exactly like Fido 9,999. They wouldn't have any trouble reproducing. If Fido 9,999 is a dog, and Fido 10,000 can reproduce with Fido 9,999, then they must be the same species and Fido 10,000 must still be a dog. So we move on to Fido 20,000. Fido 20,000 is the first to be incapable of reproducing with Fido 10,000. Finally, we have something that isn't a dog! Or wait, Fido 19,999 was still capable of reproducing with Fido 10,000, and since we determined that since Fido 10,000 could still reproduce with a dog, he must also be a dog, and therefore Fido 19,999 is a dog as well. Fido 20,000 is very similar to Fido 19,999, so Fido 20,000 must be a dog, too! I could keep chaining it like this all the way to Fido 100,000,000, which looks absolutely nothing like anything we'd think of as a dog and would be completely incapable of reproducing with one. There is no actually point where an animal gives birth to a different species. They sort of bleed into each other and we make up arbitrary demarcation points to make it easier to classify things. After all, since we can trace ancestry back pretty far, we could use the chaining method I described to claim all animals are the same species because they'd be capable of mating with some ancestor that could mate with some ancestor that could mate with some ancestor, etc until all the chains converged to one population of proto-animals. It's an interesting thought experiment but it also renders us incapable of categorizing the diversity of life as it currently exists. The important point to take away from this is that species don't really exist in nature. The more "real" way of grouping things from an evolutionary perspective is by population, which is a group of individuals capable of interbreeding. Dogs now, and dogs 100 years ago are defined as being members of the same species, but they are not members of the same population, because dogs that are currently alive are incapable of breeding with dogs 100 years ago. We find it useul to categorize them all as dogs because it would be rather ridiculous to have to come up with a new name for things every generation, but in terms of evolution, once something is dead, it's pretty much irrelevant and can't be counted as a part of anything. So Fido 10,000 may or may not make the cutoff for being of the same species as Fido based on where someone wants to draw the line, but they aren't part of the same population so it doesn't matter whether you categorize Fido or Fido 10,000 or both or neither as being a dog. Dog is not an objectively real category. The only categories that evolution actually concerns itself with are alleles, individuals and populations. Dog is a label that can be applied to individuals or populations, but there is no individual or population that encompasses all dogs. If you want to talk about the effect of evolution on a dog, you have to specify an individual or population that you are applying the label to, and you cannot conflate the properties of the two just because they share a label. A good rule of thumb is that each category is capable of producing a separate entity at the same level of itself, but not higher. An allele can be replicated to create a distinct copy of the allele, it cannot create a whole new individual by itself. An individual can reproduce and produce a distinct individual, but it cannot create a whole new population by itself. A population can give rise to a distinct population separated from the original by space or time. When saying that a dog gives birth to a non-dog, you would be describing a population level occurrence happening on the level of the individual, which doesn't happen, but which people have trouble with sometimes because we are so used to thinking of dogs as all being one "kind" of thing even though they really aren't.
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A guy sitting on earth watches a spaceship that he sees as moving at close to c. On the spaceship is a pendulum with a period of one second while at rest. The guy on Earth sees the pendulum move in slow motion. On the spaceship, a guy sees the Earth moving away at close to see. On the Earth is a pendulum with a period of one second while at rest. The guy on the spaceship sees the pendulum move in slow motion. Now, for relativity not to hold as you are claiming, one of these guys would have to have a way to determine that he is the one that is really moving and experiencing slow motion. If you can outline a method by which one would be able to detect time dilation, and therefore motion, in their own frame of reference, that would be the way to support your position. Even the most basic method of being able to tell that you are the one who is really moving in "slow motion" would suffice, with the caveat that you must be able to tell without changing your reference frame (that I'd, changing speed or direction).
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Just so we're clear, why do you think these scenarios would kill a biological system? It's very likely that one or both of us is not fully understanding what the other is trying to say.
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Biological time is relative. There is no difference between the matter in a biological system and the matter in a clock except for the pattern it is configured in. That pattern doesn't, in any way, change its relationship with time. Alright, let's say there is an astronaut in his spaceship heading back to Earth from an interstellar mission at a significant percentage of the speed of light. He receives a message from Earth, and, being the intelligent astronaut that he is, works out how long ago they must have sent it to reach him that far away. A few years later, his ship approaches Earth. Now, there are two scenarios: In the first one, the astronaut lands on Earth and thanks them for the message they sent him five years ago. In response, Earth tells him, "Five years ago? Why, we sent that a decade ago!" In the second one, the astronaut passes by Earth without slowing down, but Earth sends up a representative to hitch a ride on the spaceship as it goes on to the next mission. The astronaut tells his new crewmate how much he appreciated the message they sent him five years ago. In response, the man says, "Five years? Why, it's barely been half that time!" From the FOR of Earth, the ship has been experiencing time at a slower rate. From the point of view of the ship, Earth has experienced time at a slower rate. In the Twin Paradox, the twin in the spaceship isn't younger because he was travelling at lightspeed. He is younger because he synched back up with Earth's frame of reference, and in Earth's frame of reference, he was traveling at (well, close to) lightspeed..
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How did evolution get it right?
Delta1212 replied to callmeclean's topic in Evolution, Morphology and Exobiology
Re: placement of light sensitive cells Let's say that you have a hypothetical organism that's sort of like a blind frog. Over the course of a million years, one thousand of these frogs develop a mutation for light sensitive cells, all in random places. Some get them on the roof of their mouth. Some get them on the bottoms of their feet. Some get them on top of their head. The ones with light sensitive cells on the top of their heads are able to tell day from night as well as things like the shadows of birds passing overhead. This helps them avoid predators, so more of them survive. The ones with light sensitive cells on the bottoms of their feet receive no useful information from them and may even have the cells interfere with things like tactile sensation that are important on feet. The population of frogs with "eyes" on the tops of their heads explodes while those with "eyes" elsewhere does not because they either do not help or actively harm the frogs chances of survival. Generations down the line, all of the frogs "somehow" have the mutation in the right place for it to help the most. Looking at things now and marveling at the way all of the mutations had to be just right to build on each other and reach that point is a bit like marveling at a how someone could come up with the design for something that works as well as the stealth bomber because you can't see the numerous prototypes thatdudn't work or, going back even further, the hundreds of planes with ten rows of cloth wing or flapping helicopter blades that cropped up before a basic design to achieve flight was arrived at. To get that one mutation that happens to work just the right way in just the right spot, you need to go through thousands or even hundreds of thousands of similar but ultimately very unhelpful mutations. In the end, the "wrong" mutations all die out or become very small subsets of the population while the "right" ones multiply because they help their "host" survive and reproduce. Then the next round of mutations will be working from that base. Before we got fish with fins that were good at moving around on land, we would have had fish that had no fins, fish with fins growing out of their faces, fish with extremely thin and weak fins... They all died and the fish with the fins most helpful for moving around on land survived to reproduce. That exact same mutation may have, and probably did, show up in places where the population of fish-things did not frequently get exposed to the land. In that context, it wouldn't be a miraculous mutation that will help lead to life on land. It's a birth defect that leads to a slightly awkward swimmer who gets bred out of the gene pool because it isn't useful. The environment does not help cause mutations that will be helpful for surviving that environment. It simply kills off all the ones that don't so only the useful mutations get sustained into the next generation. Edit: Actually, the reference to genetic algorithms is a good one. One of my very first programming projects was an evolution sim. I made little circles that I assigned a set of traits to in its "DNA" and allowed to make copies of itself when it reached a certain energy threshold obtained by eating food. These traits included color, size, whether they ate the little green food pellets I generated on screen or other "animal" circles, sensors that detect colors and reactions that are triggered by these sensors firing which include changing speed and direction (either moving toward the detected object, away from it, or ignoring it). All of these traits had a random probability of "mutating" when a circle replicated and being replaced with a different value. The first circle was just a little black circle that would move in a straight line randomly bumping into food pellets. After many generations, though, I'd wind up with a variety of different survival strategies. For example, a particularly successful one that crops up sometimes is a circle that will move very slowly (to conserve energy) until something activates one of its sensors. If it is the color of food, it moves very quickly towards it. Otherwise, it moves very quickly away from it. It seems a little magical when you do something like this for yourself and see emergent behavior that you didn't program arise, but it also helps you recognize that, if you pay enough attention to catch them before they disappear, you'll see plenty of circles that run away from food or directly at predators, just one or two values off of a far more successful version. It's not magic that creates the cool ones. It's just a lot of trial and error and very quickly chucking the designs that don't work in favor of those that do.