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Cake day: June 22nd, 2023

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  • Necessity is the mother of invention. One day somebody was just that hungry, a cassava plant was available, experimentation ensues, bam staple crop. It’s not that huge of a leap though. Most societies have some kind of root or tuber food, and once you’ve got the idea that roots and tubers can be food it’s not a huge stretch to go looking for others. Pretty much all of them have to be cooked at least to be edible and palatable.


  • I’ve found the free one can sometimes answer tip of my tongue questions but yeah anything even remotely obscure it will just lie and say that doesn’t exist, especially if you stray a little too close to the puritanical guard rails. One time I was going down a rabbit hole researching human sex organ variations and it flat out told me the people in South America who grow a penis at 12 don’t exist until I found the name guevedoces on my own, and wouldn’t you know it then it knew what I was talking about.


  • No momentum at all relative to what? Relativity tells us that there is no fixed frame of reference. In practice what that means is there is no universal zero velocity. You only have velocity relative to other things. The implicit assumption in your argument is that you would have no momentum relative to the earth, which in itself is problematic. After all, the earth spins at a rate of 360 degrees per day, so not moving relative to the earth would mean moving 463.83 m/s relative to the surface of the earth at the equator, which is supersonic. But maybe you mean relative to the surface of the earth. What if you go to the moon? Or mars? Or into orbit? Maybe you mean relative to the nearest big thing. If you could somehow teleport from the ground into a plane, would the plane count as the nearest big thing? What about a bus? That’s on the ground, so maybe the nearest big thing would be the ground, if the mass of the thing matters in how the nearest big thing is determined. You can see how this can quickly turn into a mess of rules and special cases.


  • We can make some estimates for what would happen. The specific enthalpy (basically energy per kilogram) of air, modeled as a diatomic ideal gas, would be 7/2RsT, where Rs is the specific gas constant of air and T is the temperature. The specific gas constant of air is 287.05 J/(kg K), so at 293.15 Kelvin (20 C, ~70 F) the air would have 294kJ per kilogram. An average human displaces about 0.06522 cubic meters (65.22 Liters, 17.2 gallons), and air at standard conditions has a density of 1.20 kg/m^3, meaning you displace about 0.078 kg. This means an average person teleporting would create an energy difference of about 23kJ between the vacuum they leave behind and the surrounding air. That’s as much energy as a 1kg mass moving at 214 m/s (478 mph, 770 kph) or about Mach 0.62 at sea level, or a 1000 kg mass moving at 6.78 m/s (15 mph, 24.4 kph). So imagine getting crushed against a wall by Grandma driving a small sedan at a human running speed, except the wall doesn’t take any of it. That is also a bit more energy than a .50 BMG bullet, which apparently is used to shoot down helicopters.

    If you teleport really close to your starting position, we can assume the total energy would be doubled. Also consider that this analysis is conservative. The faster the teleportation happens the more energy you’re going to release. This only accounted for the energy of the air itself, not the kinetic energy of all the air that would rush in to fill the vacuum, or the energy you add to the air when you pop back in, which could be significantly more if you pop back in really fast. So it could be quite a bit of energy. I always imagined that a superhero or villain that could teleport would need some kind of force field just to survive the process, and that they could develop their ability to teleport faster to use it as a weapon, or teleport slower for stealth and not destroying their destination. Looking back at Jumper the amount of damage they do when they teleport is pretty minor, considering the math. The energy released would only grow if you could take stuff with you.




  • applebusch@lemmy.worldtoLemmy Shitpost@lemmy.worldChoose wisely!
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    1 year ago

    I agree with your choices but your logic for the teleportation doesn’t hold up. You’ve assumed your momentum wouldn’t be conserved through the teleportation in a weird way. Assuming momentum is conserved, you would still fall just as quickly. In fact, you would reach terminal velocity in short order, and would have to continually teleport to keep yourself from crashing into the ground. By itself that would be bad enough, but you moving through the air between teleports would cause the air to move as well, so assuming you could keep up and hold your elevation, your velocity relative to the ground would increase to some number higher than terminal velocity. Think Chell continually falling through portals. Now you’re stuck unless you can also teleport slightly to the side without falling. Best case you go to one of those indoor skydiving places and get in so you can slow down without dying. I was going to explore what would happen if your momentum somehow wasn’t conserved, but that would imply some absolute fixed frame of reference or magical mumbo jumbo, neither of which exist.

    You could totally travel faster though, without even needing to walk. You would also be super dangerous in one on one combat sports. A well placed 7 inch teleportation can easily get the win in the right sports.


  • Meteorology is really hard, but comparing it to politics and economics is false equivalence. Meteorology is governed by well proven mathematical models, and we can use them to make predictions. The problem is that the earth is really big, so we just don’t have computers powerful enough to simulate it finely enough. Add to that it’s a chaotic system and it becomes difficult to predict accurately very far into the future. Weather predictions have actually improved dramatically the last few decades, and I expect they will continue to do so along with advances in computing. Economics and politics may as well be random guessing, but is often worse than random guessing, because we have no reliable proven model for human behavior.