Recent comments in /f/explainlikeimfive

dmootzler t1_iy9azry wrote

Ahh I think you misunderstood my original question. I wasn’t asking about how user-specified seeds are handled.

What I meant was, when I mine/build/craft, altering the state of the world, how is that new world state persisted (since the results of my actions would not be present in the procedurally generated chunk)?

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Gnonthgol t1_iy9ain5 wrote

The electrical resistance of various metals varies with temperature. This is how electrical thermometers work and in fact how many heaters are self regulating. For copper the colder it is the less resistance there is. Until you get to a point at extremely cold temperatures where the resistance is zero. So you can send a current through the wire and there is nothing in the wire stopping it. It does still build up a magnetic field which stores the energy and can be used for various other things but you can maintain this magnetic field using very little power.

Of course this is not the entire truth, they do not make the magnets superconducting to save on the power bill. The problem is that any energy that is lost to electrical resistance gets turned into heat. And with the amount of current they need for the huge magnetic fields they need the amount of heat generated by any resistance is enough to melt the copper conductors. The Large Hadron Collider did this during an accident, called the quench incident. It was caused by a bad connector between the magnets which had a tiny bit of resistance. This caused the entire thing to explode in huge ball of green and blue sparks. Green was the vaporized copper and blue was the helium plasma. There are no footage of the fireball but there are images of the aftermath. So best keep those magnets cold and superconducting.

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left_lane_camper t1_iy99xw4 wrote

Usually batteries are used for this, as they can store far more energy and if they're big enough, their maximum power is also large enough for quick charge/discharge. This means that an ultracapacitor isn't necessary for power density reasons and the battery is better for energy density reasons.

For example, a number of electric cars are already traction-limited for acceleration and capable of driving two to three times any finite speed limit they encounter, while still having a 300-400 mile range at full charge.

Conversely, late-generation Honda Insights use a small, but high efficiency motor that is used mostly to charge a battery. It turns on, runs at max efficiency charging the battery, then turns off when the battery has enough charge. The battery provides electric traction and is capable of both load-leveling (since the motor is providing more power than is usually necessary for driving at any given moment) and is capable of providing more power than the motor is in short bursts! This drivetrain is not entirely dissimilar from a diesel-electric train.

Due to ultracapacitor's low energy density, they are only good where you need extremely high power densities (higher than are generally needed by modern electric vehicles) or extremely high charge/discharge cycles. So they've been examined for public transit purposes (where they might not even be carried by the vehicle itself, but rather be installed in a fixed location and connected to the vehicle by rail or overhead lines), but they don't really make sense for cars and trucks.

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Sing_larity t1_iy97nuc wrote

Even if not a single kid had died as a result of the inaction, which
they did, it would still be indefensible cowardice. Because the cops
wouldn't have known that at the time. Even if no kids HAD died as a
result, that doesn't change the fact that the cops pussying out put the
lives of children at risk.

​

And Cody's Video does in fact mention kids dying en route to hospital. Which was AFTER the cops arrived.

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Ippus_21 t1_iy95mrr wrote

Because a lot of the symptoms of common viral and bacterial illnesses are not caused by the infection, they're caused by our immune system ramping up to fight the infection. Many of them even serve a constructive purpose, or are side effects of stuff that serves a constructive purpose. Examples:

  • Fever - turning up the thermostat can inhibit reproduction in some pathogens
  • Congestion - increased mucus production protects mucus membranes in the respiratory tract and transports debris (dead cells, mostly) away from the respiratory tract faster. Sore throat is mostly a side effect of mucus draining down the back of your throat (into your esophagus, and the extra mucus in the stomach can cause upset stomach, or at least diminished appetite).
  • Fatigue and body aches - A Defcon-1 immune system is energy-intensive. You're tired because you're spending that energy, but also because the fatigue signals conscious you to stop doing stuff and go rest so your body can spend its energy fighting the infection.
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x1uo3yd t1_iy953n2 wrote

There main reason is History.

Scientific research didn't begin in the era of the internet. Back in the olden days scientists basically just wrote letters to each other bragging up their latest discoveries. As the number of scientists grew, everyone writing letters to everyone else became too much work, so some folks decided to create a kind of magazine where scientists could write up their discoveries once-and-for-all to get word out to all of the magazine's readers at once, and the idea of the academic journal was born.

Like any good magazine, there were editors-in-chief who decided whether to accept or deny submissions based on if the article was sufficiently on-topic for their magazine's audience and whether the article was sufficiently cool to their audience. So some of those magazines became more famous as reliably having the best and coolest stuff in their respective fields.

Also, because it would cost a fair amount of money to type up all of these submissions, bind them together nicely into a booklet, and distribute them out to the subscribers, this was not done as a free service but rather - like most any other kind of magazine - it was done as a for-profit business.

The system wasn't perfect, but at the very least it was financially sustainable enough (for most of the best journals) to survive to the present day.


In modern times, the internet offers a multitude of ways to disseminate these same sorts of scientific write-ups to vastly more people at drastically lower costs (compared to oldschool paper-based printing and publishing). However, the historical system still has significant momentum due to the best journals still have the biggest audiences and a fair amount of prestige. This leaves academics with a tough decision when it comes time to publish: "Do I publish in a prestigious oldschool journal behind paywalls, or do I publish in some online upstart journal that is free-to-all?".

There are trade-offs to choosing either option. By publishing in a prestigious oldschool journal you are making your work harder to access (essentially limiting it to folks with academic library access) but you also get some bragging rights and free advertising based solely on the fact that your article is published by that particular prestigious journal. On the other hand, publishing in some upstart online journal means that anyone who clicks the link can read your work... but the low notoriety is of no help in attracting people to your paper in the first place.

Ideally, the science should stand for itself regardless of which avenue it is published under, but unfortunately the people doing the science have careers to consider in order to keep doing that science in the first place. So, whether we like it or not, the upfront bragging rights from a prestigious journal publication may be more beneficial to a researcher's career than a free-to-all online journal publication (even if that would be better for the scientific community). Ultimately, this means that publishing in upstart journals is basically a luxury that only already-well-established researchers can risk.

1

Shawnaldo7575 t1_iy94q30 wrote

The symptoms you feel are caused by your body fighting the viruses. Fever is your body heating up to try to overheat and kill the virus. Vomit/Diarrhea is your body getting rid of whatever you ate via the nearest exit, mouth/butt. Snot, sneezing, etc is your sinus creating a mucus layer of protection to try and catch and remove the illness. Coughing is when that mucus makes it into your lungs.

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engin__r t1_iy94fgy wrote

Like people, cows only lactate when they have babies. The cows are artificially inseminated, typically by locking them in a cage and jabbing them in the cervix with a metal rod while the farmer’s arm is inserted into the cow’s rectum.

When the cow gives birth, the farmer takes away her calf to prevent it from drinking the milk.

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explainlikeimfive-ModTeam t1_iy944mq wrote

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1

NappingYG t1_iy93ns0 wrote

It uses electromagnets, that run insane ammount of electric current in order to generate required magnetic field. The only way to achieve it, that we currently know of, is by using superconductors - materials that allow electricity flow with very very little losses. (Electrical resistance of conductors increases with temperature) Superconductivity is achieved by cooling the material to as close to absolute zero as possible.

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just_a_pyro t1_iy93dx2 wrote

Those are not regular magnets, they're superconductive magnets. Superconductive materials need to be cold to stay superconductive, if they warm up they stop being so and this leads to electric resistance reappearing. If there is resistance in the wire you're losing a lot of electricity to heating the wire instead of producing magnetic field.

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