drosophila

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[–] [email protected] 3 points 2 months ago* (last edited 2 months ago) (2 children)

While things like merging movements and so on is part of the story, it's not the whole story.

You see, by saying "traffic jams are caused by merging mistakes and so on" it kinda implies that if everyone drove perfectly a highway lane could carry infinitely many cars. In actually a highway lane has a finite capacity determined by the length of the vehicles traveling on it, the length of the gap between them (indirectly determined by how fast they can start and stop), and the speed they're moving.

There are finite limits for gap widths and speed determined by physics and geometry. As the system approaches these limits it becomes less and less able to deal with small disruptions. In other words, as more cars move on a freeway a traffic jam becomes more and more likely. The small disruption which is perceived as the cause was really just the nucleation point for a phase change that the system was already poised to transition through. If it wasn't that event then something else would trigger it.

It is interesting to note that once a highway has transitioned from smooth flow to traffic jam its capacity is massively reduced, which you can see in the graphs in the above link. Another interesting thing to note is that the speed vs volume graph, if you flip it upside down, resembles a cost / demand curve from economics, where volume is the demand and time spent commuting (the inverse of speed) is cost. If you do this you see something quite odd, which is that the curve curls up around itself and goes backwards.

This is less like a normal economic situation (the more people use a resource the more they have to pay, the less people use it the less they have to pay) and more like a massively multiplayer version of the prisoner's dilemma. For awhile the cost increases only slightly with growing demand, until a certain threshold where each additional actor making a transaction has a chance to massively increase the cost for everyone, even if consumption is reduced. Actors can choose to voluntarily pay a higher time cost (wait before getting on the freeway) to avoid this, but again, it's the prisoners dilemma. People can just go, trigger a traffic jam anyway, and you'll still have to sit through it + all the time you waited trying to prevent it.

Self driving cars are often described as a way to eliminate traffic jams, but they don't change this fundamental property of how roadways work. It's true that capacity could potentially be increased somewhat by decreasing the gap between cars, since machines have faster reflexes than humans (though I'm skeptical of how much the gap can really be decreased; is every car going to weigh the same at all times? Is every car going to have tires and brakes in identical conditions? Is the condition of the asphalt going to be identical at all times and across every part of the roadway? All of these things imply a great deal of variability in stopping distance, which implies a wide safety gap.), but the prisoner's dilemma problem remains. The biggest thing that self driving cars could actually do to alleviate traffic jams would be to not enter a highway until traffic volumes were at a safe level. This can also be accomplished with a traffic volume sensor and a stop light on highway on-ramps.

Of course trains, on top of having a way higher capacity than a highway lane, don't suffer from any of this prisoner's dilemma stuff. If a train car is full and you have to wait for the next one that's equivalent to being stopped at a highway on ramp. People can't force their way into a train and make it run slower for everyone (well, unless they do something really crazy like stand in the door and stop the train from leaving).

[–] [email protected] 2 points 2 months ago

No better than what?

[–] [email protected] 2 points 2 months ago* (last edited 2 months ago) (1 children)

CRI is defined as how closely a light source matches the spectral emission of a thing glowing at a specific temperature. So, for a light source with a 4000 k color temperature its CRI describes how closely its emission matches that of an object that's been heated to 4000 k.

Because incandescent bulbs emit light by heating a filament by definition they will have 100 CRI and its impossible to get any better than that. But the emission curve of incandescent lights doesn't actually resemble that of sunlight at all (sorry for the reddit link). The sun is much hotter than any incandescent bulb and it's light is filtered by our atmosphere, resulting in a much flatter more gently sloping emission curve vs the incandescent curve which is extremely lopsided towards the red.

As you can see in the above link, there are certain high end LED bulbs that do a much better job replicating noon day sunlight than incandescents. And that flatter emissions profile probably provides better color rendering (in terms of being able to distinguish one color from another) than the incandescent ramp.

Now, whether or not you want your bulbs to look like the noon day sun is another matter. Maybe you don't want to disrupt your sleep schedule and you'd much rather their emissions resemble the sunset or a campfire (though in that case many halogen and high output incandescent lamps don't do a great job either). Or maybe you're trying to treat seasonal depression and extra sunlight is exactly what you want. But in any case I think CRI isn't a very useful unit (another reddit link).

[–] [email protected] 3 points 2 months ago* (last edited 2 months ago)

One apple (223 g) is supposed to be 116 calories.

[–] [email protected] 21 points 3 months ago* (last edited 3 months ago) (1 children)

There is already a Chinese EV that uses a sodium ion battery, the JMEV EV3.

It's a tradeoff of range vs price. The EV3 only has 155 miles of range, but thanks in part to its sodium ion battery it costs only $9220 new. Which is a price that will probably drop even more as more sodium ion plants come online and economies of scale kick in.

EDIT: even if your commute is 40 minutes long, driving 60 MPH the entire way, that range is enough to get you to work and back using a little more than half your charge. Given that it's also generally cheaper to charge an EV than pump gas, and there's less maintenance costs, I think there's absolutely a market for such a car.

[–] [email protected] 1 points 3 months ago

lol, because that's definitely the shut-in stereotype.

"Honey I'm really worried about our son, not only has he not left the house for weeks, this morning I found a bag of coffee beans in his room that was produced by a worker owned coop in Honduras!"

[–] [email protected] 10 points 3 months ago* (last edited 3 months ago)

Trying to create a cheap microwave burrito that's also healthy and filling seems like a pretty noble (if difficult) goal to me. Making it vegetarian also decreases its ecological impact (though I don't know whether or not Adams cared about that).

Trying to fortify each burrito with 100% of your daily vitamins was a really stupid idea though. It was unnecessary (just take a multivitamin if you feel like you need it), it made the burrito taste worse (Adams described it as "chalky"), and it was potentially unhealthy if someone were to eat multiple burritos per day (and thus receive multiple times the recommended daily dose of... everything).

[–] [email protected] 2 points 3 months ago

An arch user defines "doesn’t break all the time" as "I have to read the news before every update and apply a manual intervention a few times a year, and there's only been like one time in history that an update made people's installs unbootable despite them taking those precautions".

A Debian user defines "doesn’t break all the time" as "I have a cron job running that periodically runs sudo apt update. I have no idea when it does this or what's changing when it happens and nothing bad has ever happened to me".

Like, the fact that unattended-upgrades comes pre-installed and enabled by default (for security updates) in Debian GNOME vs the fact that informant exists to force you to read the news in Arch before you update should tell you that the two distros exist in two different universes.

[–] [email protected] 11 points 3 months ago* (last edited 3 months ago)

93.9% of new cars sold in Norway are EVs, a further 5% are hybrids.

I don't know what that translates to in terms of cars currently on the road though. But that's also stats for the whole country. You can imagine in a relatively affluent area where there are mostly new cars the vast majority of them are probably EVs.

[–] [email protected] 16 points 3 months ago* (last edited 3 months ago) (2 children)

I think you might be underestimating the intensity of some people's interests and how much of their being is defined by them, especially non-neurotypical people.

EDIT: Like, if you live in a van with solar panels on the roof you should probably find a partner that's also cool living inside a van.

If you spend a significant stints at home wearing a fursuit, you should probably find a partner that enjoys or at least doesn't mind living with what looks like an anthropomorphic furry creature.

If you regularly consume large doses of halcinogens to explore the limits of human consciousness you should probably find a partner that's doesn't mind hearing about how you saw an infinite blade made of time that slices the present moment into two parts: the past and the future.

[–] [email protected] 6 points 3 months ago

That's the entire rest of the world my dude.

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