Bluesky is a different protocol than Mastodon, but conceptually I think it's fair to say they're similar.
I think Bluesky would clean up if it could also interop with Mastodon - people want to leave Twitter but it sucks having to choose between Mastodon and Bluesky and so I think some folks are just in a holding pattern waiting to see what wins. Bluesky feels more like Twitter so I think it would get a lot of folks, but I think people hesitate to bet on it just yet.
Bluesky has a 300 character limit, Mastodon has 500, non-Mastodon ActivityPub servers have a configurable limit. Mastodon can render markdown, has subject lines which are commonly used as content warning tags, can translate posts. It supports custom emoji and non-Mastodon ActivityPub servers support custom emoji reactions. Bluesky has more discovery features like community-curated lists and algorithmic suggestions of who to follow.
Partially true, but vanilla Mastodon does hardcode it at 500. Some forks make it configurable (I believe glitch-soc does), and some admins have edited the hardcoded value manually.
Mastodon features a more complex content filtering based on keywords [1],[2] and you can always try to pick instance that fits your needs. Hashtag support is here since beginning if I'm not mistaken. Bluesky has a rather simplified filtering [3], [4] that most likely will be appealing to mass users, tho since service revolves around customized multiple feeds they shouldn't in theory see and interact with the content they don't like in the first place [5]. There's no hashtag support so far - which seems odd because this is a pretty much standard feature on social networks.
I do think it's interesting that recent submissions use nearly the entire 50 hours. I wonder how much better people could do if faster hardware was allowed.
Absolutely they could. All the entries so far can do even better with more RAM. That PAQ entries have command line flags to do this. That's already known in fact.
What this is looking for is fundamental improvements, not "i brute forced a known way to win this competition".
I wonder how long it will take for plastics to become biodegradable. Sort of like how wood was around for millions of years before microorganisms could break it down, maybe the landfills of today will create the equivalent of coal deposits millions of years from now.
Yes exactly. I've had this page up in a browser for many years, most of the time with only two other people. I have no idea who they are, no way to communicate with them, but feel very connected in a strange way.
OMG, you! I just guffawed in real life at my desk here. I mentioned in another comment here[0] how I've checked off and on through the years and wondered who could possibly be keeping this page open and why. Thanks for re-posting this, it's too funny to hear from one of you guys.
SO this totally popped into my brain - there was a PHP script you could add to your site called Crisc - https://web.archive.org/web/20021010104130/http://biomatic.o...
It showed your IP and you could send a message to the other visitors on the site - I was blown away at the time I saw this.
I don't know everything about nuclear fusion so I have to ask: Is it actually renewable?
In other words, are the byproducts able to form back into the "fuel" at a reasonable rate with the energy input of the Sun? I know that a selling point of fusion is that there is such an abundance of fuel that this doesn't matter. But if we treat finite energy sources as infinite, exponential growth in our energy budget means that we will undoubtedly run out of energy, as is being done with forests and such.
After all, I have a feeling people at the dawn of the industrial revolution thought the amount of coal available in the world would serve their needs "practically forever," until energy consumption scaled up by thousands of times.
So, the fusion we are talking about here is deuterium - tritium fusion as it should be the easiest to achieve. Deuterium is not a problem. A rough estimate says that there's enough of the stuff to cover 100% of the world needs for thousands of years. And it's easy to breed: surround the reactor with water so the hydrogen there can capture the stray neutrons.
Tritium, on the other hand, is a problem. It is radioactive with a half life of ~12 years and so the little we have needs to be produced since we can't really accumulate it. Currently it is produced by conventional nuclear reactors. Additionally, breeding tritium is harder than deuterium and requires a blanket around the reactor that uses other materials to multiply the number of stray neutrons. For each atom of Tritium that is fused we could get somewhere between 1.1 to 1.7 with a theoretical maximum of 2 Tritium atoms so, finally answering your question, it is renewable. It's just hard, but a piece of cake compared to actually maintaining a stable fusion.
I don't see it as intractable. We already have two ways to do that at scale. One is proven (the fission reactors), the other one is proven but not in an actual fusion reactor yet. Iter will have such a blanket for tritium breeding.
Intractable in my mind sounds more like something that you don't know how to even start.
Ultimately, no method of energy generation is truly renewable, including solar. The Sun will run out of fuel in five billion years, after all, give or take.
However, for all practical intents and purposes, solar energy is renewable. The same holds true for nuclear fusion for at least a couple of hundred years, even considering growing energy consumption.
Deuterium fuel is the most abundant. There's enough in your morning shower to supply all your energy needs for a year. There's enough in the oceans to last for billions of years. Fusion is as close to renewable as anything, because it'll last until the sun goes out.
Right now most projects are also using tritium fuel, which has to be made from lithium. That's plenty abundant but not to the extreme of deuterium. But pure deuterium fusion is possible, just a little harder. And one prominent fusion startup, Helion, is actually using deuterium (along with helium-3, which is the waste product of deuterium fusion).
By the point we've fused significant portion of Earths hydrogen, it will really not be a problem to hop over to Jupiter for some more. The scales are insane. Energy input of the Sun ALSO isn't renewable if you think like this.
People talking about fusion expect to "breed" tritium in their reactor. This takes the form of blasting GW of hot neutrons into a thousand (or ten-) tons of lithium hydroxide, and somehow extracting grams of tritium from it at parts-per-billion concentration.
There is no choice about that: it is the only way to get enough tritium to keep operating.
(As you pointed out before, elemental liquid Li or Pb would interfere with magnetic containment. LiH is an example of a diamagnetic Li-rich material resistant to radioactivation (other than the desired 3H). We need a great deal of Li in the neutron-absorbing blanket to breed tritium fuel.)
1000 tons of lithium deuteride (half 6Li, half 7Li, all 2H) would cost ~$2B for the deuterium, plus a smallish fraction of that for the 6Li-enriched lithium. Any deuterium that picks up a neutron would become tritium, adding to what is got by fooling with the lithium. Maybe you economize with half-H, half-2H, for only ~$1B.
You have many reasons not to let your LiH catch fire, beyond that it cost you $1-2B and would totally destroy your $50B reactor and be deucedly hard to put out. It burns in air to LiOH, Li3N and H2, and reacts with any water, CO2, or nitrogen you might have hoped would douse it. Li3N further reacts with the hydrogen making lithium amide LiNH2, thence various unpleasant peroxides.
Regular LiH is solid at a more-familiar operating temperature under 400C, and liquid at what might thought an extreme 700C. The deuterides would raise the melting point some. You really want something in there to scavenge any metallic lithium, if molten, because that corrodes steel and silica.
The second sentence is a good reason NOT to use hydrogen in your breeding material, since if you do you have to separate the tritium from it, and do it very rapidly.
Not getting this. I understand you have to get it out fast because you need it for fuel tomorrow. Is it that you don't want your bred tritium floating in a sea of regular hydrogen, needing separation by physical rather than chemical means?
It's a totally avoidable problem, though. Also, you really want to recycle tritium back into the reactor really quickly (like, within hours, if possible) or else closing the tritium breeding loop becomes more difficult.
Wow, that slide deck makes fusion look even worse that I had thought.
"40 years away and increasing" is an eye-opening admission. They have no plan for how to produce more tritium than they consume, never mind any way to collect it. And they don't expect to have access to enough tritium to even start operations on the successor to ITER.
Another startling omission is that Tokamak and stellarator designs are unsuitable for a production reactor, and there are no alternatives under consideration.
Finally, they have not identified a structural material that will stand up to the neutron bombardment and continue to hold the reactor together.
It makes the fusion startup companies look even more like out-and-out scams.
The traditional way to play melee is local multiplayer only, so players most players are used to the incredibly fast response of a CRT. This and the muscle memory required to play at a high level makes LCD monitors (and especially TV's) noticeable.
I have always wondered, is heat->steam->turbine->generator efficient? In my mind it just doesn't seem like it would be efficient at all. Surely there must be other ways to convert heat to electricity (Thermoelectric effect?), but why do we still use steam?
The thermal efficiency of turbines can approach 90%, which is far and away better than any other method we have. Turning energy into heat is usually not a problem.
And in a lot of cases extra heat can be put to use beyond electricity production. Steam heat and cooling is a thing for large metropolitan areas, and it can also be used for desalination water. A few Soviet nuclear plants were designed to provide both electricity and water, actually.
Peltiers and other thermoelectric generation is really really inefficient compared to basically any other energy capture method. They're about 5-15% max that we know how to make currently. Basically they only get used for things like RTGs where you need a zero maintenance very long lasting electric source; in the US that's mostly been spacecraft but in the USSR they were used for extremely remote lighthouses around the Arctic Circle where solar was impractical and resupply (and maintenance) of a diesel generator was prohibitively expensive.
Any engine is limited to the carnot cycle; the themoelectric effect still requires a cool side and heat gets conducted along the two leads to equalize the temperature. That's where the power comes from, the temperature differential across the thermocouple wires, and you consume the temperature differential when you generate electricity.
Different types of engines have different details of where that energy gets lost, but ultimately they are devices that if left to run indefinitely would equilibrate in some way and the way that they idle tells you a fair bit about where the energy flows are.
Turbines are pretty impressively efficient, but something can always be better. They often utilize the low grade waste heat in steam heating though, so a lot of times the efficiency is extremely good when you include free heating or process heat (in a plant they might use that steam to heat another piece of equipment).
Current thermoelectric tech has very low efficiencies. It's an active area of research where any small improvement could be significant. It would be an ideal way to produce power more or less directly from thermal neutron bombardment, IF a method / material can be found that can make direct thermoelectric conversion efficient enough to compete with a water or molten salt heat exchanger loop.
It hits the sweet spot on fiscal, engineering, safety, and science fronts. Energy extraction is very challenging, we're likely hundreds of years away from aneutronic fusion, for example. The research area you are asking about is direct energy conversion, of which aneutronic fusion is one small branch (though within it, there are many scientific and engineering branches to explore).
I think I may have said this before, but a statement like "we're likely hundreds of years away from aneutronic fusion" seems to me necessarily meaningless.
We're only a bit over a hundred years from developing quantum mechanics and relativity, how can we possibly say anything about hundreds of years from now?
If something is well enough understood to accurately predict the timeline, we could do it much sooner.
If we have no idea how to do something, then "hundreds of years" means nothing, except maybe "not proven impossible yet".
For me, Wikipedia was my first realization that RTL webpages exist. If you switch to an Arabic or Hebrew article you'll see what I mean. Even the Wikipedia globe graphic goes to the top right instead of the top left.
I don't know any of the languages so I don't know if the problems presented here apply to Wikipedia but it's a cool demonstration regardless.
I think its cool TI has added Python support to their graphing calculators, but let's not forget the fact that they've removed assembly program support. I think its a great shame.
Just recently some folks managed to make an LLVM backend for the eZ80 processors in the TI-84 Plus CE [0], and I was able to create a snake game in C that I could send to my high school friends [1]. I don't know of any examples, but C++ and Rust should be possible in theory too. It seemed like the possibilities were endless with such powerful compiled languages being available to these calculators, but I guess TI had other ideas in mind. At the very least, those of us who haven't updated our calculators' OS will still have assembly support available.
I remember making super slow programs in BASIC and then learning assembler language with my friends to make faster programs. A shame that children nowadays won't have that opportunity.
Today's BASIC is JavaScript. It provides relatively easy access to many things a computer can do — like BASIC did. However, the JS execution engines are highly optimized, and even my phone is a supercomputer compared to the machines that ran the BASIC of yore. It stands to reason that it will take the average newbie much longer to question whether JS is the right language.
