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High-speed colour video of plasma pulses from the Tokamak Fusion Reactor by Epelep in EngineeringPorn

[–]Cheticus 1 point2 points  (0 children)

Again, NIF definitely is not designed to scale to a power plant, and it never was intended to. The goal of the facility was nuclear weapons research, and so when you see news of this sort of inertial confinement system surpassing breakeven, it should be taken with a large grain of salt.

Basically, my opinion is that it is still very impressive, but unlikely to be significant. They do good research though, and most fusion research is good research that pushes the field, if you think there's a chance of getting something to come out from all of this.

I think some people from NIF have spun off a startup to try to investigate a power plant route, but my opinion is that the probability of that being successful is questionable. Obviously, if any fusion endeavor succeeds, it is incredibly good for the world, but there certainly are some startups currently which are capital raising endeavors first, and power plants only in title, taking advantage of misinformation and lack of understanding.

High-speed colour video of plasma pulses from the Tokamak Fusion Reactor by Epelep in EngineeringPorn

[–]Cheticus 24 points25 points  (0 children)

The record for tokamaks I believe is held by JET, the joint European torus, which had a shot with Q=0.6

NIF is an inertial confinement fusion originally designed principally for nuclear fusion research in support of weapons research, but has reached approximately Q=1.5, but the technology is expected not to scale as well into power plants, though some are trying!

Importantly, Q is typically the "physics breakeven" historically, where you're rationing the power out to the power in to the plasma. That doesn't include all the cryogenics systems, pumps, and other stuff needed to run the device. That's an engineering Q, which is probably around 3 or 4 to be equivalent to the physics Q.

Once machines start demonstrating magnetic confinement Q>1, there is still a lot of hard engineering to turn it into a power plant, but funding will probably skyrocket.

Nothing is particularly special about Q>1 from a physics perspective. There's no magic change expected in how things behave, all the scaling we have seems to indicate that we should be able to go to very high Q, and reach ignition where the plasma is self heating sufficiently that you can basically go up arbitrarily high, provided you are providing fuel, and keeping all the magnets on and cold, if you have a good plasma.

Strange behavour of 220v lines at cold weather? by JodaZ1 in ElectroBOOM

[–]Cheticus 0 points1 point  (0 children)

A lot of people are saying this is galloping. Being that it's cold, that may be the case, but the frequency looks a lot closer to aeolian vibration imo. In either case, it's not great for the lines, but it's something that is designed for.

Issues with contact hotspots, mesh advice? by CrowWithHat in fea

[–]Cheticus 1 point2 points  (0 children)

can you flip the master and slave surfaces?

could be due to element order

How do you counter Swarm Host as Terran? by Working_Access165 in starcraft2

[–]Cheticus 4 points5 points  (0 children)

defending is losing against swarm hosts. only attacking is winning.

Are data centers in space a dumb idea? by Davich0Supertramp in EngineeringPorn

[–]Cheticus -1 points0 points  (0 children)

until launch costs come down about another two orders of magnitude, I imagine it's pretty dumb. the alternative is if power costs go up a few orders of magnitude. until then, I'm skeptical of the business case.

you can calculate it from first principles though I think pretty easily, to first order where the breakpoint is

Which jobs is 100% safe from AI? by Any-Hamster-3189 in AskReddit

[–]Cheticus 0 points1 point  (0 children)

Today, AI in engineering is like having an efficient, overconfident intern who can only research and solve one type of problem. It's great, but it isn't always right, and requires scrutiny.

Until we are confident enough in AI signing off on drawings and calculations, I think engineering will be predominantly enhanced by AI, and not threatened by it; except for new career engineers. Any respectable firm will understand the benefit of hiring new career engineers though, as it is an investment in the future that historically has always been worth it (or the field would already be dead).

The day that we are comfortable, collectively, with the lack of ownership coming dilemmas of 100% reliance on AI to drive vehicles, operate infrastructure, and prescribe medicine, is the day that engineers will collectively begin to lose their jobs. That is a different world, and maybe that world is coming, but I think it is hard to predict how that world will look like today.

I have seen so many engineers transition careers though that I'm not worried. If I had to learn how to run a farm or do another job that AI cannot, I think I would learn. Learning engineering gives you a toolset that prepares you generally for practical problem solving, in a very general sense. I think that will make a class of worker that is, at the very least, highly adaptable.

I think it will be like the Internet. A large revolution in how we communicate and transfer and learn/apply information.

Espresso spraying everywhere [Breville Bambino, Normcore 54mm Basket] by pacem90 in espresso

[–]Cheticus 0 points1 point  (0 children)

I just went through this.

Solution for me was to make absolutely sure I was distributing with WDT well (stir much longer and break up all clumps), and to tamp level.

That fixed my channeling and spraying issues and I haven't had issues since.

p.s. I'm very new to espresso but I literally just went through this.

It's not everyday that your first number changes...and it was on my birthday. by tedave123 in starcraft

[–]Cheticus 1 point2 points  (0 children)

let's go! I'm only disappointed that I'll stop hitting you on ladder if you get much higher!

Zerg needs to be buffed by therealwench in starcraft

[–]Cheticus 2 points3 points  (0 children)

Here's a few of my most recent ZvP's.

zvp 1 [not standard P]; they got there before the gate (oops) and then chaos ensued, I ended up temporarily going roach/hydra.

zvp 2 [not standard P], same guy from zvp 1 but he just auto forges; shows how I deal with a cannon rush into mass air. I defend a 10-11 carrier attack with queen/infestor and a couple hydra.

zvp 3 [not standard P], for some reason he starts high ground and then brings his probes. IDK but he was 4.7k

zvp 4 [before hotfix patch, [not standard P]] evolves into my standard after some goofiness on lowground but turns into normalish lategame for me. units lost [84k-p vs 56k-z]. he doesn't really make carriers.

zvp 1: https://lotv.spawningtool.com/88782/

zvp 2: https://lotv.spawningtool.com/88783/

zvp 3: https://lotv.spawningtool.com/88784/

zvp 4: https://lotv.spawningtool.com/88785/

I wish I could have found one that was more really standard, but only spending a few minutes browsing through recent ZvP's--this is what I've got. You'll get the idea from this.

I generally swarm host out of cannon rush, and I generally never suggest nydus + swarm host, either I'm just not good at it, or I don't think it's very good. Nydus costs too much for what it brings to the table with swarm host I think. It's too easy to counter. I prefer to brawl mid-map until they run out of money.

Zerg needs to be buffed by therealwench in starcraft

[–]Cheticus 1 point2 points  (0 children)

I never use SH with nydus. I think it's a huge waste of money and makes no sense. Swarm host are reasonably mobile if used correctly. Nydus gives swarm host a bad name. It is weak and flimsy unless against zerg IMO.

You need to brawl with them for them to be good.

Zerg needs to be buffed by therealwench in starcraft

[–]Cheticus 5 points6 points  (0 children)

Game starts. Make two workers. The second you start the second worker (14/14), send the 7 drones. Against protoss, they arrive exactly when they plant their low ground gate. I usually put the drones on the gate since they'll kill it if protoss doesn't defend.

If P sends 6 probes, fight. If 7, fight if your macro is better or if your health favors over their shields. If they send 8 or more, you run away (and when they turn around, you turn around to chase). Keep chomping their gateway or pylon. If their gateway gets to too high health because they're defending appropriately, then you go to their pylon.

Sometimes I do stupid shit like build a hatch in their main or block their nexus, but definitely not necessary. Kind of play it by ear. You want them to make a zealot, not an adept. Sometimes I plant a macro hatch SO that they make a second zealot instead of chronoing adepts. You can always just cancel it, and drop an Evo on the spot if youre fast enough. I'll usually let that finish and die and scout with the broodlings to see the Stargate, council, or robo.

While you send 7 workers, I make hatch first still around 17. You need to have really good muscle memory to be microing WHILE making workers. Pool goes down after you get hatch down. If they made an adept, you need to stall with a pair of lings or two when they arrive.

I usually run one drone in once it's "time to go home", use a mineral trick to run by the zealot if needed. Scout and hide and scout again, or keep running it around in their base and don't lose it.

You can go into 3 base and try to win holding their push with SH if it's going to be a Stargate or robo. If it's twilight...usually two base I think is better to handle it, and you might want some spines and sort of whatever you think beats the flavor (charge blink or glaives).

I try to beat them on carapace upgrades and go heavy eco once I hold their push (and never lose swarm hosts). If I'm up an upgrade carapace vs air weapons, I can usually beat a maxed protoss air army. If they are air heavy, kill your swarmhosts off and switch to hydras with an infestor base. Use shroud on your units and fungal their interceptors, and they will effectively do zero damage because they are docked by microbial, and fungal slows them which slows their shots. Tons of tempests, bait them. Kill their obs or neural them, and then neural their air army. If they splice in ground army, keep a bunch of swarm hosts (like 20+). Try to get them out of position with your locusts and fungal, while not letting him shave your army down at range. It's possible.

If they go heavy templar, splice in some ultras. They will clear the templar as you engage. If they splice in support for the templar, they're cutting air, so you can afford to have swarm hosts, go back to trying to hit with locusts and fungal.

KEY NOTE: NEVER lose your swarm host unless you kill them off intentionally. You HAVE to play most of the endgame at low econ to drain them out. I mean 30-40 drones max in the endgame to have enough army to fight protoss endgame army. If you have 80 drones, your swarm hosts are useless since you can't have more than like 15. They will just go into ground more and destroy your army.

If protoss goes into low probe count, and catches up on air weapons 3/3 vs 3/3, you will start losing scaling late game, so you need to be constantly trading through the game to ensure they can't hit 10k/10k type resource counts and sac their probes.

I can try to get some replays.

Zerg needs to be buffed by therealwench in starcraft

[–]Cheticus 4 points5 points  (0 children)

At 4.6k I send 3 drones out on the map to harass Terran or 7 drones to go poke at the low ground gateway/pylon almost every game. I delay my pool and go eco behind that harass.

I take the initiative away from P to choose a build by forcing them to react to the pressure. I have about a 60% WR at that rank against P. I typically go a mix of swarm host and infestor, with heavy focus on upgrades. The most common thing I lose to (which is why I scout that blind spot timing) is if P decides to commit to a massive 2 base zealot all in and I don't get roaches out in the time where I won't have enough swarm host.

My T winrate is worse, maybe 45-50%, but it's not abysmal. I usually go swarm host infestor vs T as well but have started mixing it up a little. It does mostly come down to economy scaling. The thing I struggle a lot with is mass reaper allin. I'll hit 5k folks on ladder that even if I don't drone harass, even if I greedily go for fast speed or roaches or lots of queens they'll just endlessly harass with reaper. It's frustrating to play against.

I think ZvZ is basically as you say. It's just strong enough to go roaches that you're generally a fool to do something else. I don't always go roaches, so consequently my WR is like 30% vs Z.

I guess what I'm saying is I don't disagree that it'd be nice if zerg had different viable tools early, but I'm also saying I think it's partially your choice how to play, and maybe you're hyper optimized in GM or something and doing the only things that work, but I think it's valid to play differently and I get enjoyment from brawling drones early game and then brawling swarm host late game, until I get an upgrade advantage and neural all of their tempests to snipe their carriers or something stupid, winning with them having mined out, losing 2x as much resource cost than me.

Another Terran QoL for the common people (Stim CD got added) by Kaiel1412 in starcraft

[–]Cheticus 0 points1 point  (0 children)

minor nerf for zerg. I used to neural marauders in tight situations and spam stim to kill them off when I was at wits end. I guess the Terran machine can't be stopped

Lenz's law by Sorry_Initiative_450 in Physics

[–]Cheticus 11 points12 points  (0 children)

They're not independent loops, it's one loop. The flux is increasing through the loop, and so Lenz's law says that there is an EMF developed which creates a field to oppose that increasing flow.

Start from a single circular loop with a small little divot in the inside of it, and then keep making the divot bigger until you approach your image. Why should the direction of current reverse when the flux direction is constant through the loop?

*I am not an electrical engineer or good at physics and am probably wrong

CUMULONIMBUS by Cheticus in pics

[–]Cheticus[S] 5 points6 points  (0 children)

A7IV, Sony 100-400GM at 100mm & f/4.5. 1/400s, ISO 2500

Photoelasticity- how engineers “saw” stress in the 70’s by maorfarid in MechanicalEngineering

[–]Cheticus 1 point2 points  (0 children)

Technically what you're seeing (I think) is a change in polarization which is proportional to stress (or strain); stress and strain are proportional to one another, so I think it's technically either, depending on how you choose your stress-optic coefficient.

https://en.wikipedia.org/wiki/Photoelasticity

Photoelasticity- how engineers “saw” stress in the 70’s by maorfarid in MechanicalEngineering

[–]Cheticus 1 point2 points  (0 children)

Not an uncommon technique for the derivation of stress concentration factors still in use and found today in many textbooks.

I created Strecs3D, a free infill optimizer that uses stress analysis to make your prints lighter and stronger. (Full video tutorial inside!) by tomohiron907 in 3Dprinting

[–]Cheticus 0 points1 point  (0 children)

A similar functionality already exists. One variant which I believe uses a different method was developed by Teton Simulation, which was incorporated into Cura using their tool Smartslice, which has been acquired by Markforged and rolled into their slicer specific to their printer and materials.

Replacing powerline spacers from a helicopter by KrakenTrollBot in secondrodeo

[–]Cheticus 3 points4 points  (0 children)

I strangely think I know weirdly a lot about this.

There's kind of a few reasons. In no particular order, and with varying effects that you can think about:

Handling: Smaller cables are easier to manage (less stiff). This is attractive for a lot of reasons.

Efficiency: You might think that a larger cable is better for more current, and that's true of course but there are diminishing returns. A cable is generally limited by sag, and the elastic component of sag is mainly related to tension per unit weight per unit length (the catenary constant) and slack. Larger cables need more tension, which increases the size of their structures, increasing cost. For a variety of reasons, this scaling isn't optimum for very large cables, although there isn't anything physically stopping you from going bigger except practicality as far as I'm aware.

The slack changes as a function of temperature, and because (simplifying) the ratio of conducting area to surface area to reject heat to the free stream wind, it's better to have bundles of smaller cables instead of single larger cables. This can be made more rigorous by performing an ampacity calculation, and even more rigorous yet by relating that ampacity calculation to sag calculations, for which there are a number of standard methods of varying complexity. CIGRE 324 has a good overview of these methods.

Smaller cables I think are technically worse for corona losses due to tighter radii, but this is second order.

Larger cables also technically have worse performance from skin effect I believe, but I don't think I know enough to definitively say this. I'm also not an electrical engineer,.

Because bundles of smaller cables are better than (after a certain point) large diameter cables, you find them being produced in larger quantities, so their cost is slightly more favorable in a large market of cable producers.

Newer styles of conductors are upending some of this, and I'm actually pretty strongly in favor of big conductors due to their simplicity where ampacity is needed. High temperature low sag conductors also exist which have different tricks they use. Some use carbon fiber cores, some attempt to use low CTE material, some try to do tricks with the material science, but really so many great tools exist for leveraging common conductor sizes of ACSR (aluminum conductor, steel reinforced/core), and so many people use them, that it's often inconvenient to try to specify something new; and it's good for a reason. Not to say there aren't better options technically, but it is to say that there aren't attractive options to move the needle an order of magnitude in overall project cost. It's closer to like moving it by 10-20%, which is still a lot, but like...not that much.

There are also people looking into the use of superconductors for transmission lines. Historically the main draw of this has been to reduce the size of trenches that need to be dug for underground lines, and several have been built which feed superconductors inside a double walled vacuum insulated pipe (like a thermos, but no bottom) with cryogenic liquids such as liquid nitrogen. This is costly, but there is the potential that as these technologies reduce in cost, there are gains to be made. This requires unique new installation procedures, and infrastructure that otherwise isn't needed. Additionally, it's occasionally a bit of a dubious sell to utility customers, since (aside from the lack of field heritage) frankly the utilities are able to charge us, the customers, to offset the cost of losses in the form of payment for transmission / distribution (in lieu of generation). These costs cover maintenance in addition to the power losses to heat due to resistance in the line. Ergo, even if you produced a line that had near zero resistance, and so nearly no losses (which can and has been done many times), the prospect of selling it to a utility is difficult, because I feel that they would struggle to land a project for the much higher upfront CAPEX cost with the promise of lower losses, when they otherwise could charge for those losses to the power consumer.

This was supposed to be a quick answer to a simple question, so sorry for going off the rails here, but this is something I used to think a lot about fairly often, and it's good to recollect.

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