I think you mean room-temp SUPERconductor, you wouldn't be posting on TC without room-temp semiconductors.

Replication attempts have been mixed, but theoretical simulation has shown there might be something to it, so it's not a complete hoax. Even if it does work, it'd probably take 5 years or so before the process gets ironed out, techniques refined, and it starts seeing practical application. Also >>3242

Maybe the most interesting read from a meta-perspective: https://hackmd.io/@lifthrasiir/lk-99-prehistory

>>1623
i run a separate machine for my file server because i found out i don't like sharing ram and bandwith with the outside world. i capped the server's bandwith at a bit below my total capacity so it can do it's thing and it never causes me any trouble.

I am trying to read a handful of ext4 formatted drives from windows. However, since I used some specific format parameters so I could save disk space, some of the linus fs readers don't work. This one called ext2fds actually allows you to mount drives right in windows but it only works with the one partition I formatted with default parameters. Another, called DiskInternals Linux Reader, does work but only lets you browse the file sytems in their standalone program. You have to "save" files you want to copy over to use them normally. Real round about way of doing things but oh well.

Post edited on 31st Jan 2018, 9:01pm

I never cared too much about the X vs Wayland holy war, but today I installed a recent Ubuntu, since I needed it for some software.
I just slapped Xubuntu desktop on top of a default server install, which gave me Gnome for some reason.
When connected via an old KVM it would only allow me to select 1024x768 as resolution, and apparently there is no way to override the mode in Wayland and the only solution proposed on the internet is to go back to X.
They've been touting it as the new, 100% production ready, absolutely superior software for what, 5 years now?
And it can't even do a simple thing like custom modelines.
What a load of shit.
And while I'm at it, the gnome display manager is shit too. If the user has passwordless login enabled I can't even select the desktop environment to start in X mode.
Solution according the internets? Well you can't do that either fuckhead, just have a password.
And if you happen to have a long MotD it hangs for a minute before logging you in, displaying parts of it.
Probably because it wants to show you the entire thing and give you time to read it, but there is no way to skip, and then when it gets to the last chunk, it just shows it for a millisecond and then logs you in.
What a fucking shitfest, especially considering these projects are heavily backed by the likes of red hat and other tech giants.
It's like modern software is purposefully built to be bad.

Although I have to admit that I kinda like the visual theme used in Ubuntu.
Looks a bit like late 2000s Mac OS, but damn, skeuomorphic designs in this day and age are such a breath of fresh air.

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>>3228
>these projects are heavily backed by the likes of red hat and other tech giants
Not really. I wouldn't call Red Hat a "tech giant". Yeah, they're owned by IBM, but that's a has-been company. I don't know how often Gnome(Wayland's real reason for existing) is used in the corporate world, but I'm certain it's not common-place. So even for Red Hat, it can't be that high-priority. FAANG couldn't care less about Wayland.

>It's like modern software is purposefully built to be bad.
Xorg isn't good compared to its common, proprietary equivalents. Tangentially related, but GTK also isn't good. There was no golden age of desktop Linux.

Post edited on 29th Jun 2023, 3:59pm

>>3198
Why not just buy a pinephone or something.

Phone screens are a pain in the ass to work with, there's tiny HDMI monitors out there. Or Raspi cases with a screen built in.
>>3199
It's a better hand toaster than it is a PDA.

>>3200
At such a small size, touch screen would work better than just a simple monitor. I assume that's what OP actually means here, so you probably aren't wrong.

Source: https://www.americanlaboratory.com/913-Technical-Articles/764-Celebrating-25-Years-of-Inductively-Coupled-Plasma-Mass-Spectrometry/

Do you have an interest in this field? Any particular reason for posting this article?

>>3142
I've become an ICP-MS otaku. It's a very profitable field to be an otaku in. Also, the wikipedia page doesn't mention the history of this technique at all. It's very new as far as scientific methods go, and very widespread across many different fields and industries.

Sample introduction really is the Achilles' Heel of ICP-MS. Our nebulizer was only producing large drops rather than a fine mist, resulting in the signal gradually dropping down to only 10% of what it once was.

I'm not 100% sure what it was, but my guess is that our calibration solutions were forming silver chloride particles (due to the presence of chloride) which eventually clogged or damaged the nebulizer. I didn't realize that we had accidentally ordered a Tin standard in 40% (!) hydrochloric acid, rather than dilute nitric and hydrofluoric acid. The procedure was calling for these solutions to only be re-made rarely, but often drawn from for dilutions, giving plenty of time for silver chloride particles to nucleate and grow. Given that we regularly rinse with dilute nitric, which should dissolve all the silver chloride, I think it's more likely permanent damage to the nebulizer rather than a simple clog. The new nebulizer ($1800 price tag! ouch!) brought the signal back to where it should be (and a clearly visible fine mist, without large drops, pic related).

Also, turns out our Argon dewar that fuels the plasma (flame) drops to low pressure at around 1/2 to 1/4 remaining capacity. We need about 7-8x atmospheric pressure of argon in there to fuel the plasma adequately. A bit disappointing since I wanted to test some samples, but wasn't able to get a resupply on short notice (we don't have enough room to keep a backup dewar to swap over when we run out.)

The ice formation on all the piping is due to minor leaks. When the gas inside the dewar (7+ times atmospheric pressure) leaks out, the expansion of the gas cools it down quite significantly. This makes the metal pipes very cold, which then freezes water vapor from the air into these ice crystals. You can see a similar process if you use a can of compressed air (computer duster).

Of note, the nobel prize in physics has been awarded for work on demonstrating violations of bells inequality in a wide range of circumstances. It's surprising that the last gap here was only closed in 2017. So at this point, assuming system-measurement independence, because we have observed violations of bells inequality in a robust set of circumstances we cannot have a local hidden variables theory. Or put another way, any theory of QM that is consistent with our observations must either:

* Reject the notion of system-measurement independence (superdeterminism)
* Reject locality (assume FTL communication of some form)
* Reject realism (the notion that particles have defined properties before measurement, i.e. that "god does not play dice" as Einstein supposedly said)

Most mainstream people like to preserve the notion of independence and locality so it's usually realism that gets chucked out (resulting in either copenhagen or many worlds)


[1] https://nautil.us/they-probed-quantum-entanglement-while-everyone-shrugged-241212/
[2] https://www.quantamagazine.org/pioneering-quantum-physicists-win-nobel-prize-in-physics-20221004/

>>2940
I find it interesting how much being a NEET screws with one's sense of time. When I heard the news about this I thought about when the Literature prize was going to be awarded, and saw October, I thought fuck that's months from now. Then just after, the prize comes in. We are in October after all.

>>2941
I've lost many many years like that.

https://news.yahoo.com/why-more-physicists-starting-think-045308127.html
Not sure how relevant this is, but posting it anyway. Maybe string theory will get left in the dust bin.

2,45*3.68 = 0,0001 x (245*368)

>>2977
You can obviously carry out any finite precision arithmetic (and in practice, finite precision arithmetic is all there is) if you track the precision yourself, since that's how computers do it. But that's not strictly speaking "only addition and subtraction" as I interpreted the question since you track the pair (significand, precision). Although I suppose it's a minor point since even rational numbers are constructed as equivalence classes.

Even allowing linear functions isn't enough for arbitrary computation (since the output can only be linear in the input), but with non-linearity added we can approximate functions to arbitrary precision we choose. If we go further and allow feedback, then we just have turing machines and we can compute any computable function.

>>2978
You might also be interested in the complexity class p/poly. The circuit model of complexity is in some sense more "natural" to analyze since it's a simple feed-forward network. Of course the limitation is a circuit has fixed number of inputs, so the language decided by a given circuit has finite, bounded string length. If you loosen this by allowing circuit families, you get p/poly which is stronger than p.

There are very interesting theorems here, e.g. bounded-depth circuits using AND, OR, NOT, and mod-p gates can't compute mod q, for p and q distinct primes. (Razborov Smolensky theorem). This can be considered as a more general-case of the fact that parity is not in AC0 (try it out, computing parity for an n-bit input requires log-depth circuits!).

What's interesting is that if you allow mod-6 gates you get surprising power, and so far not much is known about what's not solvable. A somewhat recent result (2010-ish) is nexp not in acc0[m] for any m, i.e. it's only recently that we've been able to prove bounded-depth circuits with boolean and modulo gates can't decide languages in NEXP.

The above can be extended to arithmetic circuits as well, which are essentially what simple neural networks are. See https://core.ac.uk/download/pdf/4894171.pdf

Post edited on 31st Oct 2022, 2:29am

>>2979
You don't need to go to arithmetic circuits, you can look at class TC0, since majority function can approximately be treated as an activation function.

>move my workstation around devices with as little delay as possible, and without needing to connect to the internet to install anything
From what I understand NixOS can allow you to define your userspace environment declaratively, but that doesn't guarantee it will remain in sync between machines. How many devices do you have that this is a major issue? I'd probably use nix as the package manager to set up userspace however you like, then keep all configs/data/source-code on a central NAS.

But another simpler option is to avoid state syncing entirely and go full-on with thin-client approach. Dedicate the beefiest machine to being the host where all data and compute will occur and use the other machines only as remote terminals (e.g. emacs tramp, or go fancier with vscode remote/jetbrains projector).

>I'd probably use nix as the package manager to set up userspace however you like, then keep all configs/data/source-code on a central NAS.
Yes, this is my plan too. Using rsync to keep my data updated. It's way faster than copying the entire backup.
>But another simpler option is to avoid state syncing entirely and go full-on with thin-client approach
This would be a problem outside my local environment because I would depend on the network if I work on a remote machine.

>How many devices do you have that this is a major issue?
TL;DR: I work with brittle hardware so I have to setup my workstation on a new HDD 3+ times every week.

Could someone use the Joule–Thomson effect to create a showerhead whose water runs off a capillary tube and thus gets colder than room temperature without using any additional source of power or something? You would use a capillary tube for the water to run through thus getting colder.

>>2931
I don't understand the setup, how exactly do you plan to use the capillary tube to cool liquid water? There's a joule thompson inversion point where expansion ends up heating the fluid rather than cooling it (and I believe for liquid water it is as such), so exiting the capillary tube the water would end up heating slightly.

Post edited on 6th Oct 2022, 1:28pm

>>2932
I discovered this technique while reading about fridges. Yes, it works on water. I forgot to factor the exiting of the fluid from the capillary tube. In this setup the water would cool but would heat up on the person's head, just as it leaves the tube. It doesn't work.

>>2943
>Yes, it works on water
Well the effect exists for all fluids, but for liquid water expansion doesn't result in cooling. See [1]

>Although the Joule–Thomson coefficient is not a thermodynamic property for itself, the effect is important for practical purposes and values for the Joule–Thomson coefficient help to realize the changes occurring during processes. From the table, it can be seen that during expansion of liquid water the temperature increases. In the gaseous and near-critical state, temperature of water during expansion drops.


Also it should be noted that (as far as I understand) the joule-thomson effect doesn't play a major part in the refrigeration cycle, it's the phase changes between liquid/gas of the coolant that are responsible for most of the heat transfer to/from the environment.

[1] https://www.sciencedirect.com/topics/chemistry/joule-thomson-effect

Post edited on 9th Oct 2022, 12:09pm

>>4094
>I cannot access 4chan through the website.
Why not? Due to cloudflare restricting you?

Something like that, if you have any alternate way to go on 4chan I'd appreciate it.

Post edited on 7th Oct 2022, 1:53pm

>something like that
Can you elaborate? Cloudflare restrictions usually don't usually prevent viewing, they just serve you increasingly hard captchas. Unless you're doing something really silly like unthrottled scraping.

>>2936
Well, "Zscaler" has to do something with it.
I'm beginning to think it has to do something with my University's WIFI more than anything.

>>2914
Void Linux is awesome for multiple reasons, but one of them is its name.
Funnily enough, with regards to Mint, its logo was more of an issue for me than its name.

>>2914
Not at all, more than the name it's usually the community's opinion of a distro. Mint linux had a reputation of being "relatively" easy to switch to for windows users. And PopOS is supposedly the new ubuntu, a solid choice that works without any of the bloat and terrible choices canonical has been adding over the past few years.

I wish most distros would specify their userspace stack upfront though, and how they differ from whatever distro they build on top off.

>how they differ from whatever distro they build on top off.
99/100 times, they'll say they have the greatest community in the universe. 80/100 times, they'll also say theirs is more "user-friendly".

>>2833
More relevant links, on why openBSD's security claims should be taken with a grain of salt

https://web.archive.org/web/20220227172102/https://madaidans-insecurities.github.io/openbsd.html

Discussion by Luca Todesco: https://nso.group/@qwertyoruiop/110086216898968720

The majority of people use it as a status symbol. After that; it's fast, it's ubiquitous, it's identical, it matches the drapes.
To them a computer goes no further than a Facebook/email machine and a household fixture.

>>1296
>>1351
God uses CoplandOS

Will re-use this thread to review/rant on the arm (M1) mbp (provided by my employer for a short while. I used to use a 2015 mbp).

Pros:
* Speaker quality is amazing. I'm someone who's never bothered using an external speaker (or even headphones for that matter) when listening to music/watching anime, so up until now I didn't realize how much of the bass I was missing. The speakers on this are very nice at reproducing lower-frequencies.

* Keyboard feels very nice. It's extremely stable and clicky. Compared to the 2010 and 2015 models, it's much less mushy or wobbly, each key is uniform and has a satisfying snap. I don't have a thinkpad so I can't compare it to that, but after using this even external scissor keyboards feel a bit sad (I don't like mechanical keyboards so I can't compare to that). I only hate that they removed the keys for keyboard backlight control.

* The arm processor is simultaneously excellent while also a bit overrated. In day-to-day use, I don't see much difference, probably because I don't browse pages that require gigabytes of JS. But when doing compiles, it can do a make -j16 without even breaking a sweat (without blasting fans). I think the temperature benefit is the most significant thing. The battery life has been overrated, probably because of shitty software (described shortly).

* Trackpad is not as good as 2015: it's too large so your palms hit it when typing, and the palm rejection algorithm isn't as good as it used to be. Still significantly better than other laptops, but this is change for change's sake.

Cons:
* Software (latest version of osx) is absolute hot garbage. I can't count how many show-stopping bugs I've found on this system. Charging via usb-c randomly stops working. External mirroring with the laptop closed randomly stops working. Tap-to-click lags when holding modifiers or at the edges. Pinch-to-zoom randomly stops working. The thing wakes from sleep every 30 seconds, so battery life is basically no better than the intel mbps. Their openGL-on-metal wrapper is broken with multithreading (and I'm not going to rewrite perfectly good applications to use their special-snowflake graphics stack). Intel-on-arm emulation (rosetta) is very cool though, and works

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>>2817
>or even headphones for that matter
I exclusively use my laptop with earbuds.
>It's extremely stable and clicky.
How's the travel?
>Trackpad is not as good as 2015
Always using a mouse, connected through one of three USB-a ports.
>Maybe the linux-on-m1 folks can make this an enjoyable machine to use.
>linux
>enjoyable
hahahahahaha

>>2818
>laptop with earbuds.
I tried this once, I didn't like having things in my ear. I also tried the over-ear headphones but it made my ears sweaty. So I just stuck with internal speakers.

>How's the travel?
This is subjective, but the depth feels slightly less than the 2010-era unibody models, about the same as the 2012-2015 era hidpi ("retina") models, but with much crisper actuation. I guess if you were used to a mechanical keyboard you'd find it shallow though.

>>enjoyable
>hahahahahaha
I'd ordinarily agree, but at the rate osx is becoming unusable I wouldn't be surprised if linux ends up being more usable within a few years. I can't imagine how badly they've got to mess things up so that something as basic as charging stops working unless you reboot.