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flashingleds

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It can go both ways of course. The first edition of Norman’s classic ‘design of everyday things’ was 1988, and it’s interesting to read that book today and see how a lot of the hard problems he was discussing were completely solved by the advent of touchscreen interfaces (specifically, the ability to reconfigure the interface according to what tasks are relevant at that moment). Done right, touchscreens are a huge boon for usability (I mean, look at what the iphone did). Done poorly they’re a disaster, but that’s been true forever with UI design regardless of the tools at hand.

(I haven’t read the revised edition (2013) of Norman’s book, I guess he must address touchscreens)

It goes further than warnings though - at least circa 2012 using an unofficial charger (or official charger where this fragile extra wire is broken) would underclock the cpu dramatically. It happened silently, such that I didn’t realize what was happening and why my laptop was so slow until stumbling upon a random forum post about it. I was pretty sour on Dell after that experience.

Along these lines, I admit with shame that lately I’ve been switching to airplane mode before looking up or modifying a contact, because it’s not obvious to me which combination of symbol-labelled buttons will do this without initiating a phone call. I feel old.

Al-foil is ubiquitous in ultra-high vacuum labs because part of the process of reaching this vacuum level involves baking the whole chamber at 120-150dC for 24+ hours. The chambers are typically made of stainless steel which has a pretty mediocre thermal conductivity. Hence the Al-foil, to ensure even heating during the bake. Since you have to bake every time the chamber is opened, it’s easier to just leave the foil on.

Bonini's Paradox 7 years ago

The three people are known to you in advance (it’s your group). It was common to game this a little by saving the biggest person as the third one that had to break the bridge.

Brute SPL-T 8 years ago

Oh, really so much faster with pypy3? That would have been very nice to know when putting this together, but in any case is good to know for the future. Thanks for the tip.

Brute SPL-T 8 years ago

Author here. I really wasn’t very good at SPL-T before I changed gears to brute forcing it, so the whole strategy aspect is unexplored here. If you think you have a method that could be phrased in an algorithmic kind of way, please share! This topic is ripe for a more intelligent part 2, from me or someone else.

This summary doesn't give numbers, but the journal article being discussed does. About 3e3 to 1e4 S/m for different preparations, compared with zero for untreated silk. Performed as a two-probe DC measurement, so once you factor in contact resistance it might be even better. The details are scarce, so you'd probably want to see it repeated more carefully before concluding anything.

You can see in the video that he does have desoldering braid, but has chosen not to use it. Sounds like our experience differs, but personally I find desoldering braid is seldom helpful for removing parts - it tends to leave behind just enough solder to keep it stuck down, but not enough that you have good thermal conductivity to reflow it with an iron. Without using a heat gun or skillet (which he mentions) I don't know of a better way. You have a lot of experience, so if you disagree I would very much like to learn something!

This is because it just got published in Nature something, the earlier open arXiv version from April is here: https://arxiv.org/abs/1604.02265 Figure 3 is absolutely spectacular, and deserves to be admired by the whole world. A comment on the inevitable promises of revolutionized data storage: Yes the areal density is fantastically high (>500Tbit / square inch as opposed to 1Tbit/in^2 in bleeding edge HDDs / NAND flash, if I crunched the numbers correctly). But it requires ultrahigh vacuum, preparation of a clean copper crystal, dosing with copper chloride and then writing/reading with a scanning tunneling microscope, maintaining liquid nitrogen temperature. Also a modern SSD will write about 500MB in a second, while this method would write 500MB in 240 years. I don't mean to slag it off; we should all appreciate it for being an absolutely wonderful and awe inspiring technical feat. Just don't get carried away dreaming of the applications in your laptop/server/phone.

open arXiv version from April: https://arxiv.org/abs/1604.02265

Figure 3 is absolutely spectacular, and deserves to be admired by the whole world.

A comment on the inevitable promises of revolutionized data storage: Yes the areal density is fantastically high (>500Tbit / square inch as opposed to 1Tbit/in^2 in bleeding edge HDDs / NAND flash). But it requires ultrahigh vacuum, preparation of a clean copper crystal, dosing with copper chloride and then writing/reading with a scanning tunneling microscope, maintaining liquid nitrogen temperature.

Also a modern SSD will write about 500MB in a second, while this method would write 500MB in 240 years.

I don't mean to slag it off; we should all appreciate it for being an absolutely wonderful and awe inspiring technical feat. Just don't get carried away dreaming of the applications in your laptop/server/phone.

If anyone out there is looking for alternatives, last time this happened I switched to the MCP2221 from microchip. It's been in about 6 hobby projects now and I'm very happy with it. Half the price in small quantities and easier to hand solder (14SO or even DIP vs 28TSSOP)

Last year when I was looking into silicene it was all very controversial and nobody seemed to have given all the necessary evidence to prove they'd made it (i.e. honeycomb lattice with the right atomic spacing AND dirac cones in the bandstucture).

Now I guess it's not only accepted but there are already devices? That's some rapid progress.

This is a really nice example of a project post/build log.

Related, I think it would be a lot of fun to interface the Pi with the original (not very good) LCD. Then you could make some kind of 'alternate history' nextgen gameboy where the processor was massively upgraded but the screen was not - enabling low res 3D, temporal dithering to expand beyond the 2bit palette, etc.

(I guess you could also simulate this on a regular computer or even the mod discussed here, but that's somehow slightly less charming)

Coin 13 years ago

Some time back I described a project to do this with a single data track (http://www.flashingleds.net/swipecards/swipecards.html)

This was a crude first pass, which is evident from the fact that the shim is a sawed off kitchen knife. In principle if you make the electromagnets smaller you could fit three. Make them adequately decoupled and you're away.

If these guys have an alternative approach I would be interested to read about it, but as far as I can tell they don't describe the method anywhere.

It sounds like there might not be a 'next-time' in the near future, but maybe think about putting some lights on if you're doing another 3am start. Even riding my bike at 6am without eye-searingly bright front and backlights makes me very nervous, I'd be terrified skating on the road in the dark.

You know how sometimes you buy a second hand book and some jerk who owned it previously went through and underlined every second sentence, presumably for an assignment or some such?

The default behaviour on the kindle seems to be to show me underlined phrases from everybody on every book. I love the device, but was supremely happy to learn how to switch that junk off.

The reason your analogy breaks down is competition. Usually it's pretty easy to obtain food in some shape or form, so there are near endless alternatives if you face steep pricing. It's really quite difficult to be a competent doctor, so you've got limited alternatives. The magic you would need to apply is reducing the barrier to entry to medical competence somehow.

I confess to trying this myself after reading the Srivastava story. If you step back from the fact that it's a lottery, there's plenty of money involved, "what are you a gambling idiot?" etc it's actually a really fun problem to tackle. I picked out a similar style of ticket and for $20 I kept myself entertained doing analysis and testing hypotheses for the better part of a weekend. Sadly I was defeated on this occasion having found no obvious weaknesses. The main thing I learned from it all was that while a single scratch ticket is fun and exciting, 5 or more get very boring very fast. I was groaning every time a 'free ticket' showed up.

(Also: in Australia you usually see the next 4 tickets on the roll behind a clear display, so if you ended up with a good trick, even if it required running a script on your smartphone, you could have fun with it)

Regarding the point: "Just-in-time learning is the future. No ifs, ands, or buts. Any argument you might have to the contrary is not only wrong, but dangerously wrong."

I don't think I agree with you there (or perhaps I just didn't interpret the point correctly). In certain fields of study - and perhaps software engineering is one - this might be true, but it does not hold generally. If tomorrow I find myself needing to write a good zero-finding algorithm in a new language, then yes, I can probably absorb that material quickly. If I find myself needing to model the temperature dependence of something using an esoteric branch of quantum mechanics, then good luck to me without 3 years of prior study in topics that didn't seem relevant to anything at the time.

There was a great line in the old TV show Pretender along the lines of "It's my observation that anybody who begins a sentence "with all due respect" typically doesn't have it"

I've always interpreted prefaces like that (along with its relatives "with all due respect" or the suffix "I'm just saying") as a way of turning the sentence into "This is an objective observation that should be made; don't blame the messenger". Used well it's a good way to strip subjectivity from some objective facts, used poorly it's a good way to project a subjective interpretation onto objective facts.

Kill Math 14 years ago

Quite aside from any of the main points being made here, the guy is dead on about Strogatz's book. I had the same reaction to that book as I did to Lipovača's Learn You A Haskell - it's a great accessible resource to learn something new and interesting (if perhaps not immediately useful). Would appeal to the HN crowd I imagine.

I have spoken to a guy who was at one point closely involved with the D-wave people. He suggested that the actual story with the Lockheed purchase was that LM sells an awful lot of gear to Canada, and as part of the contract they are expected to buy some number of million worth of Canadian tech in return. The D-wave purchase was one of these obligated purchases.

Just a comment given in unofficial conversation, take it how you will.

It's an issue of definitions. Of course you cannot build an electronic device using only a single atom, because you need leads, interconnects, power supplies, measurement equipment etc. So when you talk about a single atom transistor, what's meant is that the critical, behaviour determining region of the device is a single atom. If you took that single atom away, you would not have a transistor any more.

In much the same way we talk about 32nm transistors in computer chips for example - it's understood that this number refers to the gate length, not your whole processor.

Unlikely to happen, but in any case also unlikely to be all that effective. Google scholar is getting good, but when looking for papers I will usually use scopus/sciencedirect (Elsevier) or ISI (Thompson Reuters). Sowing the seeds of my own destruction and so forth.

I think it's difficult to refute that if the funding was public, the results should be public. But the scientists have to publish in big journals to win public funding grants, and the big journals aren't motivated to go open access and surrender their cash cow.

So you're not likely to budge either the scientists or the journals by arguing about what's ethical. It seems to me like the best approach is to change the way public grants are awarded. If grants become conditional on you ONLY publishing in open access journals, well you don't have much choice do you? Ultimately this whole game was only ever about attracting the money you need to do your job. Pretty soon the expensive publishers stop getting submissions because they're all diverted to open-access journals.

Of course it would never be so easy in reality. There is a pretty entrenched chicken-and-egg situation with science publications, and it will be unavoidably messy to break it.

It does seem odd. What you're talking about is not even particular to big user facilities. If I don't have the (physics) facilities to do something, I just track down someone who does and ask them (which is not hard using google or looking at the relevant literature). The majority of the time they're happy to collaborate on the basis that they're on the paper. I think I'm missing some detail about this.