skysight-inc/HackerNews huggingface dataset:
Machine Learning: An Algorithmic Perspective. Python Code Samples
the Lego Mindstorms system is awesome. Squeak and Alice provide very approachable implementations of Smalltalk in a Turtle graphics-ish environment.
Sounds like the Neo-Futurists' pricing scheme: """Tickets are $9 + the roll of a single six-sided die ($10 - $15, depending on your luck!)"""
http://www.neofuturists.org/index.php?option=com_content&...
Indeed, But Microsoft is seen in... slightly less favorable light than Google. Amazon's position on the other hand could be a drawback, not an advantage. Such step could have made angry its providers.
I think you're interpreting people's irrationality in the wrong way. People are often irrationally risk averse: most people would much rather pay $X with probability 1 than $2X with probability 1/2 and $0 elsewhere. The reason lottery tickets sell is because utility functions are nonlinear. After buying a $1 lotto ticket, they're still poor; they don't miss the dollar. But if they win, suddenly they are rich, which is qualitatively different from being poor. Thus, the calculation is a small but nonzero chance of being rich, vs. the certainty of being poor. Most people don't do the math to figure out just how small.

There's a reason why people indulge "If I won the lottery..." fantasies.
I assume it's because software is the only industry where a 1-3 person startup can create a viable product in a short timeframe that can be sold for large multiples.
As omegazero pointed out, there might be a selection bias if you don't do it right -- people will back out if they see they are in the unlucky group of folks who will get charged $2X.

If you make people commit before revealing the amount, the issue is trust: how do customers know that the odds are actually 1/2 that they'll pay $0? How do they know you aren't just charging everyone $2X? You'd have to use some verifiably random bit, which gets complicated. People will smell a scam.

(Speaking of which: are there any commonly used publicly verifiable random numbers, like a die roll, but outside of any party's control? I presume there must be a need for them in a number of situations.)
I'd like to take photos without entering my PIN (preferably take-only, not view).
On a practical note, what stops them getting a refund and repurchasing until they get it for free.

Your other observation is good, too, but I think this sentence gets to the heart of the problem. The double-or-nothing transaction is irreversible, which is what makes it a bad one.

People like commercial transactions that can be reversed. Ideally, both parties should walk away feeling like they got a fine deal, but that if the deal goes sour at any point in the near future (because a part was broken; because the customer had second thoughts) they would be both be willing to "undo" it without much harm done.
blogspam: original is here:

http://www.sellsbrothers.com/fun/msiview/#Feynman
> "nothing like this will be built again"

Oh, but trust me, it will be: when fossil fuels become truly scarce and the antinuclear Luddites are shot, as they ought to have been decades ago.
Actually, this was: http://www.w3.org/History/19921103-hypertext/hypertext/WWW/L...
If you have an addictive personality then you probably should be very wary of using websites like this, I have facebook and check it for maybe 10 minutes every day or two, I couldn't use it for longer because it's so bloody boring.
What do you think of the recent Ashton/Oprah/CNN hype?
Maybe a city or museum tour guide app - go somewhere and pay to download an audio tour.

The Museum of Modern Art in NYC has something like this; http://www.moma.org/visit/plan/atthemuseum/wifi (though its currently down right now).
Actually the shortened tag is a good idea. It would make books more readable. And he could publish a list at the end of the book with the actual URLs (think of it as site version 1).
He could even call it an "index".
Assumptions are the enemy of innovation.
If Facebook was a useful promotion tool, they wouldn't have revenue issues.
Finally a seed fund in nyc. Anyone looking for a partner/team member?
I'm sure that if there were a safety issue with the windowed versions cost wouldn't have been an issue.
>make a dating site just for smart people

This has been done. (http://www.intelligentpeople.com)
They seem to use the same test for every applicant (a dusty scan of the famous Raven's Progressive Matrices.) So the system is easy to game, if you so wished.
I think the idea is that Sun is the technical steward for the project and it's worth supporting Sun (via Solaris) to continue to fund efforts to create tools of these types. I don't believe the idea is "I need a platform with great debugging so I pester my management to get me a Sun to keep around".

I don't know that I agree, but I believe that's the rationale.
I enjoy Lisp chauvinism as much as anyone but come on.

Self-hosting languages include Lisp, Forth, Pascal, C,
Modula-2, Oberon, Smalltalk, OCaml, FASM, Python, Scala,
Haskell and BASIC.

http://en.wikipedia.org/wiki/Self-hosting
And according to:
http://www.google.com/search?q=%22self+hosting+compiler%22

http://live.gnome.org/Vala
http://www.freebasic.net/index.php

Apparently Mono is self hosting (i.e. the compiler is written in C#), and I'm sure there's many other examples.

Or maybe I missed a joke you were making...
I'm more surprised that there aren't guns with iPod connectors to help feed in variable data.
I'm pretty sure syscall-level instrumentation isn't the win with DTrace, since every modern Unix provides a safe, lightweight method for collecting that info. In fact, if you know how DTrace actually works, what Sun is doing is actually scarier than, say, truss.

I'm not saying there isn't a DTrace win; just that you haven't shown it.
So that makes perfect sense, but it's not the argument I'm engaging; people really do seem to think DTrace is a killer feature for Solaris.
I like the lottery ticket analogy some people have made, but here is my twist.

My service costs $X per month. So if you like it, you'll want to pay $X. ... But for a just this month, there is a 1/10 chance your $X will get you the service for the entire year!! ... and if you don't "win", you still get what you paid for.

I think this might encourage people who are on the edge to sign up now, and still feel good no matter what the outcome, plus they might tell their friends about it.

-- David Jones
I think it's a major coup for Twitter. I seriously can't think of how they could have done things better.

I'll be surprised if twitter isn't the default communications network for phones and the majority of conversation within a few years.
Once I got rid of my fb bookmark I immediately stopped checking fb so frequently. I almost feel guilty for not keeping tabs on it these days.
No. A lottery ticket is a way to buy a fantasy: if you're a housekeeper who doesn't speak much English and already has two kids, you know you'll never be rich -- but for $1, you can spend a couple hours thinking it's a possibility.

To take advantage of this, you might charge 1.1X with a 10% chance of getting 10X worth of similar goods. But that wouldn't be too exciting, either.
Jason Calacanis 1-2 years back made a post asking for peoples advice on how to promote on Facebook. The consensus was widely and rightfully so:

1) Facebook is NOT an effective marketing platform

2) Please don't try, nobody wants it to turn into myspace

Although, like any social site, it can be useful if users spread your message - on their own.
I suspect that Feynman wouldn't have limited himself to two dimensions and would have noted what the presence of the lip means.
The only thing worse than this is the trivia questions:

Q: "When using function x does it pull from the thread pool or create a new thread"

A: Don't care, will google
LINK and @import don't behave the same. LINK styles are evaluated in document order. Evaluation of @import styles is deferred until the end of the document.
Of the math textbooks I've used, two've been good enough to keep so far:

Linear Algebra:
http://www.amazon.ca/Linear-Algebra-Applications-CD-ROM-Upda...

Calculus:
http://www.amazon.ca/Calculus-Early-Transcendentals-Tools-En...

on the more computer-sciency side, Introduction to Algorithms has a lot of good word-of-mouth. I'm not such a fan, myself, but here it is:
http://www.amazon.ca/Introduction-Algorithms-Thomas-H-Cormen...
Self-modifying code
This isn't trivia. Creating a new thread is expensive; so understanding the difference can make a huge difference in performance.

Saying "I can google this if I need to" is a cop-out: Yes, you can google if if you realize that it matters, but if you don't know the answer you're probably not going to realize that it matters.
The OP was informing the audience that this was submitted before. This is useful so that those who have seen it already (the majority) can recognize it and possibly move on, and others could go read up on the previous comments - accumulating knowledge rather than rehashing it is the basic tenet of progress.

Kindly calm down and refrain from acting out based on things you have imagined the post says.
I fit the stereotype. compass has saved me http://github.com/chriseppstein/compass/tree/master

With compass I get a programmer's mindset and lots of predefined typography goodness. It still takes lots of work, but I have been able to produce a clean site now.
RIP J G Ballard, fearless explorrer of inner space
I was also surprised by the interview process. I'd read and been told that it was likely to be confrontational and we would be expected to defend our idea, explain our market, and why we could beat our competitors. But they mostly just wanted to see our demo.
"You can already feature detect and use audio tags where available etc."

OK, but isn't this the grounds for people griping about various flavors of IE, that you have to have behavior checks for X number of browsers because they do not follow a W3C rec?
>Also, the grip hole would not be guaranteed to be in the same alignment every time

it is if it's in the center.
Witness, for example, Intel’s “new” Nehalem line - it’s great right? By Wintel standards, it is - but if Sun hadn’t lent AMD some people to design x64 and then supported the company by building its own motherboards to demonstrate what x86 multi-core could do, you’d be paying HP’s prices for Itanium desktops - Itanium performance, and Itanium security.

I call [whatever the highest HN-agreeable word that substitutes for "bullshit"].

The Itanium was never positioned for the desktop, and even if it was, it never had the performance to get the job done. It's slow, hot, and is a compromised design for desktop use.

AMD did to Intel what Toyota, Honda and Nissan did to GM in the 70s-90s: surprise and delight at the bottom end, and move upmarket slowly while the incumbent sleeps.

Intel made the mistake that Joel Spolsky famously warns us about -- don't rebuild things you don't have to; AMD bet on the opposite color and won big time.

most of the market, and many among Sun’s own staff, have no idea how the SPARC products line up against x86; no appreciation for the differences between Solaris and Linux; and no interest in learning how unloved products from Sun Ray to the CMT cryptology processors can produce huge savings and/or productivity improvements for customers.

Honestly, the more you know about "how the SPARC products line up against x86" the less palatable it is.

Sun has too many irons in the fire. On one hand you have the few-core UltraSPARC processors that power the big iron. The servers are big, hot, and not clockspeed competitive with tier-1 x86 hardware costing 1/10th the price.

On the other end you have the T1/2/2+ many-core processors that are woefully anemic price:performers except possibly in trivially parallelized tasks.

My experience (as an engineer in a multi-billion dollar company building from the ground-up over the last couple years) is that there's no compelling reason whatsoever to go with SPARC hardware unless you have to. We've purchased a few products with a legacy on SPARC, and these systems have been treated like appliances by the vendors -- they don't want us using Zones or ZFS, and they don't support us analyzing the applications using DTrace.

Linux is doing to Sun what Sun did to IBM. The difference is IBM had the benefit of more entrenchment and vastly deeper reserves. They managed to evolve away from "pushing iron as an end" to "pushing iron as a means to an end" -- where that end is consulting dollars.
That version's been done, eg. Jordan's Furniture's "If the Red Sox win the pennant, all furniture is free!" promotion. And it works pretty well. I'd imagine that the publicity Jordan's got from that was well worth the money their insurance company paid out.
haha, I can relate, I got a 2-char hotmail address! The amount of spam on that is ridiculous but I still use it. Obviously not my primary anymore.
Nick Bolton At It Again - Set To Shake Up Aussie Domain Registration Industry
Is there a way to make the operator calculus rigorous? Because it's not at all clear which operations are allowed. If we naively used the sort of operations Heaviside used, we could conclude (where p is the operator d/dt) that:

x = 1
=>
x = pt
=>
1/x = (1/p) (1/t)
=>
1/x = ln(t)
=>
x = 1/ln(t)

Which is ridiculous...
I see what you're saying, but in practice I see no correlation between people with great recall of arcane functions and syntax and good developers.

And the question wasn't, "What's the difference between pulling a thread from the pool and spinning up a new one?" That's a pretty good question, if you're going to be doing programming with threads.
That's because it's not.
Rather than put URLs in books, I think it's better to put URLs them alongside them. You can always make updates, and you can save the paper, ink and oil you would have spent printing and shipping a bibliography through the distribution channel.

Press Release: http://www.thinkcomputer.com/corporate/news/pressreleases.ht...

Example: http://www.thinkpress.com/authoritas/resources.html
Just a note: we don't sign our posts/comments here. Your username does that for you.

http://news.ycombinator.com/item?id=198817
URL Shorteners – the herpes of the web
Windows 7 RC Goes to Partners
I'm sorry if this response is off-topic, but your last question piqued my curiosity so I would like to answer it.

There is an authoritative source of random numbers. In 1955, The RAND Corporation (a Cold War-era think tank) published a wonderful book entitled "A Million Random Digits with 100,000 Normal Deviates". Amazon.com has a copy of it, including some amusing reviews: http://www.amazon.com/Million-Random-Digits-Normal-Deviates/... .

For a good source of truly random numbers accessible from an API, I personally use http://random.org . They use atmospheric noise to create random numbers, which ultimately boils down to the true randomness that is Quantum Mechanics. It's not suitable for high-security applications -- I could do some network trickery and redirect your API request to my server that always returns 1.0 -- but it's better than the PRNGs on modern computers.
Actually people are thought to be risk seeking when it comes to losses instead of gains.

http://www.jstor.org/pss/1914185

Unlike most people in this discussion, I like the idea and think it might work under certain circumstances (probably goods with low prices and high price inelasticity).
If x is a function, what does 1/x mean? The inverse of operator p is indeed 1/p (assuming that the integrator has zero initial condition) but let us not start inverting everything at will ;-)
Really? The "Programming Rules" guide took me maybe ten minutes to go through as a newer Erlang programmer. I found the advice to be invaluable.
I check it a couple of times a day, but never for more than a minute. I don't get many notifications. Email is much more important to me and through trial and error I've set things so that I get emailed about important things, and nothing else. That said, it would be very hard for me to go for a few days without having Gmail open.
You're right. The government will give you $1500k of debt to start a business. http://www.sba.gov/services/financialassistance/sbaloantopic...
If they don't like this scheme, you could allow them to pay $X with prob 1.

More generally, you could let them specify the pay probability p or price $Y >= $X. Given p, have them pay $X/p. Given $Y, make them pay with probability $X/$Y.
It is easier to replace a circular cover, since you don't have to worry about it's orientation. I suspect that this is the main reason to use a circular manhole cover over some other shape.
Honestly, I've been at a loss to understand the sudden wave of concern about link rot. In this case, the concern is over URLs published in a book on Python programming. Ten years from now, is this book going to be relevant enough that we'll really have an urgent need for all the online documents it references?

And don't even get me started on people who think it's important to preserve everything ever posted to Twitter...
I have seen man hole covers that were in the shape of other curves of constant width!! as in the rotary engine shape he describes. Reminds me of the convex solids class I took at UCLA years ago.

Boy, I always wanted to say that! If only I could pull one of those interviews.
I'm incredibly impressed that you didn't immediately close the page after seeing that pun.
Hahahaha - I love the last remnants of the old Go.com network of Disney sites. (BTW, this is from Henry Abbott's TrueHoop blog, which was bought by ESPN. It's a very good read about debunking a commonly-held belief about basketball shooting with facts.)
Kadoink Seized By Creditors
Did she quit Mixi too?
Actually, people play the lottery because they can't do math.
Ugh, don't remind me. I was Ray Allen today, and not in the good way.
People pay $99/year for mediocre e-mail just because it syncs with the iPhone.
Q: How do you increase your odds of winning Lotto by 0.0000001%?

A: Buy a ticket
Twitter startups ideas from the Web
The swing dancing fad that you experienced has evolved into a vibrant community of Lindy Hop and related dances. It's relatively small, and few people are aware of its existence... but it's very robust and spread across the world. I would say the community's size is on the same order of magnitude as that of ballroom dancing.

http://en.wikipedia.org/wiki/Lindy_Hop_today

I started doing it 6 years ago. I've been stuck doing it ever since, because of my hacker mindset, but also because of the social scene. Imho, Swing is actually much better for hackers... plenty of women, it's full of other hackers, everyone's a bit geeky, and many folks are hyper-creative and artsy. It's also easy to learn but hard to master... lots of challenge when you get really into it.

I must note that the vast majority of people have many misconceptions about swing dancing. What you saw in the fad bears little resemblance to what's done today. No one really plays Cherry Poppin Daddies or other similar pseudo-swing punk music. Lots of swing DJs are true music geeks, and play swing, soul, blues, and R&B at dances. Real swing dancing is much more about having feeling and jazz musicality than it is about acrobatics. Think of it as tap dancing with a partner. The acrobatics are definitely still around, but are basically restricted to performance. Yes, Swing is not as seductive as Salsa, but the emotion is definitely there.

Great example of what good swing looks like:
http://www.youtube.com/watch?v=P3rlvBQ7nUE
http://www.youtube.com/watch?v=0u0YWCY0sZI

In the Bay Area, check out:
http://920special.com/
http://www.redwoodcityswing.com/

In Boston, check out:
http://www.havetodance.com/calendar.html

In NYC, check out:
http://www.yehoodi.com/frimfram/

There's also a very different family of dance in the swing umbrella, West Coast Swing: http://en.wikipedia.org/wiki/West_coast_swing
Blame the website designer as much as the submitter. Submitters shouldn't have to think about "permalinks".
Slow-motion videos
I"ve done software dev work in environments like this. It was great, I was very productive and still had plenty of time to enjoy.
Ask HN: Non-YC interview, how much biz planning did you do?
Hi everyone,
My team and I are interviewing with a non-YC seed program. The interview consists of a 20-30 minute presentation/demo followed by Q&A.

We're excited and practicing like crazy. Our team is technology oriented and we're noticing this is a weakness. During one mock interview we had our butt kicked for lack of financial planning / projections.

I'm under the impression that these programs are looking for solid technology and a good team, not a full out business plan. But obviously we need some things.

So I ask: How much business planning did you do before applying to YC, TS, DreamIT, Shotput, Capital Factory, AlphaLab or others?

What are some business planning questions every startup should be able to answer? For example, we were nailed for not knowing our projected first year revenue.

Thanks!
You are right. The reviews are worth the trip over to Amazon. I suspect some Amazon programmers are having a little fun with randomness.
But clearly some spooky inversion is allowed, e.g., writing:

v = Lpi
=>
v/i = Lp

I don't even know what that means!
For it to be a lottery ticket analogy, you'd pay half the cost for a 50% change of actually getting the goods
These articles always bug me some what as they usually leave out the issue of technique. There are certainly times when I start heaving the ball at the ring with a lot less focus on technique and without taking the time to set my feet correctly. When I get my act into gear and concentrate on it I'd bet there is greater chance it's going in.

Now presumably this is less of an issue with professional players. I'm guessing LeBron James is a lot more consistent in his technique than I am but it seems like a major variable thats not really discussed.

The argument against the term "hot hand" seems to be against some silly naive notion that the stars align and you are on a shooting streak greater than some fixed probability would dictate.

But I've always thought of the term in the sense of the player shooting well i.e. the player has good technique and shot selection tonight and has raised their probability of the shot going in.

Which of course cannot be distinguished from anything else so I'm no doubt mostly wrong as well but it annoys me it isn't properly mentioned that I've seen.
There is a way that you can do this. You charge $X and simply state that every Yth customer gets it free.

Problem solved.
60 Minutes - Cold Fusion Is Hot Again
Jails are actually very efficient, and well understood and have been tested extensively by the freebsd project. User Mode Linux or handbuilt chroot 'jails' under linux are less efficient (binaries have to be in the chroot and cannot be run from the host filesystem). User Mode Linux is effectively a kernel and userland running under a users UID; it's one of the least efficient forms of virtualisation. Both of these solutions would fall under the class of pseudo-virtualisation, since they depend on a host filesystem and processor, and usually it's less easy to partition memory and harder to guarantee process isolation.

Xen, VMWare and Parallels are all examples of para-virtualisation, where multiple OS's share the underlying hardware, but have their own resource limits in terms of disk and memory access. And the hypervisor exists to manage the timesharing and access control, but the guest OS's are executing directly on the hardware.

From a hosting company point of view, jails on a BSD system are the most tractable and resource efficient, followed closely by any of the paravirtualisation solutions. UML as a hosting solution is kind of cheesy (it's great for networking simulations though). From a customer standpoint, a paravirtualisation solution offers more flexibility and power.
I had a car accident because of a rounded manhole cover. My wife had to emergency stop because a rounded cover in the middle of the road was half open, sitting vertically on top of the hole. Thankfully no one got hurt.