jwco

Faysee solves a problem I have with Snapchat: giving my friend feedback on whether I thought their message was funny or not, and worth posting on Facebook or Twitter, for example.

Faysee makes it easy to get feedback from multiple people easily, or to see if you can make friends/family laugh.

Does the video explain the app clearly?

Does it make you want to try the app?

How could we improve the app or video?

Thanks for any feedback!

Joe Laws (hn: jlaws) built this app with me. Jon Collins (hn: jonathancollins) helped fix some bugs. Jordy Clements (hn: JordyClements) is the funny Snapchat-sending friend, wearing the crustacean hat in the linked video.

I'm interested in these comments. Do you have references and/or search terms for further learning?

It's not clear how memories degrade as you rely on videos more, but it is an interesting hypothesis.

Not clear what you lose. Your brain probably still has whatever memory of these moments it would have without the video, and you can choose not to watch the video. All I think you lose is the time you spend taking the video. But if the moments you spend taking the video are just moments you would spend simply observing, the difference is very little.

here is a way to combine technology and transparency to make it more difficult for someone to do this:

guns owned in America have mandatory geolocation installed. guns lock if geolocation is disabled or hacked, an alert is autosent to local people and authorities with the last known location, and law enforces speedy investigation of the guns whereabouts and reinstallation of the geolocator. i'd like an app that tells me where the nearest guns are to me and some info about who they belong to, i.e. police, citizen, military etc. if a gun is brought near public spaces, schools, theaters, etc., it should tweet, sms, or otherwise alert local police and anyone who would like to know. i'd like to also set my own alerts, such as alert me if a non-police gun is within a few hundred feet of my location, or my kid's location, etc. the constitution says there is a "right of the people to keep and bear arms," but does not use the word "right" to defend privacy.

Thanks, but it's not clear to me that cells die without telomeres or at this Hayflick limit. http://en.wikipedia.org/wiki/Hayflick_limit says they enter senescence. They stop dividing. This seems different than cell death.

That is interesting to me too though. I don't know why cells should stop dividing without telomeres, or with telomeres below a critical length. That suggests to me there is interaction with other cellular machinery at this onset of senescence.

Can you explain this divide further?

I thought the idea was that telomeres are like chaff that the DNA drops over the course of many replication cycles instead of losing "more important" bases of DNA. In that sense telomeres might protect against loss of function (cancers). I did not know they prevented non-homologous end joining, but see how they could. I take it non-homologous end joining could lead to gain of function (cancers).

So what is the divide? Do some people think that telomeres protect cancer?

A comment above (http://news.ycombinator.com/item?id=4846137) suggests something like this. First a cell is converted into a cancerous state, perhaps even due to a lack of telomeres and subsequent loss or gain of function. Then telomerase somehow is upregulated. If there was some error correction process (to correct the loss or gain of function cancer), could the sudden increase in telomerase and telomere length prevent that error correction from occurring?

Hamming makes clear his remarks are about how to do "significant things," and he is using science as a microcosm to describe what that is, only because it is the microcosm he is most familiar with. See here:

"Why shouldn't you do significant things in this one life, however you define significant? I'm not going to define it - you know what I mean. I will talk mainly about science because that is what I have studied. But so far as I know, and I've been told by others, much of what I say applies to many fields. Outstanding work is characterized very much the same way in most fields, but I will confine myself to science."

"They see how much Pao, still merely alleging, is costing a firm such as Kleiner Perkins: time, image and distraction from its main work, finding value."

If Kleiner Perkins practices sexism and/or sexual harassment, then they brought theses costs on themselves.

Forget the suit costing these things. The practice of sexism and sexual harassment by themselves costs "time, image, and distraction from its main work, finding value."

I would not pay anything because the search engine I use doesn't display ads.

$100.00

$10.00

$1.00

I would not pay anything because I don't mind the ads.

Here are a couple reasons why teen me (I'm almost 30 now) may not have preferred eBooks over actual books:

1) I had only moved once in my life, and did not appreciate how much physical space books take up during a move. After moving ~4-5 times since going to college and graduate school, I have vowed to buy only eBooks now. Conveniently, I am also finally basically done buying academic textbooks (for which eBook versions can be scarce), having bought most of the ones I plan to use (often enough to not borrow a library copy) during my PhD and beyond.

2) In my experience, eBooks don't make it easy to annotate. Copies of my books from A Great Gatsby to Introduction to Biology are rife with pencilled in thoughts, arrows, underlines, etc. I've even enjoyed reading notes left by previous students in copies of books I've borrowed from the library (I am thinking of some comments I vehemently disagreed with in the Harvard library copy of Sartre's Search for Method, and to which I responded in turn). In that sense, library books might be more social than today's eBooks, as they can be both shared and annotated.

Actually, I think this is an interesting lie for a different reason. Look at their no. 1 competitor, Google. They had a PhD in computer science as CEO and now a guy who well on his way to a PhD came up with an algorithm that, as far as I can tell, revolutionized search. Why did this Yahoo guy lie? Maybe he felt pressure to keep up with the Google guys, and thought a modest lie about a B.S. in Comp Sci would do the trick while going undetected. It might be sign of the times--that PhDs and PhD-equivalents are heading large companies. And a funny misread too--their 2nd foremost competitor in search was founded by a dude without a B.S. at all.

Addressing your other points: I feel like a CEO should be aware of how he/she is being perceived and correct any mistakes about his/her record.

No need for (b) typos and (c) trolls, but (a) opinions are output that computers currently fail to effectively provide, but things that much of human society currently depends on. I was going to cite medicine and marketing as examples, and act like science doesn't depend on opinion, but that is actually very false. The scientific process is basically 1) experiment/observe (i.e. take pictures), 2) form opinions (calling them "hypotheses") about what we observe and 3) decide what to do next to convert that opinion into a truth value.

I don't know what "music theory" is, and I agree that I wouldn't listen to Radiohead if I didn't like the melodies (there are other mathy/geeky bands out there I don't listen to, an extreme case being Information Society giving you instructions on how to configure a modem to translate their "song" into ASCII, no. 1 listed here: http://www.cracked.com/article_18896_10-mind-blowing-easter-...).

But some theories about music are very mathematical. We probably are just beginning to understand how to think about music in terms of math, because music is complex and (at least much of Western music) discrete. An article in Science in 2008 defines equivalence relations and uses n-dimensional symmetries to describe sequences of pitches in time. See here: http://www.sciencemag.org/content/320/5874/346 and here: http://www.sciencemag.org/content/320/5874/328.full)

I think there is some truth in a Leibniz quote: "The pleasure we obtain from music comes from counting, but counting unconsciously. Music is nothing but unconscious arithmetic." (http://www-history.mcs.st-and.ac.uk/Quotations/Leibniz.html)

It's hard to say why I like Radiohead. At first I really didn't like them; I found Kid A (album) especially discomforting. I had to let go of a lot of pre- (mis?) conceptions about what makes music good before I could come to like it. I probably had to let go of a lot of pre- (mis?) conceptions about myself and my worldview at the same time to appreciate the lyrics. But now it's one of my favorite works of art.

Thanks but I am really interested in reading more about NP hardness in real world situations. Operations research may be a place to start but then my question becomes "Where does NP hardness arise in operations research?"

Here's an example of a creative way to interpret my original question: as xkcd implies, you might say eBay "solves" an NP hard problem http://xkcd.com/399/. Ebay doesn't solve the traveling salesman problem as it is normally posed in computer science, but it rephrased the problem statement in a useful way.

"Playing soccer well depends little on having good ideas."

This statement seems to me to be profoundly wrong.

Perhaps some ways of "playing soccer well" depend little on having good ideas. But soccer is a very complex game: the configuration space of the players on the field is ~2*11 dimensional per team (add the z dimension for jumping and the ball in the air and you see that the total coordinate and momentum space is even vaster than 44 dimensions). Good teams are capable of organizing into configurations on the fly which are more likely to lead to goal than other configurations, and they can do this in response to the configuration of the opposing team. The Spanish team that won the most recent World Cup is a great example of 11 players who self-organize into optimal configurations in real-time.

You might argue that some players can use pure athleticism to navigate through the 44+ dimensional space and score goals. Lionel Messi and Diego Maradona are great examples: see http://www.youtube.com/watch?v=JYet49BToLw. They share a unique build which is suited to their style of soccer playing. They are not tall, have a low center of gravity, they can accelerate and pivot very quickly, and still they have a high top speed. That allows them to make runs like those "Goals of the Century" in the linked video in which they single-handedly beat the opposing team to a score.

However I would still hesitate to say that Messi and Maradona don't need good ideas to make those runs. Exactly where they choose to run probably depends strongly on where the defenders are relative to the ball-carrier's position. Also how fast they choose to run at any moment can depend on how fast those defenders are moving--hence the utility of pivot moves. Watch Messi beat the defender that comes at him from behind at 36-37 seconds, shown from another angle at 48-49 seconds; Messi gives the illusion that he has eyes in the back of his head. But really he has played soccer so much that he can take one glace around the field and calculate which defenders can reach his position and how fast they must be moving and in what direction in order to do so. This is not a trivial calculation to do at the rapid speed required by the game.

One of my favorite positions to play is Center Midfield. This midfielder often has more control than any other player to influence to configuration space of his team. One of my favorite players to watch do this was the brilliant Zinedine Zidane. He was a technically gifted footballer, but that's a relatively small part of why I loved watching him. The main reason is because of his perspicacity and decision-making skills. It is not just as if he has eyes in the back of his head; it is as if he can see the game as we spectators see it, with a birds-eye view. His brain is closer some kind of soccer video game AI that can calculate the optimal place to put the ball based on current configuration of the 22 players.

One of my favorite matches was Zidane vs. Brazil in 2006: http://www.youtube.com/watch?v=SvYlvkWpPy4. Check out what Zidane does at 2:05-2:20. France is already up (on a Zidane assisted goal), so they do not need to score a goal. Still they would rather keep play near the opposing team's goal for the chance to score again and to decrease the likelihood of Brazil equalizing. So Zidane is basically playing keep away for the win. At 2:14 Zidane makes a hand gesture, directing a teammate into the space to his right. Brazil players respond, moving towards the space. Then he makes a pass in the completely opposite direction, which is probably what he planned to do all along. Possession is maintained by France and the clock ticks closer towards their victory.

Truly beautiful.

Just to be clear, the first comment was not a joke: "http://en.wikipedia.org/wiki/Lysergic_acid_diethylamide#Pote...

According to the Wikipedia article on LSD, the US DEA claims that the drug among other things "produces...no lasting positive effect in treating alcoholics."

The TSA chimed in, noting that LSD also produces no safeguard against "things that go BOOM!"

To quote the article: "To complicate matters further, LSD also acts at other receptors."

So LSD appears to interact with more than "one of the signaling systems in your brain."

“Design a two-dimensional cellular automata such that we can create a self-replicating pattern.”

What clients might require cellular automata, and automata such as these?

http://en.wikipedia.org/wiki/Rule_30 and http://en.wikipedia.org/wiki/Cellular_automaton tell me they have applications in cryptography and random number generation. Are there any other areas where cellular automata are applied?

Fair enough. I don't know much about Peripheral Blood Stem Cells in particular, but I am under the impression that stem cells in general are not serving much of a purpose besides waiting around to become differentiated into other cell types.

But I wouldn't be too worried about giving up any of your cells, besides brain/nerve cells.

Almost all our cells have the same genetic information (Red Blood Cells are one exception), so it is theoretically possible to turn one type into just about any other. Shinya Yamanaka's team made a huge step in that direction experimentally about 5 years ago: http://en.wikipedia.org/wiki/Induced_Pluripotent_Stem_Cell

I'm not saying that this is a viable option if you run out of PBSCs (just as it is clearly not yet an option for you to donate skin cells to help Amit), so one thing you may want to find out is if your PBSCs are limited in supply--I don't know (and I am also not in the right demographic for this donation).

I wonder if you excised the word "shamelessly" from this comment, if people would have had a more interesting discussion, i.e. about building a site that enables people (including non-hackers), say in similarly life-threatened positions, to spread word and bring people/marrow/blood/etc. to their aid, and perhaps too, the aid of anyone else in a similar situation. Because I think what you're calling for is interesting: a platform (like Facebook or Tumblr), instead of a single blog.

The first question of the FAQ (http://amitguptaneedsyou.tumblr.com/faq) should have you assuaged.

It's long, so some choice quotes:

"So you've got to always cooperate by random drift. But if we'd always cooperate, now we can guess what happens next: we invite Always defect. You have oscillations here, you have a mathematical model of human history, of economic cycles, of ups and downs."

"There is one thing that I have learned in my studies of cooperation over the last 20 years: there is no equilibrium. There is never a stable equilibrium."

"In an experimental study, people go up and down in trains in Britain and listen to what people are talking about, to find that about 60 percent of the conversation topics fit into this general framework of indirect reciprocity."

"What is very important for efficient indirect reciprocity is language.  Indirect reciprocity leads to the evolution of social intelligence and human language.  In order to evaluate the situation, you have to understand who does what to whom and why.  And we have to have a way to talk about what happened, to gain experience from others."

"As my friend David Haig at Harvard put it very nicely, "For direct reciprocity you need a face; for Indirect reciprocity you need a name."

"If too many others imitate it, it starts to become a losing strategy."

Agree, but Apple has also always appealed to artists/lovers of the arts, and post-return-of-Jobs Apple translated that into the iPod and iTunes/iTunes Store, the latter of which is filled with things like reviews and ads of sorts, or at least digital movie posters and album covers. So I wouldn't be surprised if Siri/Apple found some non-annoying way to turn you on to new movies/music.

Tom Hoover is Drew's fraternity bro, MIT '05 Course 6 classmate, and Bit 9 co-worker prior to Dropbox taking off.

He also installed Gentoo on my old laptop so I could take a Structure and Interpretation of Classical Mechanics.