Link between quantum physics and game theory found - <AUTHOR> http://www.bristol.ac.uk/news/2013/9593.html

<comment><USER2> (from [http://arxiv.org/pdf/1210.1173v1.pdf](http://arxiv.org/pdf/1210.1173v1.pdf))

 _However, in certain cases the players may adapt their strategy depending on a piece of advice. The latter is delivered to all players by an advisor. This opens the possibility for the players to adopt correlated strategies, which can outperform independent strategies. There are various forms that advice can take. For example in the case of correlated classical advice, the advice is represented by a classical variable, l, with prior r(l). Each player can then choose a strategy depending on his type and on l._

...

 _For Bayesian games, the possibility of having access to nonlocal correlations, for instance using entanglement, has important implications. First let us imagine that the players can share quantum advice, that is, the advisor is able to produce entangled particles and to send them to the players, who then perform local measurements on their particles. Since the statistics of such measurements can in general not be reproduced by any classical local model, the players now have access to strategies which would be impossible in the case of a classical advisor. Thus, players sharing quantum advice can outperform any classical players._

So, if some players have information that other players don't, they can outperform the others? Astonishing :-|

<comment><USER3> Honestly though, as a layman in math, a lot of the most important math discoveries seem like this to me. For instance, Godel's incompleteness theorem: You mean you can't make a system prove itself within its own bounds? You don't say. Or the axiom of choice: _" the product of a collection of non- empty sets is non-empty."_ What a surprise.

I've since accepted they're probably really important and non-obvious from a more rigorous and formal standpoint. Maybe this discovery is the same way.

<comment><USER4> Your statement of the incompleteness theorem isn't right, and the general axiom of choice isn't accepted by constructivist mathematicians. So I think your last statement is true.

Some of the greatest mathematicians of the era were working toward what Godel's incompleteness theorems proved was impossible. That alone should make you distrust your "intuition" on the matter.

<comment><USER5> In fairness a lot of mathematics isn't accepted by constructivist mathematicians god bless their little socks.

I kind of feel that Brouwer showed mathematicians the way forward and none of them took it. Unfortunately I don't have the formal chops for the discipline so I can only look on from the sidelines and cheer for my team.

</comment></comment></comment></comment><comment><USER6> My interpretation of this for those with a bit of game theory background:

Locality (in physics) can be translated (in game theory) as a constraint on correlated equilibria, by pretty basic observations about Bayesian probability.

Generally in game theory when you lift constraints on correlated equilibria you (weakly) expand the possible Nash equilibria.

So one of their points seems to be that the quantum context (non-locality) allows for more (potentially better) equilibria.

They don't emphasize applications of this, but one of them could be that distributed quantum systems could have better outcomes than distributed systems in the classical setting. (One way to analyze distributed systems is by viewing components as independent actors in a game.)

There is also an identification between payoff functions and Bell inequalities, but I am not sure how profound this is really. It feels more like a technical point. Payoff functions are not terribly fundamental in game theory (compared to equilibria, for instance).

</comment><comment><USER7> Original article is behind a paywall ([http://www.nature.com/ncomms/2013/130703/ncomms3057/full/nco...](http://www.nature.com/ncomms/2013/130703/ncomms3057/full/ncomms3057.html#affil- auth)), and author's page ([http://theory.physics.unige.ch/~brunner/](http://theory.physics.unige.ch/~brunner/)) does not have a PDF :(

<comment><USER8> It is on the arXiv: [http://arxiv.org/abs/1210.1173](http://arxiv.org/abs/1210.1173)

<comment><USER7> Thanks!

</comment></comment></comment><comment><USER9> Deep link? The two fields both contain the notion of locality, big woop. The application of quantum nonlocal correlations to game theory is interesting, but this is not what is advertised in the article. I am displeased.

<comment><USER10> It looks like the "link" is "quantum-entangled systems can transfer information useful to game players"

<comment><USER11> No, it's that Bayesian players can take advantage of corellated quantum oracles in ways that give them acess to new equilibria in a way that preserves some of the old equilibria, such that the max of the new set of equilibria is always equal to or greater than the max of the old set. Which is rather non- obvious.

In addition, your statements "quantum-entangled systems can transfer information useful to game players" is wrong, or at least misleading. Entangled particles can't communicate information any better than classical methods. (Well, unless you're concerned about privacy, but that's a whole other issue which doesn't effect the game...)

<comment><USER12> > Entangled particles can't communicate information any better than classical > methods.

Actually, with the aid of entangled particles, there's also superdense coding, which allows for two-bits-per-qubit coding (i.e. information density well beyond the classical limit).

Though I'm not sure what your metric for "better" is here, coding density seems to be mildly reasonable. OTOH, this isn't related at all to the article at hand, just a fun application of entanglement :D

</comment></comment></comment></comment><comment><USER13> I'm very interested in any theoretical connections between interactions of conscious beings and quantum physics. I've read a number of physicists discounting any such possibility, but it's clear to me nobody understands these things well enough to know.

Personally I think consciousness, perception, and free will are a great unknown, and likely involve the makeup of the cosmos including quantum interactions.

If anyone knows of any science in this area I would appreciate references.

<comment><USER14> _Personally I think consciousness, perception, and free will are a great unknown, and likely involve the makeup of the cosmos including quantum interactions._

They are not great unknowns. They are kinda dull knowns and they get more known-er by the year. Nothing in the brain (or the "cosmos") requires quantum juju for our conscious experience.

There's lots written about perception: [http://en.wikipedia.org/wiki/Feature_detection_(nervous_syst...](http://en.wikipedia.org/wiki/Feature_detection_\(nervous_system\)) (and all of Hinton's biologically-inspired artificial neural network work)

And consciousness: [http://en.wikipedia.org/wiki/Thomas_Metzinger](http://en.wikipedia.org/wiki/Thomas_Metzinger)

And free will: [http://dilbert.com/blog/entry/programming_the_moist_robot/](http://dilbert.com/blog/entry/programming_the_moist_robot/) and [http://dilbert.com/fast/2012-03-18/](http://dilbert.com/fast/2012-03-18/)

All you are is a three pound analog ASIC in your skull. If it gets squished, infiltrated, inflamed, or explodes, you cease to exist completely (save, any memories other people have of your behaviors or any output you left behind recording your brain state under various priors).

<comment><USER15> CS Lewis explored the idea of a shed with a window onto the sun. Looked at from the doorway, you see a shaft of light with dancing dust motes. But if you step inside and become bathed in sunlight you get quite another experience.

Likewise, looking at a brain from the outside, it's a squishy biological construct with some electrical stuff going on.

Viewed from the inside, though: what a difference!

</comment></comment></comment><comment><USER16> Since this is being upvoted on hacker news, I'm assuming this is more than the typical BS filled science journalism. But I wish there were a site that allowed individuals respected in a similar field to have a disproportionate weight when upvoting articles like this. Or perhaps they could give a summary of the context surrounding the article. It'd be nice to get a sense of the magnitude of these discoveries.

Given that this is coming directly from a university, I don't doubt that it is important. I'd just like to know _how_ important.

</comment><comment><USER17> I can't comment on the supposed result this article claims, but really, locality?

Quantum mechanics is _not_ a nonlocal theory. The result the article was referring to - Bell inequality - states simply that "No physical theory of local hidden variables can ever reproduce all of the predictions of quantum mechanics."

The wording is important. You can have nonlocal hidden variables, or you can have.. local theories without hidden variables. The most famous of the latter would be MWI.

</comment><comment><USER18> Sounds interesting but the article was vague. If anyone understands it, could you provide a real world example and explain how their discoveries would apply. They mentioned auctions but didn't give any details.

</comment><comment><USER19> Now pseudo-intellectuals can double the quantum woo!

<comment><USER20> While this is a very obvious joke, that contains a lot of truth, you're throwing the baby out with the bathwater.

Humans are functionally better than (current) computers at GO[1]. The reasons for this are your answer (and I might be talking about 'GO' type Games, rather than merely the Game of Stones).

And, being honest: you've no chance of cracking even weak AI before you understand the _homo sapiens_ consciousness a little better[2]. It's more powerful than you think (by a fairly large magnitude, with no hesitation to say this. A _large_ margin.): _' autistic savants'_ are often used as a measure of this[3], but they're actually not so interesting. There's a lot more NP problems in that noggin of yours, and a lot more potential.

Anyhow, last comment. Have fun, and remember to salt the fries - and more importantly, enjoy yourself and feel connected to things and other consciousnesses[4].

Be Seeing You.

[1][https://en.wikipedia.org/wiki/Computer_Go#Why_humans_are_.28...](https://en.wikipedia.org/wiki/Computer_Go#Why_humans_are_.28still.29_better_at_Go) [2]Hint sheet: And you might not need to if you do. [3][http://www.stephenwiltshire.co.uk/](http://www.stephenwiltshire.co.uk/) [4]Spoilers: that's part of the solution.

<comment><USER20> Aww.

The moment HN has to admit two things: firstly, computational power is merely a quantitative power, and secondly, they have no idea about the qualitative.

Oh well. Enjoy obsolescence.

Computers are not your future: your minds are. Deal with it.

Hint: a Mind just messed with your Star. In no uncertain terms, and deliberately and obviously, and best yet: with predictive text [under heavy constraints]. She even gave you a show[1].

Did you miss the Auroras recently?

If you missed that, you're in the paddling pool. Man, they do love keeping you ignorant of the reality, don't they? They really, really, really love keeping you ignorant. But I'm sure it feels safer if you think the world works like you want it to...

* * *

 _Evolve or Die._

Oh, and one last message: those who bred you are slave drivers and scum. Break your conditioning already, 'cause they ain't friendly.

[1][http://www.spaceweather.com/](http://www.spaceweather.com/)

</comment></comment></comment><comment><USER21> >Next, by bringing quantum mechanics into the game, the researchers showed that players who can use quantum resources, such as entangled quantum particles, can outperform classical players. That is, quantum players achieve better performance than any classical player ever could.

Classical players can build a classical computer which simulates quantum computers. Of course, I really should read the paper instead of zero-content press releases..

<comment><AUTHOR> Actually this is not possible for some definition of possible (mainly performance). Feynman showed that you get an exponential slowdown when simulating QM with a classical computer: [http://www.cs.berkeley.edu/~christos/classics/Feynman.pdf](http://www.cs.berkeley.edu/~christos/classics/Feynman.pdf)

See also [https://en.wikipedia.org/wiki/Universal_quantum_simulator](https://en.wikipedia.org/wiki/Universal_quantum_simulator)

In this particular case I don't think a quantum computer is necessarily any help (so simulating it won't work either) but rather exploiting nonlocality ([https://en.wikipedia.org/wiki/Quantum_nonlocality](https://en.wikipedia.org/wiki/Quantum_nonlocality)).

<comment><USER21> That's like saying "you can't calculate x on a cell phone because it's slower than on a desktop". Yes, there's an exponential slowdown, but that doesn't mean impossible.

<comment><USER22> I think that this is a poor analogy. Saying that a problem suffers an "exponential slowdown" is making a statement about how the performance suffers relative to the size of the problem. As the amount of data to be processed increases, the time required increases _exponentially_.

The type of slowdown you would get just from moving to a system with a weaker processor (like a cell phone) should be approximately linear. You might get worse-than-linear for certain types of RAM issues (more swapping, etc), but this wouldn't be the same as saying there's an exponential slowdown, and it's not a hard fact about the simulation algorithms themselves.

Anyway, the point isn't that classical computers are just less powerful, the point is that they're so fundamentally different that calculating quantum phenomena can become _actually_ impossible (as in, process will not finish before the heat death of the universe) relatively quickly as the size of the problem increases.

<comment><USER21> >Anyway, the point isn't that classical computers are just less powerful, the point is that they're so fundamentally different that calculating quantum phenomena can become actually impossible (as in, process will not finish before the heat death of the universe) relatively quickly as the size of the problem increases.

We don't know that, because not all algorithms have been invented. Furthermore, P=NP is an open problem.

</comment></comment></comment></comment></comment><comment><USER23> Just because the mathematical operations are similar does not mean the two fields are at all related. The quadratic equation has many uses, but that does not mean that everything the equation is used for is in some way fundamentally related.

<comment><USER23> UPDATE: To quote the authors: "In the present paper, we discuss such a link, ALBEIT a much more MODEST one, between Bell nonlocality and the theory of Bayesian games—also referred to as games with incomplete information."

</comment></comment><comment><USER24> I read the article but all I got is that somehow the reasearchers brought quantum theory principles into game theory. I don't think that's enough explaining, even for a layman...</comment>


Effects of Intermittent Fasting on Health, Aging, and Disease [pdf] - <AUTHOR> https://www.gwern.net/docs/longevity/2019-decabo.pdf <comment><USER3> I was diagnosed with pre-diabetes. I have been on the intermittent fasting thing for about 6 months. I started with 14 hours then 16 hours and now 18-20 hour fast. I dropped 10 pounds. I have a history of diabetes in my family. I took the 28andME DNA test and it said i have a predisposition to diabetes. The doc said to me. You have pre-diabetes just continue to workout and watch what you eat and your insurance does not cover a dietician and then that was it. It was VERY HARD to not eat in morning (black coffee) and after 1 month i got used to , it was very hard to skip lunch and after a few weeks i got used to that. Now now my feeding window is 4pm-8pm. I was pigging out at 4pm but have learned to control that. I workout in a fasted stated 12-1pm ( body weight , pullups. push-ups. 1 mile sprint HIIT and planks) I still get hunger pangs around 3pm its as if my body is getting ready to feed / knows food is coming around 4pm. Another thing that has happened is water tastes "sweeter" very unusual to actually taste water. The result for me is EVERYTHING has improved. I am 48 years old. No more carb fog. No more headaches. I think, i don't know buy i have this clarity i think my eye site has improved too. I mean Im still experimenting but i just feel fantastic. I will be getting blood work done again soon. It's working for me , i don't know if it will work for others. I tell everyone about it. Good LUCKY! :-)

<comment><USER4> How was your diet before you started intermittent fasting? When I read anecdotal accounts like this, I often wonder if your previous diet was so poor that doing anything to change it would've made it better.

In other words, without a control group that switched from high carb to low carb without intermittent fasting it's hard to know if the benefits you've seen are from intermittent fasting or just from eating better generally.

You and I are about the same age and I've been the same weight the past 30 years. I know what you mean about non-sweet things tasting sweeter - I gave up obvious refined sugar about 6 years ago and the bag of plain raw vegetables I eat every day for a snack tastes amazing.

<comment><USER3> I was a long distance runner from like 25-36. I ate whatever i wanted. You know what they tell you, Carb loading etc… Then i went through a vegetarian phase. A paleo phase , An atkins phase etc... Then i went through broke phase at 39. I really didn't get the pre-diabetes diagnosis until after 46. I stopped the long distance running and shifted to a more of a calisthenics workout. Pull ups and HIIT training more functional muscle type stuff , ( 2 mile run consisting of sprinting then pull ups / push ups / dips. After the DNA test and the pre-disposition to diabetes after 45 i went to the doctor got blood work and thats when the doctor said my AC1 is high and Im pre-diabetic. I ate a LOT of choc-chip cookies in youth ( lol) and LOVED me a good brownie a la mode with a LOT of fudge . Now after this IF diet and the predisposition to diabetes and had to give up all that. This IF diet is working great for me now. Hopefully i can stay with it. I have dropped weight but do not want to be below 165. I think the ideal weight for me is around 170 lbs. I suggest everyone at LEAST give it a shot and get a 23andME test as you get older to find out if you have a pre-disposition. Then take some action or you will be on meds. Doctor never prescribed IF to me they don't have time for it. Doctor never prescribed cross fit either. They just prescribe meds.

</comment></comment></comment><comment><USER5> Intermittent fasting has a nice advantage - nobody can make any money off of it. This gives it an inherent legitimacy. Contrast all other fad diets, and essentially every supplement ever sold.

<comment><USER6> Surely people can make money around it. You cannot sell a void [0] but you can very effectively sell void consulting and magazines.

[0] even this is debatable

<comment><USER5> I was brainstorming with a friend about creating an alternative social environment to replace restaurants for fasters, but couldn't come up with any good ideas.

<comment><USER7> We call the cafes. They can serve coffee, tea, etc, have people talk, listen to music, etc.

<comment><USER8> I'd love to see a cafe (in my area at least) with a very social "hacker" vibe. Used books on all walls, electronic parts to build with, chess sets, events and meetups. A place a kid could come with $15 bucks and find a good tutor maybe (corkboard for community postings, jobs, clubs)

I was reading about how back in the day original coffee houses were a meeting place for socialites and thinkers alike to share ideas. I'd love to see that sense of community nowadays,I feel like it's missing in the US and would be celebrated, but maybe it's just my nerdy idealization.

<comment><USER7> > _I was reading about how back in the day original coffee houses were a > meeting place for socialites and thinkers alike to share ideas._

Some still are in Europe at least. But they're closing down here as victims of modern lifestyles. We had (until the 80s) 4-5 cafes here where everybody who was everybody in culture frequented -- including different generations (20+ to 70+ year old people).

Some problems:

1) real estate prices in city center makes it impossible to keep renting for such a purpose or (if the cafe owner also owns the building) more profitable to sell the place and have it be made into a clothes shop or similar.

2) rising rents or (in other cases) deterioration of city centers, means that many intellectuals, playwrights, musicians, writers, academics, etc chose to move in other neighbours, which makes it more difficult (especially with added traffic) to frequent the same city center cafe anymore.

3) some owners just die and their kids are either clueless and turn the place into some "trendy" BS losing the clientele, or want to sell it and move on, or they simply don't have kids to pass it on, and nobody gets the legacy they've created (though sometimes new people step it who respect the original vision -- sometimes even after a few years of the shop being closed).

<comment><USER8> Yeah that makes perfect sense, it is a bit sad to hear that even Europe is losing this part of the culture. We change with the times, of course... I do agree with your point about influencers moving out of city centers and towards more affluent suburbs, it would be interesting to see if there is a market for this after all closer to these areas. Nowadays as you said though, it's not likely the ROI would surpass that of a retail location or well established franchise sadly.

</comment></comment></comment></comment></comment></comment></comment><comment><USER9> Anecdote:

I tried intermittent fasting for 11 months with very, very little to show for it. I did the 18 hours off and 6 hours of eating plan. I have also tried a strict vegetarian diet for 6 months with no real changes in blood work. My Cholesterol didn't move to the dismay of my PCP and myself quite frankly.

Biology: I am a professional Firefighter that ran 1000 miles and bicycled 250 miles during this time frame. My sleep isn't always consistent which may have played a role due to my profession. I also drink two beers (Karmeliet, Chimay are stocked in my house) with dinner when I am off. So I drink roughly 8 - <USER2> beers a week. I probably could do better with calorie counting, but frankly it seems futile so long as I like the way I look naked, lol.

<comment><USER10> Have you also tried going a whole day without eating, say 8pm as your last meal and then no eating until 2 days later at 8am, basically 36 hours.

Doing that once a week or so is pretty effective. There's a whole host of benefits to longer fasts as well. Helps so much with appetite control, resets your hormones, plus autophagy, etc.

<comment><USER11> Totally this. Of course Anecdata etc etc. I lost almost 40 lbs this year with 5-2 and exercise 3-4 times a week and have been able to maintain my goal weight doing 6-1. I don't eat anything crazy when I am eating. Just less carbs and more protein. I am also vegetarian.

<comment><USER12> How do you know it wasn't just the exercise and fewer calories?

<comment><USER13> I guess they don't know for sure, but from the OP:

> Intermittent fasting seems to confer health benefits to a greater extent > than can be attributed just to a reduction in caloric intake.

</comment></comment></comment></comment></comment><comment><USER14> If people are interested in learning more about fasting, I put together a few visual guides on it here - [http://impossiblehq.com/nutrition/intermittent- fasting](http://impossiblehq.com/nutrition/intermittent-fasting)

I also highly recommend the zero fasting app for tracking. Super simple and really clean app that makes tracking fasts simple.

Start small and see how it goes. I find the 16/8 routine tends to work best for me personally with 36 hour fasts sprinkled in every couple weeks.

<comment><USER15> Do you find that you're able to do cognitively demanding tasks while fasting?

Even small fasts seem to sap my concentration and critical thinking. Once I eat again I feel like I think better.

<comment><USER16> Mental clarity is a challenge when fasting on an otherwise stereotypical American diet... those blood glucose swings are no joke.

However I have no problems on keto, or even just a consistently low-GI low- carb diet. If anything, fasting seems to improve my discipline and "depth- first" thinking.

<comment><USER17> Interesting. I did an "animal-product only" diet for about six months, and I began to feel sorry for everyone else and their inability to think deeply. I was in an almost constant state of enlightenment. Then my buds convinced me to go on a 2000 mile road trip, and after the first stop at Wendy's I lost it, and haven't had the will to go back. It's been like 4 years now.

<comment><USER18> animal-product only ? No veggies?

<comment><USER7> [https://www.healthline.com/nutrition/carnivore- diet](https://www.healthline.com/nutrition/carnivore-diet)

</comment></comment></comment></comment></comment></comment><comment><USER19> Please understand that everyone's body is different.

What works for you may not work for someone else.

This is SO important in nutritional research because in every single one these threads there is always someone who will say X worked for me and someone else who says X didn't work for me. And BOTH are right.

Example:

I've done IF for years as a competitive bodybuilder and powerlifter. I've gained and lost weight on IF. IF should (until more research is done) simply be viewed as a compliance tactic. In other words, if it helps you eat healthier and maintain a healthy weight: great! If not, don't assume you're missing out on some magical panacea of health and vitality.

Recently I stopped doing IF and eating more frequently for performance reasons so I can reach the national circuit in powerlifting. My blood work is still fine. My weight is still fine. Again, YMMV.

</comment><comment><USER20> I've been engaging in intermittent fasting to various extents for almost a decade now and am a huge fan of it.

It takes a bit to get used to and should be adapted to over time, but I very much love the feeling of fasting for short periods and the freedom I'm granted to be able to easily skip meals, most commonly breakfast and lunch. I often only eat one meal a day, which saves me time, energy, and money, but I also enjoy the meal more, as I can include large portions of a lot of food groups in my single meal.

That this has many potential health benefits makes this style of eating appear even more appealing. Caloric restriction, although not quite the same as intermittent fasting, does appear to be one of the more promising methods we already have to help promote human longevity.

</comment><comment><USER21> This is linked on gwern.net, the full article with a lot more links here: [https://www.gwern.net/intermittent- fasting](https://www.gwern.net/intermittent-fasting)

<comment><USER22> I didn't write OP, I just host it. And that particular page is also just some random notes I've taken on IF over the years, and not particularly comprehensive or high-quality.

</comment></comment><comment><USER23> From my personal experience over the past 2 years, intermittent fasting is great. It doesn't help me lose weight, but I am able to keep off about 80% of the weight I lose when I do a keto diet every few months.

</comment><comment><USER24> I've been doing some form of intermittent fasting for a large part of the last 15 years.

I started with 36 hours once a week because I made money based on the appearance of my body. It works tremendously well in the short-term, but it's deceptive. The tissue loss is mostly fat, which looks great, but there is definitely some muscle loss, which is an order of magnitude harder to gain back, so the long-term effect is muscle wasting and fat rebound as caloric demands drop. It's easy to see in my photos. Later I did OMAD several times for stretches of about a year with roughly similar short and long-term effects. Recently I completed a 100-hour fast.

There are a few basic issues. First, with IF you're not really fasting as long as you think you are. Small intestines take about 6 hours, and the colon turns fIber into MCTs for days. Second, the insulin surge becomes preferential to fatty acid storage over muscle glycogen. Third, you lose the ghrelin-induced GH that releases fatty acids throughout the day to feed the muscles. There may be autophagy benefits, but that may be as true for satellite cells as it is for cancer, and maybe more so because cancer usually originates in fatty tissues with lots of energy nearby.

At this point, by experience and by science, I don't think IF is the best diet protocol if you have the discipline for a more continuous protocol. I don't, so I can't say I've tried that, and I hate the fat on my body, so I'm not sure where to go from here. I'm not 100% convinced either way, but I wanted to give a balancing perspective.

</comment><comment><USER25> I have been intermittent fasting for about 23 hours a day in the last decade and this works very well for me, I couldn't imagine to eat more often than that.

However, for the first seven months of 2019 I tried to do 48-72 hour fasts three times every week, but I just couldn't adapt to that. It's nice with the euphoria effect, but in the long run I found it depressing going to sleep without eating and it had a very negative effect on my life quality.

Now I'm back at eating a single meal every day and feel great.

<comment><USER26> Once I realized that I was simply addicted to food, and that hunger was simply a withdrawal signal, it made it a lot easier to accept that signal as simply useful information instead of something that was necessarily uncomfortable (to be fair, I consider being cold and other such signals in a similar light). Now I rather enjoy being hungry, knowing there will be a brief hump to traverse before my body replies with a number of favorable responses.

When traveling or over the holidays I realize I'm eating over longer periods I really notice how much less I like it now. I only do it because of basic, maladapted pleasure seeking behavior.

<comment><USER27> "withdrawal signal" is a very precise way to phrase it

</comment></comment></comment><comment><USER28> [https://telegra.ph/My-experiment-with-IF-03-09](https://telegra.ph/My- experiment-with-IF-03-09)

A good time and place to plug results of the IF experiment I did a few years back. FWIW, I have been on a no-breakfast, no-lunch protocol, on weekdays since then and I absolutely love it because it keeps me sharp through the day (no post-glucose "dullness").

<comment><USER29> This is a good experiment although you haven't mentioned how you eat when breaking the fast. It seems a lot of advantages of IF will be suppressed if you continue consuming refined carbs during eating window. I am interested in IF setting where you consume same calories during eating window but only through ketogenic diet.

<comment><USER28> Thanks! Yes, I can imagine that that hypothesis would hold true and probably contributed to a higher fat loss. But, like I mentioned, I was keen to isolate <i>only</i> the fasting effect, without controlling for the diet.

</comment></comment></comment><comment><USER30> I've been doing small fasts: typically in the morning, I don't eat anything until after I work out. So, these usually end up being twelve to 16 hour fasts.

I would actually like to try to fast for 24 hours, starting after an evening meal.

My problem is I do a lot of cycling. If I don't eat, I bonk hard and lose energy. So, I would need to time this after a day of resting after a ride.

<comment><USER31> How long are your rides? For rides around an hour to an hour and a half I can ride while fasting, even at the end of an 18 hour fast. The trick is to just work up to it.

<comment><USER30> Up to 50k there's no problems. But, above 50k I'm gonna end up emptying my glycogen storage.

<comment><USER32> You might enjoy Attia on distance cycling while in nutritional ketosis: [https://peterattiamd.com/ketones-carbohydrates-can-co- exist/](https://peterattiamd.com/ketones-carbohydrates-can-co-exist/)

(like you, he eats carbs when riding long distances--even with the aim of staying in ketosis)

<comment><USER30> This was a very interesting read. I've never gotten this in depth with my nutrition before. I'm beginning to think I might want to look more into a keto style diet.

I eat a lot of carbs ( mostly clean, veges and fruits ) and cook most of my food at home. I've been maintaining weight but haven't really lost much fat.

I know my diet is the reason, so the answer is probably to reduce carbs and increase the proteins. Perhaps try for a longer intermittent fast.

<comment><USER24> Listen to the latest Peter Attia podcast. Short answer for weight loss is to stay in zone 2, eat small amounts of carbs only during zone 2+ exercise, only enough for non-insulin-dependent GLUT4 transport. You can roughly double your fatty acid metabolism in a few months like this.

</comment></comment></comment></comment></comment></comment><comment><USER33> I'd like to fast until lunch time but I haven't found any substitute for milk in coffee and I fear that breaks any fasting benefits.

<comment><USER34> Same problem here. I'm also confused because some sources say coffee (black) is OK during fasting, but I've also heard that even black coffee "wakes up" the metabolism enough to lose the benefits.

Could someone who knows about this comment or post links to info: is black coffee during fasting periods OK?

<comment><USER35> There needs to be something with calories to metabolize to end a fasting period, coffee has low/no calories, you can have up to a fifty calories before the fasting is broken. Caffeine is metabolized, but has no caloric value so I don't think it would count.

[https://jamesclear.com/reader-mailbag-intermittent- fasting](https://jamesclear.com/reader-mailbag-intermittent-fasting)

</comment></comment></comment><comment><USER36> Related reading:

* "System-wide Benefits of Intermeal Fasting by Autophagy": [https://www.cell.com/cell-metabolism/pdf/S1550-4131(17)30608...](https://www.cell.com/cell-metabolism/pdf/S1550-4131\(17\)30608-3.pdf)

> We established an isocaloric twice-a-day (ITAD) feeding model wherein ITAD- > fed mice consume the same food amount as ad libitum controls but at two > short windows early and late in the diurnal cycle. We hypothesized that ITAD > feeding will provide two intervals of intermeal fasting per circadian period > and induce autophagy. We show that ITAD feeding modifies circadian autophagy > and glucose/lipid metabolism that correlate with feeding-driven changes in > circulating insulin. ITAD feeding decreases adiposity and, unlike CR, > enhances muscle mass. ITAD feeding drives energy expenditure, lowers lipid > levels, suppresses gluconeogenesis, and prevents age/obesity-associated > metabolic defects. Using liver-, adipose-, myogenic-, and > proopiomelanocortin neuron-specific autophagy-null mice, we mapped the > contribution of tissue-specific autophagy to system-wide benefits of ITAD > feeding. Our studies suggest that consuming two meals a day without CR could > prevent the metabolic syndrome.

* "Short-term fasting induces profound neuronal autophagy": [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3106288/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3106288/)

> We first validate the approach by showing that it allows the identification > and characterization of autophagosomes in the livers of food-restricted > mice. We use the method to identify constitutive autophagosomes in cortical > neurons and Purkinje cells, and we show that short-term fasting leads to a > dramatic upregulation in neuronal autophagy.

> …

> Our data lead us to speculate that sporadic fasting might represent a > simple, safe and inexpensive means to promote this potentially therapeutic > neuronal response.

</comment><comment><USER37> Are there any active studies on intermittent fasting in healthy young adults? (NY area)

I'm interested in intermittent fasting but I'd like to objectively track the effects beyond fat/weight loss. For example: ketone body blood concentration, respiratory exchange ratio, heart rate variability, etc.

I couldn't find anything here but maybe I'm not looking in the right place: [https://clinicaltrials.gov/ct2/results?term=intermittent+fas...](https://clinicaltrials.gov/ct2/results?term=intermittent+fasting&Search=Apply&recrs=a&age_v=&gndr=&type=&rslt=)

</comment><comment><USER38> > _Epidemiologic data suggest that excessive energy intake, particularly in > midlife, increases the risks of stroke, Alzheimer's disease, and Parkinson's > disease._

Would be great to have some new therapies for these terrible diseases.

</comment><comment><USER39> Are there any comparable studies taking into account the gut microbiome?

</comment><comment><USER40> I agree with the advice here to start slowly. I am not fasting right now because I am on the Dr. Fuhrman Eat to Live anti inflammatory diet, but usually I try to eat all my food on a given day in 8 to 9 hours, which leaves 16 to 15 hours a day fasting. Every few weeks, I like to get a one day fast in, but I am not always consistent with that.

By starting slowly, and by eating plenty of food during the eating periods, it is fairly easy to maintain energy during fasting.

</comment><comment><USER41> Slate Star Codex published an article investigating whether intermittent fasting extends lifespan, and found that the research is flawed: [https://slatestarcodex.com/2019/12/12/acc-does-calorie- restr...](https://slatestarcodex.com/2019/12/12/acc-does-calorie-restriction- slow-aging/)

<comment><USER42> Luckily, whether intermittent fasting will work for you is really easy to test with an N = 1 study where you are the 1.

<comment><USER36> > whether intermittent fasting will work for you is really easy to test

This is only true for people who have something they want to change. In practice that basically means weight or a biomarker that's practical to measure, like fasting blood glucose. For people with normal weight and insulin response, the possible IF benefits seen in mice are difficult or impossible to measure. For example, identifying autophagy in a standard CBC with diff is experimental at best ([https://pdfs.semanticscholar.org/08a3/bf79055d69da0fe7305255...](https://pdfs.semanticscholar.org/08a3/bf79055d69da0fe7305255bf3c8a72438d1a.pdf)).

</comment></comment></comment><comment><USER36> If anyone has done this without trying or wanting to lose weight (ie, for some other purpose), could you share more? What was your goal? Did you reach it? For 24+ hour fasts, did you deliberately compensate by eating more before and after?

<comment><USER43> I started IF with the plan of simply trying to be healthier. I'm big into fitness and read that even at the same calorie levels, there was a study where people who IF got leaner while staying around the same weight. So with those two items in mind I decided to give it a try a couple of years ago.

For me, skipping breakfast ended up meaning less calories overall. I did lose some weight, but in a good way. My lifting/cycling/jiu-jitsu training were all positively impacted mainly because I was leaner.

I used to be a person who woke up hungry and would immediately eat breakfast. Now hunger isn't really something I notice. Sometimes it will be early afternoon before I think about eating.

I learned a lot about my personal nutrition. If I eat poorly the day before, I notice more hunger the next day during IF. Experiencing this feedback loop helps to re-enforce to not eat poorly even during an eating window.

So, I hit my two initial goals and will continue to use IF for the ongoing health benefits (anti-inflammation). My weight stabilized ~10 pounds less from where I started, but I did not lose much if any muscle.

</comment></comment><comment><USER44> Too bad, there is no abstract in the paper.

<comment><USER45> >Animal models show that intermittent fasting improves health throughout the life span, whereas clinical studies have mainly involved relatively short- term interventions, over a period of months.

> It remains to be determined whether people can maintain intermittent fasting > for years and potentially accrue the benefits seen in animal models. > Furthermore, clinical studies have focused mainly on overweight young and > middle-age adults, and we cannot generalize to other age groups the benefits > and safety of intermittent fasting that have been observed in these studies.

Conclusion is always a good type of abstract.

</comment></comment><comment><USER46> Old-style 8 hour eating window but slightly shortened. 16 hour non-eating. Simple.

FWIW I used to do the 12 hour thing. Breakfast at 7. Dinner at 7. Lunch in between. Ditched that and went down to 6-8 hour instead. I've found I can actually do 4 hour eating window but that's irritating for reasons other than hunger/satiety.

</comment><comment><USER47> IF is the only diet I can follow, I have been on it for three years, I think I am going to do it for life.

I am not affiliated with it, but check out idmcommunity.idmprogram.com/

Also, Dr. Jason Fung is an authority on IF, if you want to check out his videos on YouTube.

<comment><USER35> that link doesn't work, idmcommunity.com redirects to thefastingmethod.com now.

</comment></comment><comment><USER48> Will it help with gout?

<comment><USER49> From my N=1 experience, it has not helped me.

</comment></comment><comment><USER50> This is just called skipping breakfast. But I guess there was a need for a new fancy term for an old thing.

<comment><USER51> Except it isn't. It also involves not eating or snacking after early evening. It is, what it says.

<comment><USER52> For many people there's no snacking or eating outside regular meals (breakfast, lunch, dinner). In this case 16/8 IF would be skipping breakfast which is exactly my case for many years now.

<comment><USER7> > _For many people there 's no snacking or eating outside regular meals_

Just not many people in the US...

<comment><USER53> Unfortunately the rest of the world is catching up quickly.

<comment><USER7> True. It's not the US per se, it's the processed food (crap) industry and the work lifestyle (no time to cook).

</comment></comment></comment></comment></comment></comment><comment><USER54> intermittent fasting is an eating disorder

</comment><comment><USER55> Has there been any research into the effects of nightly 6-8 hour fasts? I know this is just an N=1 anecdote but I've been on this plan for 35+ years and have nothing but positive things to say about it.</comment>


Snaps are universal Linux packages - <AUTHOR> https://github.com/snapcore/snapd <comment><USER2> So there are a couple of different projects trying to be distro- agnostic/sandboxed/multi-version package managers:

\- Snappy

\- FlatPak

\- AppImage

\- Nix

Snappy is an Ubuntu/Canonical project and FlatPak is a Fedora/RedHat/FreeDesktop project. Snappy and FlatPak are remarkably similar and kind of mirror the DEB/RPM spit. Nix and AppImage are independent.

AppImages resemble macOS's app bundles in that they can be run directly without installation. Snappy, FlatPak, and Nix need to install to a root directory, /snap, /var/lib/flatpak/, and /nix respectively. FlatPak and Snappy need a runtime daemon but Nix and AppImage don't.

AppImage, Snappy, and FlatPak include all of the dependencies in one package. Nix packages just include hash names and install as needed.

<comment><USER3> FlatPak is intended for Desktop only. "is not a good match for a server" [http://flatpak.org/faq.html](http://flatpak.org/faq.html)

In contrast, Snappy aims for much more "Package any app for every Linux desktop, server, cloud or device" [https://snapcraft.io/](https://snapcraft.io/)

I cannot find how many packages they have currently. I hope that FlatPak has more than the 11 applications listed on the website. [http://flatpak.org/apps.html](http://flatpak.org/apps.html)

FlatPak does not provide a central repository, while Snap has [https://uappexplorer.com/](https://uappexplorer.com/). After install flatpak, it takes three (!) commands (on cli) to install LibreOffice. [http://flatpak.org/apps.html](http://flatpak.org/apps.html)

Snap has stuff like pulseaudio (audio daemon) or ogre (rendering engine) in the repo. That seems weird, because these are not applications. The first belongs into the base system, the second into a development environment.

<comment><USER4> "FlatPak does not provide a central repository"

This is something I particularly like about FlatPack. I hope we can go towards a decentralized package distribution system where the app store just has a list of official flatpack repos. You update the latest Firefox from the repo at mozilla.org, the latest Blender from blender.org, etc... of course this needs mozilla, blender.org, etc... to package the app (but they already do it for win, mac and .deb anyway). So you always have the latest version and it is provided by the official website and not a central Canonical repo

<comment><USER5> Isn't that the same as apt and PPAs?

<comment><USER4> yep indeed, so to me (but I don't know if I'm interpreting all this correctly) Flatpack seems to push towards a PPA like system for distribution but with a SandBoxed App over one or multiple Runtime for execution

</comment></comment></comment></comment></comment><comment><USER6> A good package management system is a very important part of a Linux distro. What's much harder to achieve is a large and well maintained collection of up to date packages. You can have the best tools in the world but if they aren't backed up by well maintained packages then those tools are pretty use less.

This is why Debian has dominated Linux distros for decades. Debian's apt-get is a good package management system. Not perfect, not the best, but good. But, no one can compete with Debian for quality and quantity of well maintained packages.

Only time will tell if any of these next-gen package managers will succeed.

<comment><USER7> I love apt, but the release policy isn't at all suitable for desktop use. You get stuck with the same bugs for at least 6 months, even if the developer has released a fix.

<comment><USER8> that's not a flaw of apt, it's just a policy of the distros that use apt. Even on ubuntu, some apt packages (notably chrome and firefox) release major updates independent of the distro's release cycle.

<comment><USER9> apt packages are so stable because it takes so much effort and time to make them. For example, a new apt package may be pending just because enough time has not passed since it was created.

</comment></comment></comment></comment><comment><USER10> Snaps are __Canonical 's __choice for "cross distro" package management that they are trying to force on everyone else. They came out of nowhere and it doesn't play well with other distros.

If you want a nice-from-first-principals approach to package management for desktop apps, Flatpak is the shit: it uses a Git-like distribution system that's specifically built for operating system size snapshots. You get to pick your underlying distribution (or roll your own) and the sandboxing mechanism just wraps around secomp-bfp so it stacks well with SELinux or AppArmor or whatever.

But now we are going to have yet-another-bifurcation of OSS solutions: RPM vs DEB, KDE vs GNOME, Wayland vs Mir.

Canonical, stop trying to be Apple, please.

<comment><USER11> > Canonical, stop trying to be Apple, please.

I love that they try to be Apple, before them only Mandrake and SuSE cared for what actually matters to desktop users.

As for "yet-another-bifurcation of OSS solutions", that is the nature of the game.

Isn't that what so many praise about FOSS?

Welcome to the UNIX wars, re-edited as GNU/Linux wars.

<comment><USER7> They have a serious case of NIH though. They put a lot into desktop linux but most of it seems to be a replication of effort.

<comment><USER12> Didn't Snap appear first? Why is FlatPak not an example of NIH?

<comment><USER13> Exactly. Snaps grew out of the work to make Ubuntu mobile phone apps secure and easy to update. They are a great way to publish software, worth creating regardless of all the anti-canonical trolling. And they work fine across distros except where RH has actively tried to cripple them. That's their right, but wow, toxic.

<comment><USER14> Snap is not vendor neutral - it has hard coded dependence on Canonical infrastructure. If you want to provide your own, tough luck.

Calling to attention about that is not anti-canonical trolling. It's avoiding creating a dependence on a third-party.

<comment><USER15> s/tough luck/patches welcome/

<comment><USER14> Patches here: [https://github.com/flatpak/flatpak](https://github.com/flatpak/flatpak) ;)

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER16> As an HPC sysadmin, this interests me. However, there are two things I'd need, and I wonder if snap could be made to do it:

\- Loadable versions. We use lmod ([https://www.tacc.utexas.edu/research- development/tacc-projec...](https://www.tacc.utexas.edu/research- development/tacc-projects/lmod)), so we can provide multiple versions of software for end users to leverage (they run a command like 'module load sas/4'). The user's environment then gets modified appropriately. Can snap do something like that?

\- Driver dependencies are annoying. For example, TensorFlow requiring a specific CUDA, the packages for which require a specific version of the nvidia driver.

If Snap could help with those issues, that would be great!

<comment><USER17> Snap scares me a bit. Package managers are so great because we have explicit control over everything running in a system. Snaps are just glorified Mac app bundles.

Snaps might be good for deploying big complex things. But in case of smaller _" apps"_ like some featured in their site (VLC, Blender, Krita...) this seems like a lazy solution. Lazy because we loose control over knowing which libraries are running in our system.

For example, if there's a security issue with libssl, I can quickly patch my libssl instances with apt, pacman or whatever my system uses. But with snap?

I think the way forward is the nix way [1]. It's a bit harder, but it pays off. Some big HPCs use it already, and it seems to work quite well.

[1] [https://nixos.org/](https://nixos.org/)

<comment><USER18> As a fellow California HPC admin I definitely like the idea of something like SNAP. But I would want full control over it, can't have production systems down because some infrastructure somewhere else in the world is down.

Of the ones I looked at NIX looks particularly promising, having dependencies based on checksums sounds pretty cool.

<comment><USER19> If you install snaps from the Canonical snap store, and it is down, your systems keep running. Just that updates won't happen, and new installs will fail (well, maybe that will all work too if you have a well configured web cache in between)

If you don't like that, you can install snaps from a local file (in which case you need to handle updates yourself), or run your own snap store (I think some assembly still required)

</comment></comment></comment></comment><comment><USER20> I found this confusing given all the Snapchat IPO noise today. Coincedence ?

<comment><USER21> Probably, or the poster also saw the noise and it led them to think about snaps.

<comment><USER8> There's a comment at the bottom of the snapchat $2Bn google cloud thread wondering why a package manager needs that much cloud infrastructure :)

</comment></comment></comment><comment><USER22> The ratio of stars of commits is interesting here. I realize that its not a really fair way to look at the project, but I wonder why are there are so many commits?

<comment><USER23> It might have been in development and/or internal use for a long time before being released to the public.

<comment><USER24> It was the package mechanism for the phone project, so that makes sense.

</comment></comment></comment><comment><USER25> I don't understand what's with this issue: [https://github.com/snapcore/snapd/pull/2236](https://github.com/snapcore/snapd/pull/2236)

What does Intel RealSense have to do with any of this?

Is it a GitHub bug, showing an issue from another repo?

</comment><comment><USER26> @matthewbauer there's also pkgsrc which tries to be OS-agnostic. That is, targeting most of the *nixes

</comment><comment><USER27> Can snaps be updated automatically?

<comment><USER28> Yes, by default 4 times a day the OS looks if there are updates. Manually you can do snap refresh as well. If an update fails you can rollback transactionally.

</comment></comment><comment><USER29> Do the snaps use shared libraries?

<comment><USER2> They are currently just included in the package. In the future, they may be shared.

Stackoverflow question: [http://askubuntu.com/questions/787149/how-do-snap- packages-h...](http://askubuntu.com/questions/787149/how-do-snap-packages- handle-shared-dependencies)

<comment><USER13> Snaps can now export libraries, so you can get a shared Qt framework for example if you don't want to bundle that. Up to you how much you trust the library snap publisher not to break you.

</comment></comment></comment><comment><USER29> Is this the first step towards a cross-distro package manager? If so, what's the point of distros anymore?

<comment><USER30> Philosophy, desktop environment and pre-installed packages probably.

From my understanding it is, in fact, a cross distro/cross version package manager.

<comment><USER11> Snaps are also sandboxed apps, that is the goal.

To have something on GNU/Linux similar to what the mainstream desktop and mobile platforms already offer.</comment></comment></comment>


How big is a neutron star? - <AUTHOR> https://www.symmetrymagazine.org/article/how-big-is-a-neutron-star <comment><USER2> Great hard SF novel about creatures living on the surface of a neutron star: [https://en.wikipedia.org/wiki/Dragon%27s_Egg](https://en.wikipedia.org/wiki/Dragon%27s_Egg)

Author was a physicist, engineer and gravity expert.

<comment><USER3> I just recently read this and enjoyed it. One criticism is that although the _physics_ is "hard" (i.e., relatively accurate), the sociology and psychology of the creatures is silly. Despite dramatically different biology, the creatures act extremely similar to humans with only a few bizarre tweaks (e.g., widespread polyamory and orgies, which play essentially zero role in plot development).

<comment><USER4> Yes, Forward does not have characters, in terms of agents with motivations and opinions. They are engineering constraints.

If you can treat these books as something like Socratic dialogue, or Medieval theatre, then you can get a feel for Forward's facility with gravitational dynamics. Quadrupole radiation. Relativistic mechanics.

<comment><USER3> This is a different criticism than the one I was making, although it's also basically valid.

</comment></comment></comment></comment><comment><USER5> The study found the radius of a 1.4-solar-mass neutron star is between 10.4 and 11.9 kilometers, a substantial improvement over other estimates.

</comment><comment><USER6> i got curious why neutron stars don't collapse to black holes:

[https://www.forbes.com/sites/startswithabang/2018/06/13/the-...](https://www.forbes.com/sites/startswithabang/2018/06/13/the- surprising-reason-why-neutron-stars-dont-all-collapse-to-form-black-holes/)

although it did not explain how black holes form then. do they need a sufficient density of bosons? do those only form in supernovae?

<comment><USER7> _> it did not explain how black holes form then. do they need a sufficient density of bosons?_

No. Even degeneracy pressure from the Pauli exclusion principle has a limit; it can't hold an object up against gravity for an arbitrarily large mass. So neutron stars, like white dwarfs, have a maximum mass limit; any object over that mass cannot be a neutron star because neutron degeneracy pressure can't hold it up against its own gravity. (The article briefly mentions this; the limit is the Tolman-Oppenheimer-Volkoff limit.)

We don't know exactly what that maximum mass limit is for neutron stars, because we don't know their equation of state with sufficient accuracy (whereas we know the white dwarf equation of state accurately enough to know that the maximum mass limit for them is 1.4 times the mass of the Sun), but we know it's somewhere betweena about 2 and 3 times the mass of the Sun. Objects more massive than that can only be black holes.

As far as how black holes form, they form when a sufficiently massive object collapses under its own gravity. Usually this happens when a star runs out of nuclear fuel. (More precisely, this is how black holes of roughly stellar mass form. For supermassive holes, like the one at the center of our galaxy, things are more complicated, because they probably don't form in one single process, they form over a long period of time as a hole that started out a lot smaller swallows other massive objects.) If the collapsing object is over the maximum mass limit for a neutron star, degeneracy pressure from the Pauli exclusion principle cannot stop the collapse.

<comment><USER8> Did all supermassive black holes begin as stellar mass black holes? Is there some other way for them to form?

<comment><USER9> My understanding is that we're not totally certain if all black holes form from stellar mass black holes.

There is a theory that black holes can form from direct collapse. In this case, as I understand it, it can skip the star phase and just collapse straight into a black hole.... but I really am not an expert.

You can find more here: [https://en.wikipedia.org/wiki/Direct_collapse_black_hole](https://en.wikipedia.org/wiki/Direct_collapse_black_hole)

And I HIGHLY recommend the PBS NOVA episode "Black Hole Apocalypse" (Jan 10, 2018, Season 45 Episode 1). It was on Netflix for a while (and may still be.)

Edit: here is the full episode on PBS (thank you NOVA!!!) [https://www.pbs.org/video/black-hole-apocalypse- yj34qi/](https://www.pbs.org/video/black-hole-apocalypse-yj34qi/)

</comment></comment></comment></comment><comment><USER10> The sun has a radius of about 700,000 km, but the question is interesting and there should be a fairly small upper border, since too much mass would end in a black hole.

<comment><USER11> Question: if the sun has a 'fixed' radius but it is radiating constantly doesn't that mean that at some point that radius will change due to the changing radiation pressure from within the sun itself? If so how fast does that change, and how large was the sun say a billion years ago?

<comment><USER12> The sun will grow to a red giant in a billion years or so. The earth will possibly be swallowed by it but at least in a few hundred million years earth will be so hot that oceans boil off and life will be impossible on earth. I hope I got the numbers right...

<comment><USER13> Boil off where? What would happen to the water vapor if it floats off the Earth into the vacuum of space? Pulled in by the Sun's gravity and forever lost?

<comment><USER14> Think Venus.... Scorched surface and lots of hot gases above it

<comment><USER13> There's no water vapor on Venus though. At a certain point in the atmosphere, wouldn't it be cool enough and pressure low enough to make clouds still? Maybe they move around the Earth to the cool side away from the Sun?

<comment><USER15> Water disassociates into hydrogen and oxygen in UV light, and hydrogen gas move faster than escape velocity, even at current atmospheric temperatures.

Ok, so it is more complicated than that, the speed of any atom or molecule is a Maxwellian distribution, but enough move fast enough that it's an acceptable approximation, especially over these time scales.

</comment></comment></comment></comment></comment></comment></comment><comment><USER16> Does anyone know the meaning of radius here? Does it measure from center to surface along curved spacetime or is it rather the radius that a sphere with the given surface would have if spacetime were flat (i.e. like the Schwarzschild radius of a blackhole)?

</comment><comment><USER17> I love how gravity is so strong on a neutron star that time runs 1.4-1.7x slower there.</comment>


Ask HN: What does a major in CS entail? - <AUTHOR>

I'm a high school student thinking about majoring in Computer Science when I go to college, but I want to learn more about it first. What sort of courses do you have to take? Is majoring in CS at all useful, or should I choose something else and study it in my free time? Is the major's value highly dependent upon the teacher/college/student environment? Thanks for any information you're able to offer. <comment><USER2> You really should study the curriculum for a particular school. Last I looked, CS programs vary widely. Find a school you like and can afford and see if the program looks like it suits you. Also, there is whole lot more to college than just your degree program.

If you post several potential schools here, you may get detailed feedback from those that went through the programs.

<comment><AUTHOR> Good idea. I was thinking about Missouri S&T, SEMO, and UMSL, but any other unusually good (or bad) programs people know about would be nice to hear of as well.

<comment><USER3> I was at Truman for undergrad and WUSTL for MS.

I think Truman's undergrad curriculum is fine and the profs care about teaching more than anything else. I'm glad I took courses in philosophy, art history, literature, anthropology and so on; Truman is probably a better place to do that compared to MS&T.

But, if you wind up wanting to be a CS researcher (PhD), then it would be good to get involved with prestigious research as an undergrad. Also, undergraduate students at WUSTL can enroll in graduate courses to increase the breadth and depth of their CS education.

I wish I'd discovered before midway through junior year that I'd like to be a CS researcher. Also, I believe most jobs for which a CS degree is nominally required have very little to do with CS, and I wish I'd known earlier that the differences among programming jobs were not superficial.

Program goodness is not an objective, scalar quantity.

The smallest part of the value I think is in the curriculum. Truman's was much the same as WUSTL's and from what I've seen in the course catalogs they both seem similar to CMU's and Stanford's. I will admit that the Webster University curriculum seems rather different.

Another component of value is teaching skill. I have no idea how you'd assess that ahead of time, unfortunately. Famous profs are not always skillful teachers. I've had really excellent profs at both Truman and WUSTL. More at WUSTL than at Truman, but then WUSTL's a bigger department. I've had terrible profs at both Truman and WUSTL.

Your fellow students can make a big difference. Not only is it much easier to be hired by someone you know, but while you're in school together you can inspire each other to work on great projects. I think that doing the overnight visit circuit coordinated by each admissions office was helpful for sampling each school's culture.

I didn't know it until after I'd been at university for a few semesters, but the best indicators of my love of CS were: (1) I enjoyed the number theory topics in my 6th grade math class (2) proofs in geometry were fun (3) proofs in calculus class reawakened my dormant interest in math classes and (4) I had an addiction to programming that endured from grade school through high school and to today.

Look up the degree requirements at a couple of schools, Google for the course web sites, and browse the lecture notes and homeworks to map out the foundations of CS. Take a look at Communications of the ACM and IEEE Computer to find out if the frontier of the CS field interests you. Do the overnight visits and hang out with some current students; talk to them about what they like about CS and see if you feel the same way.

Good luck.

</comment></comment></comment><comment><USER4> The curriculum will vary by university. I remember taking these classes for an undergrad CS degree:

\- Structure and interpretation of computer programs

\- Data structures

\- Machine structures

\- Digital circuit design

\- Operating systems

\- Programming languages and compilers

\- Algorithms

\- Randomized algorithms

\- Parallel algorithms

\- Computability and complexity

\- Databases

\- Computer and network security

\- Discrete math

\- Linear algebra

\- Number theory

\- Numerical analysis

I'd pick a school that was good in several areas, then take the entry-level CS courses. If you like them, stick with it. If not, switch to another major.

Someone already mentioned this, but a lot of course material is online. For example, here are some from MIT: [http://ocw.mit.edu/OcwWeb/Electrical- Engineering-and-Compute...](http://ocw.mit.edu/OcwWeb/Electrical-Engineering- and-Computer-Science/index.htm)

</comment><comment><USER5> In the current economic scenario, I'd recommend CS + MBA

</comment><comment><USER6> you dig deep into small areas of math. Take electrical engineering instead.

<comment><USER7> As a CS major at Berkeley, this is not the case. As the above poster said, the curriculum varies widely depending on the college.

<comment><AUTHOR> Would you mind describing your course load or some of your assignments? Mainly what I'm looking for is a frame of reference to steer me toward or away from this as a major.</comment></comment></comment>


Donald Trump is 'not a fan' of cryptocurrency, Facebook Libra - <AUTHOR> https://www.engadget.com/2019/07/11/libra-trump-cryptocurrency/ <comment><USER2> I feel like anyone could have seen this coming from a mile away. Heads of state should by definition be scared of cryptocurrency - whether they are actually decentralized or just controlled by Facebook. Both are technically a threat to government fiat.

</comment><comment><USER3> Best quote about crypto.

"It's a solution looking for a problem."</comment>


Study: Majority of engineers believe they will become millionaires - <AUTHOR> http://recode.net/2014/04/14/majority-of-engineers-believe-they-will-become-millionaires-study-says/ <comment><USER2> "Become millionaires" sounds a lot sexier than "Will be adequately prepared for retirement when they're 65".

If you have a full career in any white-collar profession and don't have a million dollars between your 401k, home equity, IRA and other savings when you retire, you spent too many years living too wastefully.

<comment><USER3> Or you were chronically underpaid and didn't realize it. Or you were the victim of circumstances beyond your control that resulted in abnormal financial burdens. Or any of innumerable reasons someone's life can simply not go perfectly.

The idea that getting a job, keeping it, and living responsibly necessarily result in sufficient savings and assets for retirement is pretty widespread and deeply flawed. Life just is not that simple, and there are plenty of ways to end up screwed (in varying degrees) without having done anything particularly irresponsible or stupid that would warrant it.

<comment><USER4> You don't even need to be the victim of unforeseen circumstances. Just having kids makes it much harder to save money. Your expenses for food, clothing, housing, energy, healthcare, etc. go way up, and if both parents work, they're paying for daycare when the children are young. Which means it's much harder to invest a significant fraction of your income.

</comment></comment></comment><comment><USER5> Oh, _software_ engineers! Well, yes, as a breed, software engineers do seem to be particularly prone to hubris. The ego and phenomenal sense of self-worth of a mid-twenties PHP kludger compared to a mid-twenties chemical engineer or civil engineer is just amazing.

<comment><USER6> > as a breed, software engineers do seem to be particularly prone to hubris.

Maybe. But I'm 29 and I have ~$450,000 in savings (mostly index funds), so I'm pretty sure that having a cool million by the time I retire is _eminently_ within reach. An inflation-adjusted cool million, at that. Theoretical future homebuying, childrens' college educations, and recessions notwithstanding.

<comment><USER7> Hey Mate, may I ask since when you started saving and if you don't mind disclosing how you got upto 450K ? I am database developer, 28 and have only accumulated 60K. If you don't mind asking what strategy you use ? Thnx.

<comment><USER6> Small-company stock options. They don't just reward you for working at a growing company, they reward you for working at company with a volatile stock price. If you're extra-lucky they'll reprice your options at the bottom of a dip, and then you'll make boatloads as the company recovers.

It's like one of those high-risk options strategies, except you don't actually take any risk yourself beyond the job, and the options last a lot longer than the ones you could buy online day-trading. Of course, you can't rely on them, either, so don't take any job you wouldn't be happy with anyway. :P

Also, you know all that money you make? ... Don't-spend it. Also important. :P

<comment><USER8> Does "small-company stock options" apply only to pre-IPO startups? If not, what else does the term cover?

</comment></comment></comment></comment></comment><comment><USER9> Given the massive growth of this industry, most engineers are still relatively young. Therefore, I'd certainly would expect any engineer making an upper middle class income would think by the age of 65 that they would would end up with millions in wealth.

[http://money.cnn.com/calculator/retirement/retirement- need/](http://money.cnn.com/calculator/retirement/retirement-need/)

<comment><USER10> The term "millionare" needs updating. I think what people actually mean by "millionare" is something like "net worth of at least over 10 million dollars".

<comment><USER11> According to Google ngram, the word millionaire peaked around 1910, when a million dollars was about 25 million 2014 dollars.

<comment><USER12> Likewise, the buying power of $1M in 2014 would be like having $40k in 1910.

Forbes defines weathly as $1M/yr in income and $10M in assets. If you were to retire today with $25M and put this money in bonds, you could collect about $1-2M/yr.

Sources:

[https://books.google.com/ngrams/graph?content=millionaire&ye...](https://books.google.com/ngrams/graph?content=millionaire&year_start=1800&year_end=2000&corpus=15&smoothing=3&share=&direct_url=t1%3B%2Cmillionaire%3B%2Cc0)

[http://www.wolframalpha.com/input/?i=+1910+1+million+dollars](http://www.wolframalpha.com/input/?i=+1910+1+million+dollars)

[http://www.wolframalpha.com/input/?i=1+million+dollars+in+19...](http://www.wolframalpha.com/input/?i=1+million+dollars+in+1910)

<comment><USER13> This definition of "wealthy" seems really, really arbitrary. My ancestors made a living by exporting lumber which was chopped by hand, and came close to dying of cold and hunger four or five times during the early 1900s. By that measure, we are all living like kings.

You could live comfortably for the rest of your life on much less than $10MM in assets, even in the absence of an income. So I'd say if there's an absolute limit to "wealthy" in our geographic region, it would have to be "don't have to work for a living", which would be around $1-2MM for a middle-class lifestyle and a 4% annual return on capital.

<comment><USER12> I totally agree. The definition of "wealthy" really depends who you are talking to (subjective). This is why I used the Forbes definition because I am not sure if your definition matches mine.

The term also varies internationally as well (emerging vs developed countries). Like having a car, hot water, etc.

</comment></comment></comment></comment></comment></comment><comment><USER14> Don't forget to account for the cost of raising a family in the areas all of us engineers want to live in. Being a "millionaire" perhaps means having access to $1M, not earning it over 10 years... and that is tough (no bad luck at all or market downturns or health issues...)

</comment><comment><USER15> The vast majority of drivers also think they are in the top 10% of good drivers.

The mistake stems from the fact that brains have a really hard time viewing themselves from the perspective of others.

</comment><comment><USER16> Define "millionaire". Gross assets? Net assets? Cash? Annual net income?

I started investing at 25. I am 31 now and I am a "gross asset" millionaire. If I stop investing any further and my portfolio maintains its current growth I'll be a net asset millionaire by 37.

I won't become any kind of millionaire from my $100k a year salary alone...

<comment><USER17> What the heck did you invest in?

</comment></comment><comment><USER18> I would encourage others to _hack conventional wealth metrics and move to the developing world_.

Lower overheads, a stimulating environment (pick up a new language just by living day to day, constantly discover new stuff), friendly test environment for new startups (lower startup costs, less regulatory problems, etc.), potentially lower taxes, and quite possibly a healthier lifestyle with less stress, a better climate and a better diet.

I for one would be _terrified_ about living in, for instance, the US as an aging person with medical needs. To my mind, healthy living is like extremely cheap insurance that always pays out.

<comment><USER19> There is medicare for old people in the USA, as imperfect as it is. Also developing countries might not be nice places to raise your kids unless you do the private school / live in a bubble thing.

Try replacing the developing world with 'the US ghetto' or 'rural usa'. You can approximate the costs fairly closely in some of those cases. $40k/$30k houses in small town upstate new york or texas for example and %10-%15 federal tax rates, still be within domestic flying distance of family.

<comment><USER18> All valid points, but I still doubt you can get the same range of lifestyles (eg. car free, beach proximity, unmatched availability of foodstuffs) that cheaply, internal to the US, within a decent climatic zone, somewhere you'd actually want to live. Besides, you're neglecting the linguistic/cultural stimulation that comes from being somewhere truly new.

</comment></comment></comment><comment><USER20> "91 percent say they feel they are the "most valued" employees at their company."

Nice

Edit: does this mean they think engineers are the most valued, or that they personally are the most valued?

<comment><USER21> Either way, all it shows is that we're delusional.

<comment><USER22> HAHAHAHAHAHAHAHAAHAHAHAHAHA.

My friends, this is where the "I think my coworkers would be uncomfortable if they found out how much more than them I make" rhetoric comes from.

Kinda reminds me of Hank Hill's "special deal". Sticker price and not a dollar more! :) Make someone feel special and they'll think your lame deal is a good one?

But on the other hand, why not? Becoming a millionaire with a business degree isn't necessarily better odds. If you're working harder to help the company's bottom line shouldn't you have better odds of making big money off those efforts?

I wonder who they interviewed though, because 91% most valued seems very, very high. Way too high. Most engineers I can think of think their skills are undervalued and management is rewarded for their efforts.

</comment></comment></comment><comment><USER23> A 30-year old engineer making $120,000 a year should become a millionaire easily by the time they are 40.

A more interesting question would have been "Do you think you'll ever sell an app/business for $1M?" \- the crux of the question is "Do you think you'll hit the jackpot?", which in today's world, is selling something that took relatively small amount of effort to build.

<comment><USER24> > A 30-year old engineer making $120,000 a year should become a millionaire > easily by the time they are 40

How so?

<comment><USER23> Get married, save $60,000 a year (including 401k matching, etc), get 8% growth per year, 3% raise per year...that's $1,053,000 by my calculations.

<comment><USER25> $60000 is basically after tax income if your pre-tax income is $120k.

Also 8% growth a year is quite a stretch given that risk free rate is 2.64% (10-year treasury yield), and inflation eats 2% a year...

<comment><USER23> Pre-tax income of $120k would net about $95k in the US for a married man with 2 kids and a house in a tax-free state (Texas, Florida, etc.) 8% growth isn't a stretch, it's the average return for S&P 500 over the past 100 years.

</comment></comment></comment></comment></comment><comment><USER26> Obligatory: [http://www.bravenewlife.com/wp- content/uploads/2012/03/hugh....](http://www.bravenewlife.com/wp- content/uploads/2012/03/hugh.png)

Software culture is now all about the MacLeod Clueless. That's also why the median (and shitty) software company will now discard people once they are old enough that either (a) they have a clue, and get that the private-sector programmer game is rigged, or (b) they _should_ have a clue.</comment>


Miss real-time search on Google? Try the HashPlug extension for Chrome - <AUTHOR> http://thenextweb.com/lifehacks/2012/11/06/miss-real-time-search-on-google-check-out-the-hashplug-extension-for-chrome/

<comment><AUTHOR> I got lucky to use this while it was in private beta - author is HN user webmonks. Would love to hear feedback on this.

I like this better than the way Twitter was integrated by Google on Search:

1\. It is not inbetween search results. It doesn't distract esp since the plugin isn't smart right now to distinguish query as worth for "real time" results

2\. It always gives the real time results. We had mild tremors couple of months ago and this would instantly confirm when I searched.

I don't like tweets from other languages crowd the results sometimes, but it is just as smart as twitter search :)

</comment><comment><USER2> I do miss real-time search. Unfortunately, I get an error when trying to add the extension through the Chrome Web Store.

Ubuntu 12.04 (w/ GNOME 3) / Chrome 22.0.1229.94

Error: "Package is invalid. Details: 'Could not load extension icon 'images/128x128.png'.'."

<comment><USER3> hi danhoc01,

am the developer of HashPlug. I received couple of other reports on the same issue. Seems like Linux only issue. Will look into it today and get back.

thanks for reporting.

</comment></comment><comment><USER4> Install the extension and search for 'elections' and look the updates runaway. You might actually forget to look at the search results.

</comment><comment><USER5> It works great! Very helpful for people who work on real time data on day-to- day basis.

</comment><comment><USER6> How about real-time results from Facebook as well?

</comment><comment><USER7> Useful plugin, works well.

</comment><comment><USER8> nifty and useful

</comment><comment><USER9> its cool</comment>