Why is electricity so hard to understand? (1989) - <AUTHOR> http://amasci.com/miscon/whyhard2.html <comment><USER2> I think more than half the time I spent earning my EE degree has been spent unlearning the intuitive (but wrong) things that I was liberally taught. I was fortunate enough to have an exceptional Physics teacher in high school, who managed to avoid a lot of the bullshit that less fortunate students were fed; sadly, I compensated that with some of my own (misguided) self-study.

This experience also taught me to actively mistrust "intuition" and "common sense". Not that there isn't value in intuition (quite the contrary, it's priceless, from design to maintenance), but it's only useful when it rests on a solid theoretical foundation. _Prior_ to earning that foundation, it's nothing but a (very bad) shortcut that people take because they want to feel knowledgeable, but don't want to invest the effort of going through all that math mumbo jumbo.

<comment><USER3> I got it taught about 3 or 4 times, and every time I understood it less.

In middle school they told me, it's electrons moving at the speed of light through a conductor.

In high school they told me, no no, they don't move at the speed of light, just when one electron enters the conductor, another one on the other side will leave the conductor, like with peas in a straw. And this enter/leaf is at the speed of light.

At university they told me, no no, you got it all wrong, it's about the electro static and electro dynamic fields which stand orthogonal on each other and produce electro magnetic waves... what?!

I seriously have no idea anymore.

<comment><USER2> As far as circuits go, this is about the closest high school Physics gets to truth (and it's decently close, compared to how wrong it gets e.g. capacitors):

> In high school they told me, no no, they don't move at the speed of light, > just when one electron enters the conductor, another one on the other side > will leave the conductor, like with peas in a straw. And this enter/leaf is > at the speed of light.

although "entering" and "exiting" the conductor isn't really a good description.

A better way to think about it is that "conductor" is really just slang for "material that has a bunch of free electrons and very little room for more". This is the "sea of electrons" that Beaty talks about. It makes sense that, if all this sea flows _steadily_ (i.e. at the same rate throughout the conductor), forcing a change in the rate of flow in one part of the conductor will be felt almost immediately in another part of the conductor, no matter how distant, even if the flow itself is extremely slow.

(If you're thinking that this is only true if the "pipe" through which the "sea" flows is full, you're right, this is how free electrons behave in conductors; that's why Beaty insists that a good analogy for a conductor is "like a pipe which is already full of water".

> At university they told me, no no, you got it all wrong, it's about the > electro static and electro dynamic fields which stand orthogonal on each > other and produce electro magnetic waves... what?!

If they taught you _that_ , they are most definitely wrong, it sounds loosely like induction, but with two strange names instead of "electric" and "magnetic" :-).

This is a better description of the physical reality, and it does help you understand circuits better if you think about it, but not in a very _practical_ manner.

<comment><USER4> > If they taught you that, they are most definitely wrong, it sounds loosely > like induction, but with two strange names instead of "electric" and > "magnetic" :-).

I don't think "definitely wrong" is a good description. electrostatic and electrodynamic are perfectly good, if somewhat archaic, terms for the electric and magnetic fields. (E and H fields)

<comment><USER2> _Ah_. That's a terminology fuck-up on my side, then. I've never encountered this convention, but classical electromagnetism has almost two centuries of history behind it. A lot of weird names have been used for a lot of things.

For what it's worth, though, these are terrible names, archaic or not :-D. If they ever were in use, I'm glad we moved on.

<comment><USER4> I'm not sure they are terrible. Electrostatic describes charges at rest, capable of inducing a voltage across a dielectric. Electrodynamic describes charges in motion, capable of inducing a current across a conductor. They seem like apt descriptions to me.

<comment><USER2> It doesn't sound too bad when you put it that way, and it certainly made sense back when Ampere introduced the term, but:

* It doesn't match the way we define electrostatics, magnetostatics and electrodynamics. What defines electrodynamics isn't the fact that charges are moving (they're moving if the currents are constant, too, but the magnetic fields produced by steady currents are in magnetostatics' yard) but the interaction of charges and currents (in more formulaic terms, when both charge densities and current densities are present, not only do you get both electric and magnetic fields, as in magnetostatics, but they also vary in time).

* Charges in motion still produce a voltage across a dielectric. Calling the electric field they produce "electrostatic" when the charges are moving and the field is certainly not static.

<comment><USER4> Thanks for writing that out! Very interesting.

I guess it all comes down to the fact that a magnetic field does not exist without an electric current. One way of thinking about it sees it as charges moving, and the other way of thinking about it sees it as a static magnetic field.

I guess that's why the terms are archaic!

<comment><USER2> Indeed. That's why I think it might have made sense back in Ampere's time. The classification of these regimes (electrostatic, magnetostatic, electrodynamic) is more recent, and Ampere's own theory of electrodynamics deals more with what we term "magnetostatic" today.

<comment><USER5> I suspect that it corresponds to Newtonian Statics, the study of mass and forces. It's a subject area; an ignoring of changes. Not a state of nonmoving. The Newtonian Statics viewpoint involves summation of forces. It may also involve taking a snapshot at one point in time.

E.g., when a mass above Earth is in free fall, it still obeys Newtonian Statics: the weight/attraction force, easily analyzed from moment to moment. The resulting acceleration and trajectory then falls under "Dynamics."

In other words, electrostatics applies to capacitors and to the mechanical forces produced by electric fields. Even if currents are also present, and even if the e-fields are changing with time, electroSTATICS still applies. (A high voltage, high-amperes power line is very "electrostatic," because of the significant e-fields and resulting phenomena.)

Static Electricity then is a chapter title, with no existence in the real world. Neither can we fill a box with Newtonian Statics. To be consistent, we wouldn't say "electrostatic motor," instead call it a capacitor-motor, or an e-field motor. (Heh, a stretched spring is statically charged! Full of Newtonian-static energy!)

</comment></comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER6> It looks like interesting content, but I got a little confused by the writing style and general layout.

A more succinct, clearly defined structure would help me a lot. Each topic could be clearer on what is wrong and how is the right way.

It would help a lot just to start with a clear: "What is the right definition of the word electricity?". Then, maybe a "What is "electrical phenomena" and some examples". "Correct definition and differences of electric charge, energy and current".

For me personally, a structure that explains what is the right thing first, then goes on about misconceptions and consequence of misconceptions is much better.

I became lost while reading this and finished with basically the same confused and mistaken understanding of what is electricity as I began.

<comment><USER7> It turns out that this is not a good link to be starting with: see [https://news.ycombinator.com/item?id=12901346](https://news.ycombinator.com/item?id=12901346)

<comment><USER6> Much better. I'll spend some on it later

</comment></comment></comment><comment><USER8> Could someone write the same kind of article for chemistry ? That would help me to accept the fact that I didn't get it at all :-) Oh, while you're at it : accounting :-)

<comment><USER9> Accounting in 8 steps,

1\. Memorize this: Assets + Expenses = Liabilities + Capital + Income

2\. Everything is positive, no negative numbers!

3\. For every transaction, Total Debits = Total Credits

4\. "Credit" is source of money, "debit" is destination of money

5\. Assets and expenses increase with debits

6\. Liabilities, capital, and income increase with credits

7\. Expenses and income may only be increased (debited & credited respectively)

8\. At the end of the accounting period, distribute income less expenses to capital accounts

Example:

Your business buys a property for 90k with 50k cash down and 10k closing costs.

Assets: 90k house (debit), 50k cash (credit)

Expenses: 10k closing cost (debit)

Liabilities: 50k mortgage (credit)

Total Credits: 100k

Total Debits: 100k

<comment><USER10> shouldn't the cash be listed as capital instead of asset?

<comment><USER11> So the basic equation is "assets = capital + liabilities".

Capital+liabilities explain how your assets are "covered". Either you owe someone for the assets (liabilities), or you own the assets yourself (capital).

Sometimes it's easier to think of this as

"assets - liabilities = capital".

I.e. whatever is left after considering what you owe, you own.

If you have some cash (an asset), then you need to also list it either as a liability or capital, simply because you must always be able to answer "where did this cash from? did we borrow it (liability), or do we own it (capital)?"

<comment><USER10> Thanks for explaining it well. I was caught up in the parent post's example and tried to equate it with the equation given in it. How would the parent's example look like in balance sheet? I looked at small business example given in wikipedia, but failed at writing down parents example into assets and liabilities balance sheet. ([https://en.wikipedia.org/wiki/Balance_sheet](https://en.wikipedia.org/wiki/Balance_sheet)).

</comment></comment></comment></comment></comment><comment><USER12> Electromagnetics becomes much more elegant when cast in the language of differential forms. See e.g. [1].

[1] [http://www.uio.no/studier/emner/matnat/fys/FYS4160/v08/under...](http://www.uio.no/studier/emner/matnat/fys/FYS4160/v08/undervisningsmateriale/Kursmateriell/forms_teaching_warnick.pdf)

<comment><USER13> You can also go the fields route like Feynman would:

[https://mitpress.mit.edu/books/collective- electrodynamics](https://mitpress.mit.edu/books/collective-electrodynamics)

</comment></comment><comment><USER14> In fact, it isn't so hard that they would like you to believe - it just seems that way when they remove the best parts due to national security :D

You would have to go back to James Clerk Maxwell's original 20 equations to see what it's all about. Okey, quaternions are kind of hard, I'll admit to that, but all in all it makes much more sense.

<comment><USER15> Like QM, doing it analytically clears away misconceptions and gives a consistent view - but it isn't exactly something you can teach to children.

It's useful to be able to explain things to laypeople and the not mathematically inclined, which means tightening up the metaphors.

<comment><USER14> You have a good point, but still, it's easier to explain to children stuff that makes sense.

I teach my children that we live in a sea of energy and that you can feel it when you move. It makes much more sense to them than trying explain inertia.

I tell them that of you rotate something, it will make an energy vortex making stuff seem heavier - and I show them with a gyroscope.

Then I explain that electrons are just like little gyroscopes, but of only energy. And it all makes sense to them. They don't think it's hard at all.

<comment><USER15> Those are excellent metaphors which I've never heard anywhere else.

<comment><USER16> They're reminiscent of Feynman's anecdote about his father explaining inertia:

[https://www.youtube.com/watch?v=Zjm8JeDKvdc](https://www.youtube.com/watch?v=Zjm8JeDKvdc)

<comment><USER17> "That - he said - nobody knows". It's kind of different from "we live in a sea of energy". I honestly think inertia is a lot easier to grasp than energy. It's a phenomenon you can experiment, describe and name, energy is more abstract.

</comment></comment></comment></comment></comment></comment><comment><USER18> The real question is, why is this website so hard to understand? Publishing what looks like someones personal notebook isn't helping the cause here.

<comment><USER19> Poor selection of link. Fortunately the author saw us and pointed us toward the articles instead of the raw notes: [http://amasci.com/miscon/whyhard1.html#def](http://amasci.com/miscon/whyhard1.html#def)

<comment><USER7> I am not sure that is a big improvement. I dipped in here, and what I found was mostly a repetitive litany of complaints.

<comment><USER5> The entire essay-collection is a critique of grade-school electricity textbook chapters, in the USA. (I don't know if the texts in other countries are promoting the same misconceptions.) To avoid reading critiques/corrections, go to any other site except mine. Also see:

Am I just a pedantic nitpicker?

[http://amasci.com/miscon/nitpik.html](http://amasci.com/miscon/nitpik.html)

To deeply grasp physics, often one must UN-learn the common misconceptions which were acquired in our early school careers. The misconceptions in this list are the ones believed by educators, and taught to students.

</comment></comment></comment></comment><comment><USER20> Like incompressible fluids, electricity is hard to reason about because we work in a limit that does not obey local causality.

The entire system must be solved simultaneously, and there is not a well defined "input" or "output". This can be seen from the fact that when we analyze a circuit we also include the model the power source and the load.

The combination of non-locality and complex boundary conditions makes it hard to apply ordinary intuition. We would like to say that the power source "does something" to the circuit but causality actually runs both ways. E.g. if we have a constant voltage source, then the circuit will determine how much current flows through the source. If we have a constant resistance load, then the load will determine how much power the circuit applies to it.

<comment><USER21> Thanks+++ I think you nailed my frustrations with electricity!

</comment></comment><comment><USER22> Maybe this is the right occasion to re-ask a question I asked some years ago on stack exchange, but (despite several people trying their best to explain) still failed to understand the answer to.

So: does electricity have 'mass'? What I mean is, when current flows, is there a transfer of electrons (or something else) from the power source to whatever it is send to? And is there a difference between AC and DC?

The context of this question is that the core argument of a legal paper (of all things) I was reading at the time (on property rights of virtual goods) hinged on there being a transfer of mass, however small. I wasn't so sure.

(my SE question devolved into a semi-legal argument - I have a law degree, the context of the question is a lot more nuanced still than the above description, and is very much tied to some specific 80 year old Dutch case law - just saying that to point out that a legal argument on whether or not the question matters won't add much to the discussion.)

<comment><USER23> Information has mass. Not much. Surely charge on a dram capacitor is s bit (oh the pun) of energy and energy is mass.

An excellent example of electron movement is a DC current in a metal plating tank or refining tank. Every atom of aluminum or copper or plated anything took the movement of precisely one electron (simplification because there are some non-electroplating methods for some base/plate combos, but yeah pretty much aluminium is a block of solidified electricity)

<comment><USER22> So take one RAM stick and another, with the exact same physical makeup (I know this is impossible, but for argument's sake). Now I put some information on the one, and random noise on the other. Both will have different mass, right (because there are different amounts of electrons in the capacitors of both)? Now I put valuable information on one, and I charge all capacitors of the other (so the second one has very information density, because it can be 'compressed' trivially by saying '4GB of high bits'). The second one will be 'heavier' than the first, right? And then I copy something over that second one. It's not like there is a 'transfer' of mass from the other medium to the RAM stack, because there is a net _outflow_ of electrons, right?

</comment></comment></comment><comment><USER15> Very comprehensive!

I've occasionally tried to clear up misunderstandings of this kind on [https://electronics.stackexchange.com/](https://electronics.stackexchange.com/) , they're a common stumbling point for beginners. Especially speed of electrons vs. speed of signals.

</comment><comment><USER24> I wish academia took more time to explain things in digestible way instead of dumping loads of dry papers in rigorous form. For instance, my life would be so much easier if I saw just this thing below [1]. Alternating current described in complex numbers has so much sense after going through that material.

[1] [https://acko.net/blog/how-to-fold-a-julia- fractal/](https://acko.net/blog/how-to-fold-a-julia-fractal/)

</comment><comment><AUTHOR> Also (same site): Misconceptions – [http://amasci.com/miscon/elect.html](http://amasci.com/miscon/elect.html)

</comment><comment><USER25> It gets even more fun in semiconductors when the 'particles' become virtual but no one bothers to mention that part.

<comment><USER26> The way holes move in the semiconductor is the pointers of EE.

<comment><USER27> Adding very little to the conversation here but having done a Ph.D. in high- temperature semiconductors this made me chuckle and is nicely apt. Just like pointers, though, you can kind of get by with only a very thin understanding of them for a surprisingly long time.

</comment></comment></comment><comment><USER28> I've always been bemused by EE wallet cards that contain:

        V = IR
        I = V/R
        R = V/I

If an EE does not know this formulas, he isn't an EE. If he understands so little about algebra that he needs the three forms, he's going to be misusing the formula.

<comment><USER17> Guess like all engineering jobs, sometimes your job is so far from practice and so involved in regulations, meetings, standards, bureaucracy, reports, a little refcard with the most basic things can help to quickly reset your brain for the rare occasion where you need to actually do something.

</comment></comment><comment><USER29> Hmm. I learned about E&M theory from Halliday and Resnick, and the practical stuff from Horowitz and Winfield (The Art of Electronics) and they were pretty precise about distinctions between electrons, holes, charge, flow of charge, and so forth. Sounds like I dodged a bullet by _not_ being drawn too much to electronics as a youth, waiting instead to learn about it as a college physics major.

<comment><USER30> Ah, memories of those books too. My Dad was an EE and so I also have memories of him, on parent-teacher evenings at school, arguing with the physics teacher about whatever was on the blackboard from the day's lesson..

</comment></comment><comment><USER31> I think the main reason is that we can't physically interact with it with our hands. We don't play with it as children, the same way we do running water, throwing rocks, etc. Anything that you can't manipulate or play around with is very hard to develop an intuitive sense of. It takes a lot of study and imagination.

<comment><USER32> I a sense, I DID play with electricity as a kid. My father was an Electrical Engineer and a Ham Radio operator, so we had "stuff" around the house. I learned to solder at a young age. Some time ago, I realized that one of the best toys I had as a kid was the controller for my HO train set. It had a Speed (voltage) lever and a Forward/Reverse lever. Basically, it was a safe, variable voltage DC power supply. I could play with switches and flashlight bulbs and small motors and learn how they work. I've recently gotten back into Electronics as a hobby and I'm having all sorts of fun with Arduinos and Pis and such.

<comment><USER33> But even then it's not the same because you can't actually see the electricity. You can only see second order effects.

</comment></comment></comment><comment><USER34> This article is amazing. It helped me to understand things that I were confused about years ago. Whole website is filled (!) with these kind of articles [http://amasci.com/ele-edu.html](http://amasci.com/ele-edu.html) !

</comment><comment><USER35> Electricity doors mean one thing: the movement of electrons. There are a lot of significant ways it manifests, like in static charge and power systems, and there are a lot of insignificant ways it manifests, but it's still just electrons moving around.

</comment><comment><USER36> I actually like the water model. Here is a transistor:

[http://imgur.com/a/vhrmR](http://imgur.com/a/vhrmR)

It breaks down as an analogy as soon as magnetic fields come in to play, which is pretty much any AC circuit.

</comment><comment><USER37> What's the difference between ionized hydrogen and electricity?

<comment><USER15> As mentioned in the article, referring to "electricity" is kinf of vague. Ionized hydrogen floating about is a _plasma_ ; a collection of particle with a positive net charge. Therefore if some H+ ions move in a particular direction, that will be a flow of charge: an electric current.

Similarly H+ ions in aqueous solution can carry a current, as in electrolysis.

<comment><USER38> No, it doesn't have a positive net charge. In a plasma, the electrons are still part of the substance, but they are no longer bound to the nuclei, and are free to move about. Similar to current in an electrolyte, current in a plasma is the result of electrons moving one direction, while the nucleii are moving in the opposite direction.

</comment></comment></comment><comment><USER39> All those words and it doesn't even entertain my favorite if-i-had-a-time- machine scenario: EE would be a bit easier if Franklin had swapped positive and negative.

<comment><USER5> Sure it does. You just have to look at the list of articles, not the giant pile of random notes.

BEN FRANKLIN SHOULD HAVE SAID ELECTRONS ARE POSITIVE? Wrong. [http://amasci.com/miscon/eleca.html#frkel](http://amasci.com/miscon/eleca.html#frkel)

EE would be much HARDER if Franklin had swapped positive and negative, since then our confusion wouldn't lead us to shatteing our own misconceptions. We'd never sit down and figure out what "conventional current" actually is. No, it's not backwards. And no, electricity is not made of electrons. In acids, the electric current is entirely a flow of protons. In dirt, oceans, and human bodies the current is at least two separate flows: clouds of positive ions passing forwards through clouds of negative ions travelling backwards. With two opposite charge carriers, what then is the "true" direction of electric current? What if there are five: +Na, +K, +H, -OH, -CL ?

Cute notion: Ben Franklin's kite string was an acidic conductor, a piece of twine which becomes insulating in dry conditions, so it's an electrolyte. And acid conductors have mobile +H ions to carry the current. (What's a hydrogen atom, with one missing electron?)

In other words, Ben Franklin's kite string is a Proton Conductor.

SO HE GOT THE DIRECTION RIGHT!!!!

:)

He only was wrong in the case of metal wires. In his day, a typical "conductor" was a small boy hired to hang from silk ropes, to connect the Leyden Jar to the "Electrical Machine." Or rather than commoners, sometimes they used chains of Elizabethan royalty, all standing upon insulating stools.

</comment></comment><comment><USER40> [http://amasci.com/ele-edu.html](http://amasci.com/ele-edu.html) There's more, lots more. ;-)

</comment><comment><USER41> Perhaps Quantum Mechanics has an answer to that question. And if we can deeply understand our body, we perhaps have understood electricity.

</comment><comment><USER42> wish there was a similar website I knew of when I was a EE student -- them misconceptions were crazy enough that they led me to drop out of EE and move into comp. science :)

</comment><comment><USER43> Whaaat? Electricity does not flow at the speed of light?

OH THE HUMANITY!!!!

<comment><USER15> EM radiation moves at the speed of light; electrical fields and signals move _near_ the speed of light, depending on the surrounding dielectric properties; electrons in conductors move fairly slowly. Yes, this is kind of confusing.

</comment></comment><comment><USER44> Dear author of the website: Nice article. Please fix the TOC links on "whyhard2.html" to point to "whyhard2.html" and not to "whyhard1.html", and remove the huge whitespace between TOC and content. This was a very confusing experience and likely others will fall in this trap. Thanks!

<comment><USER5> DOH!

Fixed now.

I messed it up last time I was getting slashdotted by reddit and ycombinator, and everyone was complaining that the raw unedited notes were just a bunch of raw unedited notes.

Heh, it's still a 1995 gopher-era design, back when we put all our chapters on a single long page, to compensate for 300/2400b modem speeds. If it was broken up into many separate pages, you'd be waaaaaaiting for the text to finally appear.

<comment><USER44> Thank you very much :)

</comment></comment></comment><comment><USER45> Wires may not be hollow tubes but surely as a EE he knows that most current flows through the outer shell of the wire?

E: Yes, I was thinking standard AC for household appliances, my bad

<comment><USER46> This is not true for low frequency current.</comment></comment>


Ask HN: I would pay X for Y - <AUTHOR> I would pay $10 every 3 months for a highlevel review/changelog of the top Javascript frameworks.
I would pay $1/month for book suggestions related to technical leadership.
I would pay $2/month for 10 suggestions of breweries I haven't tried yet. <comment><USER3> I would pay $10/month for a weekly digest of the most important world news without editorializing, clickbait, celebrity news. Just important stuff. Also I would not like it to be only US-centered (that could be optional though).

EDIT: Some people asked what I mean by "important". For me, important event is the event that has potential to have a high impact on the society or any large group of people in long term. Some very recent news that I found important: results of elections in Austria, terrorist attack in Somalia, grand jury indictment against Manafort, hundreds of sexual harassment allegations in USA as a whole (I don't think reporting each individual case and celebrity implicated is important).

<comment><USER4> I think the Foreign Policy morning brief is awesome. It's not US-centric, it's fairly unbiased, and the reporting is high-quality. [https://imgur.com/a/ssfBU](https://imgur.com/a/ssfBU)

I also subscribe to [https://whatthefuckjusthappenedtoday.com/](https://whatthefuckjusthappenedtoday.com/) for US politics news.

<comment><USER5> none of the links on the morning brief site work, and when i actually go to the morning brief site it looks like most of the articles are from 2009. I thought for a second Swine flu had re-emerged.

<comment><USER4> Yeah sorry the particular page I linked to is from 2008 and is super broken. The actual morning brief these days looks like this: [https://imgur.com/a/ssfBU](https://imgur.com/a/ssfBU)

<comment><USER5> k. what's the link to that page?

<comment><USER4> It's an email, to signup go to their homepage.

</comment></comment></comment></comment></comment></comment><comment><USER6> I would pay $50 for 30 minutes of the time of a webpack configuration expert. Or a similar amount for SAAS allowing me to select modules from a UI and chain them as desired.

I gave up on my desired configuration after spending 3-5+h in frustrated powerlessness.

<comment><USER7> Having just gone through the setup process a few times, I concur. It is an excruciatingly bad entry to a powerful solution to front-end web development.

<comment><USER8> The config is pretty straight forward once you understand how it all works. The docs have example configs for anything you need. Specify an entry point, add some loaders, and maybe a plugin or two, what are you stuck on?

<comment><USER6> I agree, it is a straight forward design (you chain things one after the other).

I just couldn't make these specific items work together, at all.

</comment></comment></comment></comment><comment><USER9> I would pay $5 a month to have all physical junk mail filtered out of delivery.

Why can't I opt out of "or current resident"?

<comment><USER10> In France you just put a sticker on your letter box with something like "no ads, thank you".

Since I did it my letter box is desperately empty except the occasional paper bill.

Won't work with junk mail that is directly addressed to you of course, but in my case it's not frequent, I'm probably not in many databases.

<comment><USER11> I'm in Paris, I did it and it had absolutely no effect. I guess the spammers don't care about these stickers or not bothering you. They just want to finish their spam job as soon as possible.

</comment></comment></comment><comment><USER12> I would pay $50 a 30-60 min call with an industry vet programmer/EM to look at my career and give next steps to grow my career. I have no idea if I'm doing well or not or how to become a great programmer cause I don't know what's "next", as it's not as linear as I wish it was.

<comment><USER13> Unfortunately a good eng/em makes much more than $50/h. More like 150-300 (pretax) and that's just for a normal fulltime hour, they would def charge more for consultancy work due to the overheads. That leaves you with not-that- vet people.

Edit: I assumed major tech companies and western world, the situation is obviously different in other regions.

<comment><USER12> > _Unfortunately a good eng /em makes much more than $50/h. More like 150-300 > (pretax) and that's just for a normal fulltime hour_

That's to hire them for their work. I'm just trying to talk with them about their experience, not asking them to code/manage.

</comment></comment></comment><comment><USER14> I pay $60-$70/month to have my laundry done. They do a better job than I would, and I value my time highly. Plus the capex of a washer/drier, and the opex of detergents and dryer sheets, and I think I'm coming out well ahead...

<comment><USER15> In theory, Handy ([https://www.handy.com/services](https://www.handy.com/services)) does this for you for significantly higher rates at your own home. I've used the service before when it first started and rates were 40-60%/hour of what they are now. Seems like they could not keep up with demand - scheduled appointments would get cancelled less than an hour before and be incredibly inconvenient - <USER2> I would guess was a factor to them increasing their prices to attract more talent while keeping margins.

tl;dr; services like this exist, but 60-70$/mo is laughably low (assuming min 2-3 loads of washer + dryer per month)

<comment><USER14> This is a wash-dry-fold service out of my local laundromat. I just drop off a big sack of laundry in the morning, they weigh it and charge by the pound (Wednesdays is a sub-$1 special), and then I pick it up after work, clean, nicely folded, bagged up, and with all my shirts on hangers. It's pretty close to the best thing ever.

<comment><USER15> I see. I was envisioning a "bigger" service - your quoted price makes sense in that case.

</comment></comment></comment></comment><comment><USER16> I would pay high margins to legal firms whom I'd forward spam and they'd sue spammers on my behalf (in Poland).

<comment><USER17> 90% towards class action to sue spammers on my behalf (in US)

</comment></comment><comment><USER18> I would pay $100/hr for a competent freelance system administrator who could parachute in and deal with the various things we need dealt with.

Of course the problem here is "competent". On two different occasions people have offered to do the job and they were terrible.

<comment><USER19> I wish there was more demand for stuff like this at a reasonable price. I've worked from various freelance sites in my spare time asking a similar price, but invariably I'd only see 10% of the business that the $15/hr crowd would see.

I got a few ex-$15/hr customers, who wanted a few hours of my time purely to clean up the mess left by the last guy, and once it was cleaned up they'd take their business to the next $15/hr guy and hope he was a little better than the last one.

Bit of a tricky situation I suppose, on one hand the competent Sadmins are probably more inclined to stick to a normal job with a steady income, but the incompetent ones seem to be happy to sit around all day spamming freelancing sites.

</comment></comment><comment><USER20> I'd pay 20k for an open-hardware Notebook with a formally verified open source OS

<comment><USER21> [https://www.crowdsupply.com/sutajio- kosagi/novena](https://www.crowdsupply.com/sutajio-kosagi/novena)

</comment></comment><comment><USER22> I would pay $20/month for a simple, easy to set up affiliate management service.

Seriously - there are literally hundreds of affiliate management services out there, I've looked at dozens of them, and none of them quite fit the following requirements:

\- Simple setup \- Reasonably low cost \- Dashboard for affiliates to track clicks & signups

Most existing systems also wrap up some sort of customer referral widgety thing, which I don't need. Or, the websites are broken / look like they're from 2001.

ReferralCandy is probably the closest thing, but again, it's way more set up for "customer referrals" vs professional or semi-pro affiliates. The integration process is also super heavy.

We literally built our own affiliate management since everything that fit our requirements was so expensive. This seems like an obvious side-project for someone to knock out.

<comment><USER23> This is something I've considered doing for years after dealing with the likes of Clickbank, etc. I'd love to pick your brain for your requirements. How can I get in touch?

<comment><USER22> email@example.com

</comment></comment></comment><comment><USER10> I would pay 1€ once for an Android weather app that has no ads, that don't take 30s to load and that is instantly readable and not some fancy schmancy style that makes it hard to know what's the weather for today and where to look for next days.

Apparently it's too much to ask.

<comment><USER24> The Google weather app is easy to read and loads in <5 seconds on my OnePlus 5. Doesn't that app fit your requirements?

<comment><USER10> Now you're talking about it, it didn't appear in the top 30 apps that I found on Google Play.

However I sometimes get Google weather predictions on my (desktop) browser and find them less accurate than our local weather service (Météo France).

</comment></comment></comment><comment><USER25> I would pay $5/night for someone to clean my families dishes after dinner.

I would pay $20/month for someone to keep my clothing fresh.

<comment><USER26> I'd pay $200 a month for a professional dishwasher, but really I'd probably have to pay much more.

</comment></comment><comment><USER27> I would pay $5 to get a text transcription of any podcast.

My life doesn't support podcast-listening particularly well, and yet I know there's a lot of good info out there in the audio world.

<comment><USER28> Don't most mainstream podcasts come with a text transcription?

</comment></comment><comment><USER11> I would pay $100/year for a photo organizer SaaS, that has a read-only access on a folder in my Dropbox, and let me organize my photos by time, by people on the photo, by places, or by events that I would have created. It would let me make some requests like "Show me all photos with John on it, taken on Europe, between 2008 and 2012".

Google Photos is shitty and Google already got too much information about me.

<comment><USER29> [https://www.smugmug.com/plans/basic](https://www.smugmug.com/plans/basic)

I don't use them and it's not from your Dropbox but heard great things about them in general.

</comment></comment><comment><USER30> I would pay $50 for 30 minutes of time in person from an expert on gardens.

I would pay $10 a month for scraping 100 data entries for my side project.

<comment><USER31> Most nurseries have expert gardeners on-hand who will happily talk to you for free.

<comment><USER30> I speak with them frequently, but it would be awesome if some could be paid to come to your house and help with various issues.

<comment><USER32> I bet you can say "Hey, would you mind coming to my house this weekend? I'll buy dinner after" to someone you've spoken to before (so that they know you're not a murderer)

You might make a wise old friend out of it too :)

</comment></comment></comment></comment><comment><USER33> I would pay up to 50% (EU level) of my monthly income to live in a place with direct democracy. Fortunatly I live in the one country on earth with direct democracy so I pay less then 24%.

<comment><USER34> Which country is that?

</comment></comment><comment><USER35> I would pay $xxx for a good UX/UI designer!

<comment><USER36> Are we ([http://fairpixels.pro](http://fairpixels.pro)) within your budget? :)

<comment><USER37> That's an interesting concept. Do you do only the design/mockups or you build the frontend (HTML/CSS) as well?

I will forward the link to a friend that was looking for something similar.

</comment></comment></comment><comment><USER38> I would pay $100 for a secure, open source version of Skype that is compatible with Skype chat history and contacts.

<comment><USER12> Signal has video and voice chat

<comment><USER38> Can it seamlessly import all the Skype chat history and groups correctly? That's mostly what I'm paying for, not just "video and voice chat"

</comment></comment></comment><comment><USER39> I would pay up to $300 for a NAS with at least two hard drives bays working in RAID and an open linux-based operating system (with root access). Hard disks are no included in that price.

<comment><USER40> How about GnuBee [1]? They're currently running a campaign [2] for version 2.

1: [http://gnubee.org/](http://gnubee.org/) 2: [https://www.crowdsupply.com/gnubee/personal- cloud-2](https://www.crowdsupply.com/gnubee/personal-cloud-2)

</comment></comment><comment><USER41> I would pay $200 for a dumb phone that only makes/receives call/texts, and has whatsapp and google maps.

<comment><USER42> The technical requirements of running google maps would immediately turn your dumb phone into a smart phone.

Why don't you just uninstall everything from your phone but whatsapp and google maps?

<comment><USER41> Try to switch your SIM card on your iPhone without having access to WiFi or any other assisting device, in a remote terrain where you need the new SIM immediately.

</comment></comment></comment><comment><USER43> X = you Tuesday, Y = a hamburger today

If you don't like that Wimpy suggestion, I would pay $2000/year in union dues (or professional association of equivalently sized teeth).

</comment><comment><USER44> $20/month for a bundled subscription to various popular news sites (WSJ, NYT) & other online media (The Atlantic, New Yorker, etc.). So many of these sites are behind paywalls and everyone wants you to subscribe to them. It's unsustainable to subscribe to all of them and the days of being a dedicated reader of just 1 paper are long gone

<comment><USER45> I don't do this exactly, but have 3 newsletters that: \- publish two times a week \- include between 8 and 12 key industry stories in the specific B2B vertical of that newsletter \- Include a ~100 word summary of the linked story \- Cost $10/month each

The cool part to me is that the subscribers I do have almost never click the links; they tell me the summaries are all the info they need. So that feels like creating some value. Now, if I could just find more subscribers. :)

<comment><USER46> shameless plug missing:)

<comment><USER45> yeah, I don't care for it much when people plug their wares unless it really is applicable. In this case, no one brought up the niches I publish to so I avoided adding them in. LOL</comment></comment></comment></comment>


Ask HN: Going to Boston this weekend, what should I check out? - <AUTHOR>

I'm going on vacation with my family before going back to school. I've never been to Boston but I've heard it's very entrepreneurial. I'm going to check out Harvard, what else should I look into? <comment><USER2> After you're done with Harvard, head over to the Border Cafe on 32 Church Street near Harvard Sq, great Margarita and great food.

</comment><comment><USER3> Museum of Fine Arts, Quincy Market/Fanneiul Hall, a decent aquarium if that interests you. Good Italian food on the North End.

</comment><comment><USER4> Museum of Fine Arts, Revere Beach (if weather is good), Fenway Park</comment>


Cancel U.S. Debt - <AUTHOR> http://paul.kedrosky.com/archives/2009/01/28/ferguson_cancel.html <comment><USER2> The post is a copy of a quote from Niall Ferguson. Interesting concept that would be nice to discuss without prejudice.

Related to such a discussion is the position we are fed "too big to fail". That is, we have to bail out financial institutions such as AIG due to the size of their obligations and how interconnected they are.

I would very much like to see analysis of the concentration of these debt obligations. That is, does only 10% of people (globally) hold 90% of the bad debt? Yes, I realize the debt is really held by institutions, but people hold the ownership of the institutions. So, if the debt is cut out and thrown away as a doctor would do to a malignant tumor, do you get rid of most of the debt by only effecting a minority of interests?

Does anyone know of such an analysis?

</comment><comment><USER3> Read Article #14 of the US Constitution:

"4. The validity of the public debt of the United States, authorized by law, including debts incurred for payment of pensions and bounties for services in suppressing insurrection or rebellion, shall not be questioned. But neither the United States nor any State shall assume or pay any debt or obligation incurred in aid of insurrection or rebellion against the United States, or any claim for the loss or emancipation of any slave; but all such debts, obligations and claims shall be held illegal and void."

</comment><comment><USER4> The original article: [http://www.vanityfair.com/online/politics/2009/01/niall- ferg...](http://www.vanityfair.com/online/politics/2009/01/niall-ferguson- america-needs-to-cancel-its-debt.html)</comment>


MapReduce on Mechanical Turk - <AUTHOR> http://reports-archive.adm.cs.cmu.edu/anon/hcii/CMU-HCII-11-100.pdf

<comment><USER2> How about coding a complex program by having people writing small functions and then aggregating it?</comment>


Hateful nut church vows to picket Steve Jobs funeral - <AUTHOR> http://www.itworld.com/software/210919/westboro-baptist-church-picket-steve-jobs-funeral-because-theyre-vile-idiots

<comment><USER2> They make their money from court settlements when pissed off people violate their free speech rights. In a very literal sense, _don't feed the trolls._

<comment><USER3> Hey, some people go for the lottery, some for court settlements. I have to say it is quite funny her responses. They should counter-respond to that, if iPhone is made by god, why did jobs get paid so much for it. Oh damn. Maybe Apple is god's company?

<comment><USER2> The lottery is unreliable and has a negative expected payoff. The Phelps guys consistently get enough money from court settlements to keep on trolling. I wish people would treat them as entertainment, and otherwise ignore them. They might have to get an honest job.

Also, about that possible counter-response: they believe that Apple's actions, as well as the actions and fate of everyone, are predetermined by God. They are hard-core Calvinists, which makes most obvious arguments not really apply to their weird beliefs.</comment></comment></comment>


Ask YC:  How can I fix poor adsense targeting on my site? - <AUTHOR>

I'm getting poor targeting on http://numbrosia.com.
One way to work around it is to use url parameters such as "?cmd=puzzle_lb" instead of "?cmd=leaderboard".  This helps sometimes (e.g., the leaderboard page may still show golf ads but it also shows puzzle ads now).
However, what can I do for the main page? <comment><USER2> 1\. add more text to the page, put a paragraph or two below the puzzle describing what it is. Use Keywords in that paragraph that you want ads for. You don't have to overdo the keyword usage, just sprinkle them in a few times.

2\. Move the ads towards the center, closer to the puzzle. I wouldn't have even glanced at those ads on my widescreen if I wasn't looking for them. This will help your clickthrough rate.

3\. Don't expect to get rich off adsense puzzle ads.

<comment><USER3> I agree that adding a little more text about the kind of ads you want would help, then also use google adsense targeting. This way google will use only the text that you think will help bring up relevant ads for your site. You might also consider having an about page that beside talking about the game discusses similar games and links to them. I have found having a few pages with similar content helps google when targeting ads.

[https://www.google.com/adsense/support/bin/answer.py?answer=...](https://www.google.com/adsense/support/bin/answer.py?answer=23168)

<comment><AUTHOR> Yes, but note:

"In order to properly implement this feature, you'll need to include a significant amount of content within the section targeting tags. Including insufficient content may result in less relevant ads or PSAs."

So you can't just surround the word "puzzle" for example with section targeting.

</comment></comment></comment><comment><USER4> look at pubmatic (<http://pubmatic.com>), they do a lot of ad optimizations with 5 or 6 of the top 8 ad networks.

</comment><comment><USER5> Perhaps you should try other ad alternatives besides adsense.

</comment><comment><USER6> Check out Adpinion.com</comment>


Show HN: The Inbox Checkup – Compare your inbox mastery with everyone else - <AUTHOR> https://frontapp.com/checkup

<comment><USER2> Tried it. Seems OK. Not worth the access to data it required.

This post would do better on Reddit in dataisbeautiful or something.

Here's an example scraped from Google: [https://checkup.frontapp.com/9df36f035e474281931](https://checkup.frontapp.com/9df36f035e474281931)

More:

[https://checkup.frontapp.com/ef2358ade51b29fb9fe](https://checkup.frontapp.com/ef2358ade51b29fb9fe) [https://checkup.frontapp.com/1b68de2c4523717ee8a](https://checkup.frontapp.com/1b68de2c4523717ee8a) [https://checkup.frontapp.com/189bdd53fc517dcd1ee](https://checkup.frontapp.com/189bdd53fc517dcd1ee) [https://checkup.frontapp.com/72dd67265b3244f5b37](https://checkup.frontapp.com/72dd67265b3244f5b37) (Rank 9)

<comment><USER3> what a great way of finding other people's email addresses :)

</comment></comment><comment><USER4> Yeah, don't think I am going to provide access to my inbox to some random website. Hell, I don't think I would provide access to ANY website.

</comment><comment><USER5> The red/yellow/green coloring to me seems to imply that you want to be above average with these metrics, but I'm not sure that above average is necessarily a good thing here. Things like "response time", quicker is probably better, but "emails sent" — the two of the links from Mandatum had someone ending ~50 emails per day! It may very well depend on your job, of course, but to me, that's too much even to receive in a day (I don't want to read 50 emails.), and your email is going to be automatically sorted and likely ignored. "Contacts reached" also seems to imply higher is better, whereas I would think that more targeted conversations might be better. (But then, courtesy might demand CC'ing a list or a person in, so harder to say.) "Emails per conversation": taking more emails to conclude whatever is needed is better? Not meeting face to face if email isn't cutting it, or being clear and concise on the first email?

</comment><comment><USER6> I just tried it out on an email address that doesn't contain any sensitive information:

I think there is something off: gmail lets me browse to 50k+ emails (or conversations?), your tool reports around 1k emails received. I'm not sure that 50k number is accurate, but there are a lot more than 1k.

<comment><AUTHOR> We only look at the last 100 days. The global ranking is based on the total number of conversations you engage: threads where you and someone else write.

<comment><USER6> Right. Exactly what the tag-line says :-)

</comment></comment></comment><comment><USER7> I have always been so nervous about my email habits that I would happily share my private email with a complete stranger in order to receive a ranking. I would feel even better if I could win a prize!

<comment><AUTHOR> To address your concerns about privacy: we request an OAuth token from Gmail. While this token expires after 1h, we actually use it only once and we never store it anywhere. We analyze your email habits exclusively by looking at metadata, not at the content of emails.

Now, the app is mostly an experiment on email: while most modern communication are shared by default, emails is still completely siloed. We are allowing people to compare their email habits, without, in fact, exposing private information.

<comment><USER8> And as the NSA revelations have revealed, there's nothing damning in metadata...

I don't mean to be trite, but I'm not giving any auth information to a Show HN any more than I would some random guy on the street.

Don't get me wrong, I'm addicted to inbox zero as much as the next guy/gal, but I achieve inbox zero every day. Never mind the fact that I accomplish this by marking email I deem as irrelevant by the subject line as 'read' without ever reading it.

I'm sure I've inappropriately marked email from people I care about as 'read' without reading it, but I do get a disproportionate volume of email from robots (that belong to me, my company and others), so I view it as acceptable collateral damage.

Show me the source and maybe I'll share my auth tokens.

</comment></comment></comment><comment><USER9> This is a pretty neat tool! Could only check my personal email. Company email uses Office365.

</comment><comment><USER10> This is gmail only BTW.

</comment><comment><USER11> Getting a bad request error on signing in with Google.

</comment><comment><USER12> Thanks but no thanks

</comment><comment><USER13> are you NSA? ;)</comment>


How do I get into the start-up world? - <AUTHOR> http://eric.polerecky.com/archives/how-do-i-get-into-the-start-up-world/ <comment><USER2> Hey fellow metro Detroiter, you could perhaps present PrivateFlock at DNewTech, get some more feedback, meet other local people in the startup world, maybe an investor or a business person who can take it to the next level. If you'd like, I can put you in touch with the organizer. contact details in profile.</comment>


How should a Professor Incentivize Classroom Attendance? - <AUTHOR> http://www.freakonomics.com/2011/08/03/our-daily-bleg-how-should-a-professor-incentivize-classroom-attendance/

<comment><AUTHOR> best line- "one truth I quickly learned in college was that professors who made attendance at their lectures irrelevant were the only ones who needed an attendance policy."

<comment><USER2> Right. I never worry about attendance, or whether people are surfing the web in class or whatnot. Their money, their choice. You can lead a student to knowledge but you can't make him think (somewhat sanitized version of a Dorothy Parker quote :-). The only exception would be if no-shows cause harm to their fellow students (e.g., they're working on some kind of group project). Similarly, I don't allow loud talking in a face-to-face class -- it's up to you whether you want to pay attention, but you don't get to interfere with the students who do.</comment></comment>


Our Journey From Load and API Testing Tool to Auto Regression Testing Platform - <AUTHOR> https://blog.loadmill.com/recording-production-traffic-using-service-workers-b713d40d48bb <comment><USER2> >This came naturally and made a lot of sense — Since we enable developers to record and replay API tests in their QA environment, why not use this ability to create tests from real user behavior?

That's the thing about startups. Things that seems obvious now, might not seems that way few months ago.

<comment><USER3> Totaly</comment></comment>


How Edward J. Snowden Orchestrated a Blockbuster Story - <AUTHOR> http://www.nytimes.com/2013/06/11/us/how-edward-j-snowden-orchestrated-a-blockbuster-story.html?pagewanted=all <comment><USER2> Between the lines it seems the NYT is somewhat jealous Snowden did not come to it with his materials (when the news broke they quoted "a British newspaper" instead of mentioning The Guardian by name!).

But they do make a good point: the scope and reach of the post 9/11 intelligence apparatus does not only mean it tends to overreach, it also means it employs too many people, some of them potential whistle-blowers.

</comment><comment><USER3> I don't get it. If it he can do this, why can't someone else do the same thing? Why can't people register _that_ part of the story?

Anyone who has ever seen the show 24 can see that for every amazing tool we have to spy on Americans, there is some double-spy working within the agency using the very same tool against the government's own interest. This is exactly what is happening.

We built something we can't control. That's the story.

<comment><USER4> Proof by fictional evidence? ;)

<comment><USER5> There are plenty of real-world examples of moles and double-agents as well. Fiction can often be a useful tool to distill the essence of an argument and/or present it in a recognizable or popular dress.

Something Eric Arthur Blair demonstrated ably in his famous novel _1948_. Excuse me, George Orwell, _1984_.

</comment></comment></comment><comment><USER6> >Mr. Snowden has now turned over archives of "thousands" of documents, according to Mr. Greenwald, and "dozens" are newsworthy.

And now we all have to wait until _The Guardian_ is finished analyzing everything, covering its ass while making sure to take in a maximum amount of profits.

That's an issue I haven't heard people complain about yet. Why not make everything public? The information is getting combed... _again_!

<comment><USER7> Snowden can make it public at any time too, I suspect. If things aren't going at his pace, he can probably speed it up. It's in his interest, as well as The Guardian/WP's, to make the largest possible impact. This is his only shot.

<comment><USER8> I don't get what else there is to disclose. Snowden confirms that the NSA's has "horrifying capabilities" when it comes to collecting data. It sounds like with enough reason to and time they can bug any network and computer anywhere. Which considering they are the most powerful intelligence agency, seems likely to be true and getting more true.

</comment></comment></comment><comment><USER9> > … Mr. Snowden later sent him a homemade video with step-by-step instructions > for installing [encryption software], which Mr. Greenwald watched but never > completed… In late April or early May, he and Mr. Snowden began to talk over > an encrypted chat program.

What "encrypted chat program" they could possibly use?

<comment><USER10> Kopete with OTR? :)

</comment></comment><comment><USER11> The Rubik's Cube was a nice touch. I remember when I was inseparable from mine. (Averaged 50 seconds. Not world-class, I know, but not terrible for a 12-year-old.)</comment>


Ask HN: How to learn Electrical Theory? - <AUTHOR>

Where is a good place to learn Electrical theory? Basic stuff like Ohm's law. <comment><USER2> There are two distinctly different things to learn, what is commonly called "E&M", for Electricity and Magnetism, then also Electronics, what you need to build circuits that you can use for, say, smartphones.

You can go a long ways towards using Electronics without really understanding E&M but it helps a great deal if you do.

The second volume of The Feynman Lectures on Physics covers E&M. The first volume is classical mechanics, the third volume is quantum mechanics.

For Electronics you can't do better than The Art of Electronics by Horowitz and Hill however it is rather pricey.

</comment><comment><USER3> a book maybe ? see [http://www.reddit.com/r/electronics/wiki/beginners](http://www.reddit.com/r/electronics/wiki/beginners)</comment>


Show HN: Prolog compiler and interpreter in pure JavaScript - <AUTHOR> http://prolog.jldupont.com/ <comment><USER2>
        ?- X = 10.
        X = _
        no.

...this doesn't work like any Prolog I know. (Even defining equality manually as "eq(X, X)." doesn't work...)

<comment><USER3> Why? `?-` indicates that it's a query, it should not define anything.

<comment><USER2>
        $ swipl
        ?- X = 10.
        X = 10.

        $ gprolog
        | ?- X = 10.
        X = 10
        yes

(a) The REPL should print the variable bindings which caused the query to succeed. (b) The query `X = 10.` should succeed trivially.

I've been using Prolog on-and-off for close to a decade now and have implemented my own pseudo-Prolog (also in Javascript; was missing logic variables and extra-logical builtins). I _tried_ to get pretty much _any_ query to succeed in this interpreter and couldn't. This is not any kind of Prolog that I'm familiar with.

<comment><USER3> Yep, I agree I was wrong (having too little experience in Prolog): variables are necessary to extract values from queries.</comment></comment></comment></comment>


MIT students develop liquid fuel for electric cars - <AUTHOR> http://i.autoblog.com/2011/06/08/mit-students-develop-liquid-fuel-for-electric-cars/ <comment><USER2> The highest energy density listed for the electrolytes on the wikipedia page for flow batteries is 75 watt hours/kg, that is about 0.25Mj/kg. Gasoline is 42Mj/kg.

The original MIT release claims a 10 fold improvement in energy densities over existing flow batteries, but that is still more than an order of magnitude worse than the incumbent fuel.

<comment><USER3> Isn't that about the level where it gets interesting? My car can go something over 400 miles on a tank of gas right now. If their new batteries can get 40 miles on a "tank", and be refueled as easily as my car can now, that seems right on the threshold of being a very viable product.

<comment><USER4> Also, gas tanks could be a lot bigger without ruining cars. Things would be slightly less efficient, but if the solution is just being reused then pumping thirty gallons at once might not be the end of the world (as opposed to the ten that currently fit in my tank). If the solution weighs as much as gasoline, then that's an extra 120 lbs when the tank is full, which is a lot, but it's <5% extra.

<comment><USER5> Not to mention if the tank is full of a fluid that is not particularly dangerous, you might be able to integrate it into the structure of the car, similar to motorcycles with oil-in-frame design.

</comment></comment></comment></comment><comment><USER6> Original article: <http://web.mit.edu/newsoffice/2011/flow- batteries-0606.html>

<comment><USER7> Original paper: [http://onlinelibrary.wiley.com/doi/10.1002/aenm.201100152/ab...](http://onlinelibrary.wiley.com/doi/10.1002/aenm.201100152/abstract;jsessionid=8AE6EDCECE055B97EB99CF4483EC426C.d01t02) (free access until 27 June 2011)

This looks like a major breakthrough. Love the nickname - "Cambridge crude". As with all flow batteries, power density is low. But you could possibly compensate for that in vehicles with ultracapacitors which could also recapture energy from braking.

</comment></comment><comment><USER8> Worth noting that the liquid is rechargeable/reusable: <http://en.wikipedia.org/wiki/Flow_batteries>

According to the Wikipedia page, the main issue with these batteries is low energy density. If this group has figured it out, they may be on to something huge.

<comment><USER9> I agree, if a development like this were to happen for electric vehicles, adoption of them would skyrocket. The one thought I have is how much will this cost to produce initially per liter, as well as over time when it reaches a critical mass?

</comment></comment><comment><USER10> As I've learned when such promising technology is announced, I'll wait for system integration prototypes to roll out.

</comment><comment><USER11> Often in these sorts of articles, you can tell what the _big_ problems are by the fact that they're not even mentioned. The big unmentioned problems here seem to be:

a) Cost

b) Cost

c) Safety, and

d) Cost

I'm not sure what materials they're making these things from, but would it be fair to guess that it's something exotic and hard to fabricate?

<comment><USER12> From the article: "The tech supposedly makes the batteries up to ten times more efficient than their traditional counterparts, and even more importantly, the new tech is cheaper to produce."

<comment><USER13> Cheaper is meaningless in this context. For example, if the traditional counterparts cost $1,000/mile then $100/mile is still cheaper but still far from being pratical. We have no idea what it's cheaper than and by how much it's cheaper by.

Of course, my numbers are completely made. It's just meant as an example.

<comment><USER14> I'm pretty sure it is saying 10x better and cheaper than a standard lithium ion for the same battery size. If they are not saying that then the sentence makes no sense.

</comment></comment></comment></comment><comment><USER15> When a major change is made to how something is done, there really needs to be a very significant improvement that makes the cost of changing worthwhile.

I think eventually this will happen with electric vehicles, but no one knows for sure. Which is probably why we shouldn't subsidize solutions that are not compelling enough. The current electric vehicles aren't even as good as what they are attempting to replace and wouldn't be available at all without the massive subsidies.

If we do subsidize things in an effort to "jumpstart" the change, we might actually switch to a system that is not compelling enough and might get persuaded to jumpstart the next generation, which might have been compelling enough on its own. And be stuck with the cost of the subsidies or paying the higher cost directly.

Of course, such changes become so monolithic to begin with when government picks a standard and encourages everyone to adopt it. It may drive down costs in the short run, but it reduces progress in the long run.

For example, the adoption of the NTSC tv format and enforcing it using the FCC. We got color. Then we got closed captioning. And that was probably all the innovation we got over 50 years. But look at how quickly video has evolved on personal computers by comparison.

</comment><comment><USER16> "liquid fuel for electric cars" -- what if we used refined petroleum as a secondary energy source? we probably wouldn't even need a large electric motor any more.

</comment><comment><USER17> Here's a much better article with diagrams and more details: <http://www.greencarcongress.com/2011/05/ssfc-20110526.html>

This really will be a major step forward if it pans out. Even if it doesn't work so great for cars it could be amazing for grid storage.</comment>


Practical DevOps #2: On shaming and blaming - <AUTHOR> https://dev.to/0x12b/practical-devops-2-on-shaming-and-blaming-5ea9 <comment><USER2> Devops here. Blaming faults on a specific person is blame culture. Sorry but it will make people responsible not disclosing important incident information and instead hide it.

Basically blame its an anti devops pattern. [https://victorops.com/blog/blameless- culture](https://victorops.com/blog/blameless-culture)

<comment><AUTHOR> No offence, but did you read the article? It's all about how blame is negative and should be actively discouraged.</comment></comment>


Russia sees AI as key to world domination - <AUTHOR> https://www.voanews.com/amp/russia-sees-artificial-intelligence-key-world-domination/4012024.html <comment><AUTHOR> Increasingly, AI's role in cyberwarfare and psy-ops becomes part of the larger geo-political narrative.</comment>


Show HN: Homer – A Text Analyzer in Python - <AUTHOR> https://github.com/wyounas/homer <comment><AUTHOR> Homer is a Python package that can help make your text more clear, simple and useful for the reader.

It provides information on an overall text as well as on individual paragraphs. It gives insights into readability, length of paragraphs, length of sentences, average sentences per paragraph, average words in a sentence, etc. It is based on work by Pinker and another research study [1, 2].

This software package grew out of a personal need. Since I am not a native English speaker but am interested in writing. I write OpEds and a blog. So I designed and have been using Homer to improve my writing. I hope others will find it useful. I am aware of other tools (such as ProseLint) but I built this thinking this would help me improve my Python. :) Also, over time I plan on improving this.

References:

1- Steven Pinker's The Sense of Style:

2- [https://litlab.stanford.edu/LiteraryLabPamphlet9.pdf](https://litlab.stanford.edu/LiteraryLabPamphlet9.pdf)

<comment><USER2> Do you know how "The Sense of Style" compares to "The Elements of Style" ?

<comment><USER3> Having read both, I think _The Sense of Style_ is a very different kind of book from _The Elements of Style_. The latter is more of a collection of rules and recommendations. It is very concise, to the point, and without much argument. It simply describes what constitutes readable writing.

_The Sense of Style_ has a lot more why and how. The author showed the reasons that he recommend certain ways of writing, sometimes referencing studies in linguistics and cognitive science. The rules it contains are not as rigid as _The Elements of Style_; many of the style guides are really just something to keep in mind. Reading _The Sense of Style_ was like peeking into the thought process of the author.

</comment></comment></comment><comment><USER4> [https://github.com/amperser/proselint](https://github.com/amperser/proselint) is also very nice.

<comment><USER5> I haven't tried any of them, but I've been collecting such things in case I find the time/energy to chase down one specific yak.

[https://github.com/retextjs/awesome- retext](https://github.com/retextjs/awesome-retext) [https://github.com/textlint/textlint](https://github.com/textlint/textlint)

</comment></comment><comment><USER6> Very cool. Wonder if this could be tailored to analyze financial disclosures (10-Ks and 10-Qs) to rank management teams on their abilities to describe their company succinctly and appropriately convey messages on financial results to shareholders and the investment community.

It's a pet idea of mine that I just haven't had time to play with. Would need to adjust for size of the company and industry, at a minimum...

</comment><comment><USER7> This is really cool! Thanks.

</comment><comment><USER8> Really cool. It would be super useful to have this in other languages as well, french in my case. This would be a useful addition to a grammar checker I am currently developing.

<comment><AUTHOR> Thanks. I am sure it will be useful to have it in other languages. Will see what I can do :)</comment></comment>


Rust playpen - <AUTHOR> http://play.rust-lang.org/

<comment><AUTHOR> Also the example on [http://www.rust-lang.org/](http://www.rust-lang.org/) is now runnable and editable, powered by the same tool (it's a CORS-enabled service).</comment>


Investing Or Marketing? Real Reason Lightspeed Invested In Ning @crazy Valuation - <AUTHOR> http://www.techcrunch.com/2009/07/26/investment-or-marketing-the-real-reason-lightspeed-invested-in-ning-at-a-crazy-valuation/

<comment><USER2> Arrington writes: "They likely have a liquidation preference that lets them get their $15 million out of the company before others can take part of the pie."

But, such a liquidation preference wouldn't get them their full $15 million back if the company sells for far less than the assumed $750 million valuation, would it?

For example, the total capital raised is said to be $119 million. Lets say the company sells for $150 million. Would Lightspeed really get its full $15 million back, even though that sale price is an 80% decline from their purchase-time valuation?

<comment><USER3> Yes, because that's what a liquidation preference is.

You get your full investment back in a liquidation event before common stock gets paid off.

To illustrate, if LSVP was the only investor in Ning (which it isn't) at a $15MM on $750MM, then if the company gets sold for just $15MM, LSVP would still get $15MM back, and nobody else would get anything.

<comment><USER2> I understand liquidation preferences in general -- and if LSVP were the only investor, in a first round, the usual interpretation would make sense to me.

But with prior preferreds expecting a return, and (theoretically) no pressing need for the money and such a high valuation -- that seems an excessive amount of downside protection to offer for a smallish amount of late money in an 'up' round.

I guess the interesting scenario to me is: what if the liquidation amount is enough to give the early investors a modest return, or the latecomers their money back, but not both? Can we assume that there are tiers, and even that the earlier tiers might get an X% return before the late tier gets their full investment back?</comment></comment></comment>


U.S.'s Toughest Immigration Law Is Signed in Arizona - <AUTHOR> http://www.nytimes.com/2010/04/24/us/politics/24immig.html <comment><USER2> "police broad power to detain anyone suspected of being in the country illegally."

Isn't this going to be unfair to certain racial goups? obviously native Americans can't be illegals, and anyone that appears hispanic or meso-american is likely to predate illegal immigration, African americans are presumably in the US legally (or at least somebody had the recipts)

But what about all those white guys? Will they all have to prove that they are citizens, and their parents and grandparents were citizens. Won't these lead to all the white's being rounded up?</comment>


Drip - <AUTHOR> https://d.rip/ <comment><USER2> The picture they have selected wants to make me shut my laptop and just give up.

<comment><USER3> Look, we're all so uniquely garish in the exact same way!

<comment><USER4> Like is this a service for low key creators too, or only very flamboyant ones?

</comment></comment></comment><comment><USER5> Kinda weird that they have the exact same shade of blue and monospace font as [https://www.blackbox.cool](https://www.blackbox.cool).

Anyway, it's probably good for everyone that someone's trying to compete with Patreon -- market forces and all that.

<comment><USER6> Considering one of Blackbox's primary functions is Kickstarter fulfillment, maybe they're working together?

</comment></comment><comment><USER7> I get a totally blank white page, though the source is there. It's rare a page doesn't work at all from PrivacyBager/uBlock.

<comment><USER8> It appears that Privacy Badger blocks kickstarter.com completely. I don't know why it has that default but you can just set it to only block cookies.

</comment></comment><comment><USER9> Seems like a really bad name to me. "Hi, I'm a Drip! Won't you support my work!"

I can't imagine doing that even at my drippiest 17 year old self. I wonder how big of an issue it will be for them. *

I imagine they were thinking DRIP as in stock fund Dividend ReInvestment Program, but that doesn't really apply here. I could toss out a couple of other hypotheses, but, regardless of their reasoning, I just think the name is likely to be a liability.

* Watch me change my mind in a few months, sign up for the service and have this comment come back to bite me. ;)

</comment><comment><USER10> Weird choice of name since there's an email service w/ the exact same name - [https://www.drip.com/](https://www.drip.com/)

<comment><USER11> "weird" wouldn't be my first choice of word, desperate for a "hip", short domain and willing to take any name maybe.

</comment></comment><comment><USER12> Kickstarter version of Patreon ?

<comment><USER13> Or is it a Patreon version of Kickstarter

<comment><USER14> No, it clearly states that it is by Kickstarter in the copy.

</comment></comment></comment><comment><USER15> I assumed it was just a hip domain for drip.com

</comment><comment><USER16> >We charge 5%, in addition to any fees from our payments partners.

>We will help creators securely transfer subscription and payments information to other subscription platforms. Creators will also be able to download and export their subscriber information and any content they have posted to their Drip page

<comment><USER17> >>We charge 5%, in addition to any fees from our payments partners.

Does it mean they are costlier than Patreon?

<comment><USER18> Patreon originally had a 5% cut + the payment fee, before their new higher fee structure

</comment></comment></comment><comment><USER19> I have a Drip page for Radical Digital Painting here: [https://d.rip/jeffreyheart89](https://d.rip/jeffreyheart89)

To be honest the product and UX still has a long way to go but I enjoy Kickstarter's enthusiasm about it to say the least.

</comment><comment><USER10> How is there not an open source or at least a paid WP version of this. Seems like it's a decent plugin you could run on your own site + make a good lifestyle business out of (while saving people tons of money by letting them process their own transactions).

</comment><comment><USER20> what makes this any different than patreon

<comment><USER21> It doesn't have to be. Competition is competition.</comment></comment>


Engineers develop bone-like metal foam that can be 'healed' at room temperature - <AUTHOR> https://phys.org/news/2019-08-bone-like-metal-foam-room-temperature.html <comment><USER2> The only interesting part seems to be that it resembles bone and "repair" can be called "healing" instead.

> _While this room-temperature approach is not truly "self-healing" because it > requires an external power source and raw materials, Pikul sees it being in > line with how self-healing occurs in the body._

<comment><USER3> Bone requires an external power source too.

<comment><USER4> And raw materials.

<comment><USER5> them bones them bones need calcium!

</comment></comment></comment></comment><comment><USER6> This is a fascinating technique and an interesting step forward.

I noticed:

> The new nickel, however, reduces the healing efficiency when repeatedly > using this technique. Because the healed areas no longer have a polymer > coating, nickel would continue to amass there should another piece of the > sample need to be healed.

<comment><USER7> Yes, so I reckoned this won't be useful for "growing" foam or big breaks. At that point you'd fashion a right shape chunk of foam and fuse it on both sides I suppose.

</comment></comment><comment><USER8> This is interesting, I'm curious what applications this would be useful for. They hint at some potential uses toward the end, but don't elaborate much.

Presumably it'd be useful in applications where the parts would normally fail regularly.

<comment><USER9> I'd also assume it'd be useful for repair of critical components that undergo trauma. Such as bridges, and buildings that might be struck by vehicles, or repairing prosthetics and other things that can be damaged at the same time as the human they're attached to.

<comment><USER10> You'd need to make your bridges out of this fancy metal foam instead of boring old (read: "cheap") hot rolled I beams. That would be a massive technical challenge. It's theoretically possible but would require new construction techniques. At the very least we'd need to figure out a new way to protect it from the elements that doesn't negate the self healing properties (this foam doesn't look closed cell, hello corrosion) Probably expensive beyond all practicality.

Furthermore, vehicles basically just bounce off the structural elements of bridges and other structures like that. It's not really a problem.

If anything we'll see this kind of stuff used in expensive niche applications. Low volume bespoke electronics in high vibration environments would benefit from being able to "heal" like this. I can also see it being useful when applied as a coating that protects the material underneath, basically a self touching up paint job (like galvanizing, but possibly with a wider array of materials than just zinc). This could be very useful for items in corrosive environments.

</comment></comment></comment><comment><USER11> How does it not short out when the foam isn't completely severed? It seems like the electroplating current would just short circuit through the non- broken connections.

</comment><comment><USER12> Can we please stop with the clickbait scientific discoveries? They all follow the same formula of: 'x develops y which can "z"'. Where "z", which is always in quotes, is a gross sensationalization of some discovery or effect.

<comment><USER2> Thank you, yes.</comment></comment>


Epigramr: review anyone in your phone book (Feedback needed) - <AUTHOR>

Hey guys,

  We would appreciate honest and critical feedback on a social app we developed.
 This app helps you review people an businesses using your phone number.
Some descriptive text about the app below.
This is our site http://www.epigramr.com/
https://play.google.com/store/apps/details?id=com.cp.contactpoll
<comment></comment><comment></comment><comment></comment><comment></comment><comment></comment><comment></comment><comment></comment><comment>
Need to rate that neighbourhood pizza joint on their amazing deals? Want to find out more about that cute guy you just exchanged numbers with at last night's party? Do you have the worst history teacher ever? Who's the popular girl in class?
Find all this and more with epigramr. It lets you review anyone in your phone book anonymously! What's more, it let's you read reviews of anybody with a phone number which may or may not be in your phone book. Since our reviews are completely anonymous, you can be absolutely sure that these opinions are unbiased and undisguised!!
Just click on a contact, select a sentiment (thumbs up for positive or thumbs down for negative) and post a review! It's that simple! You could review a coffee shop, a pizza delivery, an online vendor or a friend (or worst enemy!!).
And the best part is - it's anonymous!
Other features * Instant notification when someone reviews your phone number * Reverse lookup feature, when you don't have a number in your address book * 'My Reviews' to see what others have written about you! * Alias names (or secret identities!) of your contacts </comment><comment><USER2> looks like a nice app. Especially for reviewing by phone number. I would definitely like the idea of looking at the reviews of a chinese takeout directly by number rather than fishing through zomato</comment>


Eyes reveal true hypnotic state for the first time - <AUTHOR> http://www.newscientist.com/blogs/nstv/2011/10/one-word-technique-produces-first-physical-evidence-of-hypnosis.html

<comment><USER2> Interesting - a lot of professional hypnotists (Derren Brown for example), and scientists deny the existence of a hypnotic state.

</comment><comment><USER3> We need new scientist to tell us the hypnotic state is real? Too bad there have been many studies before this which are quite conclusive.

<comment><USER2> Link to them please.

<comment><USER4> I don't have a proper cite, but I saw on a TV show where they highlighted interesting researchers who were studying cognition and perception a very interesting experiment. One of the most interesting was a researcher who took subjects and measured the Stroop effect.

In case some have not seen it, I'll describe the Stroop effect. The Stroop effect is the way the meaning of a printed word interferes with the perception of the attributes of the print. For instance, if you are shown words printed in colored ink, and asked to identify the color, you slow down significantly on words where the word is a color name.

For instance, if you see the word "lamp" printed in blue, you have no trouble quickly saying blue.

If you see the word "red" printed in blue, you want to say red, and there is a significant pause as you have to override that and say blue.

Anyway, in the segment I'm thinking of, the researcher took people and hypnotized them, and told them that when they woke up they ware going to do the test, but all the words would be in a foreign language they did not understand.

The subjects were woken up, and the test was done--in English. The subjects performed as fast on the color name words as they did on the other words, as if they could indeed no longer understand the meaning of the words.

Hypnosis is often dismissed as the subject just wanting to please the hypnotist. So they cluck like a chicken when someone rings a bell because they want to appear cooperative and make him happy. OK, that could be. But how your brain prioritizes work meaning vs. word color when you are trying to decide what color to say is not something that you can change to please the hypnotist. It's not voluntary. If you are able to do the color name words as fast as the other words, it means something really has been changed in how your brian is processing.</comment></comment></comment>


Now, a dating site for the 'ugly' - <AUTHOR> http://www.hindustantimes.com/Now-a-dating-site-for-the-ugly/H1-Article1-589870.aspx <comment><USER2> I noticed during a quick browse of several regions that there are far too many women on the site who are nowhere near ugly (I can't speak for the men, I'm afraid). This seems to indicate that there are many people in Britain (and probably elsewhere) who have a vastly inaccurate image of themselves.

</comment><comment><USER3> I suppose there is some logic to this:

"By doing this they might actually find a compatible partner - instead of spending years paying for dating sites they have no hope on."

I don't really get the whole dating thing. It looks like a broke system to me. Still, my first thought when seeing the title of this was along the lines of "Finally, a site I might join!". I don't really think I'm ugly. I think my reaction is a cross between "bizarre sense of humor" and disdain for the current system where, according to a recent article posted on HN, good looking pictures are likely to be far more out of date than more average looking pictures found on dating sites. (So: Maybe we already have dating sites for the ugly, the difference is they just lie about it.)</comment>


The Refactoring - <AUTHOR> http://math-blog.com/2014/05/05/the-refactoring/ <comment><USER2> So which one are you, the Cowboy coder or one of the Refactorers? :)</comment>


Container Security with SELinux and CoreOS - <AUTHOR> https://coreos.com/blog/container-security-selinux-coreos/ <comment><USER2> Atomic[0] provides this on a Fedora/CentOS + docker base, and it works very well. It's slightly more mature than the CoreOS version as there is support for sharing volumes (volumes mounted with z are sharable, volumes mounted with Z are specific to a container).

It's great to see this being adopted more widely - it greatly improves the security of containers, and in my experience, adds nothing to the cost of administrating systems. I'm much happier running our security-sensitive applications in containers with this than I would be without it.

0: [http://www.projectatomic.io/](http://www.projectatomic.io/)

<comment><USER3> Yeah, we're spending a little time exploring whether there's any feasible way to support sharing in a slightly more fine-grained manner - right now volumes shared between containers under Atomic are labeled such that _all_ containers can write to them, which isn't entirely optimal.

</comment></comment><comment><USER4> 'However, if the attacker is able to take advantage of a kernel bug, they may be able to escape from the container environment. ... every container runs in a different context and SELinux will forbid cross-context access, preventing any further damage from occurring.'

In this scenario SELinux will only protect you from very specific kernel bugs.

SELinux will not protect you against any kernel bug that either gives you a memory write primitive or gives you control over RIP. (Since you can just trash all the SELinux protections). It is only going to protect you from logic bugs where the kernel accidentally gives you filesystem access you weren't meant to have or something similar. Bare in mind that some of the recent kernel bugs relating to namespaces have been logic bugs.

<comment><USER5> Have you got any numbers? It would be interesting to find out what percentage of VM escape bugs have been protected by SELinux.

<comment><USER4> It could be zero. I'm really not sure. Someone has to go through the vulns and check if they are protected or not. It probably doesn't harm security and may stop some future bug but if you have limited resources to apply to security it might be worth installing grsecurity instead of this. ([https://grsecurity.net/](https://grsecurity.net/)) They are often boasting about how grsecurity would have stopped a vuln. So they seem to have a track record of useful mitigations.

<comment><USER6> Selinux should block the VENOM vulnerability in Qemu: [http://danwalsh.livejournal.com/71489.html](http://danwalsh.livejournal.com/71489.html) See also [http://www.selinuxproject.org/page/SVirt](http://www.selinuxproject.org/page/SVirt) Keep in mind that Grsec (which is definitely underdeployed in the linux community) is compatible with LSM such as SElinx and AppArmor, so you do not have to choose (you'll take a performance hit, though).

<comment><USER4> Do you know why people prefer to use labels in SELinux to isolate different Qemu instances rather than use different UIDs? Is it just a matter of convenience?

<comment><USER3> It's easy to grant a process the privilege to transition to isolated SELiniux contexts, but it's difficult to grant a process the privilege to transition to a limited range of UIDs. Doing it with SELinux also makes it easier to provide additional restrictions - there's a lot of files and device nodes that have to be a+r for normal processes, but which don't need to be available to code running in containers. Using SELinux allows you to prevent the container processes from having access to anything other than the files inside their namespace without needing to entirely refactor the permissions in the host.

</comment></comment></comment></comment></comment></comment><comment><USER7> I have been having a lot of conversations about SELinux + Containers recently. Is there more/further reading anyone can suggest about interactions/background between containers and SELinux (e.g. docker, systemd-nspawn, etc.)?

</comment><comment><USER8> Nice high level overview of container security via SELinux - anyone interested in running containers should read this.

We are exploring different operating systems for running containers and CoreOS seems like a good candidate.

</comment><comment><USER9> Does someone know how this would be manually applied to systemd-nspawn containers? Beside a kernel bug, what are the things a root process in a container could do to damage the host?

<comment><USER10> The systemd-nspawn man page has an example that might help:

      Example 6. Run a container with SELinux sandbox security contexts

      # chcon system_u:object_r:svirt_sandbox_file_t:s0:c0,c1 -R \
        /srv/container
      # systemd-nspawn -L system_u:object_r:svirt_sandbox_file_t:s0:c0,c1 \
        -Z system_u:system_r:svirt_lxc_net_t:s0:c0,c1 -D /srv/container \
        /bin/sh

In addition to -Z and -L, there's also --drop-capability.

Apart from privilege escalation bugs, any shared resource can theoretically be used to escape containers. For example, access to main memory via a device with DMA, access to the same /proc as the host, access to a shared filesystem (replace a binary that the host executes), etc.</comment></comment>


Mullenweg Speaks Out on Twitter, WordPress and the Question of Competition - <AUTHOR> http://www.readwriteweb.com/archives/mullenweg_comscore_twitter_wordpress.php

<comment><USER2> I don't think twitter is a direct competitor with blogs. As stated in the article "One of the many uses of Twitter is to link to and promote your blog posts (and other people's blog posts, as we grow, so do they, and vice versa."So basically twitter is a tool used to generate or lead traffic to blog posts.

I read economics, business and web 2.0 blogs everyday. Some of the material cannot be covered in 140 characters or it will lack substance. What I do see on twitter is a headline to catch your attention and a link to get more information on another blog.

Twitter can replace blogs that lack substance, ie the teenage girl that writes about her boring life and stupid thoughts on her blog on myspace. This could probably be done in 140 characters or less.</comment>