
Ask HN: Your biggest non-technical hack/discovery - kyro
Try to stay away from coding hacks as much as you can, which is what I meant by technical. I'm talking about social, mechanical, etc. Should be interesting, entertaining, and enlightening to hear about all the clever real world hacks you guys have come up with.<p>Also, if you have several you'd like to share, go for it.
======
nfnaaron
I hacked a skydiver once.

I was a civilian/sport/fun/non-military jumpmaster in the eighties.
Taught/supervised skydiving students from the second jump on. Sometimes sat in
the plane and supervised/critiqued, sometimes jumped out with them for some
task they were learning that involved another person in the air.

One student was having trouble staying stable when he left the plane. Tried
everything I could think of, he was just tense and maybe a little tunnel
visioned. He really wanted to succeed, and I really wanted him to.

However the student leaves the plane (there are many ways), you or the student
would typically say out loud "ready, set, go!" and go on "go." Regardless of
how he left the plane, he tumbled.

As we went up once again, near the end of the day, I had no idea what to try
except some variation of what I/we had always done. We got to altitude, turned
on jump run, and he climbed past me to stand on the step outside the plane. I
still didn't know how to help him.

He got in position, looked in at me, and almost without thinking about it,
rather than saying ready set or whatever, I took a big, obvious breath, slowly
let it out in an exaggerated, relaxed way, and casually pointed at him.

Beautiful exit, and he had a big smile when we met on the ground. Helping that
guy through that was one of the most satisfying moments in my life.

------
thesnark
I made a portrait of my girlfriend out of dice.

[http://www.elusivesnark.com/2008/11/carolines-dice-
portrait....](http://www.elusivesnark.com/2008/11/carolines-dice-
portrait.html)

~~~
dylanz
Wow... this is beautiful!

~~~
stcredzero
Not to take away from the accomplishment, but I think most of the credit goes
to the model's parents. (Intended spin is as a compliment.)

------
dryicerx
Chemistry hack.

Distilling Alcohol. I wasn't of age at the time, actually was still in high
school, and had a hard time getting alcohol, so I decided to make it my self.

Designed and built a reflux still with embedded temp sensors, a condenser, and
one-way air locked gasoline containers for fermentation. I used sugar and
yeast to ferment giving me ~10% abv, then ran it through the still 5-6 times
to get ~90% abv... it was rocket fuel. I also sent the final samples to a chem
student I knew to test for methanol as a precaution. Finally filtered several
times through activated carbon to get any final impurities out.

It was the best vodka I've ever had so far, no burn and extremely pure
ethanol. I only made a handful of batches before the excitement of it ran out.

~~~
noonespecial
Any kid smart enough to distill his own booze _and_ smart enough to check it
for the "makes you go blind" part (using a method other than the _friends at a
party_ test) should be exempt from the "drinking age" requirement.

~~~
jjs
... and, technically, _is_. ;)

------
kyro
A few of mine:

-In college, I found that the card readers to open the gates into the faculty parking lots, and into the inner ring of the campus, didn't really check for anything... other than a physical card in the slot. So 3 years worth of free parking close to campus was definitely great.

-I worked at a franchised sub shop for a time, and the music discs we were required to play were pretty horrible. Listening to Fallout Boy got really annoying after the 400th play or so. I decided to pull down the player, which could 'only' play the cds sent to us, to see if there was anything I can tweak. I found a series of 16 pins on the back, and with some googling, discovered the position to place the connectors so that I could play anything. It worked, and in no time, I turned the place into a hip hop club, making sandwiches to the tunes of Jay-Z and the like.

-Slamming the coin slots on games at arcades, dislodging a few coins.

-After taking a hot shower, I'll turn the knob so the water gets super cold for a few seconds. It's a nice way to get me going after a nice relaxing hot shower.

~~~
flooha
I do the show thing too. I'm not sure how healthy it is, but I always feel
great after doing it.

------
tomsaffell
When WilliamHill.co.uk (a gambling site) launched in the UK they offered a
promotion: _a 50% rebate on your first stake (max 50 GBP)_

The hack was simple, and spread like wildfire on campus:

    
    
      Place a GBP 100 bet on a basket ball game, at odds of 1:1.9. Get GBP 50 rebate.
    
      Get a buddy to take the opposite bet, at GBP 100 (they get GBP 50 rebate)
    
      One person wins 0, the other GBP 190. Split the 190, both parties are up GBP 45. 
    
      Repeat as many times as you have credit cards numbers (new registrations each time)
    

Lots of people pocketed hundreds of pounds in ~1 hours work, risk free, and we
were students, so it was good money. I think it was 1999, maybe 2000.

~~~
bhseo
Nice combination of bonus abuse and sportsbetting arbitrage. You can still
make money in similar ways, although online gambling operators have tightened
up the last few years.

------
noonespecial
If you hold a coin halfway into some older parking meters for a while, it will
think its slot is jammed and registers "out of order." Most cities won't
ticket an an out of order meter. Free parking. All day.

~~~
anamax
> Most cities won't ticket an an out of order meter.

"Most"? I haven't seen a parking meter in years that without "tickets issued
at broken meters" on the label.

------
louislouis
It was the last year of college, my student card had only 2 months left before
it expired. I deliberately lost it and got a replacement which extended the
expiration date to 3 years more since new cards were in for next years batch
of students. Needless to say I've enjoyed the student discounts all this time.

Hacking Bus Tickets: I was a poor student at the time and 'all day' bus
tickets were expensive for me. After 1 week of paying full prices, I had
collected enough tickets to duplicate the fonts using photoshop and print my
own tickets :D

Coke Machine: At school there was a vending machine where if you pressed the
coke button multiple times and fast enough, it would give u 2 cokes for the
price of 1.

School Passwords: I was 14 I think, coded up a basic popup box in VB saying
'Please verify your username and password', the input was sent to a txt file
and there was a nice little Netscape Navigator icon to make it seem legit lol.
I had the .exe running on startup on maybe 2-3 computers. Over 1 week I had
hundreds of passwords including the network administrator pass. :D

~~~
jrockway
_School Passwords: I was 14 I think, coded up a basic popup box in VB saying
'Please verify your username and password', the input was sent to a txt file
and there was a nice little Netscape Navigator icon to make it seem legit lol.
I had the .exe running on startup on maybe 2-3 computers. Over 1 week I had
hundreds of passwords including the network administrator pass. :D_

I think I did you one better. At my high school, the student computers in our
dorms (yes, a weird high school) were on the same network as the computer lab
computers. To log onto a computer lab computer, you put in your username,
password, and the domain name (STUDENT). We set up a computer in our room
named STUDNET and changed a few login boxes in the computer lab to log into
STUDNET instead of STUDENT. Several hours later, we had several accounts. Oh
Windows 98, how I love thee...

The printers were also on this network. They were all HP printers, they all
had the control port open (9001?), and they all had the a DNS name in the form
of "...-printer.imsa.edu". A brute-force search of our IP space gave us the IP
address of all the printers, and a quick shell-script later, the printers'
ready message became "OUT OF WATER" instead of "READY". Every printer on the
entire campus, all at once.

Oh, the chaos this caused. Upon walking into the main building, several
teachers immediately just had to show me this weird message on the printer.
"The one in my office is like this, and so is the one in the computer lab.
It's so crazy!" I especially loved watching several PhDs in the math
department calling HP to ask where to put the water in. People were talking
about this for months, and I don't think anyone ever figured out that it was
me.

So yeah. Changing the ready message on HP printers is my favorite hack, and it
still probably works.

~~~
louislouis
haha, nice hacks indeed! The following week you should've changed it to OUT OF
BATTERY

------
vital101
The remote for my car has a very weak signal strength, so sometimes when I
forget where I park I place the remote underneath my chin and press up. My
head (skull + fluid) acts as an antenna and voila! There's my car!

You might look like a fool doing it, but I promise it works!

~~~
kyro
Your skull works more as a satellite. :P

And yeah, definitely does work.

------
jacquesm
Building a windmill and powering my house with it ? (I guess that has
mechanical, but it is also technical, hard to be 'mechanical' without
'technical').

Not sure if this qualifies as a 'hack', but when abroad and stopped by the
police I suddenly only speak dutch. That seems to reduce the interest level
considerably. Saved me a few fines by cops playing the 'fleece the tourist'
game.

~~~
rjett
Does your windmill provide 100% of the power needed for your house? If so, how
big is it and how much did it cost to build?

~~~
jacquesm
I'm no longer living in Canada, where I had this set up. Under normal
conditions the windmill would be close to 60% of the power required for the
house, the rest was solar.

We did just about everything we could to conserve power though, one of the
lessons you learn fastest when working with renewables is that it is a lot
easier to save a Watt than to generate one.

The machine was a 16'er, or about 5 Meters, so a swept surface of 18 square
meters or thereabouts, it cost a small fortune to build because I was planning
to make it in larger numbers. Designed power was about 2.5 KW, it came out a
bit less than that, mostly due to a slightly larger air-gap than what I had
planned on (the plasma cutter nozzle used to cut the stator laminates was
wearing down, and cutting with a slightly larger diameter jet than planned).

The design is far from perfect but for a first try at a variable pitch machine
it worked pretty good. It survived several major storms without failure, we
only took it down because we emigrated back to Europe. It's laying in pieces
on the garage floor waiting for better times.

edit: the only way to get 100% of the power for your house from the wind would
be if you would consent to being without power every now and then. After all ,
the wind only blows so much, and when it doesn't you'll need to have either
enough power stored up in batteries or you'd have to have an alternative
source.

What people do to get to the economical equivalent without using batteries is
if their grid operator allows it do something called 'net-metering', this
allows you to pump your excess power into the grid and back out again when you
need it for the same price.

The whole uncoupling of network and electricity production is seen by plenty
of people in the renewable energy scene as a way of discouraging net-metering,
after all, if the 'base' rate per KWh is already quite a bit just for
transport then they can afford to give you a crappy price for your excess
power, and charge you _twice_ for the storage and retrieval of the power.

------
anamax
Girls like sex and want to have sex with me. All I have to do is express
interest and not piss them off until afterwards.

Generalizing "afterwards" makes relationships possible.

Women are girls in many respects.

~~~
zackattack
I can't believe how long it took for me to internalize this

------
keefe
Human beings have a nearly infinite capacity for self deception. I am not a
special, unique exception. I must be merciless in my self observation. The
only way forward is to look at where I am and make a simple, realistic plan to
take me towards my goal. Underestimating cost in time, effort and money leads
to failure.

------
thesethings
* Cooking: Ramen can be used not just for soup, but for stir-fry.

* Travel: Any supermarket is your fee-free ATM. (cashback) (US)

* Travel: In the middle of your urban trek and have to pee? Hotel lobbies usually have clean, open bathrooms. (Specifically talking about the one you're NOT staying at, when you're wandering for 10 hours in a foreign city, and don't want to go all the way back to "base.")

* Travel: Hotel lobbies often have free wifi.

* Cooking: Peel an orange _inside_ the produce bag. Makes for perfectly dry, not messy, not sticky experience. (your fingers can poke through the skin and tear it, and it doesn't tear bag. Magic.)

* Travel: I have so many Priceline and Hotwire strategies, but the short version is: use these sites to book hotels.

~~~
abalashov
Supermarkets require a purchase to provide cash-back, do they not? That would
seem to amount to some sort of fee, even if it's a lot smaller (e.g. a 50 cent
pack of gum).

EDIT: I suppose I am referring to precisely that aspect of them which would
otherwise be "ATM-like" - namely, that the function is to dispense cash on
demand, and that the fees in question would otherwise go solely toward paying
for the privilege. Cashback is a nice way to stock up on hard currency, but it
is technically a side effect of making a purchase, not an ATM, even though in
practice the side effect does not entail a "fee" in that you meant to buy
whatever you're buying regardless.

~~~
thesethings
Right. But purchasing something at a store like this when I travel is in no
way forced for me.

I find my friends and I go to grocery stores/drug stores even _more_ often
when we travel than at home. You have no stock of stuff like when at
home/work. You're constantly grabbing a drink/a snack things to take back to
"base." You often have no refrigeration, so that means more, smaller trips to
the store, too.

------
fogus
I once worked at a car wash were most of the employees were out on work
release. Anyway, the days were long and boring so I took the time to devise a
way to get free sodas out of the vending machine. I was not interested in
stealing soda, as I hated it, but only in figuring out how to do so. I
eventually did so. I was so proud of myself that I decided to show one of the
guys that I got along with pretty well. When I came back few days later the
machine was completely empty and was never again able to provide tasty
beverages for very long. Eventually the owner of the machine caught on and
removed it from our site. I was very naive.

~~~
Shooter
I once went to a conference that was held on an Arizona college campus during
summer session. The school kept having soda and vending machines disappear
periodically. It turned out that guys from the local tribe were taking the
_entire_ machines back to the reservation in their trucks, using them until
they were empty, and then lugging them back to be refilled. I'm not sure what
method they were using to get the soda out without paying, but they finally
caught some of the guys using video cameras. I think it was all done more for
the excitement than the soda...and also maybe to make a statement of some
kind. (I can't imagine hauling one of those big machines around for the soda
it would hold.)

------
iigs
It's not a specific hack, but it has given me the same feeling, something I
keep discovering: It's just a bunch of rules. Learn the rules and you
understand it.

We've probably all seen it with computing; it looks mysterious from the
outside but learn the logic and you can make it go.

Fixing cars is the same way (fuel, air, spark). Circuit design is the same way
(a few types of component, logic gates). Power engineering is the same way (W
= V*A, wire's got to be big enough). Music is generally the same way (very
math-y in both the time and frequency domains). Dating is pretty similar
(statistics play a different role here, but you can do well enough here "by
the book").

We're currently learning that raising a child is the same way. Diaper, hungry,
tired, hot/cold, {colic, teething, other age related issues}, doctor.

~~~
ax0n
I agree wholeheartedly. My best hack? I can figure out how almost anything
works, usually very quickly, by probing for rules. It works for almost
anything: mechanical, employment, electronics, etc.

Good for social engineering, too. :)

~~~
jjs
A corollary: most ostensible rules aren't the _real_ rules.

Knowing the difference is a form of power.

~~~
akamaka
Downvoted by accident, sorry. Hope we get an undo feature someday.

~~~
Torn
until then, here's a +1 to your parent

------
Shooter
I made all of the public area lights at a major hotel and convention center
strobe for about an hour during an international science fair. The hotel had a
huge glass atrium with elevators and several thousand bulbs, so it was quite a
spectacle. It looked like a single huge strobe light had landed in the city
center.

It made the news, and I won our (informal) pranks contest for that year. I
felt it mostly made up for my loss the previous year (the shaving cream dipped
in liquid nitrogen and then packed into a competitor's car was a poor showing,
prank-wise. It was unoriginal, it ruined the upholstery of the poor car, and
it wasn't as dramatic of an effect as one would think for the trouble. Too
much of the shaving cream never expanded after can removal and thawing.)

------
grizzydot
In college my friends and I would go to the driving range a lot. It was a 3
tier range with a golf ball dispenser on each level, all networked together.
We figured out (by chance) that if we swiped our range card and then quickly
selected the bucket size of range balls, it would dispense the balls before it
updated the entire system with the new dollar amount that should be on the
card. So we basically got back the cost of the card (~ $20) the day we
realized the hack just by swiping over and over (a large bucket was $12). All
in all we got around $400 worth of balls before they put in a new payment
system.

------
seven
During chaos communication camp (lots of hacker do camping) 2003 in Germany
was one of the hottest days recorded since $longtime. Normal fridges where not
allowed on the campside, because of the heavy power consumption. So I built a
fridge out of a box, a towel, plastic bottle and a fan. Worked like a charm.
Most other hacker who saw this were like: 'Damm, I told my friends this would
work...' Execution is all! :)

On the same camp, I talked Emanuel Goldstein into signing and selling me the
last VHS of Freedom Downtime that he had broad over from the US and was
intended to be a present for the camp organizers. ...Or did he talk me into
buying it...?

~~~
kyro
Wow, cool. How did you go about assembling it?

 _brought_

~~~
seven
Nothing big or special. I punched some holes into the bottle and made it drip
onto the towel that was wrapped around the box that contained our snacks etc.
Had a fan pointed to the towel. That is all. Evaporative (heat) loss is the
keyword.

What made me remember this, was the fact that I was in between about 2000
hackers who probably all thought about this.. but that I was (afaik) the only
one who actually did it.

In Nigeria they use more or less the same trick to build simple air-
conditioning. Imagine it as a wood box open on two sides with a lot of small
brittle branches inside. Water dropping into it. And a fan blowing on one open
side.

btw: although mixing up brought and broad is something that I could have found
myself and is a result of being sloppy; I always appreciate input on my
writing. As English is not my native language, I would guess that my grammar
sucks more than my spelling. :)

~~~
zeckalpha
Swamp cooler is the term.

------
chrischen
Fiddling my ID card into the lock in the door of any room in my school would
eventually unlock it. I got into a room after the teacher locked it for lunch
once (we leave for lunch and come back after).

------
Mz
I guess my biggest hack is getting myself well and off all medication with a
condition where the typical answer is drugs, drugs and more drugs (plus
surgeries) until it kills you.

Life is chemistry. Knowledge is power. But many people seem to think only
drugs are chemistry and power. <shrug>

Edit: Secondary related hack: Managing to share information about what I've
done without getting myself thrown off any of the health forums I belong to,
in spite of routinely inspiring controversy, outraged reactions, and open
hostility.

~~~
Tichy
Please tell the tale

~~~
Mz
After being bedridden for 3 1/2 months, I was diagnosed in May 2001 with
"atypical cystic fibrosis". My doctor informed me "people like you don't get
well -- symptom management is the name of the game". But I have two sons.
Since it is genetic, they tested both of them. I told them which child had it
and which didn't before they ran the test. My oldest has the same diagnosis I
have and had not been on antibiotics for over three years at the time of
testing. So when I was told "people like you don't get well", I replied "It
may be true that I will spend the rest of my life fighting off the next
infection, but This particular infection has to GO as it is killing me." My
doctor physically took a step back and looked like I had slapped him in the
face.

I spent the next five years trying to figure out what we were doing right that
my son was so healthy and talking to people in the alternative health scene
who seemed to have some clue. I gradually made changes and developed a mental
model for what was going on. For that initial five years, I intentionally
avoided joining any online CF forums or otherwise making any strong
connections to the CF community. I didn't want my analysis of what was going
on to be contaminated by the clearly failed current mental model for what is
going on with this condition and how it 'should' be treated.

After five years, I began joining CF lists and forums. Most people on such
forums have enormous difficulty believing that diet and lifestyle can do
anything meaningful for their condition. Most of them are desperate for A Cure
but they seem to all be waiting for a purple polk-dotted dancing, singing pill
that will cost gajillions of dollars and have an eight page fold out
describing the horrifying potential side effects. Eating right and giving up a
few pleasures of North American Affluenza apparently seems to them like A) it
can't possibly work and B) the prospect of giving up their couch is more
mortifying than the prospect of having their lungs consumed by infection until
some doctor decides to cut them out and replace them with the lungs of some
perfectly healthy person who died tragically young in the prime of their life.

To each his own. I'm very happy (and comfortable) without a couch, thanks. As
of this summer, I am 100% drug free for the first time in nearly nine years.
My son has been drug free for close to three years.

~~~
Tichy
Not sure why you were downvoted, except maybe for the ranting.

~~~
Mz
I was at work all day, so I was unaware of any downvoting. I don't believe I
was ranting (unless you mean the remark about the purple polka dotted dancing
singing pill). The reality of the situation is as extreme as I describe it. I
don't think you can get it across in brief without "hyperbole". I have no
reason to believe anyone here would want the long version, with the statistics
on death rates (mean age of survival: 37 in the US), drug use (many people
with CF are on $3000.00 to $4000.00 per month worth of "maintenance drugs" --
ie when they aren't considered "sick"), frequent hospitalizations (many people
are go in once or twice a year for a "tune up" -- ie when they "aren't sick"
-- and can be hospitalized multiple times per year as they deteriorate)....and
on and on. The statistics are really gruesome.

There is good reason why I get greeted with so much shock and hostility by
much of the CF community: The things I say can be done fly in the face of
everything these people know to be true. I don't see any reason why my
statements would be greeted any more warmly and acceptingly here. <shrug>

------
flooha
I'm not really sure if this qualifies as a "hack". A friend and I were riding
dirt bikes through the forest and he crashed in a mud hole which was next to a
bees' nest in the ground. He was allergic, got stung twice and we were deep in
the forest, so we had to get out asap. The bees were swarming around his bike
and going 2up on my bike was near impossible. I turned my 2-stroke bike around
and pointed the exhaust at the bees and revved the engine. The resulting cloud
of oil/gas mix subdued the bees. My friend took the throttle, I wrestled his
bike out of the mud and we made it out of the forest as fast as we could.

------
xenoterracide
College / Certification Hack. I took A+, Network+, and Linux+ and got transfer
credits for 3 linux classes, 1 networking and 1 hardware class, spending only
a few hundred dollars and saving several thousand, shaving time off my time to
graduate and having several certs to show for it.

------
dryicerx
Lockpicking count?

~~~
kyro
Sure it counts. Any particular tools/methods you use?

~~~
dryicerx
Dremel picks with wiper blade inserts, saw blades, and hacksaw blades.
Hammered/flattened nails make for great toque wrenches (alternative is the
flat metal clips on pens).

------
chaosprophet
Gunpowder on an omelet makes a huge difference to the taste, making it super
spicy. (Gunpowder is a mix of red chilly powder, salt and a number of other
spices, and is found in many Indian recipes).

------
saurabh
When i was a kid I stuck a crumbled reflective tape to the ceiling to bounce
off the remote signals to our TV. I could then just press the buttons without
giving a damn where it pointed.

------
Noether
Nowhere near as awesome as most of these, but I made a magnetic screw-picker-
upper out of a broken pair of earbuds and a bottle cap.

------
zackattack
For many years, jamba juice was running a promotion: buy a $25 gift card, get
a free jamba juice. So one day I bought a gift card, got my free razmatazz,
and was about to head out on my way when I doubled back.

Me: "I'd like another $25 gift card please."

Cashier: "That will be $25. What is your free smoothie?"

Me: "Peach pleasure."

And then I would pay with the previously purchased gift card, creating an
infinite loop with a sunk cost of $25. I was only once refused. I netted at
least 50 jamba juices for me and friends..I hope to incorporate this into a
screenplay some day.

~~~
thomaspaine
I did this with Blockbuster a few years back. I believe it was a free $5 gift
card for each $50 gift card you purchased. Most stores I've seen now have a
policy of not letting you buy gift cards with gift cards.

------
zackattack
A Combinatorial Proof of the Summation Identity (i=1,i->n,i) = n(n+1)/2

[http://img.skitch.com/20091012-mt5p22p1fxi3s1y32wqid49pwm.pn...](http://img.skitch.com/20091012-mt5p22p1fxi3s1y32wqid49pwm.png)

Zachary Burt, University of Chicago, 2007

Assume n people are in a room and they each shake hands with every other
person. This constitutes n(n-1)/2 handshakes: each person shakes hands with
every other person. The number is divided by two to account for double-
counting the handshakes.

The sum of handshakes can alternatively be computed by summing the number of
unique handshakes made by each person: person 1 shakes n-1 hands, person 2
shakes n-2 hands (for he has already shaken hands with the first person), and
so forth, until person n-1 shakes only one hand: person n has already shaken
hands with everyone else. This can be expressed as: n-1 + n-2 + n-3 + ... + 1,
or, through the commutative property of addition, 1 + 2 + .. + n-2 + n-1. This
is conveniently expressed as the summation (i=1,i->n-1,i).

We know that the summation (i=1,i->n-1,i) is equivalent to the expression
n(n-1)/2. If we replace n-1 with n, this is the same as saying (i=1,i->n,i) =
n(n+1)/2. QED.

