
2:40 - thisisblurry
http://www.leancrew.com/all-this/2012/06/240/
======
gregschlom
Interesting comment:

"A proper microwave designer would know that the best position to get
something out of the microwave is how it was put in, and take care that
regardless of microwaving time, the turntable would always stop in the
position it started."

~~~
dsirijus
At my ex-company, I've always commented how well designed was microwave
because it always end up in the same orientation as the start.

Turns out, it was just that it did a complete turnaround on a time segment (5
seconds) and it was easiest to input time in 5 second intervals.

Still, good, if not great design.

~~~
nadam
I would say it _is_ great design.

Why? Because there is an also very important requirement: when the user wants
to get his stuff out let him do it immediately: do not waste his time. This
way they did not compromise this important requirement while gave a solution
to the other problem as well.

~~~
drivingmenuts
But was that intentional design or just a happy accident and was that
"feature" recoqnized as such and institutionalized?

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noonespecial
Ceremonies and rituals are like stored procedures for humans. I wonder how
much of the ritual contained in the major world religions today are fossilized
remains of some guy just figuring out how to avoid some disease or make daily
life a touch easier and having it catch on. _"And thou shalt set thy dial for
2:40, not 2:35 unless thou then proceedeth to 2:40... 2:45 is right out."_

~~~
Monkeyget
"Civilization advances by extending the number of important operations which
we can perform without thinking about them" -- Alfred North Whitehead

I have been interested in the subject ever since I read the part of Code
Complete dealing with the notion of abstraction. If everytime you woke you had
to think about the fact that a door is a bunch of atoms that together form
different materials but together some of it being the doorknob you'd never be
able to leave your bedroom. It ties closely with the notion of affordance

A teacher told me that the reason for the banning of pork in the Quran and the
Bible is to prevent some diseases. Straigth up banning pork for health reason
solved the problem. It's probably some kind of myth.

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kjhughes
My microwave use hack isn't turntable or cup position related. It's that I
round to the least number of unique buttons to press and still get near the
needed cook time. For example, 33 sec for half a minute, not 30 sec. 99s for a
minute and a half. Over the years I must have saved nearly as much time as
it's taken me to make this post.

~~~
lifeformed
Same here, I always do 60 instead of 1:00 or 90 instead of 1:30 to save an
extra button press.

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femto
This guy needs my 1990's vintage Sanyo microwave with "boomerang turntable",
meaning the turntable always stops in the same position. This is done with a
micro-switch/cam combination on the shaft.

If you are really impatient, and don't want to wait for the turntable to
finish moving, the period of revolution is 12 seconds. Programming in
multiples of 12s means the item is ready to remove as soon as the beeper goes
off.

~~~
SeoxyS
Assuming modern microwaves have a microchip on which computation can be done,
and an electric motor of controllable speed, couldn't the microwave calculate
the speed required for the specified time to end at the right angle, with no
delay?

~~~
joezydeco
You're assuming too much.

Appliance manufacturers go for the cheapest parts possible that still perform
reliably under the warranty period. The motor driving that turntable is not a
precision stepper or brushless motor with variable microprocessor speed
control. It's a cheap A/C motor (perhaps with a drive belt for torque) that's
switched to line current by a 30-cent mechanical relay. You can tell it's A/C
when the turntable starts in a random direction each time it's energized.

~~~
raldi
Most microwaves I've seen just alternate between directions. It's not random.

~~~
joezydeco
It is random. You need a larger sample size.

There is no need to put an expensive polarity-reversal circuit (with
mechanical or electronic memory) in the assembly just to alternate the
turntable direction. The cooking effect is the same.

~~~
femto
Based on my observations, I'd say it actually does alternate. My theory is
that the motor speed is slow enough and consistent enough, as is the friction,
that the motor consistently overshoots by half a pole when it stops. Thus, it
moves in the opposite direction when turned back on. If it was moving faster,
it might well be random. What's the chances of it displaying bifurcation then
chaos? :-)

Given that the period of my oven is bang on 12 seconds, averaged over many
revolutions, I think it's probably a synchronous motor.

------
snitko
It's funny how americans boil water in microwaves, while the rest of the world
does it in kettles. There was a discussion on reddit about it. I didn't
realize it, but apparently it has to do with the fact that most americans
rarely drink tea, but rather prefer coffee from coffee machines and so they
don't need kettles. Personally, I can't imagine how one can boil water in a
microwave, it sounds ridiculous (in a good way, no offense), but these little
differences fascinate me.

~~~
nsxwolf
The first time I traveled to Australia I found an electric tea kettle in my
room, and it was one of those ah-ha moments. It was a perfectly obvious
invention, and yet, the idea had never before crossed my mind. As an American,
you boil water the hard way, or in a microwave.

You can find them in stores here, but they're not popular. I've told several
people about them, and they were just as delightfully surprised as I was.

~~~
planetguy
The problem is that electric kettles in America are slow as fuck, which I
assume is due to the 110V power supply.

Go somewhere with 240V and two things happen: (a) you're far more likely to
die of electrocution in your own house and (b) you can get a decent tea
kettle.

~~~
keithpeter
A 3kw heating element is a 3kw heating element at whatever voltage it
operates, so I suspect that there may be a limit on the _current_ that
domestic appliances can use in US kitchens.

At 110v you would be looking at 27 Amps which may be a little high. I had not
thought this one through before, thanks.

~~~
notJim
American outlets are 15 or 20 Amps, AFAIK.

~~~
hollerith
In case grandparent is too elliptical for some readers --

The maximum current determines how thick the wires have to be. Since power
(ability to heat or do other work in one unit of time) == current * voltage,
doubling the voltage doubles the amount of power a wire of a given thickness
can deliver.

~~~
keithpeter
Well done, I should have emphasised the principal.

Looks like the maximum power that a US kettle can produce is 110 * 20 = 2200
watts, so will take about 3000 * 2200 = 1.36 or 36% longer than an EU kettle
to boil.

Microwaves make more sense in that scenario

~~~
nsxwolf
Microwaves have their own problems - they can superheat water without boiling
it, which will then explode in a fury of scalding foam as soon as you jostle
it.

They're also frequently mounted overhead, where it's more dangerous to
retrieve a mug or big Pyrex cup. Contrast that with the kettle which has that
little flap over the spout and is spill resistant.

------
drewblaisdell
The author should try drinking loose leaf teas instead. I'm sure the gains of
switching away from tea bags (which often contain whatever can be swept up off
of a tea factory floor) are worth touching a hot handle.

~~~
Shenglong
Loose leaf teas are much harder to steep, and if you steep them wrong, you end
up with a rancid bitter flavor (for lots of higher quality teas).

To quote a song: "You could not feel sadness if you've never tasted joy" -
perhaps, if he's content with his tea bags, we can let him drink his tea bags.
Since switching, I can tell you first hand, that I can no longer drink tea
bags, or even poorly steeped teas without cringing. I sound like an asshole, I
know.

~~~
wizard_2
There's a great quote about not refining your tastes as it narrows your world
but instead continuing to explore the availability of the world around you. It
was either Feynman or Ryan Dahl. =p

That being said, I love me my loose tea leaves, but it's just a different
product then bagged tea, one hasn't ruined the other.

------
rvkennedy
He kinda lost me with the unfunny cartoon, the sugar but no milk, and the
_microwaving the water for your tea_ thing. For an alternative, and I think
authoritative opinion, try Christopher Hitchens, here:
[http://www.guardian.co.uk/theguardian/2011/jan/03/christophe...](http://www.guardian.co.uk/theguardian/2011/jan/03/christopher-
hitchens-tea-tips-for-america)

~~~
planetguy
Also, Douglas Adams on a very similar subject:

[http://onegoodmove.org/1gm/1gmarchive/2002/12/a_proper_cup_o...](http://onegoodmove.org/1gm/1gmarchive/2002/12/a_proper_cup_of.html)

 _So the best advice I can give to an American arriving in England is this: Go
to Marks and Spencer and buy a packet of Earl Grey tea. Go back to where
you’re staying and boil a kettle of water. While it is coming to the boil,
open the sealed packet and sniff. Careful---you may feel a bit dizzy, but this
is in fact perfectly legal. When the kettle has boiled, pour a little of it
into a teapot, swirl it around, and tip it out again. Put a couple (or three,
depending on the size of the pot) of tea bags into the pot. (If I was really
trying to lead you into the paths of righteousness, I would tell you to use
free leaves rather than bags, but let’s just take this in easy stages.) Bring
the kettle back up to the boil, and then pour the boiling water as quickly as
you can into the pot. Let is stand for two or three minutes, and then pour it
into a cup._

I don't trust the idea of microwaving water for tea, because microwaved water
will probably be sub boiling temperature.

~~~
adavies42
actually microwaved water will frequently be above boiling--microwaving lets
the water remain still enough for it to get superheated. when you disturb it
(with a teabag, spoon, etc.) it will start bubbling wildly (and quite possibly
give you a nasty scald)

~~~
planetguy
And by "frequently" you mean "almost never, cuz I've been trying to get it to
happen for years and it damn well doesn't"

~~~
evgen
It depends on what you have the water in. A very smooth-sided container with
very pure water has few nucleation sites and so the water is much more likely
to become superheated, while a beaten up mug and standard tap water is less
likely to superheat without boiling.

~~~
adavies42
happens to my tea all the time--i don't know if it's actually superheated in
the sense of being >212, but it sits perfectly still in the mug until i drop
the bag in, at which point it goes nuts with the bubbles.

------
JonnieCache
If you feel like this guy and his pyrex-cup-microwaving ways are threatening
your identity as an obsessive, over-optimizing nerd, you may wish to try
making your coffee with chemistry gear like in breaking bad:

<http://makeprojects.com/Project/The-Florence-Siphon/1151/1>

<http://www.youtube.com/watch?v=zXDOCo5Cn_g>

------
ErrantX
Microwaved tea! :S Required reading:
[http://onegoodmove.org/1gm/1gmarchive/2002/12/a_proper_cup_o...](http://onegoodmove.org/1gm/1gmarchive/2002/12/a_proper_cup_of.html)

(but in all seriousness interesting article about the problems of not
critically addressing things that annoy you)

~~~
ricardobeat
I don't think there's any physical difference between water boiled in a
microwave vs in a pot (free radicals?).

Lighter teas (white, green, chamomile, etc) are best brewed at 70-80C, so
that's not general advice :)

~~~
planetguy
There isn't any difference, except often when people microwave water they
don't get it all the way to boiling. With a kettle it's pretty obvious when
your water is at boiling.

------
przemoc
Be aware of superheating!

Well, don't worry unless you have a really smooth cup and going for 5-10
minutes or more...

~~~
rytis
And a link: <http://en.wikipedia.org/wiki/Superheating>

------
iscrewyou
A problem I didn't know existed. Will be fixing it next time I turn the damn
thing on.

------
adavies42
the design thing that i notice about most microwaves is that some of them let
you just punch in a time and hit start, while others make you hit "cook"
first.

i find this to be an excellent example of (failing at) optimizing for the
common case--probably >99% of the interactions people have with microwaves are
pure timed-cook-at-100%-power, and requiring an extra button press to enter
that mode is silly.

~~~
planetguy
Some let you just press the "add minute" button and it immediately starts
cooking on a one-minute timer. Want to cook for more than a minute? Keep
pressing that add-minute button while it's cooking.

~~~
adavies42
yes, i love that one! now _that's_ good common-case optimization.

------
beerglass
first world problem

~~~
SHIFTHAPPENZ
Yeah. I'm still not sure how i should respond to such problems. My first
reaction is to judge them as irrelevant and that a wise person would valuate
such things as misguided. On the other hand, every man (and woman) in fact is
living in his or her own world (or worlds). And it should be fair to make your
world as nice as possible.

Not sure if one can expect mankind to extend its horizons to the whole world
or universe as it really is. The older I get, the more I think of us just
being animals at all. This "look beyond your own nose" thing is maybe not so
realistic/real for our species, as nice it sounds in theory.

Reminds me of a comic <http://questionablecontent.net/view.php?comic=2202>

------
gcb
Interesting fact. Or urban legend (who can tell the difference nowadays?)

What blocks microwaves is thin metal plate in the door. With holes so you can
see inside.

It's a Faraday cage. And if you read specs in the manual, it' says the
percentage that it blocks "for sure" to match some regulation. Hint, never
close to 100%

And there's a percentage of radiation that goes out, and fry the inpatient
that keeps it's face there

~~~
patrickyeon
What blocks the radiation (at ~2.4GHz) is the metal all around the cooking
cavity. The holes aren't actually a problem: as a rule of thumb we don't worry
about shield leakage once the maximum dimension of a hole (diameter, in the
case of a round hole) is less than 1/2 wavelength. 2.4GHz has a wavelength of
12.5 cm. Leakage does not happen through those holes.

(It does happen through the gap between the door and the rest of the
microwave, but there's some neat design work to keep it from getting too bad.)

Of course it leaks, though. It leaks so much that when I was working on
sensitive RF receivers, I could see when microwaves were turned on for lunch
hour in other parts of the building. It's the leakage that makes it interfere
with wifi. Don't worry though, you absorb more RF energy through the wifi in
your devices and through your cell phone.

~~~
gcb
Wasn't implying it leaks by the holes :) just that nobody (i didn't use to)
think it was a sheet of metal there only

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isalmon
I stopped reading after I saw that he's putting sugar in his tea.

