Pancake Physics to Cut Batter Splatter 313
Anonymous Coward writes "The headline just about says it all on this one. A physics grad student in the UK has come up with the mathematical formula for how to flip a pancake and have it land correctly back in the pan. The BBC
has the details."
Ah-hah! (Score:4, Funny)
Seriously, mimicing real life movement in mathematical forumla is a tough one (that's why we don't see any battlemechs [classicbattletech.com] walking around, or tons of popular robots in every house hold.
Re:Ah-hah! (Score:2, Funny)
Would that be an African or European swallow?
Re:Ah-hah! (Score:2)
Since I have year-old twins that are just starting to eat pancakes, this will come in handy!
Pancakes, crepes, flapjack... (Score:5, Informative)
Re:Pancakes, crepes, flapjack... (Score:5, Funny)
Re:Pancakes, crepes, flapjack... (Score:2, Funny)
"People will accept your ideas much more readily if you tell them that Benjamin Franklin said it first" - Benjamin Franklin
Re:Pancakes, crepes, flapjack... (Score:2)
Re:Pancakes, crepes, flapjack... (Score:2)
"... equals the square root of Pi, times the gravity divided by the distance the pancake is from the elbow times four
You'll have to double that and add 30.
Re:Pancakes, crepes, flapjack... (Score:2)
Re:Pancakes, crepes, flapjack... (Score:2)
Actually, what I found more "confusing" was the bit at the end of the article about more Britons preferring lemon and sugar on their pancakes... Bleh. :)
Incidentally, I'm from New England, where a milkshake is only a milkshake if it has no ice cream in it, otherwise it's a frappe (unless you're in Rhode Island, where it's a cabinet), unless the ice cream is not blended, in which case it's a float.
-T
Re:Pancakes, crepes, flapjack... (Score:2)
Chocolate milk shaken up (not stirred
Re:Pancakes, crepes, flapjack... (Score:2)
Re:Pancakes, crepes, flapjack... (Score:2)
Arrrgh, you arrogant New Yorkers... New York is not part of New England! ;)
Here, we're civilized, and have frappes.
-T
Re:Pancakes, crepes, flapjack... (Score:2)
Russ %-)
Actually... (Score:5, Funny)
I think you meant:
In Heaven, the police are British, the lovers are Italian, the cooks are French, the engineers are German, and it's all organized by the Swiss.
In Hell, the police are German, the lovers are Swiss, the cooks are British, the engineers are French, and it's all organized by the Italians.
Re:Amazing Brits... (Score:2, Informative)
I for one definitely don't say give me microsoft and probably use more european software than american software. My hardware is mainly Taiwanese, Korean or Japanese except for the SGIs. The US is definitely not the fount of all knowledge and technology.
Re:Amazing Brits... (Score:4, Funny)
There should be a Six Degrees of Slashdot test: how many posts does it take to turn a discussion into one about operating systems, beowulf clusters, or the RIAA.
Re:Amazing Brits... (Score:3, Informative)
It was not always the way. After all, business computing began here with the Lyons Electronic Office [btinternet.co.uk], and in the 80's schools used the BBC Micro [mcmordie.co.uk], developed by Acorn in Cambridge.
The rot didn't set in until the 90s, and a once thriving British computer industry went down the pan. For shame.
I blame the government. It doesn't help when we have a PM keen to lick arse, whether that arse be Bill Gates' or Dubya Bush's.
Re:Amazing Brits... BCPL (Score:3, Informative)
Re:Amazing Brits... (Score:5, Funny)
Re:Amazing Brits... (Score:3, Informative)
I think the Athenians have prior art. You can have credit for the court system, with seperate judge, jury, and executioner, though. That, in my opinion, is as or more important.
Re:Amazing Brits... (Score:3, Informative)
Re:Amazing Brits... (Score:2)
Ha! I think not. The Magna Carta established that the King's power was not supreme, but he was still a hell of a lot more powerful than the parliament. The House of Lords was the only one that mattered, and members of parliament were not elected democratically anyway. The idea of the Magna Carta as the beginning of British democracy was a piece of propaganda spread centuries later (I believe it was done by the Whigs, though I can't remember for certain).
By the 17th Century we'd had a civil war during which the King was removed from power and only parliment ruled the country.
Again, untrue. Lord Oliver Cromwell set himself up as military dictator. He did TRY to make England into a democracy, of sorts, but he never liked the people who were elected, so he'd just send them all home and call for new elections. In reality, Cromwell had more power than the monarchs he'd replaced. The one useful thing that did come out of the whole situation was that the House of Commons started to equal or even dominate the House of Lords in power for the first time.
The evolution of democracy in Britain was a slow process, and I'm not sure one could really peg down a date and say "this was the effective end of the monachy's power." If I were to choose a period though, it certainly would not be before 1800.
Re:Amazing Brits... (Score:2)
Amazing Americans... (Score:2)
Re:Amazing Americans... (Score:2, Funny)
Re:Pancakes, crepes, flapjack... (Score:2)
Crepes are thinner and often smaller than pancakes. They're French originally (as I'm sure you knew already...).
Cheers,
Ian
I'm gonna nit pick. (Score:5, Insightful)
Understanding something does not equate to being able to do it.
I understand how a plane flies, but I can't fly one.
Re:I'm gonna nit pick. (Score:5, Insightful)
Stuff like how long you wait till you flip it, the perfect angle to get the spatula underneath the pancake (directly parallel to both the grill and the pancake), what to do with blueberry/raspberry/banana/etc pancakes, what to do when the cake sticks, and the rest. I'm sure you could come up with an equation to perfectly predict this and it wouldn't mean a damm thing -- like this one.
I mean you could equally use a formula to try and tell somebody how to flip eggs and it wouldn't meen a damm thing. To train line cooks to flip the proper, and perfect, Over Easy egg requires about 100-200 wasted eggs until you get it down to about 95% of the time -- and that extra 5% is a pain since each egg varies in how much force will require before it breaks, etc and usually requires thousands of eggs before you can go nearly an entire 8 hour shift without breaking at least 1 yolk open. By 'flip' an egg I mean using only your wrist, no sissy spatulas involved. It takes alot of work and effort to learn to do these things which is why almost nobody outside cooks can probably cook eggs or omeletes the *right way*, no spatulas/informercial specials involved.
Re:I'm gonna nit pick. (Score:2)
Re:I'm gonna nit pick. (Score:2)
Basically for time saving. When you are cooking 20 eggs/omelettes at a time you have to be able to flip them in about 2-3 seconds, not waste a minute or more gently flipping them over/using some other method.
Re: In England we're real tossers (Score:5, Informative)
First you make a circular movement with the pan to ensure that the pancake hasn't stuck and overcome static friction.
Then you tilt the end of the pan down slightly and make a short, sharp inward movement, to get the pancake sliding outwards.
Then you sharply flick the pan up, so that the pancake goes between one and two feet in the air (more if you're feeling cocky) and also spins enough that it lands in the pan the other way up.
I'll be very impressed if they invent a machine which can repeatably toss pancakes. There are an awful lot of variables, which he seems to ignore. But then he is a physicist, not an engineer.
Re: In England we're real tossers (Score:4, Funny)
Yeah, but that means he will be more accurate by roughly 5% because he won't be assuming that pi is 'nearly' 3 ;-)
Thank you. (Score:2)
- Then you tilt the end of the pan down slightly
- and make a short, sharp inward movement [...]
- Then you sharply flick the pan up
- so that the pancake goes between one and two feet in the air [...]
Thank you, both for the pointers and an approximation of what they formula should be rearranged to give.
The formula expressed in the article purports to give you the angular velocity of the pancake. Perhaps useful as one step in the process of computing how to build a flipping machine, but NOT the whole story even for a machine design, and definitely not what you need for training a human.
And the formula is clearly wrong, since g shouldn't be in it if you're going for angular velocity - unless you're solving for the angular velocity needed at launch to get the pancake back into the pan (in which case r shouldn't be there). So something in the article's description is wrong (though perhaps the original research was correct).
What I'd like to see is a function giving the target height for the top of the pancake's arc in terms of the radius from pivot point (probably elbow) to the center of the pancake (and possibly also parameters for the mass and diameter of the pancake if air resistance is significant.
It's a lot easier to target a particular height-of-toss than some other control parameter (such as speed), and the height will vary with the individual flipper's arm-plus-pan length.
Since the pancake has to land back in the pan the toss has to be close to straight up, which puts the pan about horizontal at launch. There will be some small inward motion from the air resistance, because the up and down trip have the 'cake at opposite angles to the wind, which might be compensated for by outward motion from sliding on the pan during the angular swing of the launch.
Oops. I take that back. (Score:2)
Oops. I take that back.
g, r and omega should all be there to let you solve for time-of-flight from angular velocity. So rearranging should let us solve first for circumferential velocity, then for flight time, and finally for height-of-throw, giving the formulation I was after.
Re:I'm gonna nit pick. (Score:2)
Heh believe it or not cooking pays fairly well for a college job. 10-12$ dollars an hour.
Re:I'm gonna nit pick. (Score:5, Insightful)
http://catb.org/esr/jargon/html/Some-AI-Koans.html [catb.org]:
In the same way, the pancake will land back in the pan as long as you understand the formula.[[Mods, mods: this is supposed to be _funny_. Its not the first time I've posted something hilarious and it got modded "Insightful"]].
Mod up parent (Score:2)
fnord
Re:I'm gonna nit pick. (Score:5, Funny)
I can remember *all* of the digits to pi
now the order.. thats a different matter...
dave
I can beat that (Score:2)
I know all the digits to pi in binary. But I do admit the same problem - I do get the order mixed up a bit.
Re:I'm gonna nit pick. (Score:2)
You pull back it goes up. You push forward it goes down. Left is left and right is right. What more do you need to know? Hey! You're a pilot!
We'll see who catches that movie reference.
Sounds good (Score:5, Interesting)
Now if we could only have some kind of a pancake flipping robot.....
Re:Sounds good (Score:2, Interesting)
Now if we could only have some kind of a pancake flipping robot.....
Yes, leave it to geeks to spend thousands of dollars, and countless man-hours developing a machine to flip a pancake over.
Re:Sounds good (Score:2)
>> Now if we could only have some kind of a pancake flipping robot.....
>
> Yes, leave it to geeks to spend thousands of dollars, and countless man-hours developing a machine to flip a pancake over.
>
> [.sig] Too much of a good thing is an awesome thing, but too much of an awesome thing is really really stupid.
And even more of an awesome thing than that ...is a surefire way to get your web site with a pancake-flipping robot slashdotted!
Re:Sounds good (Score:2)
In other news (Score:3, Funny)
Oh come on... (Score:2)
In Soviet Russia, pancake flips YOU!
Re:Hmmm. (Score:2)
WE ATE THEM.
*I'm from US
Butter! (Score:4, Funny)
A better question, what if you butter the edge as well?
Re:Butter! (Score:2, Funny)
Re:Butter! (Score:5, Funny)
Falling cats are famously able to turn around and land on their feet. Unless the height of the fall is too large, the cat has no problems with that. I forgot the exact conditions of falling cats, but they are able to turn around in a fall in a lot less than the 30 inches down from a table.
If the two were to be combined and the cat has a piece of bread strapped to it, it is the cat that prevails, being more active, heavier, and having a larger moment of inertia.
I'd imagine that the same would apply to pancakes, and I have disregarded the risk of the cat eating the food.
Re:HGG (Score:2)
> or
> butter some bread and attach it to a cat, then throw it up in the air. Cats always land on their feet, but bread always lands butter side down, so the cat/bread combination will spin round and round indefinately...
>
>Isn't that almost the secret to flight? (Throw yourself at the ground... and miss.)
"After about 200 feet, it doesn't matter which side of the bread the cat is stapled to."
Shrove Tuesday (why the BBC ran the story then) (Score:5, Informative)
Not sure about other countries but last Tuesday (4th) was Shrove Tuesday in the UK when we all make pancakes. For the religious amongst you the word 'Shrove' refers to the practice of confessing of sins, then afterwards the fast of Lent could be considered a penance of faults committed. Thats why the BBC ran the story on Tuesday. However, most of us just love eating the pancakes!
Re:Shrove Tuesday (why the BBC ran the story then) (Score:3, Informative)
I made some cracking pancakes on Tuesday, my special recipe involves grating bits of lemon and lime rind into the batter, mmmmm, that citrus flavour flows all through the pancakes, nice.
I am not religious but it is always useful to know about as many different religions as possible as this gives you many excuses to feast, well that and setting off lots of fireworks.
Re:Shrove Tuesday (why the BBC ran the story then) (Score:2)
Here in America, we call it "Fat Tuesday" (fitting considering the extra weight most Americans carry isn't it?
I'm from Detroit, and we have a large Polish population here (according to one statistic, Hamtramck has the largest population density of Polish people outside of Warsaw) and so here we have the old tradition of eating paczkis, which are pastries of Polish origin not entirely unlike a jelly donut (but don't *them* that, it's SACRILEGE to compare a paczki to a jelly donut). The paczki is one of my greatest personal weaknesses.
Re:Shrove Tuesday (why the BBC ran the story then) (Score:2)
Heh. In a large chunk of Catholic-dominated societies last Tuesday was Fat Tuesday / Mardi Gras / Carnival, celebrated by:
Drinking copious amounts of alcohol
Watching nubile young women disrobe
Dancing in the streets
Throwing / catching small trinkets (such as strings of beads) for good luck
You Brits need to get with it!
I've had the good fun of being on a float in one of St. Louis' Mardi Gras parades for several years now. This year my wife was queen of the float (yes, she found the baby in the king cake). So guess who got to ride up front with her? I'm still hoarse!
Yet another pancake formula?? (Score:2)
Problem already solved (Score:3, Funny)
Re:Problem already solved (Score:2, Informative)
Dozens of TV cooking personalities... (Score:5, Funny)
*flashy logo jumps onto the screen*
"PANCAKE CRISIS: WHEN THERE IS NOTHING ELSE TO TALK ABOUT AT 1:12 AM!"
*The camera cuts back to the weird-looking anchor Fox News always has. He smiles reassuringly, and gives you the thumbs up, proudly exclaiming, "This is Fox News! We are covering all the stories other news stations are too smart to cover!"*
Extra points if anyone can spot the Onion reference
Tiddlywinks (Score:2)
Apparently it's all in the wrist action... (Score:5, Funny)
Is that.... (Score:3, Funny)
BBC doesn't understand it (Score:5, Informative)
AFAIUI it simply means that the pancake needs to spin at such a rate that it will flip 180 degrees between leaving the pan and returning. Given that it will not fall back flat unless the flip is 180n degrees, n integral, this is pretty blindingly obvious.
Unfortunately, the equation is just that and doesn't tell you how to achieve flip rate nirvana. So here is my guide:
Re:BBC doesn't understand it (Score:2, Funny)
Re:BBC doesn't understand it (Score:2)
Re:BBC doesn't understand it (Score:2)
Minor correction. :)
-Thomas
now that we know the formula.... (Score:2)
Sure, knowing the formula is exactly the same things as being able to do is, but didn't anyone else notice that they didn't actually give this "formula" that they claim is so important?
Re:now that we know the formula.... (Score:2)
"The angular velocity of the object equals the square root of Pi, times the gravity divided by the distance the pancake is from the elbow times four - that is how to get the pancake back in the pan. " and...
"The 21-year-old explained the formula: "'W' is the angular velocity of the pancake, 'g' represents gravity and 'r' is the distance from the pivot - the elbow - to the centre of the pancake"
so w=sqrt(pi)g/4r
MIT did it first ... (Score:2, Informative)
http://web.mit.edu/newsoffice/nr/1995/40409.htm
re: story (Score:2, Funny)
err (Score:5, Interesting)
hmm . . . I notice that this formula does not factor in mass of the pancake. this makes me wonder, being not-so-smart in physics, would this formula apply for any size pancake?? and how about objects other than pancakes? could I flip say, a thanksgiving turkey and still have it land perfectly in the pan, using this formula??
and why do Scots like cheese in their pancakes?? don't they know the proper way to do anything is the American way, i.e. sugar and syrup??
Bored and tired minds want to know!!
Re:err (Score:2, Interesting)
--paul
Re:err (Score:4, Informative)
In problems driven solely by gravity, the mass typically drops out. Thank you, Equivalence Principle.
A pancake is a nicely simple and symmetric object. Indeed, the symmetry means that whenever you flip it, you're doing so about a stable axis. Other shapes, not so nice... your turkey might tumble wildly. Also, while the mass drops out of the angular velocity, it does not drop out of the formula for the needed force -- and a turkey tends to be quite a bit more massive than a crepe.
Re:err (Score:2)
Mass only drops out in a vacuum. In air, while the pancake is aloft, you have
Torque comes from air resistance and can be quite significant for a pancake weighing a few grams with a surface area of about 300 square centimeters.Think Galileo (Score:2)
Try dropping a pancake (crpe to Yanks) and and a melon at the same time. Which one hit the floor first? Oops. try it in a vacuum next time.
So if you are cooking in a vacuum, the formula applies equally well to pancakes, melons, and thanksgiving turkeys.
If you are cooking at atmospheric pressure, you will have to correct for air resistance (quite significant for a pancake).
This is what Brits have to say about it (Score:5, Interesting)
I asked a (native) British collegue about it, and this was his reply:
Ahh the wonders of pancacke day or as the French call it Mardi Gras Fat tuesday. This is the day before the start of Lent (crazy Christian starvation festival, preparing mind and body for the Easter celebrations etc). Typically people used to use up all their fatty things on this day such as butter, eggs and lard [freeserve.co.uk] etc, coz it was not the done thing to be eating lard cakes when everybody else was eating celery.
Thus the pancake tradition started. Of course, all the religous nonsense has largely disappeared but the pancakes remain in British Culture.
As far as the tossing equation goes, thats just the work of a whacked out English ale swilling academics, and is an essential part of British inventiveness and ingenuity. (You can't make great discoveries all of the time)
Hope that helps and thank you for your interest in Britain.
:-)
Re:This is what Brits have to say about it (Score:3, Funny)
No wonder our ancestors emigrated :-)
Okaaaaaay, (Score:5, Funny)
You know what? While we're at it, let's give China forks and spoons.
Spatula? (Score:2)
Wierd Al already told us (Score:2)
But I'm not sure that we are convinced enough to make Spatula City [wayuhf.com] successfull in Europe.
If you still think we should use spatulas, why don't you send a Virtual Spatula [virtualspatula.com] to prove your case.
Re:Okaaaaaay, (Score:2)
Off topic but... (Score:4, Informative)
I know this is really off topic, but it is on, if the topic is "reasonibly absurd science". In Nature [nature.com] last December, they decided to publish a short note about an Austrailian matehmatician's work on The Best Way To Lace Your Shoelaces [nature.com]
No joke.
What details? (Score:2)
Something going wrong.... (Score:4, Insightful)
What's next? Maybe, for his doctoral thesis, he should write a formula for the proper amount of syrup to be used based on it's rate of obsorbtion by the pancake.
Re:Something going wrong.... (Score:2)
As long as he includes the effects of the butter on the pancake, I'd support that doctorate
Next thing you know (Score:2)
*piled higher and deeper
ObJoke! "I'll bet you guys are excited" said the cabbie as he drove the students to their graduation ceremony. "I know I was when I got my PhD".
And they say ART is dead (Score:2)
Pancake Algebra, it actually exists... (Score:3, Informative)
not quite the same, but thoroughly enjoyable !
Francis.
WHy???? (Score:2)
Does anyone else see a flaw in this formula? (Score:4, Insightful)
(sqrt(pi)*1g)/(d*4)
Where g is the accelleration due to gravity and d is the distance from the elbow to the pancake.
In addition to the rather obvious (or at least intuitive) flaw of not considering the size/mass of the pancake, this formula cannot possibly produce the value claimed. Dimensional analysis shows that it results in an answer measured in terms of radians per second squared, and angular velocity is always measured in just radians per second.
Of course, if they *meant* to say angular accelleration, they should have said so.
Re:Does anyone else see a flaw in this formula? (Score:3, Insightful)
The angular velocity of the object equals the square root of Pi, times the gravity divided by the distance the pancake is from the elbow times four
You took this to be
(sqrt(pi)*1g)/(d*4)
when it should be interpreted as:
sqrt( pi*g / (d*4) )
then you get the right units.
Derivation of the equation (Score:2, Interesting)
1) Hang-time of the pancake:
2)Time for a 180 degree flip:
3)Starting spin condition:
4) I can substitute equation 3 into 2 to get:
5) The pancake radius cancels out!
6)Then, I set the two times equal to eachother, because we are looking for the time to flip to be exactly the hang-time:
7) Solve for angular velocity...
8) The condition at Launch is
9) So, by 7 and 8, (substituting V)..
10) which is the same as
This result is just a clean factor of two off from the article. I'm very suprised that I can put together enough physics to derive something that is apparently so newsworthy!
now someone help me find the mistake!
Lard! Eat this Shit and DIE! (Score:2, Informative)
I'm English and (unsurprisingly, as I live in England) so are most of the people that I know. There isn't any lard in my house. Or, from what I've seen when eating at friends' houses, anywhere else.
The supermarket aisles devote about 50 times more space to butters and margarines than they do to lard, so that suggests that demand for lard isn't exactly huge.
Perhaps, like all Frenchmen having smelly breath or all Australians being called Bruce, this is one of another one of those urban myths that you Americans have bought into?
(BTW, "Lard! Eat this Shit and DIE!" is a reference to the late, great, Bill Hicks. Great comedian. Great loss.)
Are Americans fat? (Score:2)
ok this is geekland! Somebody provide a reference rather than "your nation stinks more than my nation!" (oh ok it is /. I spose).
Come on then, somebody dig up stats, are the good people of the US the fattest in the world? or at least how do they compare with UK, and Oz, and say the French and Italians, and err, I dunno, some other non Western country, Japan? Egypt?
I'd love to know where the USA is on an international scale, say of % of inhabitants overweight...
Re:Are Americans fat? (Score:2)
FAT is a bad attitude & lack of respect (Score:2)
Attitude by working it off(labor/exercise) or using dietary supplements
Respect by this means: you show me you care for me by looking physically attractive to me; so as a bonus to our friendship, other people want to hang with us and are attracted to us in public.
Waddayamean, Troll!?!?! (Score:2, Interesting)
This is one of the least trollish comments I've read on this thread (though that isn't saying much). This guy just described my life spot on. I'm neither American nor fat, but in both cases I can only thank my parents. There but for the grace of god go I.
Considering this is an article about one of the many traditional annual face-stuffing days westerners celebrate, it's hardly trolling to point out how many people have, or think they have, no time to get any excercise.
Stressed-out, over-fed, under-excercised = early death. The solution is not to diet (=less food, but more stress and still no excercise), but to get plenty of excercise (helps with stress, and you can eat all you like because your body turns it into muscle or motion rather than fat).
In my final year at university, I quit smoking and started swimming just under a mile four times a week. It was the best six months of my life - I was relaxed, I had plenty of energy, muscles even started appearing! Then the exams came along, followed by life as a code-monkey, and here I am smoking, lazy, stressed and eating like a vacuum cleaner. Time to resurrect that lapsed gym membership, I think.
Re:Once (Score:2)
1) Try it over the sink.
2) Flip it with a spatula, and once both sides of the pancake are cooked, you can get 4-5 practice flips out of it before you screw up badly enough to break the pancake.
3) Repeat with next pancake.
4) Apply butter, syrup, whatever you like to the big heaping plate of pancake frags, nuke in microwave for 30 seconds. Chow time!
Re:Lemon and sugar (Score:2)
We used to just put TONS and TONS of regular granualted sugar on the pankace and roll it up.
No wonder I had so many cavities....