What Are Common Misconceptions About Mathematicians and Physicists?

[Curious3141]

These are fairly easy to do exactly, the second one in particular. Knowing that 6 x 12 = 72 quickly gives 120 with another 36 to make up, so 126 (since 6 x 120 = 720 = 756 -36 and 36 = 6 x 6). The distributive property is a key for mental exact calculation and/or estimation with multiplication and division.

The first one, too, although the first thing I did was to rearrange the product to 81*58 by prime factorisation. Then I spent a few seconds marvelling over the fact that I'd just proven 87*54 = 81*58. Some mathematician, eh?

But after I did that, it was quite easy to get the answer from 58*9*9 sequentially. The fact that 58 is just 2 less than 60 helps a lot.

 

[mfb]

I've even tried to use analogous examples using more familiar systems. "Okay, suppose you have a bathroom scale that lacks calibration data." <blank stares> "Okay, that didn't work. Well, suppose you set the thermostat to your house to some temperature, but the furnace always makes the temperature 5 degrees hotter than the thermostat setting." <hesitant nods> "There's a dial on the inside of the thermostat box that can compensate for the difference by adding an offset to the temperature selection setting, thereby ..." <blank stares>

I think I would try it like that:
"How does your thermostat know how hot it is? It needs some internal setting."I calculated 87 * 54 as 87*(44+10) = 87*2*2*11 + (87*10), as all those steps are just additions.

 

[Curious3141]

I think I would try it like that:
"How does your thermostat know how hot it is?"

The problem is that, in most lay people's minds, the answer to that is "magic". Talk of internal settings (even eschewing mild jargon like 'calibration') will still lead to glazed-over eyes.

 

[mfb]

Then you are the magician. Not that bad.

 

[George Jones]

The fact that 58 is just 2 less than 60 helps a lot.

I calculated 87 * 54 as 87*(44+10) = 87*2*2*11 + (87*10), as all those steps are just additions.

These are examples of what I meant by

The distributive property is a key for mental exact calculation and/or estimation with multiplication and division.

I calculated 87 x 54 as 87 x 54 = [87 x (5 + .4)] x 10.

 

[Astronuc]

To this day I have yet to successfully come up with a description of what I do at my job, that most people can understand. I've tried several approaches of explanation. Still no success.

In particular, I've tried dozens of times to explain to my mom what I do at work (being my mom, she wants to herself so she can tell others, if for no other reason). I've tried and failed every time.

I've even tried to use analogous examples using more familiar systems. "Okay, suppose you have a bathroom scale that lacks calibration data." <blank stares> "Okay, that didn't work. Well, suppose you set the thermostat to your house to some temperature, but the furnace always makes the temperature 5 degrees hotter than the thermostat setting." <hesitant nods> "There's a dial on the inside of the thermostat box that can compensate for the difference by adding an offset to the temperature selection setting, thereby ..." <blank stares>

I have had a similar experience with my family, particularly my mom, who wants a good story to tell her friends and other family members.

 

[OmCheeto]

This reminds me a bit of one of my interactions a couple of weeks ago when I wore my "Physics Forums" t-shirt:

...

Some people took it as a challenge to see how smart I was. One guy asked me what Einstein won his nobel prize for. Unfortunately, I can never remember if it was Brownian Motion or the Photo-electric effect, and picked the wrong one. He of course knows that mere commoners all think it should be "Relativity". Then, coincidentally, as we were at energy park, standing next to the worlds most efficient refrigerator, I asked him if he knew that Einstein's name was on a patent for a refrigerator. He said he didn't.
...

I mentioned that Leo Szilard's name was also on the patent. He'd never heard of Leo.

In another interaction, I talked with a very nice lady from Switzerland, and the conversation again turned to Einstein, and I mistakenly said he was Austrian. She corrected me, that he was actually born in Germany. I suppose I mixed him up with Arnold Schwarzenegger or someone.

hmmmm... This reminds me of an interaction with a coworker from about 20 years ago. We found an IQ quiz in a magazine, both took it, and she kicked my butt. Having never lost a magazine IQ challenge in my entire life, I immediately turned into one of the people I despise more than anything, a "You think you're so smart" type person, and asked her; "Ok then Miss Einstein, what does the "c" stand for in E=mc²"? She had not a clue.

In my defense, as a former nuclear power plant technician, I was prone to never make mistakes. (think; "really big boom", if you should) This apparently annoys people. One day, I made a mistake, and the aforementioned "Miss Einstein" did a "raise the roof", OmCheeto isn't perfect dance.

I think I might be a perfectionist, as people still do little dances when they discover that I've made a mistake.

 

[OmCheeto]

In 7th grade, I was so good at basic math, I could do it all in my head. My teacher gave me an F on an exam one day because I didn't show my work.*

After 6 or so terms of Calculus, I couldn't figure out what 6 + 7 was without using my fingers.

*If there are any middle school math teachers out there, instead of giving the student an F, and accusing him/her of cheating, walk them up to the chalkboard, give them something twice as hard as anything on the exam, and see if they can do it in their head. You may be surprised.

I had a discussion with a young lady at work, who has a daughter who had experienced the same thing, and I recommended the above solution. The young ladies response was; "No, she's just lazy". End of conversation.

 

[OmCheeto]

And if anyone doubts my genius, just check out my Facebook post from yesterday:

I made a pillow out of an old pair of pants and dryer lint one day. That reminds me, my dryer lint container* is full again. I need to make another pillow.

----------------------------------
* After Lucy passed away, I had no other use for the container.

 

[Tim92G]

Conversely, many mental calculators are rubbish at advanced math. http://en.wikipedia.org/wiki/Rüdiger_Gamm. Mental calculator world champion, and according to one of his interviews he barely passed high school level math.

 

[Traz 0]

This is another story of another famous mathmetician, let's call him John von Neumann. ;)

One day, while teaching an advanced class, he was making the chalk dust fly. "So, you can see that we can simplify this equation thusly, and it becomes clear that we can remove the following terms from both sides of the equation, and, now we see that this variable can be replaced by this function and ..."

The class is totally lost. I mean, most of them are trying to figure what to change their majors to. A couple are resting their heads on the desk, drooling. One is banging his head on the desk, quietly.

The professor is about to wrap the lesson up: " ... and so, you can clearly see that the solution is obvious ..." He pauses, staring at the board, scratching his head. "It's obvious that ..." He trails off again. "It's ob- ..."

He sets down the chalk and walks slowly from the classroom, shaking his head. His students are dumbfounded. Is the class over? Should they leave? Such is von Neumann's reputation that no one is willing to leave first, so they sit there, conversing in hushed tones.

After 15 minutes, the door bursts open, and the professor strides rapidly to the blackboard. Picking up the chalk, he resumes the lesson. "I was right. It IS obvious ..."

Pah dum-bump.