physics : Camille Minichino

Posts Tagged ‘physics’

Physics of Christmas

Filed Under : personal by Camille

Dec.16,2020

Yes, it’s time to pull out the old story. You may already have seen it in my newsletter, but here it is again with maybe slightly different numbers. They are, after all, just estimates. In a given year, who knows how many naughties vs. nices there might be?

🎁🎁🎁

**I wonder if Santa will be masked this year? He’s using gloves. And doesn’t that drink look good?**

There are about 2 billion children in the world and even at one toy each, we have something like 400,000 tons traveling at 650 miles per second to get around world in one night.

A simple calculation shows that Santa has 1/1000^th of a second to pull up on a roof, park his sleigh, hop out, climb down the chimney, figure out who’s naughty and nice, distribute the presents, eat a snack, and say Ho, Ho, Ho, all without waking the household. Then he goes back up the chimney, gets back into the sleigh, dusts off his suit, and moves on to the next house.

Not just exhausting, but physically impossible?

Even though there’s not a lot of sleigh traffic up there, it does not seem a feasible trip.

But the naysayers are way behind the times. Have they never heard of worm holes? Wormholes are features of space-time that allow a shortcut through the universe.

Imagine you’re standing in a long line at the post office. You’re at one end of the room and the clerk is at the other. Now imagine a piece of paper with a stick figure representing you at one corner, and a figure at the diagonally opposite corner to represent the clerk. Fold the paper so that your stick figure is on top of the clerk’s.

See? You’ve just taken a shortcut to the head of the line.

In another version of worm hole demonstration, dots are placed at opposite corners of a piece of paper, the paper is folded, having the dots touch, and the same effect is seen.

That’s what Santa does. With a little math and a dash of relativity theory we can show that, in fact, with every stop, Santa can come out of the chimney before he gets in!

No problem making all those stops.

So, yes, Virginia, relatively speaking, Santa can do it!

🎁🎁🎁

Tags : chimney, physics, santa, sleigh, toys

Q and A

Filed Under : personal by Camille

Sep.16,2020

Answers Please!

It’s September and time for a story from academia.What do you think of when you hear, “It’s all academic”?

That it doesn’t matter? That it’s not practical? No use arguing?

Here’s an incident that might enhance your definition.

Q: What’s the difference between a physicist and a historian?

No, it’s not a joke, it’s actually a true story of an interaction between me and a friend who is a history professor at a university in the east. By which I mean Pennsylvania, not Mongolia.

He’s a PhD history professor, a good friend, and found himself on the review panel for a doctoral thesis on a problem in the history of quantum mechanics.

He called me in a panic. He was the only nonscientist on the committee. He needed to look as smart as the rest of the members. Would I help him?

Of course.

He emailed me and attached the student’s ten-page summary and asked if I could come up with two or three intelligent questions for him to pose to the student who was defending his thesis.

“I can do that,” I said, always thrilled when someone wants to learn science, for whatever reason. I read the summary, wrote out three questions, and called him the next morning

“I can’t thank you enough,” he said. “These are great.”

“I’m glad. I’m ready to discuss them with you.”

He laughed. “Oh, no, I don’t need to discuss anything,” he said. “All I need are these questions. The answers aren’t important.”

It took a while for his message to sink in: as long as he posed an intelligent question, he’d sound smart. He could then sit back and let the others, especially the student, come up with the discussion and possible answers.

For me, it was a different take on “It’s all academic.”

How about you?

Tags : academia, history, physics

The barometer

Filed Under : Science and Math by Camille

Aug.16,2018

The start of school for many of us inspires me to drag out the famous (to some of us) story of The Barometer.

Miniature barometer next to miniature physics book. Pen for scale.

As the story goes, a physics teacher posed this question on an exam and got surprising results.

Show how it’s possible to determine the height of a tall building with the aid of a barometer.

One student answered this way:

“Take the barometer to the top of the building and attach a long piece of rope to it. Lower the barometer until it hits the sidewalk, then pull it up and measure the length of the rope, which will give you the height of the building.”

What? The teacher expected a different answer, using the standard equation involving the difference in pressure at the top and bottom of the building.

When challenged to come up with “the right answer,” the student gave several more. Among them:

1. Take the barometer out on a sunny day and measure the height of the barometer, the length of its shadow, and the length of the shadow of the building. Using simple proportion, determine the height of the building.

2. Take the barometer and begin to walk up the stairs. As you climb the stairs, you mark off the length of the barometer along the wall. You then count the number of marks, and this will give you the height of the building in barometer units.

And so on.

My favorite remains this one:

“Take the barometer to the basement and knock on the superintendent’s door. When the superintendent answers, say: ‘Mr. Superintendent, if you will tell me the height of this building, I will give you this barometer.'”

How would you grade this student?

** Legend has it that the student was Niels Bohr (1885-1962, Nobel Prize in physics, 1922), but then a legend can say anything and get away with it.

Tags : barometer, Niels Bohr, physics

The Physics of Santa

Filed Under : Science and Math by Camille

Dec.15,2016

It’s time to drag out the old physics-of-Christmas essays. In case you missed it in my newsletter, here’s my favorite version about how it’s impossible for Santa to get his job done:

There are about 2 billion children in the world and even at one toy each, we have something like 400,000 tons of sleigh, toys, and a hefty old man traveling at 650 miles per second to get around world in one night.

A simple calculation shows that Santa has 1/1000^th of a second to

• pull up on a roof

• hop out

• climb down the chimney

• figure out who’s nice

• distribute the presents

• eat a snack

• say Ho, Ho, Ho

• go back up the chimney

• dust off his suit, and move on.

Not just exhausting, but physically impossible.

Or, he could just hail a cab.

Even though there’s not a lot of sleigh traffic up there, it’s not a feasible trip.

But now, I’m about to offer a rebuttal.

All we have to do is call on worm holes, those tricky features of space-time that allow a shortcut through the universe.

Imagine you’re standing in a long line at the post office. You’re at one end of the room and the clerk is at the other, lots of people-mass in between. Now imagine a piece of paper with a stick figure representing you at one corner, and a figure at the diagonally opposite corner to represent the clerk. Fold the paper so that your stick figure is on top of the clerk’s.

See? You’ve just taken a shortcut to the head of the line.

That’s what Santa can do. With a little math and a dash of relativity theory we can show that, in fact, with every stop, Santa can come out of the chimney before he gets in!

No problem making all those stops.

So, yes, Virginia, relatively speaking, Santa can do it!

Now if only I could find the right wormhole to get me through Bay Area freeways.

Tags : physics, santa

Oh, the pressure!

Filed Under : Science and Math by Camille

Mar.13,2014

Interesting conversation with a young art graduate student the other night: He’s not thrilled with his classes, especially with the exercises his professor assigns. Bottom line—he just wants to be able to go into the classroom/studio and do his own artist-thing. Nothing should be right or wrong in an art class.

Can the same be said for physics classes? The discussion prompted me to resurrect an old physics story. As the legend goes, a physics teacher posed this question on an exam and got surprising results.

Show how it’s possible to determine the height of a tall building with the aid of a barometer.

One student answered this way:

What? The teacher expected a different answer, using an equation involving the difference in pressure at the top and bottom of the building.

ΔP/Δh = (-mg/kT)/P

When challenged to come up with “the right answer,” the student gave several. Among them:

And so on.

My favorite remains this one:

How would you grade this student?

** Legend has it that the student was Niels Bohr (1885-1962, Nobel Prize in physics, 1922), but then a legend can say anything and get away with it.

Tags : barometer, exams, physics