# Useful Books for Geometry and Topology

Useful Books for Geometry and Topology

At below I have listed some Useful Books for Geometry and Topology. I hope this list will help you.

1. Boothby, W. M. An Introduction to Differentiable Manifolds and Riemannian Geometry.
2. Conlon, L. Differentiable Manifolds: A First Course.
3. Spivak, M. A Comprehensive Introduction to Differential Geometry, Vol 1.
4. Warner, F. Foundations of Differentiable Manifolds and Lie Groups.
5. Marvin J. Greenberg, John R. Harper, Algebraic Topology: A First Course.
6. Joseph J. Rotman, an Introduction to Algebraic Topology
7. Allen Hatcher, Algebraic Topology.
8. Spanier, Edwin H. Algebraic Topology.
9. Manfredo P. Do Carmo, Differential Geometry of Curves and Surfaces
10. Alfred Gray, Modern Differential Geometry of Curves and Surfaces
11. Barrett O’Neill, Elementary Differential Geometry
12. Klingenberg, W., A Course in Differential Geometry
13. Bourbaki, N. General Topology.
14. Dixmier, J. General Topology.
15. John L. Kelley, General Topology.
16. James Munkres, Topology.

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# Carnival of Mathematics #170

I’m hosting issue number 170 because I have a thing for the number’s largest prime factor, but it turns out there’s a reason for a Martin Gardner fan like me to appreciate the number itself: 170 is the number of steps1 needed to solve a classic mechanical puzzle called The Brain invented by computer scientist Marvin H. Allison, Jr., described by Martin Gardner in his Scientific American essay “The Binary Gray Code”, and still available from Amazon.

The Brain, aka The Brain Puzzle, aka The Brain Puzzler. Here’s what Gardner says about The Brain:

It consists of a tower of eight transparent plasticdisks that rotate horizontally around their centers. The disks are slotted, with eight upright rods going through the slots. The rods can be moved to two positions, in or out, and the task is to rotate the disks to positions that permit all the rods…

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# Physicists propose a second level of quantization for quantum Shannon theory

Information theory, which was developed by Claude Shannon starting in the late 1940s, deals with questions such as how quickly information can be sent over a noisy communications channel. Both the information carriers (e.g., photons) and the channel (e.g., optical fiber cable) are assumed to be classical systems, with well-defined, perfectly distinguishable states.

In the past two decades, physicists have been developing a quantum version of information theory in which the internal state of each information carrier has quantum properties, such as superposition—the ability to occupy two or more classical states at once. But the transmission lines are generally still assumed to be classical, so that the path taken by messages in space is always well-defined.

Now in a new paper, physicists Giulio Chiribella and Hlér Kristjánsson at the University of Oxford and the University of Hong Kong have proposed a second level of quantization, in which both the information carriers and the channels can be in quantum superposition. In this new paradigm of communication, the information carriers can travel through multiple channels simultaneously.

# Sum-of-Three-Cubes Problem Solved for ‘Stubborn’ Number 33

Mathematicians long wondered whether it’s possible to express the number 33 as the sum of three cubes — that is, whether the equation 33 = x³+ y³+ z³ has a solution. They knew that 29 could be written as 3³ + 1³ + 1³, for instance, whereas 32 is not expressible as the sum of three integers each raised to the third power. But the case of 33 went unsolved for 64 years.

Read the whole article here: Sum-of-Three-Cubes Problem Solved for ‘Stubborn’ Number 33

# Heisenberg’s final theory

Last month, I was at Foundations 2018 in Utrecht. It is one of the biggest conferences on the foundations of physics, bringing together physicists, philosophers, and historians of science. A talk I found particularly interesting was that of Alexander Blum, from the Max Planck Institute for the History of Science, entitled Heisenberg’s 1958 Weltformel & the roots of post-empirical physics. Let me briefly summarize Blum’s fascinating story.

In 1958, Werner Heisenberg put forward a new theory of matter that, according to his peers (and to every physicist today) could not possibly be correct, failing to reproduce most known microscopic phenomena. Yet he firmly believed in it, worked on it restlessly (at least for a while), and presented it to the public as a major breakthrough. How was such an embarrassment possible given that Heisenberg was one of the brightest physicists of the time? One could try to find…

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# Post

## Chapter 1 First Day of School

He goes to class. There is an empty seat in front. He sits in the seat. He looks around. There are different people. He says “hi” to the girl next to him. She smiles. The teacher comes in. She closes the door. Everyone is silent. The first day of school begins.

### Chapter 2 Water on the Floor

She is thirsty. She gets a glass of water. She begins to walk. She drops the glass. There is water on the floor. The puddle is big. She gets a mop. She wipes the water off. The floor is clean. She gets another glass of water. She drinks it. She is happy.

#### Chapter 3Babysitting

Casey wants a new car. She needs money. She decides to babysit. She takes care of the child. She feeds him lunch. She reads him a story. The story is funny. The child laughs. Casey likes him. The child’s mom comes home. The child kisses Casey. Casey leaves. She will babysit him again.

### Chapter 4 Twins

Jill and Jodi are twins. They look the same. But they act differently. Jill likes sports. She is good at basketball and golf. She is also loud. She talks all day. Jodi likes reading. She can read 300 pages a day. She is also quiet. She does not like to talk. Jill and Jodi still love each other.

# Some light quantum mechanics (with minutephysics)

The math of superposition and quantum states.

Brought to you by you: http://3b1b.co/light-quantum-thanks

And by Brilliant: https://brilliant.org/3b1b

Huge thanks to my friend Evan Miyazono, both for encouraging me to do this project, and for helping me understand many things along the way.
This is a simple primer for how the math of quantum mechanics, specifically in the context of polarized light, relates to the math of classical waves, specifically classical electromagnetic waves.
I will say, if you *do* want to go off and learn the math of quantum mechanics, you just can never have too much linear algebra, so check out the series I did at http://3b1b.co/essence-of-linear-algebra

Mistakes: As several astute commenters have pointed out, the force arrow is pointing the wrong way at 2:18. Thanks for the catch!

*Note on conventions: Throughout this video, I use a single-headed right arrow to represent the horizontal direction. The standard in quantum mechanics is actually to use double-headed arrows for describing polarization states, while single-headed arrows are typically reserved for the context of spin.
What’s the difference? Well, using a double-headed arrow to represent the horizontal direction emphasizes that in a quantum mechanical context, there’s no distinction between left and right. They each have the same measurable state: horizontal (e.g. they pass through horizontally oriented filters). Once you’re in QM, these kets are typically vectors in a more abstract space where vectors are not necessarily spatial directions but instead represent any kind of state.

Because of how I chose to motivate things with classical waves, where it makes sense for this arrow to represent a unit vector in the right direction, rather than the more abstract idea of a horizontal state vector, I chose to stick with the single-headed notation throughout, though this runs slightly against convention.

Music by Vincent Rubinetti:

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# 7 Best LESSONS From Elon Musk, Warren Buffett & Other BILLIONAIRE Entrepreneurs

✎ In today’s #BelieveLife video, we share 7 best lessons from Elon Musk, Warren Buffett & other billionaire entrepreneurs.

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Leave a comment on this video and it’ll get a response. Or you can connect with me on different social platforms too:
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# Bjarne Stroustrup: Why I Created C++

## Bjarne Stroustrup: Why I Created C++

In the late 1970s, Stroustrup applied the idea of “classes” to the C programming language to create a new language that allows for high level abstraction—but is efficient and close to the hardware.

### What inspired you to create C++?

In the really old days, people had to write their code directly to work on the hardware. They wrote load and store instructions to get stuff in and out of memory and they played about with bits and bytes and stuff. You could do pretty good work with that, but it was very specialized. Then they figured out that you could build languages fit for humans for specific areas. Like they built FORTRAN for engineers and scientists and they built COBALT for businessmen. And then in the mid-’60s, a bunch of Norwegians, mostly Ole-Johan Dahl and Kristen Nygaard thought why can’t you get a language that sort of is fit for humans for all domains, not just linear algebra and business. And they built something called SIMULA. And that’s where they introduced the class as the thing you have in the program to represent a concept in your application world. So if you are a mathematician, a matrix will become a class, if you are a businessman, a personnel record might become a class, in telecommunications a dial buffer might become a class—you can represent just about anything as a class. And they went a little bit further and represented relationships between classes; any hierarchical relationship could be done as a bunch of classes. So you could say that a fire engine is a kind of a truck which is a kind of a car which is a kind of a vehicle and organize things like that. This became know as object-oriented programming or also in some variance of it as data abstraction. And my idea was very simple: to take the ideas from SIMULA for general abstraction for the benefit of sort of humans representing things… so humans could get it with low level stuff, which at that time was the best language for that was C, which was done at Bell Labs by Dennis Ritchie. And take those two ideas and bring them together so that you could do high-level abstraction, but efficiently enough and close enough to the hardware for really demanding computing tasks. And that is where I came in. And so C++ has classes like SIMULA but they run as fast as C code, so the combination becomes very useful.

### What makes C++ such a widely used language?

If I have to characterize C++’s strength, it comes from the ability to have abstractions and have them so efficient that you can afford it in infrastructure. And you can access hardware directly as you often have to do with operating systems with real time control, little things like cell phones, and so the combination is something that is good for infrastructure in general. Another aspect that’s necessary for infrastructure is stability. When you build an infrastructure it could be sort of the lowest level of IBM mainframes talking to the hardware for the higher level of software, which is a place they use C++. Or a fuel injector for a large marine diesel engine or a browser, it has to be stable for a decade or so because you can’t afford to fiddle with the stuff all the time. You can’t afford to rewrite it, I mean taking one of those ships into harbor costs a lot of money. And so you need a language that’s not just good at what it’s doing, you have to be able to rely on it being available for decades on a variety of different hardware and to be used by programmers over a decade or two at least. C++ is not about three decades old. And if that’s not the case, you have to rewrite your code all the time. And that happens primarily with experimental languages and with proprietary commercial languages that change to finish—to meet fads. C++’s problem is the complexity part because we haven’t been able to clean it up. There’s still code written in the 80’s that are running and people don’t like their running codes to break. It could cost them millions or more.
Interviewed by Max Miller

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# Who cares about topology? (Inscribed rectangle problem)

An unsolved conjecture, and a clever topological solution to a weaker version of the question. Brought to you by you: http://3b1b.co/topology-thanks
This video is based on a proof from H. Vaughan, 1977.
——————
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# How Feynman Diagrams Revolutionized Physics

***
By Thomas Lin | May 14, 2019
In the late 1940s, Richard Feynman invented a visual tool for simplifying particle calculations that forever changed theoretical physics.
As one of the most famous physicists of the 20th century, Richard Feynman was known for a lot. Early in his career, he contributed to the development of the first atomic bomb as a group leader of the Manhattan Project. Hans Bethe, the scientific leader of the project who won a Nobel Prize in Physics in 1967 (two years after Feynman did), has been quoted on what set his protégé apart: “There are two types of genius. Ordinary geniuses do great things, but they leave you room to believe that you could do the same if only you worked hard enough. Then there are magicians, and you can have no idea how they do it. Feynman was a magician.”
In his 1993 biography Genius, James Gleick called Feynman “brash,” “ebullient” and “the most brilliant, iconoclastic and influential physicist of modern times.” Feynman captured the popular imagination when he played the bongo drums and sang about orange juice. He was a fun-loving, charismatic practical joker who toured America on long road trips. His colleague Freeman Dyson described him as “half genius and half buffoon.” At times, his oxygen-sucking arrogance rubbed some the wrong way, and his performative sexism looks very different to modern eyes. Feynman will also be remembered for his teaching: The lectures he delivered to Caltech freshmen and sophomores in 1962 set the gold standard in physics instruction and, when later published as a three-volume set, sold millions of copies worldwide.
What most people outside of the physics community are likely to be least familiar with is the work that counts as Feynman’s crowning scientific achievement. With physicists in the late 1940s struggling to reformulate a relativistic quantum theory describing the interactions of electrically charged particles, Feynman conjured up some Nobel Prize-winning magic. He introduced a visual method to simplify the seemingly impossible calculations needed to describe basic particle interactions. As Gleick put it in Genius, “He took the half-made conceptions of waves and particles in the 1940s and shaped them into tools that ordinary physicists could use and understand.” Through the work of Feynman, Dyson, Julian Schwinger and Sin-Itiro Tomonaga, a new and improved theory of quantum electrodynamics was born.
Feynman’s lines and squiggles, which became known as Feynman diagrams, have since “revolutionized nearly every aspect of theoretical physics,” wrote the historian of science David Kaiser in 2005. “In the same way that computer-enabled computation might today be said to be enabling a genomic revolution, Feynman diagrams helped to transform the way physicists saw the world, and their place in it.”
To learn more about Feynman diagrams and how they’ve changed the way physicists work, watch our new In Theory video:
Decades later, as Natalie Wolchover reported in 2013, “it became apparent that Feynman’s apparatus was a Rube Goldberg machine.” Even the collision of two subatomic particles called gluons to produce four less energetic gluons, an event that happens billions of times a second during collisions at the Large Hadron Collider, she wrote, “involves 220 diagrams, which collectively contribute thousands of terms to the calculation of the scattering amplitude.” Now, a group of physicists and mathematicians is studying a geometric object called an “amplituhedron” that has the potential to further simplify calculations of particle interactions.
Meanwhile, other physicists hope that emerging connections between Feynman diagrams and number theory can help identify patterns in the values generated from more complicated diagrams. As Kevin Hartnett reported in 2016, understanding these patterns could make particle calculations much simpler, but like the amplituhedron approach, this is still a work in progress.
“Feynman diagrams remain a treasured asset in physics because they often provide good approximations to reality,” wrote the Nobel Prize-winning physicist Frank Wilczek three years ago. “They help us bring our powers of visual imagination to bear on worlds we can’t actually see.”
If you liked the fifth and final episode from season two of Quanta’s In Theory video series, you may also enjoy our previous videos on universality, quantum gravity, emergence and turbulence.

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# Time To Start Traveling On the Less Traveled Path in Math Education:Impossible Ideas

In the 20th century, math education was a cliched amalgam of authority and tradition, an impenetrable fortress to ideas and imagination that would “threaten” its history of compliance and conservatism.

While mathematics is a stake holder in truth, poetry and art speak to truths that are more accessible to all of us — especially since they speak to our hearts, first. But, even as something as wildly as endearing as the words of Robert Frost, somehow have had little currency in shaping math education.

But, that is because only mathematics is wild. Math education is not. It is in that gulf that we should see what needs to be done now in the 21st century.

We have to walk the walk. We want our students to be risk takers in the classroom. Well, so do we. We want our students to struggle. Well, so should we at times. We want our students to appreciate the failures of learning mathematics. Well, so should we.

Trying to make everything perfect — like a perfect landing in a gymnastics routine — is not only stressful, its inorganic intentions runs counter to experimenting, pushing boundaries…pushing ourselves. Guardrails are needed on highways. They shouldn’t be put up in our classrooms — especially with regards to what students can learn and when.

Math Education’s energy and direction is largely a function of the comfort zone of teachers. The general philosophy is that whatever is taught and presented must be, at first, in the comfort zone of the teacher — before it can be in the comfort zone of the students.

While there is some truth to that, there seems something very school about that — follow topics order, be aligned to a curriculum that you had no say in constructing, and get students to be tested. Don’t skid off the road.

Let Dan Finkel take some of the burden off your shoulders. In his highly watched TED Talk, the Third Principle(of Five)for Extraordinary Math Teaching is:

Your job — your desire — should be to want to find the answer. But, you shouldn’t have to a some walking math encyclopedia. Not only shouldn’t you, you also can’t. I possess some ridiculously low percentage of math knowledge in the universe — as do all of us — so, to implicitly communicate that is disingenuous. The truthful path, the easier path, is to not be worried about the answer. Most of the time you will know it, but if you don’t, get excited that moment with your students — it might not come again.

One of the most challenging ideas to any mathematician on the planet is the concept of Graham’s Number. To say it is a beast of a number is an understatement as large its very size. Truth be told, very few people on the planet really have the comfort and knowledge to explain the size of that number to themselves — let alone anyone else.

I for sure know I am not one of them. And yet, this very concept(and picture below is the book “Math Recess: Playful Learning in an Age of Disruption).

I tried to explain it, and even offered an upfront apology that my explanation, well-intentions and all, was going to fail. The idea of Graham’s Number was put in the book more as a metaphor for learning and teaching mathematics. We have to stretch the canvas of our collective imaginations and embrace all the wonderful attributes of failing, not being perfect, and just being human — before anything else.

When are kids ready for an idea like this? Honestly, not sure. But, I think it is unhealthy to dwell on it, if in the end, we become gate keepers of knowledge and ideas based on comfort zones and norms that have reached their expiration date.

How does one capture the curiosity of students in mathematics? Competency is not the road. Many have taken that road, fulfilled their obligations with courses completed and marks obtained, and never looked back at mathematics again.

That is not what I want for my own kids. They say you shouldn’t chase money in life. Chase your dreams and your heart and that will follow. Same with education. Don’t paper chase. Chase the fantastic ideas, heady, and edgy ideas of mathematics found everywhere in K to 12 mathematics — accessible to all — and you will garner those societal badges of knowledge acquisition.

Impossible ideas. Try them and share them. If they fail, well heck, try another one. Don’t spend your entire teaching career inside the guard rails — you just might have the grave misfortune of never failing.

Ironically, never failing will create the arid soil in which curiosity will fail.

And that is the final measurement for all of us — did we nurture curiosity or did we destroy it.

# How to Teach Yourself Math

Few subjects bring up as much remembered pain and anxiety as math classes. The confusing symbols, the difficult procedures and the dreaded graphs and charts.

A few people are now even suggesting that learning math can be a traumatic experience, something survived, rather than learned.

The painful history many people have with math is a shame, because math is incredibly useful. Many of the best careers are coming out of STEM fields, and rely on understanding math. Understanding the news and world events, is increasingly becoming a lesson in statistics. Finally, math, properly understood, allows you to solve many of your own problems.

In this article, I’d like to explain how you can teach yourself any kind of math, whether it be statistics, algebra or algorithms.

The first step to learning any math is to get a first-pass explanation of the topic.

There are many places where you can get this information. Some good resources that cover a huge swath of topics are:

• KhanAcademy – Huge, free resources of videos on nearly every math topic
• MIT OCW – These start at the university level, but they handle a lot of complicated math
• Coursera – Many full math classes

In addition, there are also specialized resources. These tend not to cover every conceivable topic, but they are often more entertaining, intuitive and helpful for those that they do:

• BetterExplained – Great articles giving intuitions behind calculus, algebra, exponentials and more
• 3Blue1Brown – Excellent YouTube videos exploring mathematical concepts in-depth
• Numberphile – Conversations with mathematicians about interesting math topics

Wherever you get your explanation, your first step is to watch it once, so that you feel you understand the basics of how it works.

### What If I Don’t Understand the Explanation?

If you watch the explanation, but you didn’t understand it, there are two possible problems:

1. You’re lacking some prerequisites for understanding this piece of math. That means you need to back up and go through it again. If it feels like it “went too fast” or you don’t know what the teacher is doing, you may need to go back a few lessons and learn those better before proceeding.
2. You’re trying to cover too much without going onto practice. A good pattern is to watch a chunk of explanation and then try it yourself. If you only watch, but never practice, that’s a bit like watching videos on skiing and never hitting the slopes. Eventually the explanations will stop making sense because you’ll lack firsthand experience.

Try this: Watch an explanation once, in full, as your starting point.

## Step Two: Do Practice Problems

Math isn’t something you watch and memorize, but something you do.

If you spend all your time watching videos, and then get to a set of problems, you may find it really hard to apply your math knowledge. This can lead to the feeling that you’re “bad at math” even though the problem is just that you’re using a lousy method to learn it.

You can fix this by getting to doing problems as soon as possible. A good problem should feel challenging, but not impossible. If you see the solution and don’t even understand how they got it, chances are you’re going too fast—go back and learn some of the basics before moving on.

### What if I Don’t Have Problems to Solve?

If you lack provided problems, there’s a few things you can do:

• Work through the problems done in the explanation, but without looking at the answer.
• Create your own problems and try to solve them.
• Try to prove concepts in the class. This is an advanced technique, but it is essential for truly grasping more complicated math.

Try this: After watching your explanation, do enough problems to feel comfortable that you understand the procedure.

## Step Three: Know Why The Math Works

Having an intuitive grasp is very important for math in a way that it isn’t for other subjects. While having an intuition for vocabulary words in a foreign language can help, they still need to be memorized. However, memorizing math can be dangerous if it causes you to learn it without understanding.

The next step is to convince yourself that you know why the math works. My favorite technique for doing this is the Feynman Technique, which I demonstrate here:

The Feynman Technique takes some time, so you don’t need to apply it fully to every single facet of every math problem you face. Rather, apply it selectively on the most important concepts and those that seem confusing to you, despite sufficient practice.

Try this: Identify the core concepts in the math you’re learning, and use the Feynman Technique to convince yourself you understand them.

## Step Four: Play with the Math

Practice is good, understanding is better, but playing with math is best.

Once you have solved some questions provided to you and convinced yourself you understand them, a natural extension of this is to try to play with the math you’ve been given. How do things change when you try changing the numbers or apply it to different problems?

For example, let’s say you just recently learned how to calculate compound interest. You can do the simple interest calculations on your own, and you understand why they work. How could you play with this math?

• You could see what happens as the rate of compounding increases.
• What would happen if interest were negative?
• You could try to calculate your own savings if you invested them at different rates.
• Try imagining how much of a mortgage you pay in interest, versus principal.

Excel is a good way to play around with math, since you can put the formulas in directly, without needing to do as much algebra or repeating calculations.

Try this: Take a topic of math you’ve learned recently and see how you could change the variables, apply it to different things and modify the formulas.

## Step Five: Apply the Math Outside the Classroom

Ultimately, the goal for learning math should be to use it, not merely pass a test. To do that, however, you need to break your understanding free of the textbook examples and apply it to real world situations.

This is more difficult than just solving a problem. When you solve a problem, you will start to memorize the pattern of the solution. This often allows you to solve problems without really understanding the principles behind how they work.

Applying math to real life, in contrast, requires recognizing the situation, translating it into math and then solving the problem you’ve created. This is strictly harder than solving problems, so if you want to be able to actually use what you learn, you need to practice this.

Try this: Take a topic you’ve learned recently in math and try to find a real-life situation where you could calculate it, using your own numbers or estimates if those aren’t available.

## This All Sounds Like Too Much Work!

Doing all these five steps on every single thing you learn in math is going to be time consuming. That’s fine, you don’t need to do this for every little thing you need to learn.

Instead, think of this like a progress bar. Every math concept you learn can go from steps one through five, deepening your knowledge and increasing the usefulness of the math each time. Some concepts will be important enough that you’ll want to apply them thoroughly. Others will be infrequent enough that just watching the explanation is all the time you can spare.

In particular, you should try to focus on the most important concepts for each idea. Math tends to be deep, so often in a full semester class, there may only be a handful of really big ideas, with all the other ideas being simply different manifestations of that basic concept.

Most first-year calculus courses, for instance, all center around the concept of a derivative, with everything being taught merely being different extensions and applications of that core idea. If you really understand what a derivative is and how it works, those other pieces will be much easier to learn.

# ‘The Big Bang Theory’ takes math notes from Carl Pomerance

by Bill Platt, Dartmouth College | Reference: https://phys.org

A prime number theory equation by mathematics professor emeritus Carl Pomerance turned up on The Big Bang Theory, where it was scrawled on a white board in the background of the hit sitcom about a group of friends and roommates who are scientists, many of them physicists at the California Institute of Technology.

# It’s time to have an independent domain.

After more than 15 years of having different sub-domains, mainly blogger and wordpress, now it’s time to have a domain. I will export all articles of mathpresso to the new domain as soon as possible.

thank you all because of your kind attention and support.

I will publish all details in this blog very soon.

# Fifth African-American woman to earn a PhD in mathematics

In one week, Baylor University will dedicate a new bust to commemorate Dr. Vivienne Malone-Mayes, their first African-American faculty member (hired in 1966) and the fifth African-American woman to earn a PhD in mathematics. The ceremony will be broadcast live on Baylor’s Facebook page on Tuesday, February 26th! #womeninmath#diversityinmath @bayloruniversity

Source: Facebook Page of Association for Women in Mathematics

# Nearly half of US female scientists leave full-time science after first child

Study reveals proportion of people leaving full-time careers in science after the birth of their first child.

This article has been chosen from www.nature.com | By: Holly Else |  Published: 19 FEBRUARY 2019

More than 40% of women with full-time jobs in science leave the sector or go part time after having their first child, according to a study of how parenthood affects career trajectories in the United States. By contrast, only 23% of new fathers leave or cut their working hours.

The analysis (see ‘Parents in science’), led by Erin Cech, a sociologist at the University of Michigan in Ann Arbor, might help to explain the persistent under-representation of women in jobs that involve science, technology, engineering and mathematics (STEM). The study also highlights the impact of fatherhood on a career in science, she says.

## Career versus family

Given that 90% of people in the United States become parents during their working lives, Cech and Mary Blair-Loy, a sociologist at the University of California, San Diego, sought to better understand what happens to scientists’ careers after they start a family.

They used﻿ the Scientists and Engineers Statistical Data System, a database provided by the US National Science Foundation that contains information from surveys of the US STEM workforce every two to three years.

From the 2003 data, Cech and Blair-Loy picked the child-free scientists in full-time employment and tracked their familial status in the next wave of the survey, in 2006. This gave them two groups of scientists to compare — 841 who became parents during this period, and 3,365 who remained childless throughout. The researchers also looked at how these individuals’ careers changed between 2003 and 2010.

They report that new parents are significantly more likely to leave a full-time science career for full-time non-science careers than their child-free colleagues1.

## Gender imbalance

By the end of the study period, 23% of men and 43% of women who had become parents had left full-time STEM employment. They either went part time, switched to non-STEM careers or left the workforce altogether. This compared to 16% of child-free men and 24% of child-free women. The team controlled for potential confounding differences between people with and without children.

For a subset of the people who had left science, the data set also included an entry on why they had left science. Around half of the new parents in this subset cited family-related reasons, compared with just 4% of people without children.

Taken together, these findings suggest that parenthood is an important driver of gender imbalance in STEM employment, the team says.

But Cech says that this the first time research has shown the proportion of new parents facing difficulties reconciling family life with science. She adds that there is a striking impact on new fathers as well as mothers.

“STEM work is often culturally less tolerant and supportive of caregiving responsibilities than other occupations,” Cech says. “So mothers — and fathers — may feel squeezed out of STEM work and pulled into full-time work in non-STEM fields”.

## A ‘structural’ problem

Virginia Valian, a psychologist at the City University of New York, says: “The results showing that fathers also leave STEM reinforces the hypothesis that the problem is a structural one, in which dedicated professionals are not expected to have a personal life, and, indeed, are punished for so doing.”

Ami Radunskaya, a mathematician at Pomona College in Claremont, California, who mentors young female mathematicians, says women can become exhausted from constantly having to prove themselves in a professional environment that is, “at best, challenging to everyone and, at worst, openly sexist”.

“These young women are smart and tenacious,” she says. “When these young women start a family, they realize that this exhaustion and stress is not sustainable.”

Radunskaya suggests several measures that could help to improve the situation. Policies on family leave should send the message that having children is expected and accepted, for example. Senior researchers should mentor junior members of staff, and people should accept the challenges women in science may face. “We need to have candid, non-blaming conversations about [these issues],” she adds.doi: 10.1038/d41586-019-00611-1References

# How Reading Novels in Math Class Can Strengthen Student Engagement

This article has been chosen from KQED.ORG | AUTHOR: Kara Newhouse | Published on Mar 18, 2018

Every January, Nashville teacher Joel Bezaire reads The Curious Incident of the Dog in the Night-Time aloud to his students. Sounds pretty standard, right? It would be — for an English class. But Bezaire teaches math. The novel is part of a unit on number sense.

While it’s easy to envision using math picture books in elementary school classrooms, literature for older grades poses a bigger challenge. Can reading fit into the curriculum as the books get longer and the math gets more complex?

Bezaire thinks it can, and so does another teacher, Sam Shah, of Brooklyn. The two occupy opposite ends of the secondary math spectrum — seventh-grade pre-algebra and 12th-grade calculus, respectively — and both have found ways to strengthen student engagement through reading.

Novel study in pre-algebra

During Bezaire’s Curious Incident unit, each period begins with a typical 20-minute math lesson, followed by a 15-minute discussion of the previous day’s reading. For the rest of the 55-minute period, he reads a new chapter aloud. As he reads, Bezaire often pauses to dig deeper into the story’s math. Sometimes, the concepts align directly with the day’s pre-algebra lesson. For example, on the day when they learn about prime numbers, the class also reads why the main character, Christopher, chose primes as his system for labeling chapters.

“The literary hook for this lesson is strong, and kids are really into learning more about primes thanks to the context of the story,” said Bezaire. “The lessons don’t always line up this nicely, but so much of what Christopher writes about regarding mathematics is about flexibility with numbers that it’s a really nice match.”

After class students complete written reflections about the book, with different types of questions serving multiple pedagogical goals.

Mathematical questions, which often relate to puzzling out the novel’s two mysteries, allow students to practice problem-solving strategies in a context with more buy-in than the usual practice worksheets. They also encourage deeper thinking about the reasoning behind a math strategy. For example, after students test Christopher’s method for mental math with large multiplication, they are asked how easy or hard it was and when it might be most useful.

Questions related to plot and language, Bezaire said, help his less confident math students. “Students who more easily self-identify as ‘English types’ immediately get a little more comfortable in math class if they experience those types of (literary) questions regularly.”

Others questions invite students to connect personally with the text. For instance, one question asks students to share the meaning of their name. Another asks them to consider how it might affect their interactions if they could not read facial expressions, like Christopher, who has autism. These questions allow Bezaire to learn about his students in ways that equations cannot. They also improve students’ patience and understanding with each other, he said.View image on Twitter

If any MS math teacher is interested in trying my curriculum for the novel The Curious Incident of the Dog in the Night-Time (https://prealgebraone.wordpress.com/novel-studies/ ) I have a set of 20 novels I can send you. I’ve accumulated way too many extras and would love to pass them on. #mtbos1024:56 PM – Jan 9, 201843 people are talking about thisTwitter Ads info and privacy

“Context and prior knowledge are critical components in fostering comprehension, regardless of the topic,” according to Faith Wallace, co-author of Teaching Math Through ReadingReading literature is one of several ways to build that context and background knowledge. “When math is integral to the story students can learn the concepts in a natural way, become inquisitive, engage in thoughtful conversation, and more,” said Wallace.

The combination of mathematical, literary and personal reflection, along with students’ genuine interest in the story, leads to higher student engagement, Bezaire said. Year after year, his students who previously kept quiet raised their hands during discussions of The Curious Incident. “Very often, this continues into the rest of the year after our novel study is done,” he said. “Often when middle school students get momentum in a certain class, they are hardy enough to allow it to continue even when the unit of study changes.”

Calculus Book Club

Two years ago, when a schedule change created extra periods in Sam Shah’s multivariable calculus course, he instituted a class book club. The students started with the satirical science fiction novel Flatland by Edwin Abbott and later read several nonfiction texts about mathematicians and mathematical ideas. Book club meetings took place during a block of 30 to 40 minutes a few times per month, with a rotating pair of students leading each discussion.

In the first year, Shah said, his biggest challenge was deciding how much to chime into the discussions. It’s as important to create a relaxed atmosphere for the meetings as it is to keep students focused on the text, he said.

During the second year of book club, he made an effort to intervene less often. “When I reflected upon what my goal was … it wasn’t to teach kids how to do close readings and feel like drudgery. The readings were picked to inspire kids to think, to have strong feelings about, to be curious about something mathematical that showed up, to see and think about math differently.”

“What I appreciated most is how humanizing our conversations were of mathematics — in terms of who was doing it — and how much curiosity students brought to the mathematical ideas they were exposed to.”

One student, for example, used The Calculus of Friendship by Steven Strogatz as the model for her final course project, in which she explored her identity and mathematical experiences using calculus concepts.

Although another schedule change this year forced Shah to drop book club from calculus, he has continued the club outside class with interested students.

“If you have the time, it’s a magical way to get kids to see mathematics through a number of different lenses,” he said.

Shah created a list of titles that would work well in a math book club, and Bezaire’s curriculum for The Curious Incident of the Dog in the Night-Time is available on his website. MindShift asked the two teachers to share their advice for educators who want to try incorporating literature into their own math classrooms.

Tips for Curious Incident

• Lay the groundwork for the unit by communicating with parents, other teachers, administrators, students before diving in. There may be resistance: the book has been removed from some schools because of profanity.
• Stock up on throat lozenges or tea with honey. “I speak out loud in front of classes for a living, and it’s still a stretch for me to read the book out loud four times per day,” Bezaire said.
• Pre-read each day’s reading passage to find teachable moments: clues, red herrings and math worth expanding on. Make notes in your copy of the novel to make things easier the second year.

Tips for math book club

• Bring snacks and drinks. Make the class feel like it is embarking upon something special and different.
• Don’t grade anything. Let it be fun and non-stressful.
• Don’t talk too much.
• Have all kids come with two to four discussion points to share at the start of each book club. This allows everyone to know what others found interesting and see if there were any topics that the discussion leaders should definitely address.
• Plan and lead the first book club to set an example of the structure and style.

# For a Black Mathematician, What It’s Like to Be the ‘Only One’

Fewer than 1 percent of doctorates in math are awarded to African-Americans. Edray Goins, who earned one of them, found the upper reaches of the math world a challenging place.

Article from New York Times, By Amy Harmon, Feb. 18, 2019.

BALTIMORE — It was not an overt incident of racism that prompted Edray Goins, an African-American mathematician in the prime of his career, to abandon his tenured position on the faculty of a major research university last year.

The hostilities he perceived were subtle, the signs of disrespect unspoken.

There was the time he was brushed aside by the leaders of his field when he approached with a math question at a conference. There were the reports from students in his department at Purdue University that a white professor had warned them not to work with him.

One of only perhaps a dozen black mathematicians among nearly 2,000 tenured faculty members in the nation’s top 50 math departments, Dr. Goins frequently asked himself whether he was right to factor race into the challenges he faced.

That question from a senior colleague on his area of expertise, directed to someone else? His department’s disinclination to nominate him to the committee that controls hiring? The presumption, by a famous visiting scholar, that he was another professor’s student?

What about the chorus of chortling that erupted at a lunch with white and Asian colleagues when, in response to his suggestion that they invite underrepresented minorities as seminar speakers, one feigned confusion and asked if Australians qualified.

“I can give you instance after instance,” Dr. Goins, 46, said as he navigated the annual meeting of the nation’s mathematicians in Baltimore last month. “But even for myself I question, ‘Did it really happen that way, or am I blowing it out of proportion? Is this really about race?’”

Black Americans receive about 7 percent of the doctoral degrees awarded each year across all disciplines, but they have received just 1 percent of those granted over the last decade in mathematics. Like many who see in that disparity a large pool of untapped talent, Dr. Goins has long been preoccupied with fixing what is known as the “leaky pipeline.”

Redress the racial disparities that exist at every level of math education, the logic goes, and racial diversity among those who grapple with math’s biggest problems will follow.

To that end, Dr. Goins delivers guest lectures to underrepresented middle and high school math students, organizes summer research programs for underrepresented math undergraduates, mentors underrepresented math graduate students, and heads an advocacy group that was formed in 1969 after the American Mathematical Society, the professional association for research mathematicians, rejected a proposal to address the dearth of black and Hispanic members.

Dr. Goins’s own journey through the pipeline was propelled by a magnet program that offered Advanced Placement calculus for the first time at his majority-black south Los Angeles high school. In 1990, having aced the A.P. calculus BC exam, he became the first student from the school ever to gain admission to the prestigious California Institute of Technology, just 20 miles away.Attendees gathered for the Joint Mathematics Meetings in Baltimore last month.CreditJared Soares for The New York Times

The 10 black students in his incoming class were the largest group Caltech had ever enrolled, he learned when he wrote a paper on the little-known history of being black at Caltech for a summer research project. Only three of the others graduated with him four years later.

Most of his classmates, Dr. Goins quickly realized, had arrived with math training that went far beyond his own. In his freshman year, he sometimes called his high school calculus teacher for help with the homework. In his sophomore year, he watched from his dormitory television as the 1992 Los Angeles riots erupted a few blocks from his mother’s home. But he also came to excel in applied math, which traffics in real-world problems, and, later, to immerse himself in “pure math,” which seeks to elucidate the questions intrinsic to mathematics itself.

Dr. Goins won two math prizes at Caltech, and in 1999 he received a Ph.D. from Stanford’s math department — one of three African-Americans that have ever done so, according to an informal count by William Massey, a Princeton professor who received the second. In 2004, after holding a visiting scholar position at the Institute for Advanced Study in Princeton and another at Harvard, Dr. Goins joined the faculty of Purdue in West Lafayette, Ind.

“You are such an inspiration to us all,” Talitha Washington, a black mathematician who is now a tenured professor at Howard University, wrote on his Facebook page when he received tenure in the spring of 2010.

Yet having emerged at the far end of the pipeline, Dr. Goins found himself unwilling to stay. Last fall, in a move almost unheard-of in the academic ecosystem, he traded his full professor post at Purdue, where federal resources are directed at tackling science’s unsolved problems and training a new generation of Ph.D.’s, for a full professorship at Pomona, a liberal arts college outside Los Angeles that prioritizes undergraduate teaching.

“Edray,” he recalled one colleague telling him, “you are throwing your career away.”

In an essay that has been widely shared over the last year, Dr. Goins sought to explain himself. He extolled the virtues of teaching undergraduates and vowed to continue his research. But he also gave voice to a lament about the loneliness of being black in a profession marked by extraordinary racial imbalance.

“I am an African-American male,” Dr. Goins wrote in a blog published by the American Mathematical Society. “I have been the only one in most of the universities I’ve been to — the only student or faculty in the mathematics department.”

“To say that I feel isolated,” he continued, “is an understatement.”

Experiences similar to Dr. Goins’s are reflected in recent studies by academic institutions on attrition among underrepresented minorities and women across many disciplines. Interviews with departing faculty of color indicated that “improving the climate” would be key to retaining them, according to a 2016 University of Michigan report.Officials at Columbia, which has spent over \$85 million since 2005 to increase faculty diversity, with disappointing results, suggested last fall that progress would hinge partly on majority-group faculty members adjusting their personal behavior.

“In most cases, faculty are not consciously or purposely trying to make colleagues feel unwelcome or excluded,” said Maya Tolstoy, dean of Columbia’s arts and science faculty. “But it happens.”

At the Baltimore conference, Dr. Goins delivered a keynote address titled “A Dream Deferred: 50 Years of Blacks in Mathematics.”CreditJared Soares for The New York TimesImage

And at the recent math meeting, where Dr. Goins delivered a keynote address titled “A Dream Deferred: 50 Years of Blacks in Mathematics,” his presence kindled conversations about racial slights in the math world. The presumption of competence and authority that seems to be automatically accorded other mathematicians, for instance, is often not applied to them, several black mathematicians said.

“Who do they make eye contact with? Not you,” said Nathaniel Whitaker, an African-American who heads the department of mathematics and statistics at the University of Massachusetts at Amherst.

Michael Young, a mathematician at Iowa State University, said he almost gave up on graph theory a few years ago after an encounter with some of the leaders of the field at a math institute at the University of California, Los Angeles.

“A couple of them were at a board writing something,” he recalled. “I went over and asked, ‘What are you guys working on?’”

“We’re too far in to catch you up,” he said he was told.

The ethos characterized as meritocracy, some said, is often wielded as a seemingly unassailable excuse for screening out promising minority job candidates who lack a name-brand alma mater or an illustrious mentor. Hiring committees that reflect the mostly white and Asian makeup of most math departments say they are compelled to “choose the ‘best,’” said Ryan Hynd, a black mathematician at the University of Pennsylvania, “even though there’s no guideline about what ‘best’ is.”

And Ken Ono, a prominent mathematician in Dr. Goins’s field, number theory, and a vice president of the mathematical society, said that a part of Dr. Goins was always likely to be wondering, “‘Do they see me as the token African-American, or do they see me as a number theorist?’”

“And honestly, to tell the truth, I think that answer would vary from individual to individual,” Dr. Ono said.

Most tenured math faculty members at research institutions do not leave, regardless of their race. “I’ve done well and am really enjoying myself,” wrote Chelsea Walton, a black mathematician at the University of Illinois, in a comment on Dr. Goins’s blog post.

But because role models of the same race are seen as critical to luring talented students from underrepresented minorities into a Ph.D. program, it is a blow to lose even one, Dr. Ono said. For the representation of African-Americans in math departments to reach parity with their 13-percent share of the country’s adult population, their ranks would have to increase more than tenfold. (The number of women, also notoriously low among math faculty, would need to triple.) “It’s a loss to our mathematical community that Edray may never advise graduate students again,” said Dr. Ono, who is Japanese-American.

Dr. Goins’s isolation, he himself was the first to note, was also forged by an early career failure. Near the end of his graduate studies at Stanford, he set out to prove a conjecture using techniques suggested by the solution to a 350-year-old problem, Fermat’s last theorem, which had rocked the mathematical world a few years earlier.

Dr. Goins is one of about a dozen black mathematicians among nearly 2,000 tenured faculty members in the nation’s top 50 math departments.CreditJared Soares for The New York Times

It was an ambitious undertaking whose success would probably have snagged him job offers from the most elite math departments in the country. But the conjecture was grounded in a highly technical area populated by the field’s top talent. And despite guidance from Richard Taylor, a white mathematician then at Harvard who had assisted in solving Fermat’s theorem, Dr. Goins was unable to publish the paper he produced four years later.

Several mathematicians familiar with Dr. Goins’s efforts said they did not see racial discrimination as playing a role. It is not all that unusual, they said, for such an ambitious undertaking to end in an unsatisfying result. But it also can require deep reserves of self-confidence and a professional network to bounce back.

Dr. Goins’s colleagues at Purdue said his receipt of tenure and subsequent promotion to full professor signaled the university’s willingness to overlook a sparse research portfolio in light of his extraordinary work with undergraduates, as well as the summer programs he organized for minority students.

“While these areas are not necessarily ‘traditional’ markers for excellence at major research universities, they were valued,” Greg Buzzard, the head of Purdue’s math department, who is white, said in a statement.

But Dr. Goins said he was looking for something else.

“I just never really felt respected,” he said.

At the math meeting last month, Dr. Goins’s essay was not immune from criticism.

Some black mathematicians questioned the utility of dwelling on perceived slights, many of which are unconscious or made out of ignorance.

Some who know Dr. Goins noted his sensitivity. Insults that others might shrug off, they said, might stick with him.

For Bobby Wilson, a mathematician at the University of Washington, offenses related to race “just start to wash over you.” He added: “That doesn’t mean it’s right or good.”

Over dinner one evening, another black mathematician told Dr. Goins that he was worried that his blog account of the difficulties he faced might discourage black graduate students who hope to pursue careers in academic research.

Maybe, it was suggested, he should have kept it to himself.

Dr. Goins, taking that in, was silent. His reply came only the next day.

“I didn’t write it to tell people what should happen,” he said. “I wrote it to tell people what could happen.”

Amy Harmon is a national correspondent covering the intersection of science and society. She has won two Pulitzer Prizes, one for her series “The DNA Age,” and another as part of a team for the series “How Race Is Lived in America.” @amy_harmon • Facebook

# Operator K-Theory in Geometry, Topology and Representation Theory

As the university of Kyoto has announced a conference in ” Operator K-Theory in Geometry, Topology and Representation Theory” will be held
to mark the occasion of Gennadi Kasparov’s 70th birthday:

• Operator K-Theory in Geometry, Topology and Representation Theory (Gennadi Kasparov 70)
• Venue : Kyoto University, Kyoto, Japan
• Dates : June 10-14, 2019