"You're writing about your grandmother?" a friend inquires.
"Yes," I tell her. "The one who had a Ph.D. in physics."
"What about the grandmother who was a radio broadcaster?"
"It's the same one," I say.

Born in 1897 in Toronto, Canada, the oldest of 10 children, my grandmother was a "flash," to use the slang applied to her at the turn of the 20th century. Evidently brilliant from the earliest years, she excelled in school. Her 19 grandchildren grew up knowing that she had read all of Shakespeare by the time she was 12.

My grandmother had a mind that seemed to retain everything she read or heard. In speaking to me in the 1980s, she might quote a lively conversation she'd had with a stranger while on her European honeymoon in 1924, recite a beloved poem by Tennyson, or use an inadvertent witticism of the woman who helped her in the house when her children were young. When I picture her, she is leafing through the New Statesman, completing in ink an anagram crossword puzzle, or rereading for pleasure Black Lamb and Grey Falcon, Rebecca West's two-volume history of the Balkans.

Bub, as we called her, understood the voluptuousness of reading. It is not surprising that she was a splendid writer. In 1930, Meyer Weisgal, the political representative of Chaim Weizmann in North America, was in Toronto, where he edited the journal The Jewish Standard. From 1930–32, Bub was editor of the women's section. Her weekly column, "As the Woman Sees It," is written in prose so crystalline and eloquent it remains daunting to her granddaughter.

From 1939 until 1966, she wrote and broadcast regularly her commentary on the CBC, Canada's national radio, on a program devoted to women's issues called "Trans-Canada Matinee." When I was growing up we had in our house a recording of the broadcast Bub delivered on April 12, 1943. In a country where, it emerged long after the war, a shameful 500 refugees were admitted from 1939 to 1945, my grandmother gave a detailed report about the Final Solution, condemning the Western nations, including Canada, for their indifference:

"Asking themselves the question, 'Am I my brother's keeper?' the democratic nations of the world, our country among them, answered: 'No.'"

She concluded her talk with these words: "Some action must be taken at once. If it is not, within a few months six million people will have been murdered, and the nations of the world will not be able to escape the charge of being accomplices in the bleakest crime in history."

My grandmother spoke English beautifully, of course, She pronounced the 'h' in "white" in diction so precise that my friend Rochelle's mother, a survivor of Auschwitz, told her that she had improved her newly acquired English by listening to my grandmother's broadcasts. In 1945 she won the Canadian Woman's Press Club Memorial Award for a radio broadcast titled "The Post-War Woman." It was the first time in its 10-year history that the award was given in the field of radio writing.

"Trade between nations, tariffs, inflation—these are matters that affect the welfare and happiness of every home—these are not remote questions only for the minds of statesmen," said my grandmother. "…If a democracy is to succeed, every citizen must be intelligent and responsible; must have the knowledge and information to take part in self-government. Otherwise what is the use of women's long struggle for the vote?"

In February 1947, she traveled to Lake Success, New York, to cover the United Nations Status of Women Commission at the first formal session of the U.N. Bub went to the U.N. annually for several years afterward, broadcasting on the position of women around the world.

Writing and broadcasting were not, however, the sole domain of my grandmother's accomplishments. Bub was one of twelve women to take M & P (Math and Physics) at the University of Toronto, graduating with a B.A. in 1921. In 1926, pregnant with her second child, she completed the formal requirements for a Ph.D. in physics, the first woman and first Jew to receive a doctorate in physics from U of T. Her thesis, titled "On the Characteristic X-Rays from Light Elements," had been published in 1924 in the Transactions of the Royal Society of Canada.

She returned to the Physics Department in 1941, where she worked three days a week as a demonstrator in the lab until 1968. My grandfather, Meyer, who adored her and was proud of all she achieved, was distressed not by her working but because he thought her starting pay—$1.50 an hour—far too low.

Naturally, whenever we had a question about homework, Bub was the person to call. One of the many assets of being a grandchild of Mattie Rotenberg was being able to tell your teacher that your grandmother had helped you solve a physics problem. I have a photograph of her in 1987, at age 90, sitting in a computer course among people less than half her age.

Bub was an exceptional woman not only by the standards of her era, but by ours. She and my grandfather were observant Jews. They raised their five children to believe that you could be an observant Jew and do anything. In the 1930s, when my mother and uncles were young, there were signs in the countryside outside Toronto that read: "No Jews and dogs allowed." Nevertheless, my grandparents invented for their family a unique culture of observant Anglo-Saxon aristocracy, illuminated by reason and bolstered by learning. Their children and grandchildren were brought up to have a patrician pity for anyone who did not understand that being observant while participating deeply in the world was the richest possible path.

Committed to their children's being knowledgeable Jews, my grandparents were passionate about Jewish education. When her oldest son reached kindergarten age in 1929, Bub realized that the conventional Talmud Torah education was not sufficient. Despite opposition to "segregating" children in day school and parents who said, "Why learn Hebrew? I don't want my child to be a rabbi," Bub founded the Hillcrest Progressive School, the first Jewish day school in Toronto.

She was the director of Hillcrest for years and remained active until 1944, when her youngest son left the school. All of Bub's and Gramps's grandchildren went to day schools; their great-grandchildren have as well. Although Toronto now has outstanding day schools, Bub was the pioneer.

If you interviewed my grandmother about her life, she would tell you promptly that family was always her chief priority. She held the Chanukah and Purim parties every year. She came to stay with us when our parents were on a trip or having a baby. She baked her famous "Bubba buns," cinnamon yeast rolls we devoured. The older grandchildren were lucky enough to be taken on trips with her, singly or in pairs, to New York, Montreal, Washington, California or Israel. She worried incessantly about her grandchildren's financial security, as befit a woman born very poor who married into a wealthy family that lost its money in the stock market crash of 1929. (When she urged all of us to become chartered accountants, we simply laughed.)

Grandchildren who moved away from Toronto received her weekly carbon-copy letter, telling family news and descriptions of her day, with apologies for their dullness—she who could make even the weather sound compelling. She was not a conventionally demonstrative person, although she had a weakness for babies. To me, there was something restful in her dispassion. If I told her I missed her when I called her from New York, she said immediately: "No you don't." She was the revered matriarch not only of her immediate descendants but honored by an enormous extended family. (My mother had 43 first cousins.)

Bub had a magisterial mind and a cool, anti-psychological disposition. "Pull up a plant by the roots," she would say, "and you kill the plant." Without self-deprecation, she was still so modest about her attainments that she would not have cared for this article. "I was always glad to have done it," she told my mother when asked if she enjoyed broadcasting. I cannot remember her uttering a boastful word, or indeed drawing attention to herself. And yet anyone who met her recognized her stature within minutes. She was stalwart, even-keeled and singularly uncomplaining, but she did not suffer fools gladly and could get deliciously acerbic about what she viewed as stupidity or lack of enlightenment.

Bub was not, however, the kind of woman who believed her accomplishments proved that society was equitable. On the contrary, she was very sensitive to injustice to women. She would tell me, in anguish, of the doctor, considered the best gynecologist of the day, who informed her mother after her seventh child was born that she had a heart murmur and should not have more children. When my great-grandmother pleaded with him to tell her how to prevent conception, the doctor said he could not; it was against the law. Bub's beloved mother was bedridden by her mid-50s and died at 61, worn out from pregnancy and the incessant labor of poverty.

On the other hand, Bub was sufficiently of her generation to tell me while I sat next to her at my wedding: "Take care of your husband."

I was 10 years old when I first realized her magnitude. Until then, I had vaguely longed for a grandmother who would buy me presents and dote on me. I remember vividly the day I stood outside the door of her apartment, about to visit her, when her distinction burst into my consciousness as a revelation. "There's nobody like her," I said to myself with a fascination that has not abated.

Today I think about the fact that Bub remembered the parade up University Avenue in Toronto marking the death of Queen Victoria in 1901, grew up in an era when women could not vote, and lived to see the feminist movement and the beginning of the Information Age. Knowing her for much of my adult life has given me a taste for the intimate texture of history. I remember when a one-pound tin of salmon cost five cents. I can see those printed lists, name after name read with trepidation, that annotated the slaughter of Canadian soldiers on the blood-drenched European fields of WWI. I can hear the professor who, entering the university lecture hall in which Bub and the other 11 women students sat in the first row, opened his address with the words: "Good morning, gentlemen."

My grandmother was a clipper and filer. It is typical that in the last decade of her life she could retrieve and read aloud to a visitor the warm note she received from her grade-six teacher when she graduated from college in 1921. Because of Bub, I clip any New York Times obituary of a woman scientist, especially if her most important discovery was overlooked for decades. Bub would have understood exactly how such a wrong could happen—and it would have rankled her.

My grandfather died in 1958, when Bub was 61. She kept her sorrow to herself, but spoke toward the end of her life of her pleasure in the 90th birthday celebration my uncle and aunt organized in Florida. So great was her belief in family that she allowed us to "make a fuss" over her, overcoming her embarrassment at being the focus of attention. "It was a wonderful event," she said afterward with uncharacteristic emotion. The gathering included members of four generations—Bub's siblings, children, grandchildren and great-grandchildren. "I only wish Meyer were there," she concluded.

On March 17, 1992, our second child, a daughter, was born. Replete with gratitude, I called my parents in Toronto to tell them we had decided to name her Mattie. The Jewish tradition of naming a life that has entered our world for a soul that has departed is mystically restorative.

It is because of Bub that I can talk to my son about what Jewish women can be in a way that is not theoretical and not bitter. It is because of Bub that when my daughter came home from first grade to report that girls in her class were already declaring themselves "so bad in math," I could state with conviction: "Nobody named for Mattie Rotenberg will ever say those words!"

Anecdotes like the following make me mute: One Erev Pesach my grandmother demonstrated physics at the University of Toronto for three hours, went to the radio studio to tape a live broadcast, taped two more broadcasts for the upcoming days of Yom Tov, and came home to make seder. My mother asked her, shortly before she died: "If it were possible in your day for a woman to have a full-time career, would you have done it?" Bub replied: "Not if it meant not having a family."

I do work full time, but my grandmother lives within me. When I spoke to a close friend of my longing, in my 40s, to have a third child, her initial response was laughter. Then she said: "It makes sense. You come from a family that really believes in having children." I felt Bub's blessing at our daughter's Simchat Bat ceremony.

In writing about the issue of gender and Jewish day schools, I said of my grandmother: "She is not only a private figure for me to emulate but a contributor to the history of our people. She represents a commitment to traditional Jewish life and a commitment to fulfilling all the gifts God gave her. Incorporating the story of such women into the curriculum of Jewish schools is not a parochial retrieval project for feminists but a righting of the balance for all Jews."

The most potent way I can make the case that my grandmother's example contributes to a different future not only for Jewish women but for Jewish men is to close with this story:

My uncle David, Bub's fourth child, had been a widower for several years; my cherished aunt, Cecile, died too young, at 57. Determined not to marry simply to "have someone make Shabbes dinner for me," he was alone until he was introduced to Riva by his daughter.

Very early in their acquaintance, Riva explained to my uncle that one reason she, too, had remained alone after her husband's death was that she was an independent woman who ran her own business and did not take kindly to most of the men she met, who felt entitled to be domineering.

My uncle addressed that issue simply and conclusively. "Let me tell you about my mother," he said.