Coffee Pot Book Club: Ruby Pi and the Math Girls

Today we join the Coffee Pot Book Club tour for Tom Durwood’s “Ruby Pi and the Math Girls”.

A collection of adventure stories. Resourceful girls coming of age and changing history — using mathematics.

Rupa plays Sherlock Holmes when she looks into the mysterious death of one of England’s (and India’s) foremost mathematicians. Her investigation arouses powerful forces. Ruby finds Bayes Rule to be a most useful tool as she combats deadly danger and international intrigue. In the story’s climax, Rupa is ambushed on a foggy night, on a London wharf …

Math girl Uly takes the train to Moscow to collect an award for her work in Derivations. As usual, her beautiful, red-headed sister Sasha steals all of the attention. When the family arrives to stay with a professor cousin, Uly becomes entranced with the Maya tablet the professor (Yuri Knosorov) is studying. Who will emerge when the ensuing code-breaking triggers fateful events for the family?

Here’s the excerpt:

Ruby and the Burglar


I have tried to gild war… But there was nothing dulce et decorum about the Dervish dead; nothing of the dignity of unconquerable manhood. Yet these were as brave men as ever walked the earth,–Winston Churchill, from his account of the Battle of Omdurman. At midnight, a half-dozen constables escorted a kitchen worker, dressed in white aprons, into the rooms. He wheeled a small cart.

“Try this,” said Summerscale, as he offered Rupa and Mahit two pewter bowls, cold to the touch. Spoons protruded from the bowls.

“What is it?” asked Rupa.

“You turn up your nose at English food,” said Daniel Summerscale. “Here’s a treat even you cannot refuse. It will cool you off.”

“Umm. What is it called?”

“Ice cream. I ordered it up from the kitchens.” Rupa tasted it, carefully.

“What flavor is that?” asked Mahit.

“Yours is chocolate. Hers is vanilla.”

“Hah! She’s the one who loves chocolate.”

He indicated Rupa, who seemed to be enjoying the vanilla well enough. Rupa took a biscuit in the shape of a cone that lay on the cart and scooped the ice cream into it. She took a bite. She laughed. She ate the entire bowl.

“Thank you,” she said to Daniel.

* * *

“Got it.”

Rupa’s announcement caught Summerscale napping in the red leather chair beneath the Eakins print. Mahit shook his head and peered at the clock. It was just past midnight. She had so far gone through half of the row of Anaan Warinda’s notebooks. Rupa stood and stretched her hands out, arms wide. She picked up a piece of foolscap covered in her own writing to show her companions.

“There seem to be two layers of code, one linguistic and one mathematical.”

“It’s a seven-shift Caesar Code,” Rupa explained. “You shift the letters seven down … it seems to make sense. “You find a lot of pure mathematics. Number theory, infinite series, that sort of thing. “Then one entire notebook seems devoted to equalities. Adventures in equalities.”

Her two companions regarded her blankly. “Relating one mathematical expression to another. I don’t really understand it. “But this may be what you’re hoping for…”

She wrote this on the blackboard: The coded version:

lzakp pbrjb aqgfj zmtrc vprvq pbiwl pwjoq

Tamil: Otticaivu illāmal itu payaṉaṟṟatu

Hindi: singaronist ke saath yah bikree hai

English: Without synchronization this is useless.

“Synchronization?” asked Mahit.

“It could mean many things,” said Rupa.

She shrugged. She showed them one of Anaan’s notebook pages.

“He considers fluid dynamics in this one. Apparently, fluid dynamics as they affect an underwater war vessel. These here … seem to be for, moving bombs. Motion-propelled water bombs. He calls them dhatu MacHale at one point. See? See here?”

“That exchange that you have translated,” asked Summerscale sharply. “With whom was Warinda communicating?”

To answer, Rupa wrote on the chalkboard a five-letter name, first in code, then in Tamil. Then, as she was about to return it to its original language, German —

“HEY! Hey you!” came a shout from outside.

A loud clatter exploded on the lawns below the windows. A hue and cry rose from outside. They heard heavy steps running down the stairs, joining the commotion on the lawns. A string of cursing and huffing and whistle-blowing suggested that a pursuit was underway –Daniel and Mahit both rushed down the stairs and out on the lawn. “Light the perimeters!” called Daniel. Something told Rupa to hang back. She heard someone at the door. She hid behind a bookcase. She still held the chalk in her hand. A figure appeared in the doorway. It was a woman … and she was stalking something. Silent, deliberate, the woman moved with purpose. She knew what she wanted. She wants the notebooks –The woman stepped into the light. Aquiline features gave her an almost hawk-like aspect. Her eyes were piercing and quick –the eyes of a raptor.

She saw Rupa and rushed.

Wo sind sie?” she demanded –“Where are they?”

Contempt poisoned her words. “Come, tell me, dunkelhautige–” She reached, to grab Rupa by the neck –Rupa twisted the woman’s body as she advanced, flipping her from the hallway into the study. Rupa fisted the hand with the chalk in it and blasted the woman across the jaw. The blow was unexpected and sprawled the German-speaking intruder backward, toppling over the desk –Rupa scrambled to follow her –Landing cannily on her feet, the woman stepped out of the large open arched window and leapt onto the small balcony –She vaulted over the railing.

“Hey! Stop! Stop her –”, Rupa called and waved for the constables, but they were spread too thin across the lawn headed towards St Mary’s chapel, looking for the phantom danger that had decoyed the intruder’s approach.

“Catch her! Over there –she’s near the trees!” Rupa called out the window. But the burglar had disappeared in the shadows.

Twitter : @TDurwood

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