Roberta Lincoln: [frustrated] Okay. That does it. I quit!
Mister Seven: Wait a minute, what're you...
Roberta Lincoln: I'm quitting right now!
Mister Seven: You're not acting, are you?
Roberta Lincoln: [puts on her coat and grabs her purse] Acting? I'm leaving! Goodbye.
[walks to the door. Gary locks it with his servo]
Roberta Lincoln: Hey. Hey!
Mister Seven: [activates cube on desk] Tie into computer.
Beta 5 Computer: Computer on.
Mister Seven: Scan unidentified female present.
Beta 5 Computer: Roberta Lincoln, human. Profession: secretary.
Roberta Lincoln: [nervously] Ha...
Beta 5 Computer: Employed by 347 and 201. Description: age 20; five feet, seven inches; 120 pounds. Hair presently tinted honey-blonde. Although behavior appears erratic, possesses high I.Q.
Roberta Lincoln: Heh!
Beta 5 Computer: Birthmarks:...
Roberta Lincoln: Hey.
Beta 5 Computer: Small mole on left shoulder; somewhat larger star-shaped mark on her...
Roberta Lincoln: [deactivates cube] Hey! Watch it! Okay, I'll bite. What is it?
Mister Seven: [realizing he has given himself away] Miss Lincoln... Miss Lincoln, um... What kind of work did your employers say they were doing here?
Roberta Lincoln: Research for a new encyclopedia?
[Seven looks at her]
Roberta Lincoln: No? No.
“It was a breakthrough discovery by Leavitt that enabled astronomers — including Edwin Hubble — to calculate the distance between Earth and remote galaxies and stars. During her career at the Harvard College Observatory, Leavitt also discovered more than 2,400 variable stars, approximately half of those known during her lifetime.“Silent Sky’’ ranges from 1900, when Henrietta leaves her home in rural Wisconsin and heads east (the real-life Leavitt arrived in Cambridge a bit earlier), to 1920, a year before she died of cancer at the age of 53. Henrietta’s departure from Wisconsin and her determination to have a career trigger consternation in her sister Margaret (Brenna Sweet), a gentle, music-minded homebody.Once at the observatory, Henrietta throws herself into her work as a “computer,’’ the term referring then to the task of scrutinizing square, windowpane-like photographic plates to measure and record variations in the brightness of stars. What animates Henrietta is a belief that there are galaxies beyond our own — a belief that defies the consensus among her male superiors.Henrietta’s colleagues at the observatory, also both based on historical characters, are two very different women: Williamina Fleming, played by the delightful Juliet Bowler with a Scottish accent and an air of hearty bonhomie, and Annie Cannon, portrayed by Cassandra Meyer with an intensity of focus that conveys the character’s no-nonsense approach to her work. (Later, in a development that connects the trio’s professional striving and struggles for equality to similar struggles going on in the wider world, Annie becomes a suffragette, marching for women’s right to vote.) The camaraderie among the three actresses, and their characters, is a pleasure to behold.More problematic is a fictional male character named Peter Shaw, the head astronomer’s apprentice. Though Marcus Hunter delivers a nicely shaded performance as Peter, the character is too bumbling and good-natured to adequately represent the repressive male power structure. Moreover, Peter’s attraction to Henrietta, and hers to him, pushes “Silent Sky’’ into more conventional channels. Soon, she is coping with work-life tension and tradeoffs, the stuff of countless rom-coms.These detours into overly familiar territory don’t seriously weaken the play because playwright Gunderson’s touch is so sure and so lyrically expressive in capturing the other love of Henrietta’s life: the sky and all its riches. Early in “Silent Sky,’’ before she begins work at the observatory, she exclaims: “I have questions, I have fundamental problems with the state of human knowledge! Who are we, why are we — where are we?’’That last one, at least, Henrietta Leavitt helped humanity answer.”