Some books in the sciences pretty cheap

At the moment, all these are anywhere from free to two bucks. The Darwin books are always cheap, the others are probably temporarily cheap.

If you've not read The Autobiography of Charles Darwin, you should. It is always avaialable for next to nothing on the kindle, currently this version is 99 cents.

Concerning his autobiography--written when Darwin was 59 and originally published as the first part of “The Life and Letters of Charles Darwin” (1887)--Darwin explained: “A German editor [wrote] to me for an account of the development of my mind and character with some sketch of my autobiography. I have thought that the attempt would amuse me, and might possibly interest my children or their children. I have attempted to write the following account of myself as if I were a dead man in another world looking back at my own life. Nor have I found this difficult, for life is nearly over with me. I have taken no pains about my style of writing.”

Darwin’s son Francis, who edited “Life and Letters,” stated: “My father’s autobiographical recollections were written for his children—and written without any thought that they would ever be published. To many this may seem an impossibility; but those who knew my father will understand how it was not only possible, but natural.”

The autobiography was reprinted in 1908 as a section of editor George Iles’ larger “Little Masterpieces of Autobiography: Men of Science.” This Kindle edition, equivalent to a physical book of approximately 24 pages, includes the complete text of that 1908 reprint.

(You can get The Origin of Species by Means of Natural Selection for free or a buck as well.)

Jared Diamond's The World Until Yesterday: What Can We Learn from Traditional Societies? is currently cheap, $1.99 in Kindle form.

Most of us take for granted the features of our modern society, from air travel and telecommunications to literacy and obesity. Yet for nearly all of its six million years of existence, human society had none of these things. While the gulf that divides us from our primitive ancestors may seem unbridgeably wide, we can glimpse much of our former lifestyle in those largely traditional societies still or recently in existence. Societies like those of the New Guinea Highlanders remind us that it was only yesterday—in evolutionary time—when everything changed and that we moderns still possess bodies and social practices often better adapted to traditional than to modern conditions.The World Until Yesterday provides a mesmerizing firsthand picture of the human past as it had been for millions of years—a past that has mostly vanished—and considers what the differences between that past and our present mean for our lives today.

This is Jared Diamond’s most personal book to date, as he draws extensively from his decades of field work in the Pacific islands, as well as evidence from Inuit, Amazonian Indians, Kalahari San people, and others. Diamond doesn’t romanticize traditional societies—after all, we are shocked by some of their practices—but he finds that their solutions to universal human problems such as child rearing, elder care, dispute resolution, risk, and physical fitness have much to teach us. Provocative, enlightening, and entertaining, The World Until Yesterday is an essential and fascinating read.

I've not read this but it looks really interesting and cheap at twice the price: Close to Shore: The Terrifying Shark Attacks of 1916

Combining rich historical detail and a harrowing, pulse-pounding narrative, Close to Shore brilliantly re-creates the summer of 1916, when a rogue Great White shark attacked swimmers along the New Jersey shore, triggering mass hysteria and launching the most extensive shark hunt in history.

In July 1916 a lone Great White left its usual deep-ocean habitat and headed in the direction of the New Jersey shoreline. There, near the towns of Beach Haven and Spring Lake--and, incredibly, a farming community eleven miles inland--the most ferocious and unpredictable of predators began a deadly rampage: the first shark attacks on swimmers in U.S. history.

Capuzzo interweaves a vivid portrait of the era and meticulously drawn characters with chilling accounts of the shark's five attacks and the frenzied hunt that ensued. From the unnerving inevitability of the first attack on the esteemed son of a prosperous Philadelphia physician to the spine-tingling moment when a farm boy swimming in Matawan Creek feels the sandpaper-like skin of the passing shark, Close to Shore is an undeniably gripping saga.

Heightening the drama are stories of the resulting panic in the citizenry, press and politicians, and of colorful personalities such as Herman Oelrichs, a flamboyant millionaire who made a bet that a shark was no match for a man (and set out to prove it); Museum of Natural History ichthyologist John Treadwell Nichols, faced with the challenge of stopping a mythic sea creature about which little was known; and, most memorable, the rogue Great White itself moving through a world that couldn't conceive of either its destructive power or its moral right to destroy.

Scrupulously researched and superbly written, Close to Shore brings to life a breathtaking, pivotal moment in American history. Masterfully written and suffused with fascinating period detail and insights into the science and behavior of sharks, Close to Shore recounts a breathtaking, pivotal moment in American history with startling immediacy.

Genius in the Shadows: A Biography of Leo Szilard, the Man Behind the Bomb by by William Lanouette looks interesting:

Well-known names such as Albert Einstein, Enrico Fermi, J. Robert Oppenheimer, and Edward Teller are usually those that surround the creation of the atom bomb. One name that is rarely mentioned is Leo Szilard, known in scientific circles as “father of the atom bomb.” The man who first developed the idea of harnessing energy from nuclear chain reactions, he is curiously buried with barely a trace in the history of this well-known and controversial topic.
Born in Hungary and educated in Berlin, he escaped Hitler’s Germany in 1933 and that first year developed his concept of nuclear chain reactions. In order to prevent Nazi scientists from stealing his ideas, he kept his theories secret, until he and Albert Einstein pressed the US government to research atomic reactions and designed the first nuclear reactor. Though he started his career out lobbying for civilian control of atomic energy, he concluded it with founding, in 1962, the first political action committee for arms control, the Council for a Livable World.

Besides his career in atomic energy, he also studied biology and sparked ideas that won others the Nobel Prize. The Salk Institute for Biological Studies in La Jolla, California, where Szilard spent his final days, was developed from his concepts to blend science and social issues.