German physicist Albert Einstein is one of the most famous scientists of all time, the personification of genius and the subject of a whole industry of scholarship. In The Einsteinian Revolution, two experts on Einstein’s life and his theory of relativity, Israeli physicist Hanoch Gutfreund and German historian of science Jurgen Renn, offer an original and penetrating(犀利的)analysis of Einstein’s revolutionary contributions to physics and our view of the physical world.

By setting Einstein’s work in the long course of the evolution of scientific knowledge, Gutfreund and Renn discover the popular misconception of Einstein as an unconventional scientific genius who single-handedly created modern physics—and by pure thought alone.

As a large part of the book explains, Einstein typically argued that science progresses through steady evolution, not through revolutionary breaks with the past. He saw his theory of relativity not as something from scratch, but a natural extension of the classical physics developed by pioneers such as Italian astronomer Galileo Galilei and English physicist Isaac Newton in the sixteenth and seventeenth centuries, as well as nineteenth-century physicists.

The authors highlight how classical physics cannot be separated cleanly from modern Einsteinian physics. The book also includes substantial sections on Polish astronomer Nicolaus Copernicus and Galileo whose methods inspired Einstein. When Einstein considered himself as standing on their shoulders, he meant that, without their contributions, he would not have formulated(阐述)the theory of relativity.

The Einsteinian Revolution is an important and thought-provoking contribution to the scholarly literature on Einstein and his surprising scientific creativity between 1905and 1925.Gutfreund and Renn might not have given the final answer as to why Einstein, of all people, revolutionized physics in the way that he did. But they argue in fascinating detail that, to understand his genius, one must take into account not just the earlier history of physics but also the history of knowledge more broadly. Although not always an easy read, the book will interest physicists and historians alike.

Having an older brother comes with plenty of benefits. Big brothers tend to look after their younger brothers and sisters, and despite the occasional unpleasant moments here and there, many siblings(兄弟姐妹) enjoy life-long close relationships. However, a new study finds an interesting disadvantage. Children with older brothers take longer when it comes to developing language skills.

Researchers studied more than 1,000 children from birth to the age of five-and-a-half years old. Each child’s language skills were tested at ages 2, 3,and 5.5,using tests specially designed to measure lots of aspects of language development such as vocabulary, syntax(句法), and verbal(文字的)reasoning. What the research team discovered was significant. Children with an older brother had, on average, a two-month delay in their language development compared to studied children with an older sister.

As far as explaining this phenomenon(现象), researchers have proposed two assumptions. The first is that older sisters tend to talk more often than older brothers, which would compensate(补偿)for parents potentially being less present than they were for their first child. The second assumption is that older sisters usually compete with their siblings less than older brothers for their parents attention. The study’s authors say they can’t say for certain why children with older brothers have a harder time developing language skills. In the future they would like to study if culture or location impacts the prevalence(盛行)of these results.

The study is published in Psychological Science.