You may have heard the term "Big History" thrown around in pop-science media in recent years. Big History is styled as an emerging field of scholarship, aimed at providing a coherent account of the history of everything, ever - unifying natural sciences, social sciences, and other disciplines to render a comprehensible trajectory from the Big Bang to the shooting of Franz Ferdinand and beyond.

David Baker boasts the world's first PhD in Big History, studying under the man who coined the term, Australian David Christian, at Macquarie University. Baker's new book, The Shortest History of the World: A Fascinating Journey Through Life, The Universe, & Everything, appears as an essential introduction to the worldview and project of Big History, with all its interesting ideas and foibles.

Baker divides his history of the world into four parts, or "phases": The Inanimate Phase, from the Big Bang to the formation of the Earth; The Animate Phase, from the emergence of life to the evolution of humans; The Cultural Phase, accounting for human history and pre-history; and The Unknown Phase, scrying from the immediate future to the end of the universe.

In a humble 200 pages, Baker aims to convey the gist of totality.

The theme uniting the eras and timescales that Baker places as the spine of his history is complexity. Baker seeks to illustrate an increasing presence and extent of "complexity" in the universe over time; marked, for example, in the movement from the formation of atoms, to the formation of compounds, to the formation of super-structures of atoms and compounds, to life, to complex life, to all the overly complex nonsense humans construct.

Complexity, Baker says, emerges in the flows of energy in the universe, which occur as the second law of thermodynamics works to correct the disuniformity in the energy distribution of the early universe. The numeric simplicity of this model makes it a good anchor for a narrative, but whether it has claims to genuine scientific applicability is likely arguable.

His style is approachably conventional for pop-sci non-fiction. The playbook featuring the likes of Yuval Noah Harrari and his book Sapiens is plumbed, down to the minimalist design of the cover. Baker's conveying of scientific and other theories is simple, and often evocative, if general - its generality being aggravated by its undemanding length. Baker's writing style reflects his time in educational media. He is happy to use "stuff" as a term of art and science, as a vessel for making potential erudite concepts approachable. His casual quips usually land. His book reads something like an Attenborough or Cox documentary, which recommends it, if that genre of scientific communication interests you.

Unsurprisingly, given the brevity of the book, Baker's explanations are however liable to be so reduced as to be undefended - reliant upon an audience's willingness to be amazed, and their faith in the author's scientific authority. Unintuitive cosmological concepts, for example, wanting for elaboration, test a reader's suspension of disbelief. The book also contains the occasional simple infographic which does not reliably add much to the commentary.

This is an issue that becomes increasingly prominent as Baker moves into a discussion of human history and social phenomena. Here too do the criticisms of Big History's ideological commitment to detached rationalism become tangible. Presenting brief theories of social organisation and development, gender hierarchies, class, and historical phenomena like slavery and colonialism in the tones and attitudes of scientific study, when these represent live and complicated issues, irks the authority of the narrative.

Reflecting another criticism of Big History, Baker's book further possesses a myth-making quality which is out of step with its avowedly secular and scientific intentions. A funny spirit of scientific transcendentalism, for example, underwrites it; as Baker asserts: "We are the universe looking at itself." All this tends to complicate and render the apparently simple aspirations of Big History towards a scientifically detached and objective explanation of human history naive, even offensive.

Ultimately, the biggest virtue of The Shortest History lies in its earnest curiosity as science entertainment. In attempting to answer big questions, it poses big questions, and in showcasing varied and unintuitive theories, and trying to think across discourses, timescales, and distances, it may prompt audiences, particularly younger audiences, towards an interest in learning. Though an interesting journey for those interested in a scientific narrative of time, the complexities of historiography complicate this book and Big History's project.