Marcia Bartusiak

Black Hole is a short but engrossing history of science about the discovery of black holes. Bartusiak writers with passion and a sense of narrative mystery, while retaining factual accuracy. I would read more by her. It's for a general audience on a subject as esoteric and complex as they come, but she manages to hold interest. Black holes seem almost normal today but they were once thought so exotic as to be impossible. She restores that past sense of impossibility and incredulity, before show more black holes became accepted. show less

It is difficult to believe, in this day and age, with the Hubble Space Telescope and other enormous telescopes regularly providing us with stunning views of the Universe, that astronomy in the early twentieth century more closely resembled the studies of the Renaissance than modern space studies. Little was understood about the Universe beyond the Milky Way and, in fact, the most commonly held belief was that the Milky Way was the Universe, in its entirety. Marcia Bartusiak’s “The Day We show more Found the Universe” chronicles the work of the men, and in some cases women, who laid the groundwork for the study of modern astronomy and who discovered how small and insignificant our galaxy, star, and planet truly are in this great Universe.

The first half of Bartusiak’s work is dedicated to the battle over the nature of galaxies, what were then termed “nebula” and which appeared in telescopes as a hazy collection of “shining fluid.” Some astronomers believed them to be accumulations of dust or gas within the Milky Way, while others argued that they were, in fact, island universes, much like our own galaxy and situated at substantial distances away from us. As telescopes improved, these nebulas gained greater definition and the battle ultimately culminated in the Great Debate, conducted in April 1920 before the members of the National Academy of Sciences. On one side of the debate was Harlow Shapley of the Mount Wilson Observatory, the man who first discovered that the Milky Way galaxy was far larger than originally believed and that the Sun was not at its center. He argued that the Milky Way was the entirety of the Universe and that the “spiral nebula” as they were then called (the last quarter century of telescopic development had allowed for greater clarity of galaxies) were merely collections of gas within our own galaxy. He also argued that Adriaan Van Maanen’s discovery of rotation within the nebulae rendered it impossible for them to be situated very far from our own galaxy as the relative speeds required then would have them rotating faster than the speed of light.

On the other side of the debate was Heber Curtis of the Lick Observatory, who argued that the light spectrum emanating from the nebulae matched that of collections of stars, rather than accumulations of gas. He also argued that the Milky Way was one-tenth the size Shapley believed which allowed him to partially reconcile the “island universe” hypothesis with Van Maanen’s ultimately disproven observations.

The Great Debate actually decided little since the two scientists were mostly speaking past each other. In fact, they both ended up being partially right and partially wrong. What the Great Debate did do was focus the work of another astronomer at Mount Wilson: Edwin Hubble.

The second half of “The Day We Found the Universe” follows Hubble’s work at Mount Wilson’s Hooker Telescope, then the largest telescope in the world. Hubble was the first to discover Cepheid variable stars in the spiral nebulae. These variable stars (whose size and luminosity change with regularity) were proven to be useful in calculating stellar distance by Henrietta Swan Leavitt fifteen years earlier. Using these standard candles, Hubble proved that these spiral nebulae were actually “island universes” far beyond the reaches of the Milky Way galaxy. Hubble’s work then went to figuring out how these galaxies moved and he was able to prove that galaxies were moving away from us and how quickly they were doing so. This discovery would ultimately inform the discussion of the nature and creation of the Universe in the following decades.

Bartusiak writes with vigor and makes a potentially dry subject come to life. Some of the discussion gets a bit academic and may be difficult to follow for readers without at least a little understanding of astronomy but, for the most part “The Day We Found the Universe” is a wonderful and readable book, capable of sparking interest in astronomy in any reader. show less

This book provides a virtual front row seat to the discoveries of facts about the universe that were bigger, stranger, and more spectacular than anybody could have imagined at the beginning of the 20th Century. Today the newness has worn off of such terms as expanding universe, space-time continuum, and multiple galaxies. So it's good to imagine the excitement that must have been felt when these words were first uttered. If these concepts seem unfathomable now, they were even more show more unbelievable then.

This book covers the professional biographies of multiple individuals who played important roles in the advancement of astronomy from 1900 to 1930. Consequently the book's structure reminds me of Doris Kearns Goodwin's book, Team of Rivals where she provided multiple mini-biographies of Lincoln's cabinet. The author, Marcia Bartusiak, in this book skillfully hops from one personality to another, each mini-biography being told chronologically, but generally jumping backward in time when changing from one astronomer to another. The narrative is written with such skill that it's hard to imagine it being told in any other way.

Of course Edwin Hubble ends up being the star in the end. But the service provided by this book is to tell the story of others who provided the base of knowledge upon which Hubble was able to build. Among the personalities involved, Hubble was not the most likeable person to select if one were choosing a storybook hero. He was physically attractive, but a stuffed-shirt guilty of some boorish behavior. Nevertheless, in addition to being very intelligent, he had the luck of being at the right place at the right time. All the others in this story were very intelligent people, and there were several who could have achieved the findings regarding the size of the universe before Hubble, but for various reasons didn't do it.

The following quote from the book provides a good summary of the excitement and significance of the time.

"...perhaps never again will astronomy face such a dramatic shift in its conception of the universe. It took only three short decades―from 1900 to 1930, ... ―to make this mind-altering transition. The Milky Way, once the universe's lone inhabitant floating in an ocean of darkness, was suddenly joined by billions of other star-filled islands, arranged outward as far as telescopes could peer. ... Astronomers barely had time to adjust to this astounding celestial vastness when they were faced with the knowledge that space-time ... was expanding in all directions ...

Conservative religious people who feel that science is always chipping away at their views of the universe should remember that when evidence of the "Big Bang" was first reported that many religious people enthusiastically welcomed the news as vindication of their views about creation. This is a reminder that science goes where the evidence leads, and occasionally science and religious myths may end up in the same ball park (metaphorically speaking).

One of the individuals who could have beaten Hubble to his findings was Harlow Shapley. Unfortunately, he was so convinced of the single galaxy model that he didn't look for contrary evidence. When he first received a letter from Hubble describing his initial findings, Shapley was quoted as saying, "the letter has destroyed my universe!" The book's narrative goes on to say, "Once proven wrong, ...(Shapley)... didn't look back and quickly adjusted to the new cosmic landscape, soon becoming its most boisterous promoter."

Here's my favorite quotation by Harlow Shapley from his 1969 memoir:
"The solar system is off center and consequently man is too."

The above quotation is a comment about the discovery that the solar system is not located at the center of our galaxy. And for that matter, the Milky Way Galaxy is only one of many billions of galaxies and isn't at the center of anything, least of all the universe. So if God created the universe for the exclusive enjoyment of earthlings, he/she/it apparently selected an arrangement that emphasized our insignificance. After Copernicus discovered that the earth wasn't in the center of the solar system, we should have known that there was going to be more news headed in that direction.

The following is from the author's blog:
"... taking the Copernican principle to its finale―our universe may not be the only one. As physicists attempt to construct a theory that unifies all the forces of nature, one theme repeatedly arises: that additional cosmic realms may be lurking in other dimensions. We could be part of the multiverse; the Big Bang might have occurred when universes outside our dimensional borders bumped into one another." show less

A good history of astronomy from the late 19th century to the 1930s that discusses the discovery of the true significance of spiral nebulae, the size of the universe and its expansion. Other advances during this time, e.g. the nature and classification of stars, are mostly not discussed. Many later misconceptions about who did what are debunked, and there is fascinating discussion of the people involved with no attempt to gloss over their often too human characteristics.