Name: The Extravagant Universe
ISBN: 9780691117423

The Extravagant Universe

One of the world's leading astronomers, Robert Kirshner, takes readers inside a lively research team on the quest that led them to an extraordinary cosmological discovery: the expansion of the universe is accelerating under the influence of a dark energy that makes space itself expand. In addition to sharing the story of this exciting discovery, Kirshner also brings the science up-to-date in a new epilogue. He explains how the idea of an accelerating universe -- once a daring interpretation of sketchy data -- is now the standard assumption in cosmology today. This measurement of dark energy -- a quality of space itself that causes cosmic acceleration -- points to a gaping hole in our understanding of fundamental physics. In 1917, Einstein proposed the "cosmological constant" to explain a static universe. When observations proved that the universe was expanding, he cast this early form of dark energy aside. But recent observations described first-hand in this book show that the cosmological constant -- or something just like it -- dominates the universe's mass and energy budget and determines its fate and shape. Warned by Einstein's blunder, and contradicted by the initial results of a competing research team, Kirshner and his colleagues were reluctant to accept their own result. But, convinced by evidence built on their hard-earned understanding of exploding stars, they announced their conclusion that the universe is accelerating in February 1998.

What Hacker News says

nonameiguessAug 2026

You're halfway there, but the only impediment isn't on the side of the researchers. Many of these topics they're trying to solve involve human subject research. Even with tireless embodied researchers who work around the clock and don't require breaks, you can't make the thing you're studying happen faster. The biggest reason we use poor proxy measures for things like longevity and mortality research is the simple impracticality of finding two groups of randomly selected people, ensuring you can control their entire lives for 60 years, the only difference between them is one variable, and see who lives longer. Putting aside the ethics, even if you could find willing subjects and actually control their entire lives to that extent, it would still take 60 years to gather the data you need. It doesn't make any difference whether robots or humans are running the program.

One of my favorite books from the past few decades is The Extravagant Universe, written by one of the astronomers who helped discover dark energy and develop the current most-accepted model of cosmology. I love this book because of the emphasis on physical process in astronomy. Part of the reason it took decades to study this problem is they need to collect data from supernovae. Those only happen so often in places we're looking. You can't automate alignment of the heavens. It happens when it happens.

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nonameiguessAug 2023

To the Wheeler question, I would say he was just wrong. Pre-eminent physicist of the 20th century he may have been, smarter that I'll ever be, but he was also nearly 90 at that point and had retired 22 years earlier.

To (1), he's talking about the distance ladder. Distances to various galaxies were computed by the teams involved in developing the LCDM model by scouring the skies for instances of type IA supernovae in this galaxies. When these are called "standard candles," what that means is that the luminosity is known and thus the distance can be computed using the inverse square law by comparing the observed brightness to the known luminosity. Historically, this wasn't a super-reliable method and yielded some bounded error rate for various reasons, including dust causing some reddening of the light that could be mistaken for redshift, as well as the fact that type IA supernovae are not all collapsing stars of exactly equal mass and you might catch them at different times after the initial supernova.

What Wheeler probably didn't realize at that point was the methods and frankly just downright tedious repeated measurement work over the course of decades that astronomers had been doing to make this more reliable and accurate. If you want to know all about this via first-hand account from one of the astronomers credited with the dark energy discovery, read The Extravagant Universe by Robert Kirschner. It's very accessible, not super-technical, but goes into painstaking detail on exactly how astronomers made the type IA work as a standard candle.

It's also just a great testament to the work involved in experimental astronomy, down to the logistics of convincing a scheduling committee for the various telescopes capable of seeing that far that what you're looking for is worth looking for.

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nonameiguessJul 2023

Somewhat shame on Science Daily for this title. The actual article title is "JWST early Universe observations and ΛCDM cosmology," which is quite a bit more accurate. This isn't a research result. It's a proposed model that was created specifically to fit data that isn't adequately explained by current models. It has made no other novel predictions or been corroborated in any way. The current ΛCDM model took years of data collection by multiple teams to even be formulated at all and eventually had multiple lines of evidence from many different areas of research all corroborate it. We don't just overhaul paradigms and change the age of the universe because one team did some math that explains one otherwise unexplained phenomenon.

I really, really wish science journalists could be as intellectually humble and conservative as the actual scientists.

Read The Extravagant Universe if you want one of the great all-time tales of experimental physics, describing the lengths to which astronomers go to collect data, how long it takes, and how reluctant they were to even claim they were explaining anything until they were absolutely sure, straight from the hand of one of the astronomers leading the collection team that discovered dark energy.

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flyingdutchmanOct 2011

Robert Kirshner advised both Schmidt and Riess at Harvard and was an integral member of the High-Z Search Team. His book The Extravagant Universe is worth reading if you are interested in the topic. http://www.amazon.com/dp/069111742X/?tag=googhydr-20&hva... Many thought that Kirshner himself would get the Nobel for his work in the field, and I am sure it is a little bitter-sweet (if mostly sweet) for his team members to be among the winners.

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