The uncertainty of astronomical science
From today’s first press conference at the AAS meeting, astronomers have found that two of the fundamental objects they use as units of measure might not be as reliable a unit of measure as they thought.
- Astronomers have discovered that the Cepheid variable stars that they use to estimate the distances to the nearest galaxies are not necessarily the stars they thought. At least two Cepheids, which are variable stars, do not pulse reliably (one actually stopped pulsing entirely). Another is surrounded by a previously unknown nebula cloud, which affects its apparent brightness, an essential data-point when using these stars as a measuring tool. Here’s one press release.
- The Crab Nebula threw out some gigantic gamma ray bursts last fall. In addition, astronomers have found that the nebula actually flickers wildly, and is also changing in gamma ray energy output over the long term, declining by seven percent in the last two years. No one yet knows what exactly causes these different variations. Like Cepheids, the Crab has been used as a standard for measuring the energy of astronomical gamma ray objects. This is no longer reliable. Here’s one press release, plus images.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News