The 4 Percent Universe: Dark Matter, Dark Energy, and the Race to Discover the Rest of Reality - Richard Panek (2011)

Footnotes

* Today we would say that retrograde motion is the result of Earth overtaking another planet, or vice versa, in their orbits around the Sun.

 

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* The distinction that eventually got Galileo into trouble with the Church.

 

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* Yes, the eponymous Halley's Comet.

 

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* The diameter of the light-collecting surface.

 

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* Technically the term applies to the expansion—to everything that has happened after the singularity—though through common usage it has also come to mean the singularity itself.

 

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* Einstein thought his theory made a third prediction, involving the redshifting or blueshifting of light by gravity, but it turned out not to be specific to general relativity.

 

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* Absolute zero, in principle the coldest temperature possible, is -459.67° Fahrenheit, or -273.15° Celsius. By convention, scientists designate absolute zero as 0 Kelvin and count upward in increments of degrees Celsius. So 10°C above absolute zero is 10 K.

 

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* When the editor of the Astronomical Journal said that, as a matter of policy, the resulting paper couldn't list the names of students as authors, Rubin offered to withdraw it. The editor declined her offer and the article appeared with the students' names intact.

 

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† Women had previously not been welcome at either Mount Palomar or its nearby Carnegie Institution sibling, Mount Wilson, ostensibly because the observatories didn't have facilities for both sexes. "This," the astronomer Olin Eggen grandly announced to Rubin on her first tour of Mount Palomar, throwing open a door, "is the famous toilet."

 

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* Between her visit to Burke's office in December 1964 and her first day of work on April 1, 1965, Burke took the lunchtime phone call in which he directed Arno Penzias at Bell Labs to Bob Dicke at Princeton.

 

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* The name the Physics Department in Princeton favored, from a suggestion by John Archibald Wheeler.

 

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* The astrophysicist wrote a note of apology to Peebles that evening.

 

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* Later reduced by other astronomers to fifty times—but still...

 

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* In a 1969 paper that he adapted from a talk he'd given two years earlier, Peebles mentioned that the density of matter in galaxies "could be augmented by dark matter"—perhaps the first use of the term since Zwicky. It was, however, an anomalous usage; Peebles otherwise adopted the industry standard "missing mass."

 

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* Supernovae receive alphabetical labels based on the order of discovery within a year, first uppercase once through the alphabet (A, B, C ... X, Y, Z), then back to the beginning of the alphabet but lowercase and doubling up (aa ... az, ba ... bz).

 

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* Quotations from e-mails throughout the book preserve the original spelling, capitalization, and punctuation.

 

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* Their italics.

 

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* Guth, the son of a New Jersey grocer-turned-dry-cleaner who always seemed on the verge of going out of business, was partial to economic considerations. His insight had possibly not only saved cosmology but salvaged a career that was already on its fourth postdoctoral fellowship.

 

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* Who by now realized that inflation would explain why his 1977 U-2 experiment might have failed to find the rotation of the universe: The universe as a whole might indeed be rotating, but we wouldn't be able to detect the effect in our little inflationary bubble.

 

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* Actually, gravity is the weakest of the four forces. But "It's not the strong nuclear, it's jealousy" doesn't really land, as they say in standup.

 

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† A poke in the eye, or at least a joke: The other option was the Astrophysical Journal, but the High-z team wanted to underscore that they were doing astronomy.

 

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* Checking into a local hotel on a previous visit, I asked the desk clerk where I could find the headquarters for the Hubble Space Telescope. He disappeared into a back room to confer with a supervisor, then returned to the counter. "The Hubble Space Telescope is"—he paused, and pointed—"up there."

 

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* And therefore also said nothing about a value of omega for the total amount of matter. So if you wanted a flat, omega-equals-1, inflationary universe, the number 0.1 for the ratio of baryonic matter to critical density wasn't particularly troubling. The ratio of total density—baryonic and non-baryonic matter—to the critical density could still be equal to or even greater than 1.

 

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* The acronym preceded, and inspired, MACHO.

 

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* !

 

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* Currents that move around the vertical axis.

 

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* In contrast, Mount Washington, New Hampshire, at an elevation 3,000 feet lower than the South Pole, long held the record for highest wind measured at the surface of the Earth: 231 mph.

 

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* More precisely, Einstein argued that this was the logic physicists had already been following; they just didn't know it or, in some cases, including that of Einstein early in his career, refused to acknowledge it.

 

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* Or "N*** Prize," as some scientists, including Kirshner, often prefer to write it; apparently science can banish medieval superstition only so much.

 

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* For his part, Petit recalled sitting at his desk the day his article ran and looking at other newspapers and media outlets to see how they had covered the big news, finding nothing, and thinking, "What the fuck."

 

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* Some of the citations to Finkbeiner refer to unpublished information from her notes and interviews. The author gives special thanks for this extraordinary courtesy.