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Pluto Update Note about Pluto Earlier versions of the Voyages Through Time curriculum contained information about Pluto when it was classified as a planet. Pluto has since been declassified from a planet and is now known as a "dwarf planet." The Voyages Through Time curriculum has been updated to reflect this change. In the modules Planetary Evolution and Origin of Life, the Planetary Systems Database as been updated so the content reflects the change in Pluto's classification, as well as several handouts:
Also included is a newly updated version of the Planetary Systems Database, featured in lessons in Planetary Evolution and Origin of Life.
If you purchased the modules after February 4th, 2011 your package will contain these revised CD-ROMs. If you have already purchased some or all of the modules in the curriculum and received your CD-ROMs, you may wish to download revised versions of the activities in your module that are affected by this change. Those revised versions are provided in the table below. Module 2: Planetary Evolution
Age of the Universe VTT Update A Note about the Age of the Universe The first edition of the Voyages Through Time curriculum assumed the age of the universe to be 15 billion years +/- a few billion years. The activities in each module were built around that value. Recent observations, however, indicate the universe may be slightly younger. The four lines of evidence supporting the age of the universe are:
The booklet, An Ancient Universe: How Astronomers Know the Vast Scale of Cosmic Time, is a guide for teachers, students and the public. The booklet was written by a subcommittee of the American Astronomical Society's Astronomy Education Board, and published in 2004 by the American Astronomical Society with the Astronomical Society of the Pacific. A PDF version is available, and hard copies may be requested. UCLA Professor Edwin L. (Ned) Wright's site includes calculations of the age of the elements, star clusters and white dwarfs. The Wilkinson Microwave Anisotropy Probe (WMAP) site illustrates the slight — very slight — temperature fluctuations in the radiant heat leftover from the Big Bang. The Voyages Through Time curriculum has been updated with the newest estimate of 13.7 billion years for the age of the universe. If you purchased the modules after May 1st, 2005, your package will contain these revised CD-ROMs. If you have already purchased some or all of the modules in the curriculum and received your CD-ROMs, you may wish to download revised versions of the activities in your module that are affected by this new estimate. Those revised versions are provided in the table below. Note that when you click on a link for downloading, you are asked for a username and password. The links are password protected, so that your students will not have access to the answer keys. To learn the username and password, insert any Voyages Through Time Teacher CD into your CD-ROM drive, and open the application. Click on the "Getting Started" button. The Username you need to enter is the second-to-last word on that page. The Password you need to enter is the last word on that page (without the period.) Module 1: Cosmic Evolution
Module 2: Planetary Evolution
Module 3: Origin of Life
Module 4: Evolution of Life
Module 5: Hominid Evolution
Module 6: Evolution of Technology
More information about the current estimate From a NASA press release dated April 24, 2002: Astronomers liken the new age-dating observation to "estimating how long ago a campfire was burning by measuring the temperature of the smoldering coals. In this case, the 'coals' are white dwarf stars, the burned-out remnants of the earliest stars that formed in our galaxy. Hot, dense spheres of carbon 'ash' left behind by the nuclear furnaces inside long-dead stars, white dwarfs cool down at a predictable rate - the older the star, the cooler it is, making it a perfect 'clock' that has been ticking for almost as long as the universe has existed." For more on white dwarf stars, see the Science Background section for "Lesson 6: The Evolution of Stars", in the Cosmic Evolution module. "As white dwarfs cool, they grow fainter, and this required that Hubble take many snapshots of the ancient globular star cluster M4 that contains the white dwarfs. The observations amounted to nearly eight days of exposure time over a 67-day period. This allowed for ever fainter dwarfs to become visible, until at last the coolest - and oldest - dwarfs were seen. These stars are so dim, they have less than one-billionth the apparent brightness of the faintest stars that can be seen with the naked eye." "Globular clusters are the first pioneer settlers of the Milky Way Galaxy. Many coalesced to build the hub of our galaxy and formed billions of years before the appearance of the Milky Way's magnificent pinwheel disk. Today 150 globular clusters survive in a spherical "halo" surrounding the galaxy. The globular cluster M4 was selected because it is nearest to Earth (7,000 light years away), so the intrinsically dimmest white dwarfs would still be bright enough to be seen by Hubble." |
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