This article in the on-line magazine The Conversation explains how, beginning with the collision of India with Asia 20 mya, followed by the opening of the Great Rift Valley, the climate and landscape of East Africa changed from flat wet forest to desert, mountainous forest and lakes which appeared and disappeared following a 20,000 Milankovitch-like periodic cycle in climate. According to the authors, the disappearance of these lakes forced the newly emerged Homo Erectus to move out of Africa to find habitable land 1.8 mya.
Earth is unique in several important ways:
- It is the only planet where life is known
- Granite has been discovered nowhere except on Earth
- Granite now forms the continents of Earth
- The first minute fragments of rocks (zircons) were formed inside granite 4.4 bya
- Life appears in the earliest known continental fragments
Robert Hazen of the Carnegie Institution for Science believes this is no co-incidence. He thinks that the origin of life was a geochemical processes that resulted from interactions of oceans, atmosphere, and rocks and minerals.
This theory, and other aspects of the link between early life and plate tectonics, are explored in a BBC podcast broadcast on 3 Jul 2013 (available here). The programme discusses the question of whether life on Earth could help to create granite and hence be the cause of Plate Tectonics.
For more links see the programme’s page
181 scientists have worked on the paper issued on 20 March which, following extensive analysis of the data obtained from the Planck Satellite, have concluded that:
The simplest inflationary models have passed an exacting test with the Planck data
The full text of their paper is available from:
The Planck space mission has released the most accurate and detailed map ever made of the oldest light in the universe, revealing new information about its age, contents and origins.
Planck is a European Space Agency mission. NASA contributed mission-enabling technology for both of Planck’s science instruments, and U.S., European and Canadian scientists work together to analyze the Planck data.
The map results suggest the universe is expanding more slowly than scientists thought, and is 13.8 billion years old, 100 million years older than previous estimates. The data also show there is less dark energy and more matter, both normal and dark matter, in the universe than previously known. Dark matter is an invisible substance that can only be seen through the effects of its gravity, while dark energy is pushing our universe apart. The nature of both remains mysterious.
It looks very much like we have “a” Higgs boson
No more Higgs-like, Higgs-ish or even Higgsy boson. The CMS and ATLAS collaborations, the two large experiments operating at the Large Hadron Collider (LHC) at CERN, have now gathered sufficient evidence to say that the new boson discovered last summer is almost certainly “a” Higgs boson. Note that we are going to call it “a” Higgs boson and not “the” Higgs boson since we still need more data to determine what type of Higgs boson we have found. But all the analysis conducted so far strongly indicates that we are indeed dealing with a type of Higgs boson.
via Quantum Diaries.
NASA will host a news conference at 8 a.m. PDT (11 a.m. EDT) Thursday, March 21, to discuss the first cosmology results from Planck, a European Space Agency mission with significant NASA participation.
The briefing will be held at NASA Headquarters in Washington. It will be broadcast live on NASA Television and streamed on the agency’s website.
Planck launched into space in 2009 and has been scanning the skies ever since, mapping cosmic microwave background, or the afterglow, of the big bang that created our universe more than 13 billion years ago.
The briefing participants are:
– Paul Hertz, director of astrophysics, NASA, Washington
– Charles Lawrence, U.S. Planck project scientist, NASA’s Jet Propulsion Laboratory (JPL), Pasadena, Calif.
– Martin White, U.S. Planck scientist, University of California, Berkeley, Calif.
– Krzysztof Gorski, U.S. Planck scientist, JPL
– Marc Kamionkowski, professor of physics and astronomy, John Hopkins University, Baltimore, Md.
Questions may be submitted via Twitter to #AskNASA.
You live in the universe, but do you really understand what the universe is like, where you are within it, or how you got here?
If you can show that you understand the basic facts about where you are and how you came to be here then you can become a Citizen of the Universe and receive your very own badge, similar to the one shown here, with your name and city (or any other information you desire) and your Grade.
You can then use your Citizen’s badge on your email or social network page.
To apply for your badge, visit Citizen of the Universe.
One Day Universe on 21 September 2013 will be a 13.7-hour celebration of science from the Big Bang to the Anthropocene, one hour for each billion years of history. It will involve over 20 speakers presenting Big History to an anticipated audience of 700 at a cost of each of almost $1000. It will take place in the Liberty Science Center, Jersey City.
The day will be organized in 5 sessions:
Beginning with the Big Bang, this segment will address the development of the early Universe, the Standard Model, unanswered cosmological questions, and how we have come to understand our own place in this enormously fascinating Universe.
Physicists, chemists and biologists will discuss the evolution of matter from the first subatomic particles to the emergence of life. These experts will explain the proceses from which complex chemicals emerged and how those chemicals gave rise to life.
Geologists will discuss the intricate processes and systems that are constantly reshaping the Earth and its biosphere. These presenters will reflect on how the Earth was formed and how its geological processes have contributed to the evolution of life.
This segment will address human evolution and its relationship with the studies of anthropology, philosophy, psychology, economics, sociology, religion and more. Central themes include collective learning, agriculture, social networks, and more.
A newly-coined term, the Anthropocene refers to a geological period characterized by a human-dominated environment. This segment will address the challenges of the 21st century in light of this emerging reality of pervasive human influence.
Little Big Histories will be interspersed throughout the day, interdisciplinary, multi-dimensional segments will explore common themes like: water, energy, food, fashion, economics, alcohol, architecture and more!
A number of ancillary projects are also planned in cooperation with corporate sponsors.
The cost of the event is $995 (early registration discount of $200 before 15 March 2013). The fee includes all meals, refreshments, receptions, local transportation, and more for the 14-hour program. A number of faculty and student stipends will be available. All attendees must fill out a brief application before paying registration fees.
Alternatively you can watch internet livestream for $10. Viewers can also participate via an interactive portal.
The strategy is to replicate One Day Universe as an annual celebration of Big History, the discovery of which is perhaps the most significant accomplishment of human civilization. One Day Universe is produced by Metanexus in partnership with Liberty Science Center.
Sixty years after James Watson and Francis Crick established that DNA forms a double helix, a quadruple-stranded DNA helix has turned up.
Quadruple helices that intertwine four, rather than two, DNA strands had been made in the laboratory, but were regarded as curiosities as there was no evidence that they existed in nature. Now, they have been identified in a range of human cancer cells.
The four-stranded packages of DNA, dubbed G-quadruplexes, are formed by the interaction of four guanine bases that together form a square. They appear to be transitory structures, and were most abundant when cells were poised to divide. They appeared in the core of chromosomes and also in telomeres, the caps on the tips of chromosomes that protect them from damage.
Because cancer cells divide so rapidly, and often have defects in their telomeres, the quadruple helix might be a feature unique to cancer cells. If so, any treatments that target them will not harm healthy cells.
“I hope our discovery challenges the dogma that we really understand DNA structure because Watson and Crick solved it in 1953,” says Shankar Balasubramanian of the University of Cambridge, UK.
Animals evolved gradually, from the lowly sponge to the menagerie of tentacled, winged and brainy creatures that inhabit Earth today. This idea makes such intuitive sense that biologists are now stunned by genome-sequencing data suggesting that the sponges were preceded by complex marine predators called comb jellies.