The Story of Earth: How Life and Rocks Co-Evolved

 Dr. Robert Hazen, Carnegie Institution for Science, Geophysical Laboratory:

The story of Earth is a 4.5-billion-year saga of dramatic transformations, driven by physical, chemical, and—based on a fascinating growing body of evidence—biological processes. The co-evolution of life and rocks, the new paradigm that frames this lecture, unfolds in an irreversible sequence of evolutionary stages. Each stage re-sculpted our planet’s surface, each introduced new planetary processes and phenomena, and each inexorably paved the way for the next. This grand and intertwined tale of Earth’s living and non-living spheres is only now coming into focus. Sequential changes of terrestrial planets and moons are best preserved in their rich mineralogical record. “Mineral evolution,” the study of our planet’s diversifying near-surface environment, began with a dozen different mineral species that formed in the cooling envelopes of exploding stars. Dust and gas from those stars clumped together to form our stellar nebula, the nebula formed the Sun and countless planetesimals, and alteration of planetesimals by water and heat resulted in the approximately 250 minerals found today in meteorites that fall to Earth. Following Earth’s growth and separation into the core, mantle, and crust, mineral evolution progressed by a sequence of chemical and physical processes, which led to perhaps 1500 mineral species. According to some origin-of-life scenarios, a planet must evolve through at least some of these stages of chemical processing as a prerequisite for life. Once life emerged, mineralogy and biology co-evolved, as changes in the chemistry of oceans and atmosphere dramatically increased Earth’s mineral diversity to the almost 5000 species known today.

The Concept of Mass with Jim Baggott

Interesting talk by Jimm Baggott on his latest book “Mass: The quest to understand matter from Greek atoms to quantum fields”. In this Royal Institution Lecture Jimm Baggott tries to answer questions like: Do elementary particles have mass? Does the Higg’s boson exist? 

Q&A: The Concept of Mass – with Jim Baggott

Thorium to light up the world : Srikumar Banerjee

This talk was given at a local TEDx event, produced independently of the TED Conferences. Twenty percent of the world’s population have no access to electricity. As people’s aspirations for a better quality of life increases, the demand for energy will also rise. Finding efficient resources that can sustain humanity’s needs is a challenge, especially resources that will maintain the balance in the environment and reduce the possibility of climate change. Srikumar Banerjee presents the advantages of thorium as a cleaner and more sustainable energy source.

Srikumar Banerjee, nuclear scientist and metallurgical engineer, is the Indian Department of Atomic Energy’s Chair Professor at Bhabha Atomic Research Centre. Homi J. Bhabha, after whom the Centre is named, started India’s three-stage nuclear power programme in the 50s. It is one of the best-known efforts to develop thorium-based nuclear power, thorium having greater safety benefits, absence of non-fertile isotopes and higher occurrence and availability. Banerjee’s work provides the basis for analysing the microstructural evolution and radiation stability of structural materials in nuclear reactors.

Richard Feynman’s Story of Particle Physics

A 40 minute audio recording, restored with visual aids and diagrams, given by the legendary physicist and educator Richard Feynman on the history and development of the search for the fundamental structure of matter, from atomic physics to elementary particle physics.
The story of how humanity’s knowledge of matter, from the Periodic Table to the Standard Model of Particle Physics, developed is a very interesting one and shows that once we think we have found simplicity in physics, more complicated and unexpected phenomena and patterns occur again at a deeper level as nature does not give up its secrets so easily and never seems to let us get too complacent in our assumed mastery of a particular field. This has of course generated more and more discoveries and technological breakthroughs in their wake, accelerating our knowledge of matter and energy and increasing our power to manipulate it.

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