The lectures begin at 6:30PM and will last approximately one hour. Doors open to the public at 6:00PM.
We provide informational materials about our research programs and light refreshments. Limited parking is available off Jocelyn and 32nd Streets in our lots, and there is street parking in the area. The campus is a three-block walk from Connecticut Avenue and two blocks south of Military Road.
Lectures Are Free, But Seating is Limited. Skip the registration line by signing up online, click here.
5251 Broad Branch Road, NW, Washington, DC 20015 - Greenewalt Building (PDF of directions)
When: Thursday, 16 April 2016
Title: "The Quest for Room Temperature Superconductivity"
Speaker: Viktor Struzhkin - The superconductivity (zero resistance and expulsion of the magnetic field from the material - Meissner effect) is a quantum phenomenon defying classical understanding. It was discovered by a Dutch scientist named Heike Kamerlingh Onnes in 1911. The explanation didn’t emerge until 1957, when American scientists Bardeen, Cooper, and Shriffer had discovered the role of crystal lattice polarization (dynamic lattice distortions by quanta of lattice vibrations - phonons) and electron pairing (formation of Cooper pairs) in the mechanism of superconductivity. During several decades after the theoretical explanation, the researchers made great efforts to increase the critical temperature by making new superconducting materials. However, the research that was guided by theory was not able to reach critical temperatures above 23 K (twenty three degrees above absolute zero temperature). Many potential applications of superconductivity in electronics, power transmission and storage, maglev trains, etc., were suggested, but low critical temperatures of superconducting state prevented most of them from being practical.
The dominant pessimistic view of 30 K limit on critical temperature was shattered by Bednorz and Muller discovery in 1987 of the high-TC (high critical Temperature) superconductivity in complex copper-based oxides (cuprates), having critical temperatures as high as 133 K. The quest for room temperature superconductivity had begun. The mechanism of high temperature superconductivity is still debated, but nearly everyone agrees that magnetic interactions play a major role in the very high critical parameters of new superconductors. Historically, and practically, the compression of the crystal lattice of superconducting materials has played a major role in tuning and optimizing critical temperatures. The record of TC=164 K (more than half of the room temperature) was reached at a high pressure of 30 GPa (or 300,000 atmospheres) in our laboratory. We have developed highly sensitive techniques capable of detecting superconductivity and related quantum phenomena to very high pressures. These techniques have made possible many fascinating discoveries of new superconductors that reach very high TC in vastly different material families. Our efforts in finding higher critical temperature superconductivity will be summarized and brought to your attention. The chances of finding room temperature superconductors are high, but the experimental challenges are tremendous.
When: Thursday, 14 May 2015
Title: "Alien Worlds and the Origins of Science"
Speaker: Paul Butler - Modern science began with Copernicus speculating that the Earth is a planet and that all the planets orbit the Sun. Bruno followed up by speculating that the Sun is a star, that other stars have planets, and other planets are inhabited by life. For this and other heresies, Bruno was burned at the stake in a public square in Rome in 1600. Astronomy and extrasolar planets were a really hot field at the time.
Over the past 20 years more than a thousand extrasolar planets have been found, first from ground-based precision Doppler surveys, and more recently by the Kepler space mission. We have concentrated on building precise Doppler systems to survey the nearest stars. Our systems at Lick, Keck, AAT, and Magellan have found hundreds of planets, including five of the first six extrasolar planets, the first saturn-mass planet, the first neptune-mass planet, the first terrestrial mass planet, and the first multiple planet systems.
We are focused on surveying the nearest stars with new custom built spectrometers designed to achieve the highest possible Doppler precision: The Planet Finder Spectrometer on the 6.5-m Magellan Telescope, and the Levy spectrometer on the 2.4-m Automated Planet Finding Telescope. These spectrometer will lead to the discovery of many terrestrial mass and potentially habitable planets over the next decade. Within a generation new technology giant telescopes and adaptive optics systems will be able to directly image these systems and begin the detailed search for life.
To support Carnegie Science, please visit: http://carnegiescience.edu/support
When: Thursday, 13 November 2014
Title: "What Are You Breathing? Stable Isotopes in the Atmosphere"
Speaker: Douglas Rumble - Our atmosphere contains only a handful of major gases but many hundreds of minor ones. Each one of these gas species has its own signature stable isotope compostion. Analysis of isotopes makes it possible to trace chemical reactions governing atmospheric chemistry. Isotopic signatures of atmospheric gases are preserved in rocks, under favorable conditions, leaving behind a record of changes in atmospheric chemistry over the past 3 billion years. Watch Doug's lecture here!
When: Thursday, 9 October 2014
Title: "The Geology of Diamonds and Why Yours Is Remarkable!"
Speaker: Steven Shirey - To the geologist, diamonds worn as expensive jewelry are a scientific opportunity of far greater value than just gems. Diamonds are erupted in kimberlite volcanoes and carry within them the deepest, oldest, and most pristine mineral inclusions from the mantle known on Earth. Most of these amazing specimens come from the mantle keels of continents at depths greater than 150km but some derive from greater depths including the mantle transition zone (410-660km) and the top of the lower mantle (>660km). We will explore how diamonds form and what their inclusions tell us about continent formation, mantle circulation and the water content of the mantle.