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Sep 30, 2015,10:51am EDT
Updated Sep 30, 2015, 03:56pm EDT
This article is more than 9 years old.
The dominant science news story of the moment is the latest discovery of water on Mars, which is fortuitously timed to coincide with the release of the movie The Martian this week. A little over a month from now, the big story will be the 100th anniversary of Einstein's completion of General Relativity. These might not seem like they have much to do with each other, but in fact, Mars missions have a closer connection to relativity than you might think.
John Grunsfeld, associate administrator at NASA's Science Mission Directorate, speaks with... [+]
General relativity famously involves the warping of space and time by gravity, and it was observations during a 1919 eclipse showing the bending of light that catapulted Einstein to fame. Stars near the disk of the Sun had their apparent position (relative to stars farther from the Sun) shifted slightly, as the rays that passed close to the Sun were deflected by its warping of spacetime. The measured deflection agreed nicely with Einstein's prediction, and the rest is one of the great hyperbolic headlines is history.
Of course, relativity makes lots of predictions about what should happen near a massive object like the Sun, and the bending of starlight only tests one. Another thing that ought to happen is a slight "stretching" of space-- which is why discussions of relativity almost always include stretched rubber sheets. The distance between two points in space will be slightly longer along a path that passes close to the Sun than along one that never goes near it.
Embedding diagrams showing the spacetime distortion in the vicinity of a massive object, and the... [+]
This is kind of a difficult thing to get your head around, but like everything else, it comes back to the fact that keeping the laws of physics consistent regardless of how you're moving requires the mixing of space and time. In special relativity, what one observer sees as purely a distance in space, somebody moving at constant speed relative to them will see as a mix of space and time-- the position of the two endpoints is measured at two slightly different times. This is the root of most of the "paradoxes" of relativity. The exact mix of space and time depends on the speed of the observer, and the equations of relativity tell you how to calculate that.
General relativity tells us that the exact mix of space and time for a particular measurement also depends on the presence of gravity. What an observer near the Sun sees as purely a distance in space will look, from far away, like a mix of space and time. This mixing changes the result for distance measurements.
The Viking spacecraft arrived at Mars in the summer of 1976 and passed through superior conjunction on November 25, as Mars passed directly behind the Sun as seen from Earth. This provided researchers the opportunity to use the spacecraft in an experiment to test general relativity.
This image shows the surface of Mars looking across the Viking 2 Lander. (Source: NASA)
After completing the primary missions, the Viking continuation mission objectives included a radio science solar conjunction relativity experiment. Scientists began an experiment that used the landers and orbiters as transponders, sending radio signals to the lander on Mars and instructing the lander to the return signals. The round-trip travel times of the radio signals going from Earth to the Viking landers and orbiters were measured.
Using dual-band, one-way ranging allowed estimation of the contribution of the solar-corona plasma to the echo delays obtained from ranging to the spacecraft.
The data confirmed the Shapiro time delay effect, which states that radar signals passing near a massive object take slightly longer to travel to a target and longer to return than they would if the mass of the object were not present.
Published by Albert Einstein in 1916, the general theory of relativity predicted that the round-trip or echo delays of light signals traveling between the Earth and Mars would be increased by the direct effect of solar gravity. The theory included gravitational time dilation, where time passes differently in regions of different gravitational potential.
NASA has continued to test general relativity, most recently with the Cassini space probe (see a NASA artist rending of its testing at right) and Gravity Probe B, which also confirmed the theory.
For more moments in tech history, see this blog. EDN strives to be historically accurate with these postings. Should you see an error, please notify us.
Editor’s note: This article was originally posted on November 25, 2013 and edited on November 25, 2019.
por II Shapiro · 1977 · Mencionado por 117 — Measurements of the round-trip time of flight of radio signals transmitted from the earth to the Viking spacecraft are being analyzed to test the predictions ...
22 oct 2024 — The predicted general relativistic effect of solar gravity on the round-trip times of electromagnetic signals traveling between earth and Mars ...
por RD Reasenberg · 1979 · Mencionado por 742 — Abstract. Analysis of 14 months of data obtained from radio ranging to the Viking spacecraft verified, to an estimated accuracy of 0.1%, the prediction of ...
por RD Reasenberg · 1982 · Mencionado por 4 — The predicted general relativistic effect of solar gravity on the round-trip times of electromagnetic signals traveling between Earth and Mars has been ...
por RD Reasenberg · 1979 · Mencionado por 742 — Printed in U.S.A. VIKING RELATIVITY EXPERIMENT: VERIFICATION OF SIGNAL RETARDATION BY SOLAR GRAVITY R. D. REASENBERG, I. I. SHAPIRO, P. E. MACNEIL, AND ...
21 nov 2024 — Measurements of the round-trip time of flight of radio signals transmitted from the earth to the Viking spacecraft are being analyzed to test ...
por RD Reasenberg · 1982 · Mencionado por 4 — New results from the Viking relativity experiment The predicted general relativistic effect of solar gravity on the round-trip times of electromagnetic ...
por II Shapiro · 1977 · Mencionado por 117 — Abstract. Measurements of the round-trip time of flight of radio signals transmitted from the earth to the Viking spacecraft are being analyzed ...
25 nov 1976 — The theory included gravitational time dilation, where time passes differently in regions of different gravitational potential. NASA has ...
Madeleine Albright: First Woman Secretary of State
February 26, 2023
"I, Madeleine Albright, do solemnly swear that I will support and defend the Constitute of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; that I take the obligation freely, without any mental reservation or purpose of evasion; and that I will well and faithfully discharge the duties of the office on which I am about to enter. So help me God."
With those words, Madeleine Albright, an immigrant, became the 64th U.S. Secretary of State, the first time in American history a woman would head the State Department. She would be charged with working with then President Bill Clinton and other government officials to plan the way the United States acts and communicates with other nations, its foreign policy.
The first Secretary of State was Thomas Jefferson, appointed by President George Washington in 1789. The Secretary of State is the fourth in order of succession to the presidency after the vice president, the speaker of the House, and the president pro tempore. Because she was not born in the U.S., Madeleine Albright was not eligible to become president.
The journey to her confirmation as Secretary of States spanned two continents and 20 years of government service. She earned a master's degree and a Ph.D. in public law and government, served as professor of foreign policy before being appointed American ambassador to the U.N.
Madeleine Albright was born Marie Jana Korbelova in Prague, Czechoslovakia on May 15, 1937, the oldest of three children of Josef and Anna (Speeglova) Korbel.
Her father, Josef, was a diplomat with the Czechoslovakian government before the outbreak of World War II. When he was just five years old, Archduke Franz Ferdinand, the heir to Austro-Hungarian throne and his wife Sophie, the Duchess of Hohenberg, were assassinated by Gavrilo Princip. This sets off a series of cascading declarations that lead to World War I, which ended up in the death of more than 8.5 million soldiers, and as many as 12.5 million civilians in the four years of battle. At the age of 9, he was living in a free country for the first time.
Since wars begin in the minds of men, it is in the minds of men that the defenses of peace must be constructed.
Struggles which shaped Czechoslovakia include Hitler and the Nazi party taking control of Germany in 1933. In 1938, Britain, Italy and France made a treaty, the Munich Agreement, which allowed Germany to occupy a Czech territory in which more than half of the population was German. This granted Germany 38% of Czechoslovakia's land.
Madeleine Albright was two at the time and living in Belgrade. Hitler soon took complete control of the country. German tanks rolled into Prague on March 15, 1939. Targeted by the Gestapo, the family went into hiding before finally granted permission to leave the country.
The Korbels arrived in New York in late 1948.
Albright first became involved in politics while campaigning for Edmund Muskie during his 1968 run for presidency. She lived foreign policy as a refugee from oppression, studied and taught it as a professor, nurtured its development as an advisor to politicians and diplomats.
Her job at the United Nations, the term coined by Franklin D. Roosevelt, originated after World War II, when nations of the world had a strong desire to never again engage in a war of such proportions.
Among the United Nations’ pledges are to "save humanity from the scourge of war," "protect human right and the equal rights of men and women and of nations large and small," "promote justice and respect for international law," and "promote social progress, better standards of life, and freedom."
Before her confirmation hearing as U.S. representative to the U.N. on January 21, 1993... Albright admitted in her opening statement that while the United Nations is important, it also has many problems. "The United Nations remains bogged down by an unwieldly and inefficiently administered staff, overlapping responsibilities, and a financial crisis."
Under President Bill Clinton, she became the country’s representative to the United Nations (1993-97) and secretary of state (1997-2001), making her the highest-ranking woman in the history of American government at the time.
In 2001, she founded what is now the Albright Stonebridge Group, an international consulting firm, and in 2005 the Albright Capital Management, focusing on emerging markets.
Madeleine Albright, a champion of women’s rights internationally and a vocal advocate for Democratic women in U.S. politics, died March 23, 2022 at the age of 84.
"My most joyful experience was marriage and raising a family. My most painful was divorce and finding a way to move on and up. The most riveting was learning about my Jewish heritage. The saddest was discovering that my grandparents died in concentration camps."
You know, they say in foreign policy business that we aren't to let ourselves be influenced by emotions, but how can forget that murdered children are not emotions, but that they are human beings whose potential contributions are forever lost.
Like this post? Stop by and read “Francis Perkins: The First Woman to Sit in the Cabinet of the United States.” Frances Perkins was the secretary of labor under President Franklin Roosevelt, the first female cabinet secretary, the longest serving secretary of labor and one of the architects of Roosevelt’s New Deal economic policies.
Madeleine Albright, the first woman to serve as the U.S. secretary of state, died Wednesday, her family said in a statement.
She was 84.
Albright died of cancer, her family said, adding that she was "surrounded by family and friends" at the time.
"We have lost a loving mother, grandmother, sister, aunt and friend," the statement said, as well as a "tireless champion of democracy and human rights."
President Joe Biden remembered Albright as “a force for goodness, grace, and decency—and for freedom.” She “defied convention and broke barriers again and again,” Biden said in a statement.
He ordered flags to be flown at half-mast in her honor until March 27.
Then-President Bill Clinton named Albright the U.S. ambassador to the United Nations shortly after he was inaugurated in 1993, and nominated her as the secretary of state three years later. She was confirmed in 1997 by a vote of 99-0. At the time, she was the highest-ranking woman in the history of the U.S. government.
President Bill Clinton with Secretary of State Madeleine Albright in 1999.Cynthia Johnson / Getty Images file
Albright served in the post for four years, actively promoting the expansion of NATO and military intervention in Kosovo.
On Wednesday, Clinton remembered Albright as "an extraordinary human being."
"Because she knew firsthand that America's policy decisions had the power to make a difference in people's lives around the world, she saw her jobs as both an obligation and an opportunity. And she made the most of them in advancing peace, security and shared prosperity," the former president said, adding he last spoke to Albright two weeks ago.
So remarkable was the fighting to the east of Atlanta on July 22, 1864, that it earned its place as the only engagement of the Civil War to be widely referred to by the date of its occurrence. Also known as the Battle of Atlanta, this was the largest engagement of the four-month-long Atlanta Campaign for control of the city and the region. Although Confederate commander John Bell Hood’s forces flanked William T. Sherman’s line and were able to crush the end of it, they could go no further. On July 22, 1864, the Confederates came closer to achieving a major tactical victory than on any other day of the Atlanta Campaign.
Prolific Civil War historian Earl Hess’s July 22 is a thorough study of all aspects of the most prominent battle of the Civil War’s Atlanta Campaign. Based on exhaustive research in primary sources, Hess has crafted a unique and compelling study of not only the tactics and strategy associated with the engagement but also of the personal experiences of Union and Confederate soldiers and the effects the battle had on them. This book offers fresh insights to the significance that the Battle of July 22 held for the larger Atlanta campaign and the entire Union war effort. Hess also provides a thorough discussion of the death of Maj.
La iglesia de Saint-Laurent de París es una iglesia fundada en el siglo XV localizada en el X Distrito, en el antiguo recinto de Saint-Laurent, 119, rue du Faubourg-Saint-Martin, 68, boulevard de Strasbourg y 68, boulevard de Magenta.
La iglesia está construida sobre el eje norte-sur de París que conecta Senlis y Orleans y que fue trazado por los romanos durante la mitad del siglo ii a. C., la actual rue du Faubourg-Saint-Martin, rue Saint-Martin, rue Saint-Jacques y rue du Faubourg-Saint-Jacques.
Después de las clasificaciones y registros iniciales como monumentos históricos, el 1 de febrero de 1945 (79 años), la iglesia fue enteramente clasificada por decreto del 16 de diciembre de 2016.1
Principale rue du faubourg formé au-delà de la porte Saint-Martin.
Histoire de la rue
Anciennement rue du Faubourg Saint-Martin, entre le boulevard Saint-Denis et la rue du Chteau d'Eau, et rue du Faubourg Saint-Laurent pour le surplus. Pendant la Révolution, ces deux parties ont été réunies sous le nom de rue du Faubourg du Nord.
Larg. : 18 m (moindre), depuis l'origine de la voie jusqu'à la rue du 8 Mai 1945 : 30 m, entre les rues du 8 Mai 1945 et du Chteau Landon ; 20 m, le surplus.
Tema anterior
![John Grunsfeld, associate administrator at NASA's Science Mission Directorate, speaks with... [+] colleagues at a press conference where NASA announced new findings that provide the 'strongest evidence yet' of salty liquid water currently existing on Mars. (Photo by Win McNamee/Getty Images)](https://imageio.forbes.com/specials-images/imageserve/490420754/640x0.jpg?format=jpg&width=1440)
President Bill Clinton with Secretary of State Madeleine Albright in 1999.Cynthia Johnson / Getty Images file
