Notices tagged with otd, page 6

Gravitational waves were first detected by LIGO #OTD in 2015, 100 years after they were predicted by Einstein.

This discovery, announced the following February, marked the beginning of gravitational wave astronomy.

The description of what was discovered and how it happened fits in a short post. It is simultaneously so amazing and so preposterous that some people who hear it will want to spend the rest of their lives understanding how it could be true and what we can learn from it:

Irène Joliot-Curie was born #OTD in 1897.

She was known for her work on radioactivity, and was awarded the 1935 Nobel Prize in Chemistry for demonstrating the artificial radioactivity of stable elements bombarded with alpha particles.

I have a lot of problems with the Nobel Prize's focus on individual accomplishment, and its history of sexism. Still, it's remarkable that there's a family with three prize winners – four if you include the in-laws!

Dr. Mae Jemison, the first Black woman to go into space, headed into orbit on the shuttle Endeavour #OTD in 1992.

In this photo she is being suited up before launch by Sharon McDougle.

Image: NASA

Physicist Gabriele Veneziano, a central figure in the development of string theory, was born #OTD in 1942.

This photo (our coffee cups in the dish rack at the Kavli Institute for Theoretical Physics) is the closest I've come to collaborating with him.

The Voyager 1 space probe was launched from Cape Canaveral #OTD in 1977, a few weeks after Voyager 2.

Now it's the most distant human-made object – about 14.96 billion miles from Earth, racing away from us at 38,000 miles per hour with respect to the Sun.

Images: NASA/KSC/JPL

Teacher and astronaut Christa McAuliffe was born #OTD in 1948. Selected as the first American civilian to go into space, she was one of the seven crew members onboard the Space Shuttle Challenger when it was lost in 1986.

Image: NASA

Karl Jansky invented the field of radio astronomy #OTD in 1932.

During a solar eclipse he saw no change in the faint radio hiss he'd been monitoring, which ruled out the sun as a source. He soon attributed this "star noise" to large ionized gas clouds near the center of the Milky Way.

Guion Stewart Bluford Jr. became the first Black American astronaut to travel into space #OTD in 1983, on the Orbiter Challenger as part of mission STS-8.

Image: NASA

Michael Faraday first demonstrated the phenomenon of electromagnetic induction #OTD in 1831.

He coiled insulated wire around two sides of an iron ring, then observed a brief current in one as he connected the other to a battery.

Image: The Royal Institution, Paul Wilkinson

Geneticist Liane Russell was born #OTD in 1923.

She pioneered the study of mutagenesis and teratogenesis due to radiation, and identified the role of the Y chromosome in sex determination. Her work led to diagnostic x-ray safety standards for women of childbearing age.

Science, the joy of wild places, and civic engagement as a response to fascism – this is one of my favorite threads.

Mathematician Katherine Johnson was born #OTD in 1918.

Her orbital mechanics computations played a vital role in many early NASA missions. Astronaut John Glenn trusted her calculations more than those of his onboard flight computer.

Image: NASA

Depending on your time zone, Voyager 2's closest approach to Neptune was either yesterday (the 24th) or #OTD in 1989. It took place around 4am UTC.

Here's a short thread with some great images captured by the probe, and some proposed cargo for a future mission. #ReturnToNeptune

(Definitely read this one to the end.)

Mathematician Karen Keskulla Uhlenbeck was born #OTD in 1942.

She is known for her work on PDEs, calculus of variations, topology, and gauge theory, and was the second woman (after Emmy Noether!) to give the plenary lecture to the International Congress of Mathematicians.

The Voyager 2 spacecraft launched #OTD in 1977.

It is currently 12.4 billion miles from Earth, hurtling through interstellar space at about 34,400 mph with respect to the sun.

Voyager 2 is so far from Earth that round trip for signals is 36.5 hours.

Only its twin Voyager 1 (which launched a few weeks later, but took a more direct route out of the solar system) is further.

Image: NASA/JPL-Caltech

Margaret Hamilton, a pioneer of software engineering who led NASA's in-flight software team for the Apollo mission, was born #OTD in 1936.

Image: NASA

The physicist Hans Christian Ørsted was born #OTD in 1777.

In 1820 he demonstrated an unexpected connection between electric and magnetic phenomenon, believed by many to be unrelated, initiating the development of the theory of electromagnetism.

This observation started physicists down a path they would follow for the next few hundred years.

Image: Danmarks Tekniske Museum

Engineer and inventor Frances Hugle was born #OTD in 1927.

She pioneered techniques used in microcircuitry fabrication and obtained patents for many of them, including methods for printing circuits and producing semiconducting films.

Image: IEEE

Cell biologist Elaine Diacumakos, who pioneered techniques for inserting material into cells, was born #OTD in 1930.

In 1979, Diacumakos and colleague William Anderson were first to insert a functioning gene into a defective (mouse) cell to correct a genetic defect.

Image: Rockefeller U

Nuclear physicist Leona Woods Marshall Libby was born #OTD in 1919.

She helped direct the development of the Hanford site reactors during the Manhattan Project, was the only woman on Enrico Fermi's Chicago Pile team, and was present when Chicago Pile-1 went critical.

Paul Dirac (1902, discovered the relativistic equation for the wave function of fermions), Ernest Lawrence (1901, invented the cyclotron), and Roger Penrose (1931, developed the global view of spacetime and much of what we know about singularities in GR) were all born #OTD. Pretty good day for physics.