Problem: Supergirl is a fictional superhero appearing in American comic books published by DC Comics. The character was created by writer Otto Binder and designed by artist Al Plastino. Supergirl first appeared in a story published in Action Comics #252 (May 1959) titled "The Supergirl from Krypton". Kara Zor-El is the biological cousin of Kal-El (Superman).

Summer Glau voices the post-Crisis version of Kara Zor-El in Superman/Batman: Apocalypse, which is based on the Superman/Batman storyline "The Supergirl from Krypton." Despite this, it was confirmed by director Lauren Montgomery that Supergirl's name was removed from the title due to the much slower sales of the previous Wonder Woman animated movie, and the character was not permitted to appear on the cover in her trademark outfit. In the movie, Kara arrives on Earth in a rocket and is discovered by Batman and Superman. After living amongst the human race and receiving training from the Amazons, Kara is kidnapped by Darkseid and brainwashed into becoming one of his Female Furies. She is ultimately rescued by her cousin, and returns to Earth. After arriving back at the Kent home, Kara and Clark are attacked by Darkseid, and a massive battle ensues. Kara nearly defeats Darkseid thanksto her Amazonian training but is overpowered and almost killed. Kara ultimately saves the day by using a Boom Tube to teleport Darkseid into an unknown area of space, where he is shown to be frozen and floating aimlessly. At the film's conclusion, Kara adopts the Supergirl identity and vows to fight injustice alongside her cousin.  Molly Quinn voices Supergirl in Superman: Unbound.  Supergirl appears in Lego DC Comics Super Heroes: Justice League: Cosmic Clash, voiced by Jessica DiCicco.  DC Super Hero Girls or DC Superhero Girls (in various countries) is an American super hero action figure franchise created by DC Comics (a subsidiary of Time Warner) and Mattel that launched in the third quarter of 2015. The franchise was announced in April 2015. The range is to include books from Random House, Lego tie-ins and action figures from Mattel. The website was launched in early July 2015. Characters featured at launch were Wonder Woman, Batgirl, Harley Quinn, Poison Ivy, Katana, and Bumblebee. Other characters including Hal Jordan, Barry Allen, Star Sapphire, Beast Boy, Cheetah, Hawkgirl and Catwoman also appear. Amanda Waller is featured as the principal of the series' setting Super Hero High. Many other DC Comics Heroes and Villains appear in the background as cameos. The story is about at Super Hero High School, well-known DC heroes attend classes and deal with all the awkwardness of growing up (with the added stress of having superpowers). Supergirl was voiced by Anais Fairweather. A movie DC Super Hero Girls: Hero of the Year based on the series, was released in 2016.

When did Supergirl first appear in animation?

Answer with quotes: A movie DC Super Hero Girls: Hero of the Year based on the series, was released in 2016.

Question:
Andrei Dmitrievich Sakharov (Russian: Andrei Dmitrievich Sakharov; 21 May 1921 - 14 December 1989) was a Russian nuclear physicist, dissident, and activist for disarmament, peace and human rights. He became renowned as the designer of the Soviet Union's RDS-37, a codename for Soviet development of thermonuclear weapons. Sakharov later became an advocate of civil liberties and civil reforms in the Soviet Union, for which he faced state persecution; these efforts earned him the Nobel Peace Prize in 1975.
After 1965 Sakharov returned to fundamental science and began working on particle physics and physical cosmology.  He mainly tried to explain the baryon asymmetry of the universe; in that regard, he was the first to propose proton decay and to consider CPT-symmetric events occurring before the Big Bang:  We can visualize that neutral spinless maximons (or photons) are produced at t < 0 from contracting matter having an excess of antiquarks, that they pass "one through the other" at the instant t = 0 when the density is infinite, and decay with an excess of quarks when t > 0, realizing total CPT symmetry of the universe. All the phenomena at t < 0 are assumed in this hypothesis to be CPT reflections of the phenomena at t > 0.  Sakharov was the first scientist to introduce twin universes he called "sheets". He achieved a complete CPT symmetry since the second sheet is populated by invisible "shadow matter" which is antimatter (C-symmetry) because of an opposite CP-violation there, and the two sheets are mirror of each other both in space (P-symmetry) and time (T-symmetry) through the same initial gravitational singularity.  In his first model the two universes did not interact, except via local matter accumulation whose density and pressure become high enough to connect the two sheets through a bridge without spacetime between them, but with a continuity of geodesics beyond the Schwarzschild radius with no singularity, allowing an exchange of matter between the two conjugated sheets, based on an idea after Igor Dmitriyevich Novikov. Novikov called such singularities a collapse and an anticollapse, which are an alternative to the couple black hole and white hole in the wormhole model. Sakharov also proposed the idea of induced gravity as an alternative theory of quantum gravity.
Answer this question using a quote from the text above:

What happen in the 70s

Answer:
Sakharov was the first scientist to introduce twin universes he called "sheets".