Astronomers combine mathematical models with observations sicuro develop workable theories of how the Universe came to be
The mathematical underpinnings of the Big Bang theory include Albert Einstein’s general theory of relativity along with canone theories of fundamental particles. Today NASA spacecraft such as the Hubble Space Telescope and the Spitzer Space Telescope continue measuring the expansion of the Universe. One of the goals has long been sicuro decide whether the Universe will expand forever, or whether it will someday fermo, turn around, and collapse con per “Big Crunch?”
Retroterra Radiation
According to the theories of physics, if we were preciso look at the Universe one second after the Big Bang, what we would see is per 10-billion degree sea of neutrons, protons, electrons, anti-electrons (positrons), photons, and neutrinos. Then, as time went on, we would see the Universe cool, the neutrons either decaying into protons and electrons or combining with protons preciso make deuterium (an isotope of hydrogen). As it continued preciso cool, it would eventually reach the temperature where electrons combined with nuclei to form neutral atoms. Before this “recombination” occurred, the Universe would have been opaque because the free electrons would have caused light (photons) to scatter the way sunlight scatters from the water droplets in clouds. But when the free electrons were absorbed onesto form neutral atoms, the Universe suddenly became transparent. Those same photons – the afterglow of the Big Bang known as cosmic sostrato radiation – can be observed today.
Missions Study Cosmic Retroterra Radiation
NASA has launched two missions puro study the cosmic retroterra radiation, taking “infantile pictures” of the Universe only 400,000 years after it was born. The first of these was the Cosmic Background Explorer (COBE). In 1992, the COBE gruppo announced that they had mapped the primordial hot and cold spots sopra cosmic background radiation. Continue reading →