THE COSMIC DAWN - How the universe gave birth to the first stars. HD

Cosmic Dawn Script There was once a time when there was no light at all, no sun, stars or galaxies lighting up the vastness of space. But then, there was the spark of light and the first stars were born. This time is called The Cosmic Dawn. How did the universe create light? When did the first light appear? How do we know all of this, when it happened so long ago? -- The universe is roughly 14 billion years old. After the hot, dense big bang the universe was dark and cold. Filled mainly with hydrogen and some helium atoms. Spread vastly apart floating through space, in a time known as ‘the dark ages’. Over millions of years gravity slowly took effect on these atoms and they started to clump together to form clouds of gas. As gravity was pulling the atoms closer together, the heat generated by this was counteracting gravity, stopping the state getting any denser. Some of the hydrogen atoms would meet to form hydrogen molecules. This is crucial as the hydrogen molecules could absorb small amounts of heat. Letting the gas get slightly cooler, giving gravity the upper hand. In turn enabling denser and hotter environments. After around 180 million years the density and temperature would have got so intense that thermonuclear nuclear fusion was able to take place, providing the engine room for a star to glow. These stars would of been very different to those of present. Essentially only having Hydrogen and Helium to work with, the initial star would have been made up of you guessed it…..Hydrogen and Helium. This original star type would have been up to 100 times bigger and 20 times hotter than our sun. Shining an ultraviolet blue due to the abundance of ultraviolet radiation. The star would be a lot more violent in nature and its lifespan would be very short. Only 3 million years, compared to our sun which is halfway through its life in the billions of years. (4.6 Billion) The nuclear fusion happening at the centre paved the way for new heavier elements to form, that would carry on into the next generation of stars which again created more elements and heavier metals needed to actually produce life! You are literally a combination of stuff made in the core of previous generations of stars!! -- How do we know all of this? The Hydrogen that filled the universe after the big bang was awash with radiation. This radiation is called the Cosmic Microwave Background and can still be observed today through radio waves, helping us paint a picture of our universe. When the first starts were born, the hydrogen surrounding them got excited (took on additional energy) which enabled them to absorb radiation at a specific wavelength (1.4). As the universe has expanded since then, so would this wavelength frequency. The challenge for scientists was to find this faint and specific frequency and see if there was a blip in radiation. A match was made and confirmed the theory. The actual signal though was twice as large as originally expected, which me