When the universe was 380,000 years old, its thermal radiation spectrum consisted mostly of gamma rays with a few x-rays and ultraviolet photons. Over time, as the universe has expanded and cooled down it shifted to wavelengths that are more in tune with human eyes. The cosmic microwave background is one such example of this change in wavelength – when we observe it today at a range of 1mm to 1m wavelengths (microwaves), it appears black because there’s no light left after 380 thousand years for us to see.
The first stars formed when the universe was about 380,000 years old. These were mostly massive and short-lived stars that would quickly explode as supernovae after only tens of millions of years. It’s these explosions that are thought to have seeded populations of heavy elements in space – this means it’s possible that we’re all made up at least partly from those early generations of star formation!
It’s these explosions that are thought to have seeded populations of heavy elements in space – this means it’s possible that we’re all made up at least partly from those early generations of star formation!
Dynamics: The universe was mostly composed of hydrogen and helium when it was 380,000 years old. At the time, there were also other elements present in low quantities such as lithium (Li), beryllium (Be), and some trace amounts of important heavy metals like zinc and iron; allowing for planets like ours to exist over time. These initial stars would quickly explode after only tens of millions(?) of years, with their eventual deaths leading to universal distribution of heavy metals across galaxies. This is one explanation why the universe is made up of mostly hydrogen and helium- it’s because they had already seeded the population of heavy elements in space, meaning that we’re all at least partly from those early generations of star formation!
This article lists some of the major discoveries that were made in order to come up with this conclusion. These include:
measuring temperatures from large samples of galaxies, both nearby and far away -detecting helium spectra at 380,000 years old as opposed to much older or younger ages. When these measurements are taken along with other data, it can be extrapolated that stars must have first appeared when the universe was about 400 million years old (400 mya). This is important information for scientists studying how the universe has evolved over time!
The bright light we see today was created by those early generations of star formation which happened around 400 million years ago; meaning that most elements observed in space exist because of this time.
“The early universe was a much more violent place than it is now when the density of particles was higher and stars were being born at an incredible rate,” said John Wise, assistant research professor in astronomy at UT Austin’s McDonald Observatory. “It appears that galaxies are continuing to grow over time.”
“We know from our observations that there isn’t any new star formation occurring right now [at 380,000 years old],” he added. “So if we extrapolate backward…we would have come up with 800 mya as a point where you wouldn’t see anything but black holes.”
This number agrees nicely with other measurements are taken which suggest that the universe must be about 400 million years old (400 million years old) when density was much higher and star formation and the production of heavy elements were happening at an incredible rate.
“You don’t need to know any physics or astronomy to understand what is going on in this picture,” Smith said, “but just looking at it gives you a sense of how vast the universe must be.”
The photon spectrum also tells astronomers that after 380,000 years old there are no other sources of light besides stars. There are only black holes existing now as well which have been around since (before) before the time when most galaxies formed – about 800 million years ago.
This number agrees nicely with other measurements taken by scientists who suggest that the Universe must be 400 million years old when density was great enough and the conditions right for stars to form.
The universe was 380,000 when it consisted mostly of visible light or radiation.
Its thermal energy spectrum is made up almost entirely of photons in a particular wavelength range at this age which coincides with what we would expect from the Big Bang theory. And as time goes on these wavelengths will have more infrared than they did before because there are no longer any sources of other colors besides galaxies forming after that point so all their emissions were shifted toward shorter wavelengths towards reds and infrareds due to increased expansion rate over time since then.
