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Like Taylor Swift, Our Universe Has Gone Through Many Different Eras

While Taylor's Eras Tour explores decades of music, our universe’s eras set the stage for life to exist today. By unraveling cosmic history, scientists can investigate how it happened, from the universe’s origin and evolution to its possible fate.

A navy blue rectangle forms the background of an infographic. In the top left corner, it says, “History of the Universe.”  An elongated conical shape spans the width of the image. The smaller end of the horn, beginning at a miniscule point, is on the left side of the image and the wider end is on the right. The outline of the horn quickly expands, tracing out the left end of the horn to be about a quarter of the height of the image. The bell shape gradually grows wider as it approaches the right side of the image. The rightmost side of the horn flares outward like a bell. From the left to the right of the horn are 8 ovals that appear to subdivide it. The first oval contains light blue blobs on a dark blue background. Beneath it, it says, “10^-32 seconds, Inflation, initial expansion.” The second oval contains a light blue fog, blue and white orbs, and short, tightly zig-zagged blue lines. Half the white orbs have plus signs, and half have minus signs on them. Beneath the second oval, it says, “1 microsecond, First Particles, neutrons, protons, and electrons form.” The third oval contains a similar blue fog, but the white and blue orbs are stuck to one another in small clusters with no positive or negative signs. The zig-zagged lines remain. Beneath the third oval, it says, “3 minutes, First Nuclei, helium and hydrogen form.” The fourth oval contains a light blue background with some darker blue speckling on it, like on a fresh brown egg. In front of the background are several small spheres. Each sphere is either surrounded by one or two oval outlines. For the spheres with two ovals, the ovals are the same size but are perpendicular to one another. On each oval, in both cases, is a single dot which intersects with the line of the oval as if it traces an orbital. There are still a couple of zig-zagged lines, though much less than in the previous two ovals. Beneath the fourth oval, it says, “380,000 years, First Light, the first atoms form.” The fifth oval contains a blue camouflage-like pattern with a few white dots. Beneath it, it says, “200 million years, First Stars, gas and dust condense into stars.” The sixth oval contains a similar blue camouflage pattern, though it appears to be more transparent. There are several white dots, more than in the fifth oval, and a few white spiral shapes dispersed throughout. Underneath, it says, “400 million years, Galaxies & Dark Matter, galaxies form in dark matter cradles.” In the seventh oval, the blue camouflage pattern has faded, leaving behind a dark blue background with some very thin fog. There are several white dots and white spirals. Beneath the seventh oval, it says, “10 billion years, Dark Energy, expansion accelerates.” The eighth oval is similar to the seventh oval — it features a dark blue background with some thin haze, tens of white dots of varying size, and several spiral shapes of varying size. However, the eighth oval is considerably larger than the rest of the ovals, as it rests at the very end of the flare of the bell shape. Beneath the eighth oval, it says, “13.8 billion years, Today, humans observe the universe.” Credit: NASA

This infographic outlines the history of the universe.

0 SECONDS | In the beginning, the universe debuted extremely small, hot, and dense

Scientists aren’t sure what exactly existed at the very beginning of the universe, but they think there wasn’t any normal matter or physics. Things probably didn’t behave like we expect them to today.

A small flash of white light appears in the middle of a completely black image. The flash expands rapidly, glowing purple and consuming the entire image. The white light shrinks, returning to a pinprick at the center of the image. As it collapses, purple streams and waves pulse outward from the white light’s center. Alongside the waves flow hundreds of small galaxies — spiral and spherical collections of dots of light. The galaxies race out from the center, starting as miniscule specks and becoming larger blobs and smudges as they draw closer, speckling the screen. Credit: NASA’s Goddard Space Flight Center/CI Lab

Artist's interpretation of the beginning of the universe, with representations of the early cosmos and its expansion.

10^-32 SECONDS | The universe rapidly, fearless-ly inflated

When the universe debuted, it almost immediately became unstable. Space expanded faster than the speed of light during a very brief period known as inflation. Scientists are still exploring what drove this exponential expansion.

1 MICROSECOND | Inflation’s end started the story of us: we wouldn’t be here if inflation continued

When inflation ended, the universe continued to expand, but much slower. All the energy that previously drove the rapid expansion went into light and matter — normal stuff! Small subatomic particles — protons, neutrons, and electrons — now floated around, though the universe was too hot for them to combine and form atoms.

The particles gravitated together, especially in clumpy spots. The push and pull between gravity and the particles’ inability to stick together created oscillations, or sound waves.

In front of a dark blue background, hundreds of small red and blue spheres float around, at varying distances from the viewer. In the middle of the screen, two large red and blue spheres collide in the foreground. As they collide, a white flash of light radiates outward. As it fades, the two spheres become visible again, now stuck together. After the first collision, several similar collisions and white flashes are visible in the background. In the top left corner, a clump with one blue sphere and one red sphere races towards another clump with two red spheres and one blue sphere. They collide and there is a flash of white light. As the light clears, a clump with two red spheres and two blue spheres is visible in its place, and a single red sphere floats away toward the center of the screen. Credit: NASA’s Goddard Space Flight Center

Artist's interpretation of protons and neutrons colliding to form ionized deuterium — a hydrogen isotope with one proton and one neutron — and ionized helium — two protons and two neutrons.

THREE MINUTES | Protons and neutrons combined all too well

After about three minutes, the universe had expanded and cooled enough for protons and neutrons to stick together. This created the very first elements: hydrogen, helium, and very small amounts of lithium and beryllium.

But it was still too hot for electrons to combine with the protons and neutrons. These free electrons floated around in a hot foggy soup that scattered light and made the universe appear dark.

In a fuzzy gray fog, hundreds of medium-sized red spheres and small green spheres wiggle around, never moving farther than one diameter from their original position. Hundreds of glowing blue daggers of light bounce between the different spheres, changing direction when they collide with them. Suddenly, the red and green spheres combine, turning brown. The daggers no longer collide with the spheres and instead race away in every direction into open space. A single glowing blue dagger of light zooms away from the spheres and fog into an open blackness speckled with thousands of tiny stars. Credit: NASA/JPL-Caltech

This animated artist’s concept begins by showing ionized atoms (red blobs), free electrons (green blobs), and photons of light (blue flashes). The ionized atoms scattered light until neutral atoms (shown as brown blobs) formed, clearing the way for light to travel farther through space.

380 THOUSAND YEARS | Neutral atoms formed and left a blank space for light

As the universe expanded and cooled further, electrons joined atoms and made them neutral. With the electron plasma out of the way, some light could travel much farther.

A wide oval stretches across a rectangular black background. The oval is about twice as wide as it is tall. It is covered in speckles of varying colors from blue to yellow and red. The colors group together to form large splotches of reds, oranges, and yellows, as well as other splotches of blues and greens. In the bottom left corner, there is a horizontal rectangle with a spectrum of colors, with blue on the left, yellow in the center, and red on the right. Above the rectangle is a label reading “temperature.” Below the rectangle, on the left side under the blue is a label reading, “cooler.” On the right side, under the red, is a label reading “warmer.” Credit: ESA and the Planck Collaboration

An image of the cosmic microwave background (CMB) across the entire sky, taken by ESA's (European Space Agency) Planck space telescope. The CMB is the oldest light we can observe in the universe. Frozen sound waves are visible as miniscule fluctuations in temperature, shown through blue (colder) and red (warmer) coloring.

As neutral atoms formed, the sound waves created by the push and pull between subatomic particles stopped. The waves froze, leaving ripples that were slightly denser than their surroundings. The excess matter attracted even more matter, both normal and “dark.” Dark matter has gravitational influence on its surroundings but is invisible and does not interact with light.

In front of a navy-blue background, tens of light blue orbs float at varying sizes, representing varying distances from the viewer. There are three large blue orbs in the foreground, with small plus signs at their centers. Several yellow streaks of light race across the screen. As the streaks collide with blue orbs, the orbs flash and grow slightly larger, absorbing the yellow streaks, before returning to their original state. The yellow streaks of light do not re-emerge from the orbs. Credit: NASA’s Goddard Space Flight Center

This animation illustrates the absorption of photons — light particles — by neutral hydrogen atoms.

ALSO 380 THOUSAND YEARS | The universe became dark — call it what you want, but scientists call this time period the Dark Ages 

Other than the cosmic microwave background, there wasn't much light during this era since stars hadn’t formed yet. And what light there was usually didn't make it very far since neutral hydrogen atoms are really good at absorbing light. This kicked off an era known as the cosmic dark ages.

A dense orange fog floats in front of a black background that is just barely visible through the thick fog. There are dozens of glowing purple orbs within the fog, clustered in a circle in the center of the visual. One by one, the purple orbs send out bright white circular flashes of light. Following each flash of light, a white ring expands outward from the center of the orb, before fading away once its diameter reaches about one sixth of the image size. Credit: NASA’s Goddard Space Flight Center

This animation illustrates the beginning of star formation as gas begins to clump due to gravity. These protostars heat up as material compresses inside them and throw off material at high speeds, creating shockwaves shown here as expanding rings of light.

200 MILLION YEARS | Stars created daylight (that was still blocked by hydrogen atoms)

Over time, denser areas pulled in more and more matter, in some places becoming so heavy it triggered a collapse. When the matter fell inward, it became hot enough for nuclear fusion to start, marking the birth of the first stars!

In front of a black background, there are millions of glowing green dots. They form a fine, wispy web stretching across the image, like old cobwebs that have collected dust. Over time, more dots collect at the vertices of the web. As the web gets thicker and thicker, the vertices grow and start moving towards each other and towards the center. The smaller dots circle the clumps, like bees buzzing around a hive, until they are pulled inward to join them. Eventually, the clumps merge to create a glowing green mass. The central mass ensnares more dots, coercing even those from the farthest reaches of the screen to circle it. Credit: Simulation: Wu, Hahn, Wechsler, Abel (KIPAC), Visualization: Kaehler (KIPAC)

A simulation of dark matter forming structure due to gravity.

400 MILLION YEARS | Dark matter acted like an invisible string tying galaxies together

As the universe expanded, the frozen sound waves created earlier — which now included stars, gas, dust, and more elements produced by stars — stretched and continued attracting more mass. Pulling material together eventually formed the first galaxies, galaxy clusters, and wide-scale, web-like structure.

A borderless three-dimensional cube rotates from left to right in front of a black background. In the cube are many organic cloud-like blobs. They are primarily purplish blue and black, with the centers being darker than the outsides. In the space between the clouds is a light blue translucent material through which more blobs can be seen further back in the cube. As the cube rotates, the blobs become increasingly red and the blue translucent material becomes increasingly see through. After becoming bright red, the blobs start to fade and become a translucent yellow fog before disappearing completely. As they fade, millions of small yellow-ish stars become visible. The stars dot the cube in every dimension. Credit: M. Alvarez, R. Kaehler and T. Abel

In this animation, ultraviolet light from stars ionizes hydrogen atoms by breaking off their electrons. Regions already ionized are blue and translucent, areas undergoing ionization are red and white, and regions of neutral gas are dark and opaque.

1 BILLION YEARS | Ultraviolet light from stars made the universe transparent for evermore

The first stars were massive and hot, meaning they burned their fuel supplies quickly and lived short lives. However, they gave off energetic ultraviolet light that helped break apart the neutral hydrogen around the stars and allowed light to travel farther.

An animation on a black rectangular background. On the left of the visual is a graph constructed with blue text and the line on the graph. The y-axis of the graph reads “Expansion Speed.” The x-axis is labeled “Time.” At the origin, the x-axis reads, “10 billion years ago.” Halfway across the x-axis is labeled “7 Billion years ago.” At the end of the x-axis is labeled “now.” On the graph is a line which draws itself out. It starts at the top of the y-axis. It slopes down to the right, linearly, as if it were going to draw a straight line from the top left corner of the graph to the bottom right corner of the graph. Around the 7-billion mark, the line begins to decrease in slope very gradually. Three quarters of the way across the x-axis and three quarters of the way down the y-axis, the line reaches a minimum, before quickly curving upwards. It rapidly slopes upward, reaching one quarter from the top of the y-axis as it reaches the end of the x-axis labeled “now.” At the same time, on the right hand of the visual is a tiny dark blue sphere which holds within it glowing lighter blue spheres — galaxies and stars — and a lighter blue webbing. As the line crawls across the graph, the sphere expands. At first, its swelling gently slows, corresponding to the decreasing line on the graph. As the line reaches its minimum and the slope decreases, the sphere slows down its expansion further. Then, as the line arcs back upward, the sphere expands rapidly until it grows larger than the right half of the image and encroaches on the graph. Credit: NASA's Goddard Space Flight Center

Animation showing a graph of the universe’s expansion over time. While cosmic expansion slowed following the end of inflation, it began picking up the pace around 5 billion years ago. Scientists still aren't sure why.

SOMETIME AFTER 10 BILLION YEARS | Dark energy became dominant, accelerating cosmic expansion and creating a big question…?

By studying the universe’s expansion rate over time, scientists made the shocking discovery that it’s speeding up. They had thought eventually gravity should cause the matter to attract itself and slow down expansion. Some mysterious pressure, dubbed dark energy, seems to be accelerating cosmic expansion. About 10 billion years into the universe’s story, dark energy – whatever it may be – became dominant over matter.

A small blue sphere hangs in front of inky blackness. The lower half of the sphere is shrouded in shadow, making it appear hemispherical. The sphere is a rich blue, with swirling white patterns across it — Earth. In the foreground of the image is a gray horizon, covered in small craters and divots — the Moon. Credit: NASA

An image of Earth rising in the Moon’s sky. Nicknamed “Earthrise,” Apollo 8 astronauts saw this sight during the first crewed mission to the Moon.

13.8 BILLION YEARS | The universe as we know it today: 359,785,714,285.7 fortnights from the beginning

We owe our universe today to each of its unique stages. However, scientists still have many questions about these eras.

Our upcoming Nancy Grace Roman Space Telescope will look back in time to explore cosmic mysteries like dark energy and dark matter – two poorly understood aspects of the universe that govern its evolution and ultimate fate.

Make sure to follow us on Tumblr for your regular dose of space!

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doctarjaferson

1 year ago

Stars Make Firework Supplies!

The next time you see fireworks, take a moment to celebrate the cosmic pyrotechnics that made them possible. From the oxygen and potassium that help fireworks burn to the aluminum that makes sparklers sparkle, most of the elements in the universe wouldn’t be here without stars.

From the time the universe was only a few minutes old until it was about 400 million years old, the cosmos was made of just hydrogen, helium and a teensy bit of lithium. It took some stellar activity to produce the rest of the elements!

Stars are element factories

Even after more than 13 billion years, the hydrogen and helium that formed soon after the big bang still make up over 90 percent of the atoms in the cosmos. Most of the other elements come from stars.

Stars began popping into the universe about 400 million years after the big bang. That sounds like a long time, but it’s only about 3% of the universe’s current age!

Our Nancy Grace Roman Space Telescope will study the universe’s early days to help us learn more about how we went from a hot, soupy sea of atoms to the bigger cosmic structures we see today. We know hydrogen and helium atoms gravitated together to form stars, where atoms could fuse together to make new elements, but we're not sure when it began happening. Roman will help us find out.

The central parts of atoms, called nuclei, are super antisocial – it takes a lot of heat and pressure to force them close together. Strong gravity in the fiery cores of the first stars provided just the right conditions for hydrogen and helium atoms to combine to form more elements and generate energy. The same process continues today in stars like our Sun and provides some special firework supplies.

Carbon makes fireworks explode, helps launch them into the sky, and is even an ingredient in the “black snakes” that seem to grow out of tiny pellets. Fireworks glow pink with help from the element lithium. Both of these elements are created by average, Sun-like stars as they cycle from normal stars to red giants to white dwarfs.

Eventually stars release their elements into the cosmos, where they can be recycled into later generations of stars and planets. Sometimes they encounter cosmic rays, which are nuclei that have been boosted to high speed by the most energetic events in the universe. When cosmic rays collide with atoms, the impact can break them apart, forming simpler elements. That’s how we get boron, which can make fireworks green, and beryllium, which can make them silver or white!

Since massive stars have even stronger gravity in their cores, they can fuse more elements – all the way up to iron. (The process stops there because instead of producing energy, fusing iron is so hard to do that it uses up energy.)

That means the sodium that makes fireworks yellow, the aluminum that produces silver sparks (like in sparklers), and even the oxygen that helps fireworks ignite were all first made in stars, too! A lot of these more complex elements that we take for granted are actually pretty rare throughout the cosmos, adding up to less than 10 percent of the atoms in the universe combined!

Fusion in stars only got us through iron on the periodic table, so where do the rest of our elements come from? It’s what happens next in massive stars that produces some of the even more exotic elements.

Dying stars make elements too!

Once a star many times the Sun’s mass burns through its fuel, gravity is no longer held in check, and its core collapses under its own weight. There, atoms are crushed extremely close together – and they don’t like that! Eventually it reaches a breaking point and the star explodes as a brilliant supernova. Talk about fireworks! These exploding stars make elements like copper, which makes fireworks blue, and zinc, which creates a smoky effect.

Something similar can happen when a white dwarf star – the small, dense core left behind after a Sun-like star runs out of fuel – steals material from a neighboring star. These white dwarfs can explode as supernovae too, spewing elements like the calcium that makes fireworks orange into the cosmos.

When stars collide

White dwarfs aren’t the only “dead” stars that can shower their surroundings with new elements. Stars that are too massive to leave behind white dwarfs but not massive enough to create black holes end up as neutron stars.

If two of these extremely dense stellar skeletons collide, they can produce all kinds of elements, including the barium that makes fireworks bright green and the antimony that creates a glitter effect. Reading this on a phone or computer? You can thank crashing dead stars for some of the metals that make up your device, too!

As for most of the remaining elements we know of, we've only seen them in labs on Earth so far.

Sounds like we’ve got it all figured out, right? But there are still lots of open questions. Our Roman Space Telescope will help us learn more about how elements were created and distributed throughout galaxies. That’s important because the right materials had to come together to form the air we breathe, our bodies, the planet we live on, and yes – even fireworks!

So when you’re watching fireworks, think about their cosmic origins!

Learn more about the Roman Space Telescope at: https://roman.gsfc.nasa.gov/

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

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doctarjaferson

1 month ago