The JWST and the History of the Universe

Everything we see on Earth — the plants, people, and microscopic organisms moving through the oceans — is made of elements that were created in the early years after the initial expansion of our universe.

This expansion, known as the Big Bang, involved particles that combined to create atoms, stars, comets, and planets like the one we live on. Understanding this expansion and the origins of our universe is a vital field of scientific study. In order to best predict what lies in the future of our universe, we must first look to the past.

In 2021, with the goal of understanding the past and future of the universe, NASA launched the James Webb Space Telescope. This telescope is now 1 million miles away, orbiting the sun and providing crucial data about every phase of the universe’s expansion since the Big Bang.

Understanding the Big Bang

In 1927, Belgian astronomer Georges Lemaitre developed the theory of the expanding universe known as the Big Bang theory. Lemaitre’s theory was supported by an astronomer in California named Edwin Hubble who used his telescope to observe other galaxies beyond the Milky Way. In his observations, Hubble discovered that these galaxies were all moving away from each other.

The Big Bang theory holds that 13.8 billion years ago, the universe began as a single particle that split and exploded, leading to a rapidly expanding wave of heat and gas. In the early years after that explosion, the expanding universe was gaseous and made predominantly of hydrogen and helium. These gasses cooled and the pressure from gravity led to the creation of stars, additional elements, planets, and more.

Since Hubble and Lemaitre, scientists have found significant evidence supporting the Big Bang theory, such as redshift and cosmic microwave background radiation. Redshift is a stretching effect that occurs when a source of light is moving away from an observer, causing the light to appear to shift towards the red side of the light spectrum. Cosmic microwave background (CMB) radiation is the collection of particles and photons that existed in the first 300,000 years of the universe. When this collection cooled, it began to travel through the universe and can now be studied by scientists seeking to learn more about the earliest years of the universe. These phenomena support the theory that the universe is expanding, with everything moving further and further away as time progresses.

Telescopes such as the NASA Hubble Space Telescope and the James Webb Space Telescope provide data every day that helps scientists develop a clearer understanding of the Big Bang and the origins of everything.

James Webb Telescope and Big Bang: Understanding the Connection

The James Webb Telescope is a $10 billion tool that allows humankind to see further into the past than ever before. This telescope is equipped with infrared vision and greater sensitivity than any other telescope.

The advanced imaging technology of the JWST makes it an essential tool for studying the origins of the universe and, hopefully, capturing images of the first galaxies formed after the Big Bang.

Infrared Vision

Light travels at 186,000 miles per second. When you look up at the night sky and search for your favorite constellations, you’re looking at light that was emitted by the star millions of years ago. That light traveled across space and time to finally reach your eyes. The redshift phenomenon means that, in order to see the light emitted from the oldest parts of our universe, scientists need a telescope that can see light that has shifted to the red side of the spectrum over the course of billions of years.

The Hubble Space Telescope is able to see light from up to 10 billion years ago, but the Webb Telescope surpasses Hubble and captures images of light from 13.5 billion years ago. While the Hubble collects visible light, however, the short wavelengths of visible light are more likely to bounce off of objects. The Webb collects infrared light that isn’t blocked by cosmic dust, as well as nonvisible infrared light coming from low-energy planets. Webb’s mirrors reflect light into instruments that focus the light onto highly sensitive infrared detectors. These detectors collect information from the oldest and most distant parts of our universe.

Greater Sensitivity

Since experts believe the Big Bang occurred nearly 14 billion years ago, James Webb’s structure is focused on detecting the oldest light possible. To collect different data than Hubble, Webb needed new innovations such as the telescope’s mirror, which actually consists of 18 hexagonal mirrors.

The Webb primary mirror is six times larger than Hubble’s primary mirror, and its size and gold-plated beryllium material allow for the reflection and collection of infrared light from the earliest galaxies. The telescope’s sensitivity to these infrared waves is aided by a sun shield the size of a tennis court. The shield puts the telescope in permanent shadow despite its orbit around the sun.

These tools allow the Webb Telescope to detect extremely faint signals from the oldest segments of our universe.

Potential Discoveries

The James Webb Space Telescope has played a pivotal role in important scientific discoveries, such as the confirmation of our universe’s expansion rate.

Webb is currently being used to explore exoplanets, planets that exist outside our solar system. These planets, some a similar size to Earth, can be studied through a process called spectroscopy. As light leaves a star and passes through an exoplanet’s atmosphere, the molecules in the atmosphere impact the light waves that reach the Webb telescope. Spectroscopy helps to inform scientists about the presence of elements such as sodium, methane, and water in exoplanets’ atmospheres. Someday, the Webb telescope may aid in the discovery of exoplanets with similar atmospheres to Earth.

There are countless potential discoveries waiting for Webb in the future, with experts using the telescope to search for additional evidence of cosmic inflation, dark matter, and other unknown phenomena.

Impact on Our Understanding of the Universe

James Webb’s findings allow us to look into the distant past and dream of the future in new and exciting ways.

Scientists reach a great many technological milestones in the process of studying the origins of the universe. These advancements, including solar panels and water filtration technology, have immediate effects on our technology on Earth and the future of space exploration. Finding exoplanets with atmospheres similar to Earth may lead to a shift in our knowledge of life beyond Earth. Seeing images that are closer and closer to the Big Bang may lead to revolutionary changes in our understanding of the origins of our universe.

Cultures around the world have long theorized about the creation of the world and the wider universe. Over the centuries, as we’ve developed a deeper scientific understanding of the natural world, these theories have shifted and grown. With every new image and data point collected by Webb, humankind finds more answers to celebrate and more questions to contemplate.