For hundreds of thousands of years after the big bang, the universe was made up of a hot soup of subatomic particles - particles that are smaller than the atoms we are comprised of - which were spread evenly in all directions.
Subscribe now for unlimited access.
$0/
(min cost $0)
or signup to continue reading
There were no galaxies, no stars, and no planets.
Our universe was perfectly smooth ... almost.
In some parts of the universe, the particles were packed together a little more tightly than other places.
These regions which were denser had a slightly stronger force of gravity, causing them to pull in more material.
Over time, these regions became more and more dense, causing their gravity to become stronger and stronger, and as a result our universe started to become clumpy.
As the universe evolved, these clumps of particles cooled and became individual clouds of gas, giving birth to the first stars.
As a result, these stars formed in isolated groups, leading to the galaxies that we see today.
On the largest-size scales, these galaxies clump together in strings, like the silk of a giant spider's web, that stretches out in all directions across the cosmos.
Studying the structure of this cosmic web allows us to understand the evolution of our universe from its soupy origin to today.
By studying how the universe has evolved, we can answer some of the biggest questions in science today.
To do this, we need a detailed map of the cosmic web, so we can piece together how it has grown over time.
However, mapping the cosmic web is no easy feat. It is made up of billions and billions of galaxies that cover literally the entire sky and far back in time.
We therefore need powerful telescopes that can observe as many galaxies as quickly as possible.
READ MORE SUNDAY SPACE:
Over the past few decades, telescopes have become more efficient at observing galaxies, and have provided some incredible maps of the nearby cosmic web.
The Sloan Digital Sky Survey (SDSS), which has been in operation since 2000, has utilised a powerful 2.5m telescope in New Mexico, USA.
This telescope can look at 1.5 square-degree patches of the sky at a time, an area equal to about eight full moons, and detect the light from up to 640 galaxies at a time.
Over the first eight years of its operation, SDSS mapped almost 1 million galaxies across the sky in the northern hemisphere, allowing us to understand the evolution of our universe in much greater detail.
The 2-degree Field Galaxy Redshift Survey (2dFGRS) is another influential galaxy survey, operating from Siding Spring Observatory here in Australia. The survey used the 4m Anglo-Australian Telescope to provide a map of the cosmic web across the southern sky.
While the results from SDSS, 2dFGRS and many other galaxy surveys have been groundbreaking, we are now entering a new era of telescope power, which will drastically extend our map of the cosmic web.
The 4MOST Hemisphere Survey (4HS) will begin operation in 2024. 4HS will utilise the VISTA telescope in Chile, which can observe over 2400 galaxies at once, with the goal to map 6.5 million galaxies across the southern hemisphere.
Mapping the cosmic web is a long and difficult process, but also a necessary one. It tells us about the detailed workings of our universe, and reveals our place in this grand structure.
- Bailey Martin is a research student specialising in cosmology at Mount Stromlo Observatory.
