Take a Flight Through the Most Detailed 3D Map of the Universe Ever Made

Once I accidentally took a photo of one of the most important stars in the Universe…

Andromeda Galaxy imaged at the SFU Trotter Observatory processed by Matthew Cimone

That star highlighted in the photo is called M31_V1 and resides in the Andromeda Galaxy. The Andromeda – AKA M31- is the closest galaxy to our own Milky Way. But before it was known as a galaxy, it was called the Andromeda Nebula. Before this particular star in Andromeda was studied by Edwin Hubble, namesake of the Hubble Space Telescope, we didn’t actually know if other galaxies even existed. Think about that! As recently as a hundred years ago, we thought the Milky Way might be the ENTIRE Universe. Even then…that’s pretty big. The Milky Way is on the order of 150,000 light years across. A light year is about 10 TRILLION kilometers so even at the speed of light it would take nearly the same length of time to cross the Milky Way as humans have existed on planet Earth.  M31_V1 changed all that.

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A New Telescope is Ready to Start Searching for Answers to Explain Dark Energy

Back in 2015, construction began on a new telescope called the Dark Energy Spectroscopic Instrument (DESI). Later this year, it will begin its five-year mission. Its goal? To create a 3D map of the Universe with unprecedented detail, showing the distribution of matter.

That detailed map will allow astronomers to investigate important aspects of cosmology, including dark energy and its role in the expansion of the Universe.

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Over a Hundred New Large Objects Found in the Kuiper Belt

Hey Pluto, Sedna, Haumea, Makemake Et al.: You’ve got company!

While searching for distant galaxies and supernovae, the Dark Energy Survey’s powerful 570-megapixel digital camera spotted a few other moving “dots” in its field of view. Turns out, the DES has found more than 100 previously unknown trans-Neptunian objects (TNOs), minor planets located in Kuiper Belt of our Solar System.

A new paper describes how the researchers connected the moving dots to find the new TNOs, and also says this new approach could help look for the hypothetical Planet Nine and other undiscovered worlds.

Guess you never know what you’ll find once you start looking!

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New Research Casts A Shadow On The Existence Of Dark Energy

The cosmic distance ladder for measuring galactic distances.

The universe is expanding. When we look in all directions, we see distant galaxies speeding away from us, their light redshifted due to cosmic expansion. This has been known since 1929 when Edwin Hubble calcuated the relation between a galaxy’s distance and its redshift. Then in the late 1990s, two studies of distant supernovae found that the expansion of the universe is accelerating. Something, some dark energy, must be driving cosmic expansion.

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New Telescope Instrument Will Watch the Sky with 5,000 Eyes

Dark Energy is the mysterious force driving the expansion of the Universe. We don’t know what dark energy is, even though it makes up about 68% of the Universe. And the expansion is accelerating, which only adds to the mystery.

A new instrument called the Dark Energy Spectroscopic Instrument (DESI) will study dark energy. It’s doing so with 5,000 new robotic “eyes.”

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Meet WFIRST, The Space Telescope with the Power of 100 Hubbles

WFIRST ain’t your grandma’s space telescope. Despite having the same size mirror as the surprisingly reliable Hubble Space Telescope, clocking in at 2.4 meters across, this puppy will pack a punch with a gigantic 300 megapixel camera, enabling it to snap a single image with an area a hundred times greater than the Hubble.

With that fantastic camera and the addition of one of the most sensitive coronagraphs ever made – letting it block out distant starlight on a star-by-star basis – this next-generation telescope will uncover some of the deepest mysteries of the cosmos.

Oh, and also find about a million exoplanets.

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Uh oh, a Recent Study Suggests that Dark Energy’s Strength is Increasing

Staring into the Darkness

The expansion of our universe is accelerating. Every single day, the distances between galaxies grows ever greater. And what’s more, that expansion rate is getting faster and faster – that’s what it means to live in a universe with accelerated expansion. This strange phenomenon is called dark energy, and was first spotted in surveys of distant supernova explosions about twenty years ago. Since then, multiple independent lines of evidence have all come to the same morose conclusion: the universe is getting fatter and fatter faster and faster.

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Gravitational waves were only recently observed, and now astronomers are already thinking of ways to use them: like accurately measuring the expansion rate of the Universe

Neutron stars scream in waves of spacetime when they die, and astronomers have outlined a plan to use their gravitational  agony to trace the history of the universe. Join us as we explore how to turn their pain into our cosmological profit.

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If There is a Multiverse, Can There be Life There Too?

The Multiverse Theory, which states that there may be multiple or even an infinite number of Universes, is a time-honored concept in cosmology and theoretical physics. While the term goes back to the late 19th century, the scientific basis of this theory arose from quantum physics and the study of cosmological forces like black holes, singularities, and problems arising out of the Big Bang Theory.

One of the most burning questions when it comes to this theory is whether or not life could exist in multiple Universes. If indeed the laws of physics change from one Universe to the next, what could this mean for life itself? According to a new series of studies by a team of international researchers, it is possible that life could be common throughout the Multiverse (if it actually exists).

The studies, titled “The impact of dark energy on galaxy formation. What does the future of our Universe hold?” and “Galaxy formation efficiency and the multiverse explanation of the cosmological constant with EAGLE simulations“, recently appeared in the Monthly Notices of the Royal Astronomical Society. The former study was led by Jaime Salcido, a postgraduate student at Durham University’s Institute for Computational Cosmology.

Einstein Lecturing
Albert Einstein during a lecture in Vienna in 1921. Credit: National Library of Austria/F. Schmutzer/Public Domain

The latter was led by Luke Barnes, a John Templeton Research Fellow at the University of Sydney’s Sydney Institute for Astronomy. Both teams included members from the University of Western Australia’s International Center for Radio Astronomy Research, the Liverpool John Moores University’s Astrophysics Research Institute, and Leiden University’s Leiden Observatory.

Together, the research team sought to determine how the accelerated expansion of the cosmos could have effected the rate of star and galaxy formation in our Universe. This accelerate rate of expansion, which is an integral part of the Lambda-Cold Dark Matter (Lambda-CDM) model of cosmology, arose out of problems posed by Einstein’s Theory of General Relativity.

As a consequence of Einstein’s field equations, physicist’s understood that the Universe would either be in a state of expansion or contraction since the Big Bang. In 1919, Einstein responded by proposing the “Cosmological Constant” (represented by Lambda), which was a force that “held back” the effects of gravity and thus ensured that the Universe was static and unchanging.

Shortly thereafter, Einstein retracted this proposal when Edwin Hubble revealed (based on redshift measurements of other galaxies) that the Universe was indeed in a state of expansion. Einstein apparently went as far as to declare the Cosmological Constant “the biggest blunder” of his career as a result. However, research into cosmological expansion during the late 1990s caused his theory to be reevaluated.

Artist’s impression of the Lambda Cold Dark Matter (LCDM) cosmological model of the Universe. Credit: Wikipedia Commons/Alex Mittelmann, Coldcreation

In short, ongoing studies of the large-scale Universe revealed that during the past 5 billion years, cosmic expansion has accelerated. As such, astronomers began to hypothesize the existence of a mysterious, invisible force that was driving this acceleration. Popularly known as “Dark Energy”, this force is also referred to as the Cosmological Constant (CC) since it is responsible for counter-effecting the effects of gravity.

Since that time, astrophysicists and cosmologists have sought to understand how Dark Energy could have effected cosmic evolution. This is an issue since our current cosmological models predict that there must be more Dark Energy in our Universe than has been observed. However, accounting for larger amounts of Dark Energy would cause such a rapid expansion that it would dilute matter before any stars, planets or life could form.

For the first study, Salcido and the team therefore sought to determine how the presence of more Dark Energy could effect the rate of star formation in our Universe. To do this, they conducted hydrodynamical simulations using the EAGLE (Evolution and Assembly of GaLaxies and their Environments) project – one of the most realistic simulations of the observed Universe.

Using these simulations, the team considered the effects that Dark Energy (at its observed value) would have on star formation over the past 13.8 billion years, and an additional 13.8 billion years into the future. From this, the team developed a simple analytic model that indicated that Dark Energy – despite the difference in the rate of cosmic expansion – would have a negligible impact on star formation in the Universe.

Timeline of the Big Bang and the expansion of the Universe. Credit: NASA

They further showed that the impact of Lambda only becomes significant when the Universe has already produced most of its stellar mass and only causes decreases in the total density of star formation by about 15%. As Salcido explained in a Durham University press release:

“For many physicists, the unexplained but seemingly special amount of dark energy in our Universe is a frustrating puzzle. Our simulations show that even if there was much more dark energy or even very little in the Universe then it would only have a minimal effect on star and planet formation, raising the prospect that life could exist throughout the Multiverse.”

For the second study, the team used the same simulation from the EAGLE collaboration to investigate the effect of varying degrees of the CC on the formation on galaxies and stars. This consisted of simulating Universes that had Lambda values ranging from 0 to 300 times the current value observed in our Universe.

However, since the Universe’s rate of star formation peaked at around 3.5 billion years before the onset of accelerating expansion (ca. 8.5 billion years ago and 5.3 billion years after the Big Bang), increases in the CC had only a small effect on the rate of star formation.

 

Taken together, these simulations indicated that in a Multiverse, where the laws of physics may differ widely, the effects of more dark energy cosmic accelerated expansion would not have a significant impact on the rates of star or galaxy formation. This, in turn, indicates that other Universes in the Multiverse would be just about as habitable as our own, at least in theory. As Dr. Barnes explained:

“The Multiverse was previously thought to explain the observed value of dark energy as a lottery – we have a lucky ticket and live in the Universe that forms beautiful galaxies which permit life as we know it. Our work shows that our ticket seems a little too lucky, so to speak. It’s more special than it needs to be for life. This is a problem for the Multiverse; a puzzle remains.”

However, the team’s studies also cast doubt on the ability of Multiverse Theory to explain the observed value of Dark Energy in our Universe. According to their research, if we do live in a Multiverse, we would be observing as much as 50 times more Dark Energy than what we are. Although their results do not rule out the possibility of the Multiverse, the tiny amount of Dark Energy we’ve observed would be better explained by the presence of a as-yet undiscovered law of nature.

As Professor Richard Bower, a member of Durham University’s Institute for Computational Cosmology and a co-author on the paper, explained:

“The formation of stars in a universe is a battle between the attraction of gravity, and the repulsion of dark energy. We have found in our simulations that Universes with much more dark energy than ours can happily form stars. So why such a paltry amount of dark energy in our Universe? I think we should be looking for a new law of physics to explain this strange property of our Universe, and the Multiverse theory does little to rescue physicists’ discomfort.”

These studies are timely since they come on the heels of Stephen Hawking’s final theory, which cast doubt on the existence of the Multiverse and proposed a finite and reasonably smooth Universe instead. Basically, all three studies indicate that the debate about whether or not we live in a Multiverse and the role of Dark Energy in cosmic evolution is far from over. But we can look forward to next-generation missions providing some helpful clues in the future.

These include the James Webb Space Telescope (JWST), the Wide Field Infrared Survey Telescope (WFIRST), and ground-based observatories like the Square Kilometer Array (SKA). In addition to studying exoplanets and objects in our Solar System, these mission will be dedicated to studying how the first stars and galaxies formed and determining the role played by Dark Energy.

What’s more, all of these missions are expected to be gathering their first light sometime in the 2020s. So stay tuned, because more information – with cosmological implications – will be arriving in just a few years time!

Further Reading: Durham University