If you thought dark matter was difficult to study, studying dark energy is even more challenging. Dark energy is perhaps the most subtle phenomenon in the universe. It drives the evolution of the cosmos, but its effects are only seen on intergalactic scales. So to study dark energy in detail, you need a great deal of observations of wide areas of the sky.Continue reading “On its Hunt for Dark Energy, a Telescope Stopped to Look at the Lobster Nebula”
For over a century, astronomers have known that the Universe has been expanding since the Big Bang. For the first eight billion years, the expansion rate was relatively consistent since it was held back by the force of gravitation. However, thanks to missions like the Hubble Space Telescope, astronomers have since learned that roughly five billion years ago, the rate of expansion has been accelerating. This led to the widely-accepted theory that a mysterious force is behind the expansion (known as Dark Energy), while some insist that the force of gravity may have changed over time.
This is a contentious hypothesis since it means that Einstein’s General Theory of Relativity (which has been validated nine ways from Sunday) is wrong. But according to a new study by the international Dark Energy Survey (DES) Collaboration, the nature of gravity has remained the same throughout the entire history of the Universe. These findings come shortly before two next-generation space telescopes (Nancy Grace Roman and Euclid) are sent to space to conduct even more precise measurements of gravity and its role in cosmic evolution.Continue reading “A New Study Confirms That Gravity has Remained Constant for the Entire age of the Universe”
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Dark energy is central to our modern theory of cosmology. We know the universe is expanding at an ever-increasing rate, and the clearest explanation is that some kind of energy is driving it. Since this energy doesn’t emit light, we call it dark energy. But simply giving dark energy a name doesn’t mean we fully understand it. We can see what dark energy does, but its fundamental nature is perhaps the biggest scientific mystery we have.Continue reading “Neutron Stars Could be the Best way to Measure Dark Energy”
According to our current Cosmological models, the Universe began with a Big Bang roughly 13.8 billion years ago. During the earliest periods, the Universe was permeated by an opaque cloud of hot plasma, preventing atoms from forming. About 380,000 years later, the Universe began to cool and much of the energy generated by the Big Bang converted into light. This afterglow is now visible to astronomers as the Cosmic Microwave Background (CMB), first observed during the 1960s.
One peculiar characteristic about the CMB that attracted a lot of attention was the tiny fluctuations in temperature, which could provide information about the early Universe. In particular, there is a rather large spot in the CMB that is cooler than the surrounding afterglow, known as the CMB Cold Spot. After decades of studying the CMB’s temperature fluctuations, a team of scientists recently confirmed the existence of the largest cold spots in the CMB afterglow – the Eridanus Supervoid – might be the explanation for the CMB Cold Spot that astronomers have been looking for!Continue reading “Finally, an Explanation for the Cold Spot in the Cosmic Microwave Background”
About 25 years ago, astrophysicists noticed something very interesting about the Universe. The fact that it was in a state of expansion had been known since the 1920s, thanks to the observation of Edwin Hubble. But thanks to the observations astronomers were making with the space observatory that bore his name (the Hubble Space Telescope), they began to notice how the rate of cosmic expansion was getting faster!
This has led to the theory that the Universe is filled with an invisible and mysterious force, known as Dark Energy (DE). Decades after it was proposed, scientists are still trying to pin down this elusive force that makes up about 70% of the energy budget of the Universe. According to a recent study by an international team of researchers, the XENON1T experiment may have already detected this elusive force, opening new possibilities for future DE research.Continue reading “A Particle Physics Experiment Might Have Directly Observed Dark Energy”
It is hard for humans to wrap their heads around the fact that there are galaxies so far away that the light coming from them can be warped in a way that they actually experience a type of time delay. But that is exactly what is happening with extreme forms of gravitational lensing, such as those that give us the beautiful images of Einstein rings. In fact, the time dilation around some of these galaxies can be so extreme that the light from a single event, such as a supernova, can actually show up on Earth at dramatically different times. That is exactly what a team led by Dr. Steven Rodney at the University of South Carolina and Dr. Gabriel Brammer of the University of Copenhagen has found. Except three copies of this supernova have already appeared – and the team thinks it will show up again one more time, 20 years from now.Continue reading “Astronomers saw the Same Supernova Three Times Thanks to Gravitational Lensing. And in Twenty Years They Think They’ll see it one More Time”
Cosmology is now stranger to large scale surveys. The discipline prides itself on data collection, and when the data it is collecting is about galaxies that are billions of years old its easy to see why more data would be better. Now, with a flurry of 29 new papers, the partial results from the largest cosmological survey ever – the Dark Energy Survey (DES) – have been released. And it largely confirms what we already knew.Continue reading “Dark Energy Survey is out. 29 Papers Covering 226 Million Galaxies Across 7 Billion Light-Years of Space”
“Science is not only compatible with spirituality; it is a profound source of spirituality. When we recognize our place in an immensity of light years and in the passage of ages, when we grasp the intricacy, beauty and subtlety of life, then that soaring feeling, that sense of elation and humility combined, is surely spiritual.” – Carl Sagan “The Demon-Haunted World.”
Learning about the Universe, I’ve felt spiritual moments, as Sagan describes them, as I better understand my connection to the wider everything. Like when I first learned that I was literally made of the ashes of the stars – the atoms in my body spread into the eternal ether by supernovae. Another spiritual moment was seeing this image for the first time:Continue reading “One of These Pictures Is the Brain, the Other is the Universe. Can You Tell Which is Which?”
Once I accidentally took a photo of one of the most important stars in the Universe…
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.Continue reading “Take a Flight Through the Most Detailed 3D Map of the Universe Ever Made”
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.Continue reading “A New Telescope is Ready to Start Searching for Answers to Explain Dark Energy”