Gravitational Wave Signal

Gravitational waves from a double black hole merger about 1.3 billion light-years away from us were directly detected on September 14, 2015. This gigantic, distant, and ancient event caused our space-time to expand and contract by 1/100,000 of a nanometer due to the sub-atomic effects of passing gravitational waves. They were measured by the two Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors last year, while it recently made big headlines earlier this year celebrating 100 years of Albert Einstein's general relativity. This measurement provides a verification of the theory's correctness, more proof for the existence of black holes, and reveals a phenomenon which had never before been directly seen in nature, opening windows into new areas of astronomy and cosmology research.

""These amazing observations are the confirmation of a lot of theoretical work, including Einstein’s general theory of relativity, which predicts gravitational waves,” says physicist Stephen Hawking at the University of Cambridge, UK" (source).


A double black hole merger from long ago recently caused minute changes in our space-time (Image: LIGO).

The Milky Way Domain

The acclaimed work by Nick Risinger, Photopic Sky Survey, can be admired here as a marvelous 360-degree photomosaic of the Universe joined together in 2011, and it portrays a boundless continuum of stars and galaxies, each one regularly visible to the naked eye on a really clear night. Begin the simulated arena looking towards the galactic center of the Milky Way, and every direction you go expands the background into a gorgeous panorama with rich interstellar details that appear to make the screen look replete with starry objects. It is honestly quite entertaining just to move around some particular region and then gain a better perspective back from planet Earth, the vantage point looking free through the atmosphere, set aside from the Sun and the Moon. A few major identifiable celestial objects include the Pleiades (M45), Andromeda Galaxy (M31), the Large Magellanic Cloud (LMC), the Small Magellanic Cloud (SMC), and the Orion Nebula (M42), and they can easily be spotted in this 37,440-exposure, 5000-megapixel shot. The image provides an alluring insight into the breathtaking cosmic matter radiating light from the galactic realm of the Milky Way and space within the Virgo supercluster of the observable universe.


Andromeda (M31) is shown here as it is Milky Way's closest spiral galaxy neighbor (Image: NASA).

Primordial Gravitational Waves

On March 17, 2014, it was officially announced that signs of gravitational waves, or ripples in the fabric of space-time, had been discovered in the data collected from the Cosmic Microwave Background radiation as an imprint left by our Universe approximately 380,000 years after the Big Bang. This is considered to be a plausible advance towards the indirect detection of Albert Einstein's gravity waves, originally predicted to exist in his general theory of relativity of 1916. The BICEP2 team, located at the South Pole, has identified a swirling pattern throughout the light of the CMB known as B-mode polarization, believed to be the result of inflationary gravitational waves. "We’ve found the smoking gun evidence for inflation and we’ve also produced the first image of gravitational waves across the sky" (source).


A polarized light pattern in the CMB caused by early gravitational waves (Image: BICEP2).

Finding gravitational waves embedded in the CMB would reasonably support the theory of inflation, originally proposed by physicist Alan Guth, which describes an initial period of highly accelerated expansion for the Universe that smoothed out irregularities in space-time and made the cosmos look almost the same in every direction. The CMB is the oldest electromagnetic radiation we can see from after that period, thought to have emerged at a time when matter was only beginning to form structures out of a hot and dense plasma. This early light now fills every region of space and reaches us in the form of microwaves with an average temperature of 2.725 K, while it is considered to be the Big Bang's afterglow. Along with providing important information about the universe's early development, including tentative effects of ancient gravity waves, the CMB also reveals key insights into features of today's universe such as apparent composition and overall uniformity.

Special Note: Although there is new evidence suggesting that interstellar dust levels may have modified the interpretation of these results by being higher than previously determined, the theoretical basis for gravitational waves is still very strong and this latest outcome does not completely rule out their existence. 8*]

Matter and Antimatter Tales

The distinct inequality between everyday matter and antimatter in the Universe is one of the most fascinating and extraordinary puzzles known to modern cosmology. Baryon asymmetry shows that there is an inferable amount of antimatter unavailable within our observable Universe. The natural phenomenon is left to generate wonder about whether it is simply missing or located somewhere else.

Daily experience is mostly due to baryonic matter's physical influence on reality as regular matter. Not to be confused with matter from the element Barium, a particle of baryonic matter, or a baryon, is a type of composite particle (hadron) made up of three elementary particle quarks, same as a proton or a neutron. An electron is a different kind of elementary particle that is classified as a lepton but also plays an important role as a fundamental constituent of the atom.

Antimatter is the substance composed entirely out of antiparticles, which are equal in mass to their respective matter counterparts but carry the opposite (occasionally neutral) charge and quantum spin. Antielectrons (positrons) for example, appear naturally from specific radioactive decay (Beta+), deep within atmospheric thunderstorm activity, and traveling along cosmic rays projected by stars and black holes. The first person to ever predict antimatter existed was Nobel laureate Paul Dirac in 1931, following his work for the Dirac sea, his theoretical model of the vacuum. Determinately, I believe dark matter is inherently different from antimatter because Earthly antimatter is more recurrent.

When a particle of matter collides with its antimatter partner, the result is they annihilate one another in an exciting flash of energy producing photons and then they disappear. Given presumed equal initial amounts of matter and antimatter, this process is thought to have taken place repeatedly in the moments early after the Big Bang, while somehow leaving behind a significant portion of baryonic matter that characterizes the universe we live in today.

The massless photon and the hypothetical graviton are both bosonic particles considered to be their own antiparticle. A neutrino is another particle, an electrically neutral lepton, that has an antiparticle mostly due to its different spin. "Neutrinos are fundamental particles that were first formed in the first second of the early universe, before even atoms could form" (source). It is now known that neutrinos have a non-zero mass and, through a special process called neutrino oscillation, periodically morph into one of three uniquely-termed flavors: electron, muon, and tau. Neutrinos are variably encountered as a part of the large amount of radiation emitted by our Sun, and are relatively abundant throughout the relic particle radiation left from the Big Bang. Also found within nuclear reactions, neutrinos were first postulated by Nobel laureate Wolfgang Pauli in 1930.

Modern neutrino oscillation research has led scientists to believe that neutrinos played an important role by inducing the baryonic asymmetry in the developing cosmos. "Reactions involving neutrinos and antineutrinos in the early universe could have skewed the ratio of matter and antimatter production, leading to our matter-dominated universe" (source). A fourth kind of sterile neutrino depends upon the existence of a particle with some mass that is essentially detectable only through its gravitational influence. "In addition, data from WMAP show the most likely number of neutrino families in the early Universe was four, and the Chandra X-ray Observatory detected faint pulses of X-rays (from a dim dwarf galaxy) suggesting the decay of heavier neutrinos into lighter ones" (source). Sterile neutrino masses are theorized to be their own antiparticle, which enables neutrinoless double beta decay, and they are also granted to be the ideal candidate to explain dark matter. "Not only could this "sterile" neutrino be the stuff of dark matter, thought to make up the bulk of our universe, it might also help to explain how an excess of matter over antimatter arose in our universe" (source).

For the first time, low-temperature antihydrogen was produced and isolated by physicists at CERN using the Antihydrogen Laser Physics Apparatus (ALPHA) in 2010. The next year, more antihydrogen atoms were captured and studied for an outstanding duration of 1000 seconds. The very latest research efforts are geared towards providing useful information on the emission spectrum, potentially equal to that of the element hydrogen, by using microwave radiation on the trapped anti-atoms. Whether or not antimatter is destined to exist here on Earth indefinitely is worth the contemplation.

Studying ephemeral antimatter is done to look for discrepancies in the Charge, Parity, and Time reversal symmetry of the physical laws that operate within our world. A particle moving forward through time in our universe is described to be virtually indistinguishable from an antiparticle moving backwards through time in a mirror universe, according to fundamental CPT symmetry. Investigating the cause for the apparent abundance of matter over antimatter in the universe would help to resolve the baryon asymmetry conundrum while also expanding our knowledge on the physical processes required for a universe to develop into one like ours. An improved understanding of the nature of antimatter might eventually shed light on any unexplored aspects of its behavior and what techniques can be employed for its practical use.

Innumerable Galaxies

From September 2003 to January 2004, the NASA Hubble Space Telescope was pointed at a region of space with a low brightness and only a few stars in the near field. The region was about the size of a grain of sand at a distance of one meter away from the human eye. With all of the data accumulated during that time, the telescope captured an image that exemplifies just how immense the universe really is.


"Humankind's deepest portrait of the visible universe ever" as referred to by NASA (Image: NASA).

The Hubble Ultra Deep Field image is considered to be one of the most humbling and profound images of all time. The countless number of individual galaxies revealed is not only surprising but also very informative. An image like this makes the universe look like it is truly abundant with other galaxies and stars. It is also interesting to note that the light from the farthest galaxies in this picture has been traveling towards us since early after the Big Bang and represents what those galaxies looked like about 13 billion years ago. This information has enabled a base measurement of early galaxies' distribution and their evolution.

Hubble's successor, the James Webb Space Telescope, is scheduled to be up and running in 2018.

Universes and Black Holes

When I read articles about physics and astronomy, I can't help but get excited when a brand new theory catches my attention and completely changes the way I look at the world around me. A while ago, I stumbled upon such a theory developed by theoretical physicist Nikodem Poplawski, which instills in me great admiration towards modern cosmology research.


An artist's rendition of a universe containing a black hole (Image: Unattributed).

A black hole is a region of space from which light and matter cannot escape. It is twice as wide as its Schwarzschild radius and contains a singularity of infinite density and zero volume at its center. Here is an article from the National Geographic website that describes just how every black hole may contain another universe.

So, after reading this article, I was interested to know if anyone else was silently questioning their Earthly existence and what they thought about this. I wasn't about to get too excited before Discover Magazine was amusingly there to remind me just how our universe is not a black hole by clearing up the confusion.

"If anything, our universe bears a passing resemblance to a white hole" with a singularity in the past and no singularity in the future (source).

In this article, I learned that a solution to Albert Einstein's equation that describes the universe expanding from the Big Bang can be used to show how the time-reversal of a black hole is actually very similar. The author Sean Carroll is also careful to compare the extent of our observable universe (characterized as the Hubble length) with the Schwarzschild radius of a black hole in order to validate how the universe is spatially flat.