Dark Energy, The CMB, & String Theory

The photonic emission of the Cosmic Microwave Background radiation that happened about 380,000 years after the Big Bang provides a unique way to understand the emission of energized particles in every direction from a totally opaque and dense universe, which is similar to a plasma with no atoms. According to the holographic principle, if one wants to visualize something like dark energy as the driving force behind the expansion of our universe, then this event and its existence within at least the 5th dimension, which is the place where cosmic superstrings exist, space-time is curled up into a tiny 6-dimensional loop, and gravity is unified with the electromagnetic force, should be genuinely explored.

The CMB was first detected by the Holmdel Horn Antenna in 1964. The accelerating expansion of our universe through dark energy was originally conjectured in 1921, along with Kaluza-Klein theory as a precursor to string theory. Among this radiation one can find that the universe at its birth emitted many different kinds of particles, including lots of energy and matter. Both dark energy and the relic radiation can be measured together and directly related to each other due to the wavelengths of light that eventually red-shift over time. Today, the CMB sits around us everywhere in the sky as a microwave echo of energy from the abyss that was once emitted by the universe when it was only in its youth.

Dark energy, similar to vacuum energy in otherwise empty space, is thought to expand space from every point and in every direction. The CMB's photons emerged from a dark universe the same way as dark energy expands the particular space that it's inherent to. Experiments such as the Fermilab Holometer are currently working to find evidence that would show the universe itself is a giant hologram. This would eventually shed light on dark energy and also support modern interpretations of string theory, including M-theory, with its 11 dimensions of reality.


A 6-dimensional Calabi–Yau manifold, as known to superstring theory and mirror symmetry (Image: Wolfram).

Higgs Boson Found

In around December of 2011, preliminary research efforts began to hint at the presence of a new bosonic particle with Higgs-like properties. It was officially announced on July 4, 2012, by the ATLAS and CMS teams working at CERN, that these findings were definitely signs of something important. Regarded as the key to understanding the origin of mass, even the spark that caused the Big Bang, the new Higgs boson's unique yet brief appearance quickly became the object of joyous celebration worldwide as the excitation ripples of a particle collision revealed a signal, measuring near the 125-126 GeV mass-energy range, that had finally brought into reality the standard model particle predicted to exist since 1964.


Results consistent with the expected signature of the Higgs boson (Image: CMS).

Out of the four fundamental interactions known to exist: gravitation, electromagnetism, the strong nuclear force, and the weak nuclear force, it is believed that the exchange of a boson acting as a force carrier particle is what allows each kind of field or interaction to work. Just as the photon mediates the electromagnetic force, and the strong force gluon holds together particles inside the nucleus of an atom, the Higgs boson is responsible for converting Higgs field energy into corresponding elementary particles with mass.

Although fermions are the elementary particles that acquire mass to become the basic building blocks of ordinary matter, coupling with the Higgs field, an invisible energy condensate which permeates throughout everything and the vacuum of empty space, is also thought to give the weak nuclear force bosons: W+, W-, and Z, their exceptionally large masses. This process is due to a spontaneous symmetry breaking of the electroweak interaction, which sets apart the electromagnetic and weak forces, described to be unified parts of the same interaction only in an environment like that of the early Universe.

The level of certainty in this finding suggests that there is enough evidence to conclude a reasonably sound discovery. "A 5-sigma result represents a one-in-3.5 million chance of the result being noise. This is undeniable proof that a boson, with very Higgs-like qualities, has been discovered by the two detectors" (source). Along with being its own antiparticle, various other specific properties characterize the standard model Higgs boson, a few of which were accurately detected in the experimental results of this year. The recently found boson's rapid decay into the appropriate lighter particles, for example, serves as some evidence to label it the Higgs boson and to support the concept of the Higgs field. Future research efforts in this area may also clear the way for an new sector of physics entirely. "Supersymmetry provides both a natural context for the Higgs field and a possible explanation for the small but finite value of dark energy" (source). Known for its major innovations in modern science, the Large Hadron Collider's recent landmark achievement will serve as a crowning jewel for everyone who has patiently worked hard in anticipation of the new boson's arrival.

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.

Particle Accelerator by CERN

Tonight, I write to express my interest in Earth's largest operating machine. The Large Hadron Collider is the most complex scientific instrument in use today. It is run by the European Organization for Nuclear Research (CERN) and it is buried 574 ft (175 m) below ground on the border of France and Switzerland, near Geneva, Switzerland.


The LHC can be found buried underground in Europe (Image: CERN).


The central LHC accelerating ring. It spans a 5.3 mile long (8.6 km) diameter (Image: CERN).

When powered up, the LHC releases beams made up of protons or other ions through a series of interconnected ring-shaped tunnels. Accelerated by giant superconducting magnets, the particles reach speeds approximating 99.9% the speed of light. As they approach the largest ring (highlighted in yellow), which is nearly 17 mi (27 km) in circumference, engineers collide the particles in testing rooms the size of warehouses. Results are then recorded by sensors placed in these rooms and studied in order to provide useful information about the nature of the particles that belong to the standard model of particle physics. Scientists and engineers examine the results of current research efforts either to try to prove the existence of the Higgs boson, the key to the origin of mass in the universe, or to gain additional knowledge regarding the dynamics of subatomic particles.


Engineers working inside the LHC (Image: CERN).

Engineers have been maintaining and upgrading the LHC ever since achieving the first successful particle beam circulation in September of 2008. This year, on March 30, 2010, the LHC broke the record for the highest-energy man-made collision event ever planned between two 3.5 teraelectronvolt beams. It might also be able to shed light on the unification of fundamental forces, such as that of the electroweak interaction, found at very high temperatures. With a maximum operating energy of 14 TeV, the LHC is set to advance a new era in physics over the next few years.