Tuesday, October 29, 2019

A Potential Wormhole Detection Method

Credit: Shutterstock

Wormholes have been ubiquitous in science fiction for a long time. The prospect of a portal which transports you across the universe is too good to pass up. Surprisingly, wormholes are now a physical possibility. Wormholes agree with Einstein’s general theory of relativity, which means their existence is permitted by the laws of physics. However, just because they can exist, doesn’t mean they do exist, since a positive detection of wormholes has never been made. Recently, physicists De-Chang Dai and Dejan Stojkovic published a paper outlining what a possible wormhole detection could look like, and how to look for them.

An important thing to note is that wormholes are two-directional. Theoretically, if objects can travel from point A to point B using the wormhole, then they can also travel from point B back to point A. This paper rests on the fact that if matter can be exchanged in this manner across a wormhole, then forces must also behave in the same way. For example, if a negative charge is on side A of a wormhole, and a positive charge is on side B of a wormhole, then the two charges experience an attraction to one another, due to the electromagnetic force transmitted across the wormhole. To an observer unaware of the wormhole on side A, this behaviour would look very strange, as it would appear that the negatively charged particle is experiencing a force from nowhere.

The authors propose that a similar method could be used to detect wormholes candidates. Rather than charged particles, however, the paper suggests using stars as wormhole detectors. One popular idea is that black holes themselves may harbour wormholes. Suppose we want to determine whether the black hole in the centre of our galaxy, Sagittarius A*, contains a wormhole. The paper suggests observing the orbits of stars around Sagittarius A* and looking for any unexplained deviations. Such deviations may suggest that the stars are experiencing gravitational attraction to massive objects, like other stars, on the other side of the wormhole.

Unfortunately, there is a catch. Unexpected deviations in the stars’ orbits may be caused be the black hole containing a wormhole, but this is not the only potential cause. There exist many other explanations that do not include wormholes which can explain the perturbation of a star’s orbit around a black hole, such as other stars which may be obscured from view. Consequently, although this paper proposes an exciting prospect, it is by no means a definitive detection method.

Sunday, October 27, 2019

The 2019 Nobel Prize in Physics

Credit: Nobel Institute

On October 8, the 2019 Nobel Prizes in Physics were announced. This year, there were three recipients: Swiss astrophysicists Michel Mayor and Didier Queloz, and Canadian physicist James Peebles. Peebles will receive one half of the associated monetary prize, and Mayor and Queloz will split the other half.

Michel Mayor and Didier Queloz are being recognized for one of the most revolutionary discoveries in modern astronomy: the detection of the first exoplanet orbiting a main sequence star. The planet 51 Pegasi b, also known as Dimidium, was discovered in 1995 around the star 51 Pegasi 47.9 lightyears from Earth using the radial velocity method. It had a mass of around 146 Earth masses and orbited its host star in 4.23 days. This discovery proved to the scientific community and the world at large that planets exist beyond the solar system. Since then, exoplanetary astronomy has experienced a massive boom in research, resulting in over 4,000 known exoplanets.

51 Pegasi b is a significant discovery not just because it demonstrated that exoplanets exist, but because it showed astronomers that exoplanetary systems will vary greatly from our own. 51 Pegasi b is the only planet in its system, and it is a Jupiter-sized planet that orbits its star very closely. Comparing this to our own eight-planet system, where the closest gas giant to the Sun takes 12 years to orbit the Sun, this system is in stark contrast to our own. 51 Pegasi b is the original “hot Jupiter”, a class of planet that further research has shown is one of the most common types of exoplanet. This discovery paved the way for the exoplanetary astronomy of today, which will hopefully culminate in the discovery of truly habitable worlds, and perhaps extraterrestrial life, sometime in the future.

James Peebles is being recognized for his ground-breaking contributions to theoretical studies in physical cosmology. Once, physical cosmology was not considered a serious or rigorous branch of physics. However, thanks to the work of physicists such as Peebles, it is now our best tool for understanding how the origins and eventual fate of the universe. He has been previously recognized by the Shaw Prize, whose citation for Peebles stated that he transformed “a highly speculative field into a precision science."

Peebles made significant contributions to the Big Bang model, our current theory which describes the origin of the universe. He also predicted several ways in which the Big Bang model could be experimentally supported, such as the cosmic microwave background (CMB). He made further significant contributions to big bang nucleosynthesis, models of the formation of large-scale structure in the universe, and the ever-mysterious dark matter and dark energy. The significance of Peebles’ career cannot be understated, as thanks to his work, we have an exceptional understanding of the origin and evolution of the universe. Studies in physical cosmology will ideally lead to, sometime in the future, a complete understanding of dark matter and dark energy; this would be a grand triumph in our quest to understand reality.

Mice with Human Brain Cells

A recent study published in the Journal of Neuroscience worked on implementing human brain cells into mice brains. The presence of human brain cells in the mouse’s brain allows scientists to study different neurological diseases and conditions in a whole brain, rather than a laboratory dish. According to Steve Goldman, the study’s lead from Rochester University Medical Centre, these mice still have their own neurons which are responsible for sending and receiving information from various parts of the body. What makes them unique is the presence of human glial cells that are responsible for supporting neurons. 

Rochester University scientists extracted glial cells from the human fetus and injected it into young mice. In fact, each mouse received 300,000 human glials which multiplied to 12 billion after a year, ultimately moving the mouse counterparts to the margins and replacing the native cells. The extracted glial cells were ‘astrocytes’ which are responsible for maintaining the ionic environment within the human brain. They also play an important role in the movement of electrical signals from one neuron to the other. 

According to NewScientist, human astrocytes are almost 20 times the size of mouse glial cells. Therefore, by implementing human glial cells in mice brain, a huge difference is noticed in the conduction of electrical messages, eventually leading to changes in mice intelligence. Interestingly, Goldman’s team used standard memory and cognition tests to realize that mice with human glial cells have a much better memory, almost 4 times greater than the control mice.

Learn more by reading the full article at New Scientist:

Original Journal:

Image Credit: EXPRESS (express.co.uk)

Saturday, September 28, 2019

A Safe Way to Fix a Heart

Karen Christman, one of the inventors of VentriGel and the CEO of Ventrix, is a Department of Bioengineering professor at UC San Diego.

From UC San Diego, a spin-off company known as Ventrix has accomplished a phase 1 clinical trial to test if a hydrogel - referred to as VentriGel - can safely heal cardiac tissue and thus allow the heart to function normally again in patients who have recently undergone a heart attack. 

Heart attacks can take a large toll on cardiac tissue, leading to scarring. Scarred tissue greatly impairs cardiac function due to damaged cardiac muscle. The idea centered around VentriGel is for it to serve as a scaffold that can bring new cells over to the damaged sites of the heart and essentially fix the cardiac muscle, thereby restoring heart function. 

The production of this hydrogel is relatively straightforward. Cardiac cells are eliminated from pig cardiac connective tissue and the tissue is then freeze-dried, turned into a powder and finally into a liquid. Via an injection, the liquid enters heart muscle where physiological temperature turns the liquid into a porous gel. 

The clinical trials are FDA approved and they explored the effects of this hydrogel in 15 patients who had heart attacks that specifically left their left ventricular chamber fairly damaged. Before injecting VentriGel a maximum of 18 times, the patients had a walking test and several other cardiac assessments. These assessments were repeated after three and six months and MRIs were conducted three and six months post procedure. 

After the injection of VentriGel, patients were observed to increase their walking distance and had overall better heart health. Ventrix is hoping to move forward with phase 2 trials in which a more generalized cohort will be used to comprehend the potential hydrogel has on improving the lives of people suffering from heart attacks. 

Read more at:

Image Credit:
David Baillot/University of California San Diego

Thursday, September 26, 2019

Amphetamine as a Performance-Enhancing Drug

In 1837, Romanian chemist  Lazar Edeleanu synthesized Amphetamine, which was later used by the US army to prevent fatigue among soldiers in World War II battlefields (1). Since then, the usage of amphetamines has broadened greatly. In the 1950s, it first appeared as the performance-enhancing drug used by athletes (2).
Amphetamine is part of a group of central nervous system stimulants which increase the effect of neurotransmitters noradrenaline, dopamine, and serotonin (3)(4). In the production of these neurotransmitters, chemoreceptors act as monitors. Chemoreceptors detect the presence of amphetamines in blood and send a message to the hypothalamus, the coordinating center. Subsequently, all receiver neurons act as a regulator for the hypothalamus’s message. In a healthy brain, neurotransmitters are released to synapses by an action potential. After creating an electric message in the receiver neuron, neurotransmitters would move back into the sender neuron’s axon through the process of reuptake. Amphetamines disrupt the process of reuptake, causing a more frequent signal production than normal.

Amphetamine increases noradrenaline’s effect by stimulating receptors in vessels. The resultant vessel constriction enhances the transportation of oxygen and nutrients to the brain and heart, which prevents the occurrence of lactic acid fermentation and fatigue (5). Although this improves performance in competitions, high noradrenaline in the blood causes anxiety, hypertension and heart attack (6). Inhibiting the reuptake of dopamine and serotonin (increasing their effects) causes euphoria, enthusiasm and self-satisfaction, which are psychologically beneficial for athletes before stressful contests. However, the extreme sense of satisfaction is addictive meaning that after a while, the brain would only function naturally if amphetamine is present (7)(8).

Learn more about amphetamine by checking out the article's resources:

(1) https://www.sciencehistory.org/distillations/magazine/fast-times-the-life-death-and-rebirth-of-amphetamine
(2) https://pdfs.semanticscholar.org/d932/06b1bc088c8c6bf2909397e11d772cac7ca9.pdf
(3) https://www.medicalnewstoday.com/articles/221211.php  
(4) https://www.ncbi.nlm.nih.gov/pubmed/2853386
(5) http://www.netdoctor.co.uk/medicines/heart-and-blood/a7006/noradrenaline-norepinephrine/
(6) https://www.livestrong.com/article/138774-high-norepinephrine-symptoms/ 

(7) https://www.psychologytoday.com/us/blog/evolutionary-psychiatry/201105/dopamine-primer
(8) http://www.psypost.org/2017/01/increased-serotonin-ramp-motivation-lower

Image Credit: Clarity Way

Monday, September 16, 2019

James Webb Space Telescope Fully Assembled

Image Credit: NASA

One of humanity’s most valuable resources for exploring the universe is space-based telescopes. Perhaps the most famous of these telescopes is Hubble, which has had an impressive 29-year career. With time comes age, however, and there now exist improved pieces of technology that compete with Hubble. As a result, plans for the James Webb Space Telescope, a next-generation space observatory, were created. Originally it had a planned launch date of 2011, however, billions of dollars over funding and eight years later, JWST still has not launched. This date is now firmly on the horizon because for the first time, its two halves were joined together by NASA engineers.

JWST is composed of two main parts: the telescope itself, the iconic golden mirror made of 18 hexagons, and the spacecraft itself, equipped with a sunshield to protect the telescope’s scientific instruments from harmful solar radiation. Until now, these two parts have been separated. Each piece has undergone several brutal tests, designed to simulate both the ascent to space on a rocket and placement in space. However, they have not yet been tested together; now, this is possible.

This assembly is a major milestone in the project’s history. The telescope has survived cancellation attempts and waves of criticism after successive launch dates have not been met. Thankfully, this indicates that the end is near, with a current projected launch date of March 30, 2021.

JWST will play a crucial role in observational astrophysics for the coming decades of the 21st century. As the successor to Hubble, it will provide us with an even better ability to observe the universe. Compared to the Hubble, it has significantly increased resolution and sensitivity, allowing for never-before-seen images of the cosmos to be captured. Observing primarily in the infrared spectrum the James Webb Space Telescope will allow scientists around the world to explore some of the most fundamental mysteries in astronomy and cosmology. It will be able to see farther back into the history of the universe than ever before, perhaps even observing the first galaxies to have ever formed.

Physicists Discover a New Phase of Matter

The three most common states of matter (solid, liquid, and gas) have been known to humans for as long as we have been able to observe them. Then, as science began to progress, we began discovering new states of matter that are infrequently, or even never, observed in nature. These include common states such as plasma, and much more exotic states such as Bose-Einstein condensates and superconductors. This list of exotic states continues to grow, with its most recent addition being topological superconductivity.

Although the quest for new, more exotic states of matter may seem like nothing more than an investigation into how strange nature can be, topological superconductivity has important implications for our future. In their paper, Mayer et al. report that this new state could increase storage in electronic devices, and more importantly, improve quantum computing.

Quantum computers are of such interest because they can perform calculations far faster than the computers of today. Currently, computers operate fundamentally on digital bits, which consist of binary inputs 0 or 1, to execute commands, complete tasks, and run calculations. However, quantum computers operate instead on qubits, quantum systems which are capable of taking on any value between 0 and 1, significantly decreasing calculation time.

The study focused on what are known as Majorana fermions, which are of particular interest to quantum information researchers because they can store quantum information in such a way that it is shielded from any environmental interference. However, there was no known substance that could successfully contain these particles for actual use, until the recent discovery of topological superconductivity.

Due to its ability to host Majorana fermions, topological superconductivity shows promise for fault-tolerant quantum computing. This would allow qubits to store information while providing that state the ability to be manipulated without causing error. The information encoded by each qubit can now be protected from errors that arise either from interactions with the surrounding environment, or from interactions within the computer. This discovery will have important implications for our future, as the age of quantum computing will soon be upon us.

Read the research paper here: https://arxiv.org/pdf/1906.01179.pdf