Posted on by Sinenhlanhla Sikhosana

Mysteries of the Universe

How much of our universe do we know?

Public science engagements have been the fuel that drives my love for astronomy. Whenever I have astronomy-related public engagements these are some of the questions I often get: Is there life out there? What is the fate of our universe? How was the universe formed? In this blog, I am to tackle these questions and give a brief overview of the universe as we know it.

The longest presiding theory of how the universe formed is The Big Bang Theory (no Sheldon is not part of it); According to this theory, 13.8 billion years ago the universe was just a single point (singularity) an explosion occurred (‘big bang’) and the universe started expanding. This period of rapid expansion (inflation) lasted for a short moment, as the expansion slowed down the temperature decreased to a point where basic building blocks of particles started forming (nucleosynthesis). This epoch was followed by a phase where the universe was a dense plasma (Cosmic Microwave Background) the remnants of this plasma are still visible today and can be observed using radio telescopes (e.g. ACT; PLANCK). As the universe continued expanding clumps of matter were pulled by gravity and stars were birthed. As more matter accreted larger structures started forming; first galaxies, then clusters of galaxies and these structure formations evolved to the universe we have today.

Source: phys.org

The Lambda Cold Dark Matter (LCDM) model is the mathematical representation of the Big Bang theory. Lambda (Λ) is the cosmological constant which was used by Einstein to compute his theory of general relativity; it is related to dark energy (which could be understood as a force that pulls things apart, causing the universe to expand). Cold dark matter is deferent to the normal matter (baryonic) as it does not emit light (‘photons’) but its existence is proved through its gravitational effects. According to this model, the universe is constituted of 68% dark energy, 27% dark matter and 5% ‘normal’ matter. So, all the stars you see at night and the billions of galaxies that have been observed only make up 5% of the universe! Using the LCDM model we can also predict the fate of our universe; currently, cosmologists believe that our universe is ‘flat’, hence, it will continue expanding forever and eventually the universe will be a cold frozen place. No need to worry though, it won’t happen any time soon (soon being billion years scale).

Although the Big Bang theory and the LCDM model explain the bulk of the observable universe, it has been adapted to further explain the physical phenomenon that we observe today (e.g. The Oscillating Universe Theory).

The curious mind never rests! So now that we have a clearer idea of the origins of the universe more questions pop up. One of the prominent questions is: Are we alone in the universe? I believe not, but of course, we have to back our beliefs with scientific evidence. There are two main approaches to answering this question; searching for earth-like planets and awaiting signals from aliens.

Kepler, a NASA space telescope is on a mission to locate planets that are in the habitable zone which could sustain life. To date, Kepler has detected 4164 exoplanets and recently it was reported that the most earth-like planet was discovered by the Kepler mission. This exoplanet orbits a star similar to our sun, it’s 1.06 times bigger and receives 75% of the sunlight that Earth receives from the sun. As exciting as it may sound, this planet is 300 light-years away from us; this means that if we were able to travel at the speed of light, it would take us 300 years to reach this planet. So please take care of our planet, we have no alternative home!

The SETI Institute, on the other hand, aims to use radio telescopes to ‘listen’ to extraterrestrial intelligent life. Their strategy is to search for narrow-band radio transmissions that come from outside our solar system, these transmissions would indicate extraterrestrial technological advancement and signal the possibility of intelligent life outside our solar system. A SETI Institute researcher once presented at a conference I was attending, a student asked: ‘So if we do eventually find aliens, what’s the plan?’. The presenter didn’t quite answer the question, my only hope is that they would be kinder than humans.

Astronomy is an exciting field because it is continuously evolving. With the majority of the Square Kilometre Array (SKA) being hosted by South Africa, there has never been a better time for young students to hop on the astronomy bandwagon. The SKA project will require expertise from various fields such as; Engineering, Artisan, Computer Science etc. The beauty of astronomy is that it doesn’t box one to a particular set of skills but instead exposes one to various fields.

The ultimate ‘cherry on top’ is that although many questions have been answered, many more are yet to be asked. Sometimes it takes decades to answer one question (e.g. the existence of gravitational waves) and at times the discovery of one phenomenon raises a thousand more questions (e.g. Fast Radio Bursts). So if you, like me, are always on a quest for problems to solve; then astronomy will be equally fascinating for you.

Posted on by Itumeleng

Publish or impoverish: the new academic struggle

Staying motivated and focused in graduate school it is not an easy task, and in my recent blogs (here, here, and here) I shared tips and resources I use to survive graduate school. But, there is a far more powerful and enticing incentive to stay motivated-MONEY! It is of course welcomed in most scientific research (lab consumables, technical services, glassware…) and paying hard-working graduate students 😉 , but here I will discuss a more sinister and insidious aspect of money — when it is used to ‘motivate’ scientist to publish. I would like to preface this blog by stating that the thoughts and opinions expressed here are neither a condemnation nor an endorsement — that judgement I leave to you.

The route to academic success and tenure is paved with

 the blood, sweat, and tears of newly appointed faculty members. In most countries, a new assistant professor (the equivalent of a senior lecturer in South Africa) is hired on a probation basis and after a set time (5-7 years) there is an evaluation. Then, depending on certain factors (number of students, external funding acquired, collaborators, and published articles) a judgement would then be made to either terminate or give tenure to the

 person. This story focuses on the last issue — published articles. Now, all journals are not created equal and some have a higher impact factor(IF), and a publication in a high IF journals like such as: Nature, Science, Cell, and The Lancet usually guarantees tenure.

An article published in Science a few weeks ago sent shockwaves through the academic world when it revealed that most countries, notably China, Arab states, and South Africa where paying academics for publishing. However, this payment system opens a Pandora’s box- how much of the scientists’ publishing is fueled by greed and the need to enrich themselves? Will proper scientific conduct be upheld in order for academics to enrich themselves? How sustainable is this system in developing future scientists? Now, these questions are not without merit. In countries where this system has been put in place, there have been recorded occurrences of scientific misconduct (such as data manipulation, unethical experiments). No, I’m not saying that financial incentives always lead to misconduct, as unethical science occurs in “unpaid” systems too. But attaching a monetary value to an article certainly can nudge some to take that extra step towards cheating, if you were ever so inclined…payment

 

In South Africa, the rise up the academic ladder is contingent on multiple factors, publications being one of them. Primarily, most researchers in South Africa all seek the coveted NRF rating, and this has a great impact on the progress up the academic ladder. Your rating is strongly related to the number and quality of publications you’ve produced. Fair enough. But there is also a cash incentive system, which – in most cases – purely counts the number of publications (quality matters little).

A recent report highlighted that the ‘cash for publication’ system has led to increased research output at Stellenbosch University and North West University. Although both institutions state that it is “not all about money” they attribute the increased number of publications in international journals to the system. Of course, there are universities that do not provide these direct cash incentives (the University of Cape Town and the University of Witwatersrand, for example) and they have seen increases in research output, particularly publications in international journals. But the institutions that believe in the cash incentive system argue that it’s sometimes just the little shove that their academics and students need to take the extra step. After all, would you not be motivated to turn that minuscule little Honours thesis into a proper publication if it could get you some extra research money? Research (especially student-led research) may, therefore, become peer reviewed and published because of that extra financial lure.

For me, a report published by Prof. Catriona Macleod of Rhodes University (another university that does not offer these direct cash incentives) in South Africa perfectly echoes my sentiments on the matter. In it, she highlights three points of the incentive system that seem to be counterproductive, that is, 1) it leads to what she termed “salami-slicing” research, where instead of publishing a comprehensive paper there is an incentive to split that paper into several papers, 2) it discourages collaborations, as the money is shared equally between authors (more collaborators = less money), and 3) there is no distinction made between high IF journals and low IF journals. The tough call for many SA researchers is therefore that the cash incentive system works directly opposite to the prestige and career rewards associated with the NRF rating system (which focuses on quality, collaborations, and international recognition).

Admittedly, every researcher has their own motives for doing science and those would dictate their career trajectory. What keeps you motivated? What aspirations keep you in science?