One of Albert Einstein’s greatest contributions to science was the theory of special relativity. Many of us have heard of this theory, but do you actually know what it means? It is half of the overall theory of relativity; special relativity is concerned with constant speeds, whereas the other part, general relativity, is concerned with acceleration. 

The main theory of special relativity is that the speed of light is constant to all observers. This is very counterintuitive to how other relative speeds work. 

Imagine you are driving down the motorway at 100km/h and another car overtook you at 110km/h. To you, it would look like they were moving at 10km/h as you are already moving at 100km/h. However, if they were moving at the speed of light, no matter how fast you were moving, they would still look like they are moving at the speed of light.

Very strange things start to happen at such high speeds. If you were travelling at the speed of light, you would experience distances being shorter in the direction of motion and time passing more slowly, relative to a stationary observer. This is known as time dilation. As speed = distance/time, as you try to increase your speed, your distance decreases and time increases meaning that your speed cannot increase past a maximum value, which is the speed of light.

Another reason why the speed of light is the fastest speed you can travel at, is due to Einstein’s very famous equation, E=mc². This equation shows that energy and mass are just different forms of the same thing. In fact, one joule of energy is equivalent to one gram of mass times the speed of light squared. 

As you increase your speed up to the speed of light, your kinetic energy increases. As energy and mass are equivalent, this increase in energy causes your mass to increase. This makes it harder and harder to accelerate, as you get heavier and heavier. Eventually, you will be so heavy that you cannot accelerate at all and you will not be able to move faster than the speed of light. 

So, in summary, special relativity means that very strange things start to happen close to the speed of light.

Most of you have probably noticed that I recently sprained my ankle and am therefore currently on crutches. And the people who have known me for multiple years will know that this is not the first time that I’ve been on crutches and that I’ve also injured my arms/hands multiple times. I think at this point, it’s fair to say that I am rather accident-prone. Interestingly, my mum is also accident-prone, which led me to wonder whether being accident-prone is something that runs in families, i.e. if there is a genetic component linked to getting lots of injuries.

Intuitively it seems like a plausible explanation; things like bone density and collagen (the main structural protein in connective tissues such as tendons and ligaments) production are controlled by your genes, which means that you would have inherited alleles for these traits from your parents.

Based on research that has been conducted on athletes, this might indeed be the case. Researchers have found that versions of the collagen gene COL1A1 were underrepresented in athletes who had ACL injuries and that another collagen gene COL5A1 was also linked to higher Achilles tendon injury risks. Another study, done by the National Institute of Health in America, was able to identify a link between the GDF-5 gene and bone health. There are many more similar studies out there, which have all identifies links between variants of some genes and higher risks of injury. While this does indicate that being injury prone is linked to genetics, all the different genes that are being identified, also indicate that it is a very complex trait and that there might be different types of injury which people can be particularly prone to.

This is of particular interest to athletes, especially professional athletes, as further research into this area could allow the athletes to get genetic tests done, which would help them identify if they are at higher risks of injury or not. This information would then allow them to take precautions to avoid getting injured. There are however ethical issues with such genetic tests, as depending on how the genetic information is stored, other people may be able to get access to it, which could potentially lessen the chances of an athlete being able to compete for a team if they are more injury-prone, or more generally, it could have implications on health insurance costs.

Just to be clear, I’m not saying that being injury prone is completely genetic. I’m very sure that there are many other factors, especially lifestyle factors, that contribute to it, but at least now those of us who are accident-prone know that we can partially blame our parents for all of our injuries.

Below is a picture of the Sahel, a transitional strip of land measuring 8000 km long and 15 km wide. It sits below dry desert land (Sahara Desert) and above tropical savanna (Sudanian Savanna). Countries that lie in it include Mali, Niger and Senegal.

As a result of desertification, population growth and unsustainable agricultural practices the Sahel has turned from being fertile and fruitful into dry and barren. Millions of people who have depended on food that has been grown and purchased from this land have been put under immense hardship.

An English Biologist, Richard St. Barbe Baker, conceived in 1952 the idea of a ‘green barrier’ to reverse desertification in the Sahel. It took till 2007 for the African Union to transform this idea to the affirmative action that would change present and future lives across Africa for the better.

After a decade of planting trees the project is now 15% complete. Soil that was once eroded by the wind and replaced with sand is now protected by the trees that stabilize, increase water retention and introduce nutrients to it.

The canopy of these trees increases the humidity of the environment and blocks sunlight, reducing the need for water. Their leaves can also be used as compost.

Not only do these trees benefit the land. Crops cultivated from gardens have generated an economy that people can sustain themselves with and sell to others.

When it is completed the Great Green Wall will be three times the size of Great Barrier Reef, making it the largest living structure on the planet.

To read more visit https://www.greatgreenwall.org/

In Psych over the last two weeks, we have had to examine and understand the impact that mobile phones have on our learning. When I first started reading the assigned material, I rolled my eyes. This was just another push for us to get off our phones in lectures as phones were a distraction. I am sure we have all heard an adult or two in our life tell us to put our phones away… 

Nonetheless, I had to do the assignment. So, I started reading about a study which discussed how the presence of a phone can cause distraction. In this particular experiment, the participants had to carry out certain cognitive and critical thinking tasks. These were a way to measure attention and some of the tasks required complex thinking, These tasks were timed. 

The first study was conducted and used the experimenter’s phone which was left on the corner of the desk while the attention tasks were completed. The second study was conducted with a different group of people and this group of participants had their own phones on the desk while they carried out similar cognitive tasks. Results showed that there was a statistically significant difference between the groups who had their phone on the desk when participants had to carry out tasks which were cognitively demanding and required specific attention. 

So, according to this research, there is a potential correlation between having your phone near you when you have to carry out tasks which require some extra brainpower. Our generation is heavily reliant on our phones and I am sure that the majority of us can agree that we use them on a regular basis. But maybe it is time we think about the resulting impact of this phone attachment.

Honestly thinking about it, I think my Psych lecturers have done a pretty good job by setting us this analysis task. The data which has been presented does actually show some correlation between attention and phone presence. 

It seems that there is not enough research to use the findings against us and fully ban phones within lecture theatres. And it is important to note that there are a lot of factors such as type of phone and phone usage, which were not taken into account.

Whether you have gotten some insight into my psych paper, or have learnt something about how the presence of a phone is distracting, hopefully, we are able to do some critical reflection on the ever-growing issues relating to phone usage!

Carbon and nitrogen are two of the most abundant and important elements for life on Earth. Carbon is the basis of all living organisms, our atmosphere is 78% nitrogen, and humans are made up of 18% carbon and 3% nitrogen. But where did these elements come from?

When intermediate mass stars, like our Sun, reach the end of their lives, the nuclear fusion in their cores stops and it forms a helium core. It also forms a large hydrogen envelope around this core, turning it into a red giant. 

The gravity of the star causes this hydrogen envelope to collapse slightly, causing more pressure at the core, allowing more nuclear fusion to occur. This forms larger elements up to carbon, nitrogen and oxygen, in what is known as the CNO cycle. Eventually this process stops, and it forms a carbon and oxygen core. The hydrogen envelope is then sent out from stellar winds, taking some of the carbon and nitrogen formed in the fusion reactions with it. 

This leaves behind a carbon and oxygen white dwarf, surrounded by a planetary nebula, made from the gases sent out from the envelope. This produces most of the carbon and nitrogen in the Universe and can create beautiful colours and patterns as in the Cat’s Eye Nebula shown below. 

So, just remember, all life comes from dead stars. 

It may be surprising that hypothetical rabbits were the cause of one of the most famous mathematical results, but it’s true. I know many people don’t love maths (although you should) but don’t get scared off. As long as you can handle addition, you’ll be alright, trust me.  

You’ve probably heard of the Fibonacci sequence, where each new number is the sum of the two numbers that come before it. It starts with…

1 1 2 3 5 8 13 21 34 55 89 144 233 377 610…

But where did this come from? Way back in the 12^th century, Leonardo Pisano, now known as Fibonacci, came up with this sequence by thinking about pairs of imaginary rabbits. 

He supposed that if you start with two baby rabbits, one male and one female (1 pair). One month later they are now fully grown and are able to reproduce (still 1 pair). After two months, they have produced a pair of baby rabbits, again one male and one female, (2 pairs). After three months, the original pair will have reproduced again, and the younger pair will now be fully grown (3 pairs). This process then continues, producing more and more rabbits until the world is overtaken by rabbits. The first six generations are shown in the diagram below. 

This pattern of how many pairs of rabbits there are, gives you the Fibonacci sequence. While this is interesting from a mathematical point of view, it is clearly not an accurate representation of how rabbits reproduce. This scenario requires rabbits to reproduce exactly once a month and then produce exactly one male and one female rabbit, which is not the case in nature. That’s not to mention the excessive inbreeding and the fact that rabbits have to be immortal for this to work. 

So, take some time to imagine some animals and maybe you will become the next famous mathematician.

References:

Knot, R. (2013, November 04). The life and numbers of Fibonacci. Retrieved from https://plus.maths.org/content/life-and-numbers-fibonacci

Thomas, R. (2015, January 06). The Fibonacci sequence: A brief introduction. Retrieved from https://plus.maths.org/content/fibonacci-sequence-brief-introduction

Tucker. (2013, May 10). Rich with Fibonacci Gold. Retrieved from https://artblot.wordpress.com/2013/05/10/rich-with-fibonacci-gold/

I’m sure that at one point in your existence you have come across the term ‘antibiotic apocalypse’. Maybe you were reading an article on it whilst inhaling your 3^rd bottle of antibiotics for that tiny chest cold that you had.

But what do you actually know about this so called ‘apocalypse’? What actually is it and how does it work? Here is a very brief breakdown on what you need to know about antibiotic resistance, without any of the technical jargon that we so disgust.

Antibiotic resistance is a rapidly increasing problem in our current day. It currently kills an estimated 700,000 people each year worldwide and some experts predict that by 2050 this number could rise to 10 million.

So, what is actually going on to make the bacteria resistant to our drugs? I’d like to introduce my old friend… our favourite NCEA Level 2 concept… natural selection! Or in some cases the term coined ‘survival of the fittest’. Bacteria learn, or more accurately, adapt. And there are many ways that this can happen. Bacteria can inherit resistance, or acquire it through quite a few different ways, such as:

• Vertical gene transfer; spontaneous mutations. These instances are quite rare in that a bacterium will acquire a mutation that allows them to be resistant. But due to the rapid replication of bacteria, if one does occur, it will flourish in the population and pass on its resistance to its offspring
• Horizontal gene transfer; this can be done one of 3 ways.
  • Neighbouring cells get a bit too cosy and end up sharing some bacteria that have the resistant strains
  • A virus (bacteriophage) goes between two cells and carries some DNA with it
  • Free DNA in the environment, such of that from a cell that just died can be up taken by the cell

The resistance mechanism itself can also be a variety of things. Usually it has something to do with the enzymes inside of the bacteria that are able to degrade or modify the antibiotic so that it is no longer viable. Some cells have a resistance mechanism that is literarily just a pump that pushes the antibiotic out of the cell immediately after entering it.

We are in a constant race with bacteria, as they are constantly mutating and adapting to our antibiotics. Seeing as the ‘golden age’ for antibiotic development was in the 1920s-1960s, and we didn’t really develop any new antibiotics from 1960s-2000s, we may be in a bit of a pickle.

And of course, like almost every single human problem, the root of the problem lies in the money. Drug companies don’t want to invest in antibiotic development because it is not an attractive proposition right now. If we are able to discover a new antibiotic, the last thing we should do is expose the bacteria to it and allow them to adapt to it. So, if a drug company was to fund research for antibiotics, if they were successful in discovering one, we would have to store them away until some deadly virus comes along that we REALLY need the antibiotic for. And this means that the companies won’t be getting any money, so therefore, they don’t develop them.

And that is your very brief introduction to all you really need to know about the world of antibiotic resistance.

 Nowadays it is statistics that helps us to determine if we should accept any hypothesis in science. Before statistics was introduced, scientists hardly do more than one trials in experiments, so there were not so much reliability in their results–they mixed up the systematic errors and random errors, so 1. it becomes hard for these scientists to decide how much away from the prediction shall be considered as an error; 2. they wouldn’t be sure whether such error, if exists, came from just chance or anything incorrect in their theoretical predictions. All these wouldn’t be realized without introducing the idea of randomness.

 Randomness is purely conceptual, that people are experiencing randomness every day without noticing. Intuitively people tend to seek causal links between events and ideas, that everything would be caused by something, and would also cause something. But the appearance of randomness has no reason, so it is anti-intuitional. How on earth did people come up with the idea of randomness?

 In 1877, Darwin’s cousin, Francis Galton conducted an experiment. Galton set up a piece of wood, such that the top half of the board is lined with little bars, and the bottom half is a row of vertical grooves. Small balls fell right down from the middle of the top, and after a row of little deflections, landed in the trough below. Of course, you can’t figure out which vertical slot you’re going to land in. The collision is random. This board is called the Galton Board.

Though we’re not able to calculate precisely, of which ball falls into which slot at the end; the results still appear to be the same shape every time. Statistically this is known as Normal Distribution. Galton used this to simulate the heights of people at one generation, and the little bars on top half of the board simulates the influencing factors to people’s height. What’s more interesting is that Galton then took the experiment one step further and attached another Galton plate to the original one. In other words, let the ball normally distributed in the vertical slot fall down again, pass through a lot of small blocks again, and fall into a row of vertical slots again. The distribution of small balls in the second vertical slot magnifies the trend of normal distribution. That is, the number of balls between the vertical grooves will become more even. This curve, made up of little balls, is going to flatten out. The doubled Galton plate simulates the inheritance of two generations. In the real world, the result should be that in the first generation, very tall and very short people were in the minority; but in the second generation, there will be more people who are very tall and very short, and fewer people who are average height, similar to the distribution of small balls in the second Galton plate.

 However, this isn’t the case in the reality. In any generation, the very tall and the very short are in the minority. This shouldn’t be true if the height of the next generation is inherited from the previous generation, which predict that the very tall people are likely to have children who are taller than their parents. And as the generations go on, there will be more and more, very, very tall people; also, there will be more and more, very, very short people. But that didn’t happen. Tall people tend to have shorter offspring in the next generation; and short people tend to have taller offspring in the next generation. Overall, the distribution of height in each generation does not show increasing polarization. Such phenomena is called regression, towards the average. But what causes such a regression? Galton thought about this question for 12 years, and came up with the conclusion that there is no reason for this. The height of individuals in one generation is correlated with the height of individuals in the next generation, but does not cause any change. From then, causation has been criticized across all science areas.

(Inspired from a new book: “The Book of Why: The New Science of Cause and Effect”, Authors: Judea Pearl, Dana Mackenzie)

Background:

  One ordinary people may become a hero someday. As time proceeds, with probability acting ubiquitously, nothing is impossible, and we need to be ready for any sort of critical situation at any time.

 On 14th of May in 2018, the captain Chuanjian Liu was flying his flight, 3U8633, at 9800m altitude above the Tibetan Plateau. About half an hour after he has taken off, at 7 am, ‘one of the cockpit windshields on the copilot’s side blew off during the climb towards cruising altitude’, after some cracks appearing for some unknown reason. Some panels and instruments in the cockpit has blown out immediately. The copilot had half of his body blew outside due to the extraordinarily unbalanced pressure inside and outside the aircraft body; but he had his belt on, and the broken windshield was right at the front of the cockpit so wind was blowing into the aeroplane, thus the lucky copilot essentially managed to climb back into the cockpit, with his right arm and waist wounded. It was such an urgent condition: under -40℃, pilots only had their shirts on; at a speed of approximately 225 m/s whilst wind kept blowing in, with almost no air supplied inside the cockpit for a few minutes; the plane was on a position flying down towards a sea of mountains; and the automatic cruising system was out of control, the pilots weren’t even sure if the apparatuses were working, or providing incorrect data; with hardly any contact to the control towers or to each other due to the loudness of the wind; the unbalanced pressure has injured the copilot’s ear. It was the crucial moment for 128 lives.

 As a miracle, following his rich experience, our captain managed to divert to Chengdu Shuangliu International Airport, with 0 death, by manually looking outside to see the direction of flight. Recently there was a movie newly released, themed in this event.

Scientific Comments:

Apparently, there are lots of engineering issued involved, but a detail caught my attention as a statistician. Once in an interview in early 2019, Chuanjian mentioned that the safety notes under urgent circumstances are now electronic on a pad, which was sucked outside the window immediately once the accident happened. However, even if the pad did not go missing, it was still not helpful because there was nothing about what to do when the windshield blows off. Statistically the safety notes shall contain those most crucial circumstances, but how to decide which ones are the most crucial ones?

  It isn’t necessary to go deeper into more detailed probabilities for each individual onboard with further assumptions; they are lucky enough, that they’ve got a captain who loves swimming and diving, so he was able to remain awake and calm, to adjust the flight parameters first, at the moment suddenly there was no air supplied. Yes, due to the effect of survivorship bias, it may not be necessary to include such a circumstance in the safety notes for a pilot, but how if we didn’t have a captain who loves swimming, and wouldn’t be so comfortable with vacuum? How if the copilot totally relaxed and didn’t have any belt at all? How if the airport was not so close to the location where the accident happened? Shall we still expect the same luck for such accident next time? Is the luck itself, real or random, in this event? We can’t expect the same things to happen all the time when similar events occur, since the chance for all the details to re-appear will be extremely low. Even if the same thing happened 28 years ago on a British plane, BAC1-11 5390, when the body of captain was entirely sucked outside the cockpit and the airplane was driven by the copilot until landed at Southampton. When we simply think such kind of events has a low chance of occurring, or pilots are supposed to successfully deal with them every time, and thus no longer consider such situations in the safety notes, then these events will be more likely to be disastrous once they really happen.

 Like driving an airplane, our decisions about what to write in the safety guide also needs the tool of statistics, to get out of the fog and into power.

Background:

 On 14th of May in 2018, the captain Chuanjian Liu was flying his flight, 3U8633, at 9800m altitude above the Tibetan Plateau. About half an hour after he has taken off, at 7 am, ‘one of the cockpit windshields on the copilot’s side blew off during the climb towards cruising altitude’, after some cracks appearing for some unknown reason. Some panels and instruments in the cockpit have been blown out immediately. The copilot had half of his body blew outside due to the extraordinarily unbalanced pressure inside and outside the aircraft body; but he had his belt on, and the broken windshield was right at the front of the cockpit so wind was blowing into the aeroplane, thus the lucky copilot essentially managed to climb back into the cockpit, with his right arm and waist wounded. It was such an urgent condition: under -40℃, pilots only had their shirts on; at a speed of approximately 225 m/s whilst wind kept blowing in, with almost no air supplied inside the cockpit for a few minutes; the plane was on a position flying down towards a sea of mountains; and the automatic cruising system was out of control, the pilots weren’t even sure if the apparatuses were working; with hardly any contact to the control towers or to each other due to the loudness of the wind; the unbalanced pressure has injured the copilot’s ear. It was the crucial moment for 128 lives.

Scientific Comments:

 From Wikipedia, for the family of Airbus A320s as the same type of aircraft in this event, ‘Through 2015, the Airbus A320 family has experienced 0.12 fatal hull-loss accidents for every million takeoffs, and 0.26 total hull-loss accidents for every million takeoffs; one of the lowest fatality rates of any airliner.’ Assume these accidents are independent with each other and the chance of getting an event for each take-off is distributed evenly, we can use discrete uniform distribution to get the probability for each Airbus A320 craft to have any hull-loss accident, after a randomly selected take-off, is (0.12+0.26)*10^-6=3.8*10^-7. For this specific aircraft in this accident, which has been used for 19912.25 hours of flights for 12920 take-offs, and had its most recent inspection one month ago with everything fine. Thus this accident is independent with any prior flight records, so we can use Geometric Distribution to get that the probability for this aeroplane, to have any sorts of hull-loss accident at this particular flight (3U8633, 6:25 AM 14th May 2018, Chongqing – Lhasa), with no prior hull-loss accidents, is 3.7814*10^-7. Even if chance is that small, once it happens, everything becomes disastrous for 128 lives. By definition, the expected value of death becomes (3.7814*10^-7)*128=4.840192*10^-5. If we have more data on more reasons of deaths, we may compare this expected death value to see which disasters we shall try the best to happen. It seems cruel to simply evaluating lives as numbers, but this could be the way to minimize the harm of deaths to a society.

Essentially…

 As a miracle, following his rich experience, our captain managed to divert to Chengdu Shuangliu International Airport, with 0 death, by manually looking outside to see the direction of flight. One ordinary people may become a hero someday. As time proceeds, with probability acting ubiquitously, nothing is impossible, and we need to be ready for any sort of critical situation at any time.