close

Science

What’s the Matter with Antimatter?

Matter Antimatter

 

We see symmetry in nature all the time. At our scale, almost every species on earth has some form of external body-plan symmetry; notable exceptions exist, such as flounder. But the symmetry of objects extends into natural processes and even fundamental physics principles. One such symmetry arises with the property of matter known as charge; a rather abstract notion that we can understand as a driving principle behind circuitry and chemistry. But, questions as to why the most basic components of nature have the charges they do and what the significance of charge is are the questions that are on the minds of physicists. An experiment conducted by The Alpha Collaboration published in Nature earlier this year sought to expound on and explore these questions. First, however, some background.

In 1928, a young physicist, Paul Dirac, developed an equation that married Einstein’s Special Relativity – the theory of the very fast with Schrodinger’s quantum wave mechanics – a description of the fundamental nature of matter. His goal was to produce an equation that accurately describes the quantum behavior of matter at high speeds. But Dirac had outdone himself; not only did the equation seamlessly blend special relativity with quantum mechanics, but it made unexpected predictions. In the same way that the square root of 4 is both positive 2 and negative 2, when solving his own equation for the electron, Dirac found that there were two energies for the resulting particle – one positive and one negative. Instead of discarding the negative solution, Dirac supposed that it may represent a different particle, one with characteristics identical to the electron in every way with the exception of one – its charge. Thus the solutions to the equation are a negatively charged electron and a positively charged positron. The notion of antimatter was born. Following this, Dirac’s idea was treated as being an artifact of the mathematics. That is, until antimatter was discovered four years later in 1932.

Since then, the last 85 years have seen an incredible amount of knowledge and application as a result of the discovery of antimatter. One such example is our current understanding of radioactive decay, in particular beta-radiation, in which either a proton or neutron transforms into the other, producing an antimatter particle. This property of the decay is actually exploited in a modern medical technology – positron emission tomography, or P.E.T. scanning for short.

Whilst we’re at it though, an aside. Beta radiation, when you hear about it, can seem as if its reasoning is pulled out of thin air. It turns out that its cause, is actually due to a fundamental physical force known as the weak interaction. The weak interaction is one of the four fundamental mechanisms for change in the universe, and can cause an interchange of matter with antimatter as well as altering the constituents of protons and neutrons. There’s some modern physics for you.

Oh, and in case you’re curious, when normal matter and antimatter engage with one another, they undergo a friendly process known as annihilation and are converted into pure energy in a quantum explosion. In fact, on the same trail of logic: if matter and antimatter create pure energy, can the reverse be said? Astonishingly, the answer is yes! This is actually the main method of antimatter production; we pump enough energy into a vacuum or fire it at an object and the result is a plethora of matter and antimatter particles. When this happens with an electron and positron spontaneously in a vacuum, it is known as pair production.

We’ve already established that the only difference between particles and their respective antiparticles is their charges. We also know that atoms are composed of positive protons and negative electrons (with most having neutral neutrons for stability), making them neutral overall. So it stands to reason if we just flip the charge of every constituent – protons to anti-protons etc., then the overall properties shouldn’t change –because the atoms don’t have total charge anyway. So here are the real questions: is the logic right, does anything change?

Now we’re equipped to talk about the experiment. One of the most well-understood systems in all of physics is that of the hydrogen atom; composed of a proton and an electron. But a classic way of probing hydrogen is to give the electron some energy and see how it responds. The goal of the experiment was to determine whether or not anti-hydrogen responds the same as normal hydrogen. Due to the obvious issues in handling antimatter, the anti-hydrogen must be created, contained and experimented on in very creative ways. First, the basic ingredients must be made in a particle accelerator. Then, the anti-hydrogen was cooked up by combining its pre-prepared ingredients: an antiproton and positron. It was then trapped and contained in a magnetic field so that it wouldn’t interact with anything made of matter. In order to determine its response to light, the antihydrogen was stimulated with a laser and its response recorded.

The results were rewarding and found an identical response to light from anti-hydrogen as they found from hydrogen. As far as interactions with matter and antimatter go, the experiment found light doesn’t seem to care which is which. This is a big step experimentally into understanding the fundamental symmetries of the universe.

But here’s the rub: why is there more matter than antimatter in the universe, and why are we made of matter? We look out at the cosmos and see galaxies and stars only composed of one. We know this is true because otherwise there would be annihilation constantly and we could see its effects. Perhaps it’s all antimatter and we’re the only matter. But that raises more questions of its own and answers less of ours. In any case, this is a big problem in modern astrophysics and cosmology. Had the experiment shown a different response to light from anti-hydrogen we might have an inkling; but no cigar. Every day we understand antimatter and its properties better both experimentally and theoretically. Its origins and seeming lack of ubiquity on the other hand? Right now it’s a matter of speculation.

 

read more

Healthy Skepticism

Web
  Health advertising, like any other advertising, is meant to be compelling. Health ads may promise to fix anything and

Up all night to get lucky

untitled

We’ve all been in that situation before. Hands on head, clock ticking on one side, papers scattered all over, caffeine or energy drink on one end, table lamp on the other and a bleak computer screen with the words ‘’DEADLINE DUE TOMORROW” right in front . And cue *panic attack*.

As university students, we’re all extremely prone to pull the eventual all-nighter now and then. Some of us do it most of the time and emerge victorious 10/10 (I suspect witchcraft involved with this), but with most, it’s usually just rushing to pass or achieve an average mark. We’re well aware of the consequences associated with our decision of pulling an all-nighter but why do we still do it? Well, science states and proves that when the human brain is subjected to any severe/ intense form of stress and or pressure, it chooses to take the quickest route and carry out the said task as soon as possible. This is simply a survival mechanism. The response enables the human brain to quickly react to life-threatening situations. A semester paper due the next day or an impending exam, etc. would be the precise definition of a life-threatening situation. So, as much as people advise us to get seven to eight hours of sleep, we’re somehow going to deny that suggestion completely, respond to our hormonal and physiological changes and jump on to the bandwagon to complete what’s thought to be, a ‘’successful all-nighter”.

Procrastination here is the mother of all evil and most definitely one of the factors aiding the attempt of an all-nighter. Now, as an avid procrastinator myself I can confirm that the guilt and panic does not kick in until the very last minute; that no matter what task big or small, it just somehow decides to get delayed by itself (or the universe conspiring against it) and if there was a rehabilitation centre for this disease, I would willingly admit myself to it. I say this as I rush to write this overdue article. Guilty as charged. Once procrastination comes into play, the situation all goes downhill and we’re trapped into what seems to be a time crunch filled between caffeine and a computer screen. In this small time frame where we work tirelessly trying to finish our task and when we take the irrational decision of not sleeping, what do you think happens to your brain?

Well first and foremost, your hormone levels rise. Cortisol is a stress hormone and as stated earlier, since your stress levels are already high, deciding to stay awake the whole night makes it rise even more resulting in a decrease in memory, bone density and lowering of immunity. Another two hormones that mess things up are leptin and ghrelin which regulate appetite. In individuals who lack sleep, the body tends to produce less leptin and more ghrelin making you feel constantly hungry. Safe to say, if you’re trying to lose weight or be healthy don’t even TRY to attempt an all-nighter. Secondly, your thalamus goes haywire. The thalamus is an essential component of the vertebrate brain and controls consciousness and alertness .Without this functioning properly, the human mind loses its ability to recognize faces and facts. This can be linked with the popular ideology that an all-nighter doesn’t actually help you retain information, but rather forget it and that your prefrontal lobes get tied up. Working memory is divided into four subsystems and all of these are connected to how well your frontal lobe works, and this takes a hit when you don’t sleep.

Now that you’ve been enlightened about the biological consequences of an all-nighter and will still do it anyways, here are some alternatives you can choose to follow:

1. Switch from caffeine to fruit. Eating an apple has been scientifically proven to keep you more awake than consuming a gazillion amounts of decaf.

2. Read and read and read. Rereading the material during the daytime, and then sleeping on it, helps encode that material into your long-term memory whereas if you study all throughout the night, your brain will have difficulties recalling the necessary information.

3. Chuck out the energy drinks and hit the gym instead. Exercise has scientifically be proven to boost your mood and give you more energy due to the mood-enhancing chemicals that are pumped out when you exercise. So in between breaks, squeeze in a squat or two to pump up some of that energy.

4. Stay cool (literally). When the effects of your sleep rhythm start to chime in, it signals your body to sleep by making you feel colder. Resist the urge to turn up the heat and layer down.

5. Vicks it up. A lesser-known trick for an extra boost is found in Vicks Vapor Rub. Since it is a drug containing menthol and camphor, it tries to stimulate your senses and keep you awake.

read more

Living in a dematerial world

untitled3
The other day, amidst my regular schedule of procrastination, I stumbled upon an article that talked about something called dematerialisation

Forever young

white_live-forever_3436769236
Scientists spend a lot of time reading papers to stay on top of the latest discoveries. So when I stumbled

Following the piper: science can’t save the world

Portrait Of Copernicus

Scientism: the uncritical application of scientific or quasi-scientifi c methods to inappropriate fields of study or investigation – Collins English Dictionary

Science, as a paradigm, has had remarkable success in answering the questions it was created to answer, namely those that relate to physical reality. This has led many to wallow in the belief that science is the only legitimate paradigm with which to answer any and all questions. Although science isn’t a religion, many people misuse science in the same way that many others misuse religion — they apply the paradigm to inappropriate questions, and dismiss alternative answers.

Signs that suggest a person is a follower of scientism:

– They deride something as being unscientific, when it has nothing to do with science.

– They quote a famous scientist, or a popular writer, as if the quote ends the argument.

– They say science can solve any problem, often going further by saying that science will solve all problems.

– They dismiss hypotheses that challenge what they perceive as the scientific status quo, for example claiming that an idea is “un-Darwian”, even though they also cite science’s ability to reject long-held ideas in favour of new ones that better fit the evidence as making the field superior.

– They believe science will allow them to live forever in some way, and if they die science will resurrect them to live forever.

– They believe science will inevitably create a utopia.

For the most part, these behaviours are no more damaging than other irrational modes of argument, but there is one result of this belief that is a problem: when people abdicate the responsibility of altering their behaviour to make the world a better place, because that is the job of science.

They think it doesn’t matter if species go extinct and eco-systems get destroyed, because science will just recreate them. It doesn’t matter if wealth inequality is increasing, because science will invent new things that will grow the economy. It doesn’t matter if their products create new forms of pollution, because science will just clean it up.

However, time and time again science has been shown to be inadequate to the task of saving the world on its own. Usually, the solution to one problem creates one or more new problems that need to be solved, and sometimes the negative effects are hard to predict. When people proposed the use of chlorofluro-carbons (CFCs) as a refrigerant, to replace the toxic compounds used at the time, it is understandable that looking at the structure of CFC, one would not have made the leap to the destruction of the ozone layer.

Often the consequences are entirely predictable, however. When antibiotics, used in intensive farming to increase the growth rate of animals, led to deadly bacteria which were resistant to multiple types of antibiotics, that consequence was obvious and inevitable.

More damningly for scientism, oftentimes science simply can’t solve a problem. Often, the ‘Green Revolution’ is used as an example of the omnipotence of science, but I would contend that it is in fact a demonstration of the limitations of science. The Green Revolution aimed to solve the problem of chronic hunger in many parts of the world by increasing crop yield. New farming techniques such as irrigation and artificial fertiliser use, as well as improved seed strains, were introduced to developing nations in the 1970s. As a result, cereal output doubled over the next few decades, which would be a clear win, if the population hadn’t also doubled over the same time period, increasing the total number of people living with hunger.

According to the United Nations, “the number of hungry people in the world grew by 15 million from 1970 to 1980, to 475 million … [then the rate grew faster] reaching 512 million in 1985”. The people living in hunger didn’t own land, and didn’t benefit from the increased crop yields. Additionally, the increased population and profitability of farmland exacerbated the problem of wilderness areas being cleared.

Is the problem intractable? No. Hunger continued to increase, peaking at more than a billion people during the 1990s, but since then has been steadily declining. The change the realisation that using science to increase crop yields wasn’t enough without social change to reduce and reverse population growth, economic change to direct funds to the most poor and lower income inequality, and political change to provide people the freedom to control and improve their lives. None of this could be provided by science alone.

Science will be instrumental in solving problems to make the world a better place, but on its own, unscrupulous use will be at the expense of us all. Other disciplines, such as sociology, politcal science and social justice need to be supported by science so it can make appropriate contributions to society, and the world.

Individually, we need to stop abdicating personal responsibility in favour of relying on science (or anything else), and accept that we are accountable for the changes we make to the world, and obliged to make our effect a positive one.

read more