Term 2 Blog Post 1: Antimatter - One of the Greatest Unsolved Problem in Physics

I did some research recently on the topic antimatter, and here's what I have found out!

Antimatter – one of the greatest unsolved problems in physics

Introduction:

I still remember the time when I was primary 4; the year when I first heard the word “Antimatter”. At that time, I was new to science and had only begun to learn matter. On top of that, I already had problems which some of the concepts during my science lesson, but something about that word made me very curious. After probing my teacher countless times and sending emails about what antimatter is, I always got the same reply, “You are still very new to science to be able to comprehend what antimatter is about, if you are interested, you could look it up on the internet yourself.” So I guess I made the right choice as I am able to do a science ACE topic on this.

What is antimatter?

We already know that matter is made up of 3 different kinds of particles, electrons, protons and neutrons. So antimatter would basically be a mirror image of matter! Electrons would be antielectrons(positrons), protons would be antiprotons and neutrons would be antineutrons in antimatter! Maybe if you think matter and antimatter as play dough, it would be easier for you to understand. If you cut out a round shape, you would have gotten a circle, but if you look at the dough, there would be another circle shape hole there, which is just like the opposite of the circle you created! So I thought to myself, does this mean that to create matter, you would have to create antimatter, and vice versa?

Production of antimatter:

After more research, I found my answer; whenever producing matter or antimatter, you can only produce a pair of particle and its mirror image, an antiparticle. At least experiments now only show that nobody has managed to create only matter, or only antimatter. So once again, this led to another question of my, does this mean that there are equal amounts of matter and antimatter in the world? Also, if that were the case, and since matter makes up our world, does that also mean that there is another world, made up totally of antimatter?

Travelling way back in time:

After even more research, I found out that in the beginning, there was an equal amount of matter and antimatter, but something happened and thus, the Universe became biased and produced more matter. The things is, while the Universe was expanding and rapidly producing both matter and antimatter, its temperature became to drop continuously and soon it had dropped too low to create any more pairs of matter and antimatter. Particles and antiparticles annihilated each other in pairs and soon everything was gone – all but the surplus of matter that was produced. This then became that made up all of us today!

What happens when matter and antimatter meet?

So in the previous section I mentioned about matter and antimatter annihilating each other when they contact. It’s just like matter and antimatter do not really like each other, and so when they meet, they destroy each other, leaving behind the energy that created them. You can imagine as if you took the circle that you cut out of the dough and put it back into the hole – both the circle shape and the circle hole shape disappears!

Uses of antimatter:

I would like to quote a sentence from Wikipedia, “In antimatter-matter collisions resulting in photon emission, the entire rest mass of the particles is converted to kinetic energy.” I also found out that the energy per unit mass that the collision of antimatter and matter is 9×1016 J/kg, which is even more than the energy produced from nuclear fission which is at 8×1013 J/kg! This means if antimatter could be harnessed, we would solve a lot of the Earth’s resources problems! Antimatter could be used to fuel spaceships, powering cities, or even in regular transport! I then thought to myself, why then isn’t antimatter already being used now?

The flaws of using antimatter:

I found a rather disappointing answer to my previous question. This is another quote from Wikipedia, “Scientists claim antimatter is the costliest material to make.” Well, while I was researching again, I definitely found a lot of figures and values of how much it cost to create antimatter, but it would be meaningless to just copy and paste values here. Even then, I was left staring incredulously at the computer screen when I saw how much money was used to create antimatter and matter, when there are so many people in the world who could be saved by that amount. Nevertheless, the price of creating antimatter to use as fuel does not make up for the result gained, due to many inefficiencies. Furthermore, antimatter cannot be easily stored in containers like petrol – once it contacts with anything made up of matter; well you know what would happen. A Penning trap is thus used to contain antimatter, which is extremely inconvenient if we wanted to use it for anything. On top of that a Penning trap cannot contain any antimatter that is composed of uncharged particles, and so an atomic trap is used instead.

The people vital to our current understanding of antimatter:

Paul Dirac


The modern theory of antimatter begun with him, in 1982, with a paper. He also realised that his relativistic version of the Schrödinger wave equation for electrons was predicting the possibility of positrons.

Carl David Anderson



He was the one that discovered antimatter in 1932.

Arthur Schuster



He hypothesised antiatoms, whole antimatter solar systems and discussed the possibility of matter and antimatter annihilating each other.


Reflection:

I really tried my best to make this report as organised as possible. I also tried to simplify all the complicated terms and words that I found on various websites, and made sure that this report was not just a compilation of “copy and paste” information, but instead one that was written by me, with help from sources. Well, you could just try searching “Antimatter” on Google and a whole lot of stuff that I have never learnt or even knew about would come out. I guess that I must have missed out certain details, but overall, I feel that I did quite a good job in the making of this report, though I felt that adding too many pictures was unnecessary, and only added the photographs of the scientist as it saves space, printer ink and allows more information. The most important thing of course, is that I have learnt a lot about antimatter, AND of course revised about the things I already knew about matter. Perhaps, maybe in few years time, the knowledge might come in handy in some kind of project or science syllabus!

Bibliography:

http://press.web.cern.ch/livefromcern/antimatter/

http://en.wikipedia.org/wiki/Antimatter

http://www.lbl.gov/abc/Antimatter.html

http://www.upscale.utoronto.ca/PVB/Harrison/AntiMatter/AntiMatter.html

http://books.google.com.sg/books?id=7WqZ357pgOIC&printsec=frontcover&dq=antimatter&source=bl&ots=ScYj0q2qYR&sig=EqduRJwawazq9VfNviNP33UBFzw&hl=en&ei=tzFVTIqIO420rAfQiZHzAw&sa=X&oi=book_result&ct=result&resnum=13&ved=0CEkQ6AEwDA#v=onepage&q&f=false