Physicists Have Observed the Light Spectrum of Antimatter for First Time.

Andrew Howson

Mr. Ippolito

Core Biology Honors

Crew, Bec. "Physicists Have Observed the Light Spectrum of Antimatter for First Time."ScienceAlert. N.p., 20 Dec. 2016. Web. 24 Apr. 2017.

<http://www.sciencealert.com/physicists-have-observed-the-light-spectrum-of-antimatter-for-first-time>

For this current event, I chose the article “Physicists Have Observed the Light Spectrum of Antimatter for First Time” by Bec Crew. This article describes a study done at CERN where scientists were able to isolate antimatter particles and observe how they interact with visible light.

Antimatter is a substance predicted by an equation developed by Paul Dirac in 1928 which combined quantum mechanics, a relatively new field of study at the time, and special relativity, which was developed earlier by Albert Einstein (in 1905). This equation had two solutions: one positive and one negative. This was a contradiction of most accepted theories of physics at the time because most physicists at the time believed that the energy of a particle could only be a positive number. Paul Dirac interpreted his equation to mean that every particle must have an antiparticle that is the exact opposite of that particle. For example, a particle scientists have detected called a positron is the antiparticle corresponding to an electron. When a particle of matter and its corresponding antimatter particle interract, they annihilate each other, creating an immense amount of energy, mostly in the form of light.

One of the major problems in modern physics is that the Big Bang should have created equal amounts of matter and antimatter, yet we observe the universe as pretty much only containing regular matter. This is a problem because according to current models, the universe should have annihilated itself from the beginning because the amount of regular matter and antimatter should have been equal, yet for some reason we don’t yet know, it wasn’t.

What the experiment described in this article did was isolate atoms of antihydrogen (14 of them were able to be isolated without them being annihilated by regular hydrogen), use a laser to observe how it interacts with light, and compare its reaction to that of regular hydrogen. What the scientists hypothesised was that, in congruence with the Standard Model of particle physics (the theoretical model upon which much of modern particle physics is based on), antihydrogen should interact with light in the exact same way that regular hydrogen does. The results observed by scientists with the light spectra they tested confirmed their hypothesis, however they have acknowledged there are still many more factors that have to be tested before they reach a final conclusion.

If, however, antimatter ends up not mirroring regular matter in any way, our current models of physics will need to be changed because much of what we base them off of, such as the theory of relativity, would turn out to be flawed. Adrian Cho, one of the scientists who took part in the experiment explained this by stating that “Special relativity assumes that a single unified thing called spacetime splits differently into space and time for observers moving relative to each other. It posits that neither observer can say who is really moving and who is stationary. But, that can’t be exactly right if matter and antimatter don't mirror each other.”

I found this article extremely interesting. All terms were generally well explained and it was engaging. The main problem was that I found that I needed a bit more information regarding antimatter, but I was able to find it easily.

(Additional source for the description of antimatter:

"CERN Accelerating Science." Antimatter | CERN. N.p., n.d. Web. 24 Apr. 2017.

<https://home.cern/topics/antimatter>)