In this new post I'll be discussing a topic I am very passionate about, partly due to my involvement with it for about 3 years.
This is probably not the first time you've heard about the Large Hadron Collider (LHC). It's one of the most (if not THE most) hyped scientific projects since the Space Race. Something to be expected for a project with a projected total cost of about 5 billion dollars, involving a collaboration between over 100 countries and that took 10 years to finish. It also generated and continues to generate great expectations. It promised, among other things, to either confirm our current understanding of the workings of the universe or shake the foundations of modern physics. As you may imagine,the technology developed to conduct the experiments required to achieve such objectives is quite complex and interesting.
What is the Large Hadron Collider?
As its name suggests, it is a huge machine (a 27 kilometers -17 mi- circumference beneath the Franco-Swiss border) built by the European Organization for Nuclear Research (CERN) whose purpose is to accelerate and collide particles (the building blocks of matter) of a very specific kind called hadrons (about which I'll write in detail in a separate post). The LHC is the biggest particle collider in the world.
So, why do we need particle colliders after all?
Before being able to answer that question we should take a look at physics' most famous equation:
This equation is known as the mass-energy equivalence and was first proposed by Albert Einstein as part of his theory of special relativity. In simple terms, it basically estates that mass (m) is interchangeable with energy (E).
One of the main focuses of research in modern physics is the study of particles so massive and unstable that their lifespan is too short to be observed in nature. Now we return to particle colliders. What they do is accelerate two particles to relativistic speeds (close to the speed of light -c-) so they acquire enough energy so that a collision between both can produce particles more massive than both the original particles put together.
Being able to do this in a controlled environment can help physicists answer some of the fundamental open questions in physics.
So far, so good but how can you observe and measure the characteristics and behavior of such tiny things?
This is one of the main problems you face when dealing with things you can't even see under a microscope.
Classical physics made things relatively simple as it deals with things we interact with in a daily basis: things we can see, hear and/or touch. Now we have to deal with things which we cannot directly perceive. For that, scientists and engineers developed the next generation of microscopes, our way of interacting with the universe's sub-atomic secrets.
Since we can't interact directly with most subatomic particles, the devices developed to measure and observe them and their characteristics are designed to interact with them producing reactions we humans can see. This sort of "indirect detection" device was pioneered by Ernest Rutheford.
Rutheford was working with alpha particles. He placed a radioactive source in such a way that it would shoot a stream into a very thin gold foil which stood in front of a screen, the alpha particles would pass through the foil and hit the screen producing flashes of light. This way, the experimenter would know when and where an alpha particle would hit.
To make the measurements needed, the LHC has 4 detectors. We will focus on one of them: ATLAS.
The ATLAS detector
ATLAS is a multipurpose detector used to look for signs of new physics. It is a gigantic cylinder wraped around the pipe where the collisions occur. The idea is that the particles produced as a result of the collisions will fly directly into the detector.
As any modern detector, ATLAS has multiple layers tasked with measuring different things. It's first layer, called the tracking chamber, determines very accurately the trajectories of electrically charged particles. Next, the particles continue into the electromagnetic calorimeter which determines the total energies of electrons, positrons (particles identical to electrons but with opposite electrical charge) and photons (particles of light). After that, the hadron calorimeter measures the total energy of hadrons. The last detecting layers are the muon chambers which detect muons (another type of particle).
The entire detector is wrapped inside a magnet used to curve the path of electrically charged particles. From the radius of curvature we can deduce the momentum (the quantity of movement) and from its direction the sign of the charge.
The ATLAS detector is a very powerful technological tool that allows us to sense the universe in a very unique way. It is not only able of detecting particles generated at the LHC but it also interacts with what lies beyond our solar system by detecting cosmic rays (high energy particles mainly originating outside the solar system).
The purpose of this blog is to explore the marvels of human creativity from discovery to invention, travelling through abstractions and orders of magnitude from quantum to cosmos. This inaugural post focuses on the overlap between physical science, engineering and technology, and the impact of the quantum world on everyday technology.
We live in a world where technology advances at an ever increasing rate, with a new revolution lurking at every corner. This technological progress often comes coupled with an expansion of the understanding of the principles that rule the universe we live in. The 20th century brought us one of the greatest advancements in scientific history, the Quantum revolution challenged many of the preconceptions of classical physics and brought us closer to understanding the workings of the subatomic world. This schism in physical science produced ripples that propagated throughout all fields of human knowledge. Thus, quantum physics paired with the new developments it triggered in the understanding of the behaviour of materials, semiconductors in particular, and channeled by the spark of human creativity, opened the floodgates for the unprecedented stream of innovations in the field of electronics that changed our lives forever. This technological revolution was spearheaded by the invention of the transistor (1947), which allowed us to move past the bulky, unreliable and inefficient vacuum tubes and boost the development of the complex, reliable, portable, consumer-oriented and increasingly powerful technologies we use nowadays (cell phones, personal computers, pacemakers, etc.).
We might be witnessing another big leap in electronics fueled by our knowledge of the quantum world, the emergence of the quantum dot. As everything quantum, a quantum dot’s reduced size is the source of its power. Their size ranges between 2 and 10 nanometers, which translates in about 10 to 50 atoms. This confers the device the power of controlling single electrons, a level of detail that a transistor is not able of achieving. This property allows for a universe of possibilities for the enhancement of technologies we use in our everyday life.
A quantum dot emits light whose color is defined by its size. Smaller sizes tend to the bluer side of the color spectrum (more energy). Conversely, larger dots tend to the red side of the spectrum (less energy). This allows for very precise color tuning which other light-emitting technologies currently used (LEDs) don’t posses. The use of quantum dots in LCD screens has allowed for displays with more precise colors and wider color ranges. Another big advantage quantum dots provide is lower power consumption. This is particularly beneficial for portable device screens as they represent the first source of battery life exhaustion. It is no coincidence that companies such as Amazon (Kindle Fire HDX) and Sony (Triluminos TVs) have been implementing LCD displays with quantum dots. It is rumored thatApple might use this technology in the upcoming iPhone 6.
How do we actually unleash the genius within each person?
First we need to recognise (and trust) that every person is special and has his or her own unique talents and abilities. Yet, how many of us have seen teachers who have gave students the disapproving shake of the head, or have heard parents tell their children that they will amount to nothing if they do not get good grades in school?
Having a system is not enough, it must come with people who truly believe in it.
It is very important that the education system is designed to promote a diversity of talents and recognise each child's unique ability. For example, by having a wide range of subjects for students to choose from and different educational paths for students with different interests and aptitude.
Still, the results we achieve ultimately boils down to the quality of educators implementing the system. Teachers need to believe that every student is capable of great things, even if it is not in the subject area that they are teaching. Teachers are not just there to teach their own subjects, they are there to be a role model for the students and to provide advice on handling problems life may throw at every student.