Quirky Quantum and Nuclear Physics Quiz

Answer: Albert Einstein

Albert Einstein is deified amongst scientific communities. His style, inimitable; his physical knowledge, paralleled by an elite few. A common misconception is that Albert Einstein received the Nobel Prize for his work on the Theory of Relativity. However, this is false as he received the prize not for his almost ubiquitously known equation, E = mc^2, but for his work on the photoelectric effect, a magnificently interesting field of particle physics.

Answer: Photon

The concept of the photon really did signify the dawning of a new physical age. Up until Planck's research into black body radiation, light (a part of the electromagnetic [EM] spectrum) was believed to have travelled as a continuous wave. However, it was later suggested that visible radiation was emitted in the form of a bundle (or quantum) of energy known as a photon. The significance of this is that light does not just behave as a wave, but, in certain circumstances, it can also behave as a particle!

The equation E = hf means that the energy of a photon is equal to the Planck constant multiplied by the frequency of said photon. As the Planck constant never changes, the energy of the photon is dependent upon only the frequency. There are other variations of the equation which can be used when the wavelength of the photon is known but not the frequency. This equation is E = hc / (lambda) where once again, 'E' is the energy of a photon and 'h' is the Planck constant. The letter 'c', the same as that used in Einstein's famous equation, represents the speed of light in a vacuum (300,000,000 metres per second). The Greek letter lambda represents the wavelength of the photon.

Answer: The photon has no mass

It has been established that only things with zero mass are able to reach the speed of light and a photon is one such entity. There have been experiments undertaken by physicists which aim to accelerate particles to the speed of light, 'c'. However, they have realised that as the particle (which has a mass) approaches the speed of light, it gets increasingly difficult to provide the energy necessary to undergo further acceleration.

They have also discovered that as the particle is accelerated extremely close to the value, 'c', the particle would need an infinite amount of energy to actually accelerate further to the value 'c'.

Answer: Louis de Broglie

Lambda in this instance is named the de Broglie wavelength. The equation is split in two halves, where 'p' (momentum) illustrates the particle nature of a photon (light) as waves cannot have a momentum. The other half is 'h/lambda' (Planck constant / de Broglie wavelength) and this illustrates the wave nature of particles.

This is self-explanatory as waves must have wavelengths. As both of these phenomena occur simultaneously, it is given the title, wave-particle duality. A rather amusing term was given to the idea of a photon amongst other things exhibiting wave-particle duality and that is "wavicle". Simply genius!

Answer: Halflife

Halflife is defined as the time taken for half of the nuclei of a radioactive substance to decay. The concept of halflife is what characterises an exponential decay graph. As the halflife of a particular radioactive substance will predominantly be constant the gradient of the line on a graph will start at time = 0 and the percentage of undecayed nuclei will fall with a steep gradient.

As more halflifes pass the gradient gets progressively less steep. Ultimately a curve will be formed.

Answer: Plum Pudding

Sir Joseph John Thomson was a Nobel Prize winning physicist who greatly contributed towards the development of the modern atomic model. This is not just due to his assertion (now regarded as ultimately incorrect) of the plum pudding atomic arrangement but also due to his discovery of the electron. The electron is at the very foundation of modern science as it helps explain anything from botanical processes such as photosynthesis to chemical geometry and the shape of molecules.

Ernest Rutherford and his team, which included Hans Geiger whose name is given to a radioactivity detector, were also interested in the atom and wanted to determine its structure. The experiment, described above, showed that the alpha particles would either travel undisturbed, be slightly deflected or would be backscattered in the direction of the source. This determined that the atom wasn't as JJ Thomson had stated but remarkably different; the atom was mainly empty space with electrons in orbitals around a small, positively charged nucleus containing the majority of the atomic mass.

Answer: Femtometre

As physicists encounter the increasingly large and the extremely small they need to have more extreme units to quantify exactly what it is we are observing or hypothesising. Such quantities are mind-boggling when we consider how difficult humans find splitting up even the tiny distance between one millimetre and the next on a ruler!

At the atomic level the units used are far smaller than the millimetre. The diameter of an entire atom is approximately x10^-10m which is given the name ångström after the Swedish physicist of the same name. Smaller again is the nuclear size of roughly x10^-15m which is a femtometre.

Answer: Fusion

Nuclear fusion is an important concept for satisfying the future energy demands of an increasingly global, industrialised population. The idea behind nuclear fusion is to release energy, id est an exothermic reaction, but this reaction itself requires energy. The energy needed to be put into the nuclear reaction is so that two positively charged nuclei (which would usually repel) can fuse and in so doing will release energy. There is a greater amount of energy given out after the fusion than is supplied to satisfy the reaction requirements. This type of nuclear reaction takes place naturally on the Sun and other stars.

Nuclear fission is the opposite where an atom, often uranium, is bombarded with a neutron. The uranium absorbs the neutron and subsequently splits into smaller nuclear fragments. Energy is given off in this reaction also.

Answer: Large Hadron Collider

The Large Hadron Collider or LHC is a very high energy accelerator of particles. The LHC attempts to collide particles travelling in opposite directions at over 99% of the speed of light, 'c', but never reaching the full speed of light. This is in the hope of discovering smaller particles within the nucleus of atoms. Amongst such particles supposedly lies the Higgs boson which is what particle physicists believe is the source of mass in matter. Whether it exists or not is of crucial importance to the current Standard Model hypothesised in the physical science. If it exists the model can be further developed; if not, it is back to the drawing board!

Answer: Alpha Radiation

Marie Curie, who died of leukaemia, was an inspiration to generations of female scientists as she is one of the most decorated and celebrated physicists in history. Not only did she receive a Nobel Prize in 1903 for her work in the field of physics but also received a Nobel Prize for chemistry in 1911. This made her not just the first female recipient of a Nobel award but also the only person to receive a Nobel Prize in two different sciences in over 100 years! In a scientific discipline that is as traditionally male dominated as physics, her achievements and determination seem all the more inspiring.

The near ubiquitous smoke detector is an important use of alpha radiation (helium nuclei) and saves many lives worldwide each year. Within the smoke detector there is a radioactive source and a receiver which detects the flow of alpha particles. When smoke particles interrupt the flow, the receiver detects this and the alarm is sounded.

Thanks for playing the quiz and I hope you enjoyed the topic.