Intro

​

While I was researching Quantum Physics Applications in Visual Effects, I stumbled across a few atomic physics articles. Which immediately got me thinking....Why not apply this to visual effects software as well. (You can find the Quantum Physics article HERE.) Here is an application of atomic physics in Houdini. I've left out a lot of historical events, as this article will be focused on the application of the physical theories than historical lessons. 

​

Try not to go Hulk...

​

What is Atomic Physics?

​

Atomic Physics is the scientific study of the structure of the atom, the atom's energy states. As well as how atomic particles interact with magnetic fields. 

​

A basic atom contains a nuclei made up of protons, and neutrons. These protons and neutrons are made up of other atoms called quarks. Orbiting around the nuclei, are other particles called electrons. Depending on how atoms react in their environment, they can be classified as Ions, Neutral Atoms, Anions, or Cations.

​

Using this physical field, one can begin the study of atomic energy. Atomic energy is also the source of power for both nuclear reactors and weapons. This energy comes from the fission or and fusion of atoms. 

​

Atomic Theories 

​

There are 5 main theories in atomic physics. As well as some important models to make note of. Here they are.

​

The Five Atomic Theories

​

Dalton's Theory

​

In 1808, John Dalton was the first person publish a theory on how atoms might work. His idea theorized that all matter consists of indivisible particles called atoms. Atoms of the same element would be similar in shape and mass, created or destroyed, and were the smallest unit of matter that could take part in a chemical reaction. He also predicted that atoms of different elements may combine with each other. Some of these points he was right about, but others he was a tad off.

​

J.J. Thomson's Theory

​

Sir Joseph John Thomson discovered the electron in 1897. During this discovery he theorized that all matter contains particles of the same kind that are smaller than the atoms that form them. He was correct, and this helped him find these electrified particles that he first called corpuscles.

​

Rutherford's Hypothesis

​

In 1899, a scientist called Ernest Rutherford discovered that uranium emits particles that contain a positive charge. He called them alpha particles. Rutherford then wanted to see what would happen once these particles passed through a sheet of gold. He theorized, based on Thomson's theory that the mass and charge in the gold would be too small to change the path of these particles. However, he was wrong. More particles were deflected than he expected from the gold sheet. Therefore, he alpha particle's charge must not be continuous or the same throughout. 

​

He then predicted a model where the charge is concentrated in a very small area that he called the nucleus. 

​

Bohr's Theory

​

Niels Bohr first proposed this theory in 1913. It is a theory of atomic structure in which a hydrogen atom consists of a proton as nucleus, with a single electron moving in a circular orbit around it.  His theory also included ideas of how to incorporate quantum theory into atomic models. Since atoms emit wavelengths of light, Bohr proposed that these wavelengths were formed when an electron makes a transition from an outer orbit to one closer towards the nucleus.

​

Quark Theory

​

While dissecting the particles of the nucleus, smaller particles were discovered called quarks. Quarks are known to make up the matter of protons, neutrons, and other nuclear particles. There are six types of quarks that help make up the electromagnetic charge of particles. Up and down quarks, strange, charm, and top and bottom quarks all help define the properties of quarks. Quark properties are called flavors.

​

Other Important Atomic Theories

​

Other Physical Models of the Atom

​

The modern model of the atom is considered to be a positively charged nucleolus surrounded by negatively charged electrons. However, this was not always considered the case. Before this was considered fact, scientists proposed several different ideas of how atoms might be formed.This helped form the 5 atomic theories listed above. However, there were a few others. 

​

James Chadwick suggested in 1932 that in order for a nucleus to remain neutral and keep it's charge, it must contain a neutral particle. This theory helped him discover the neutron measure it's mass.

​

However, in 1926 our buddy Erwin Schrödinger created his theory of wave mechanics. This concept is widely heralded as a founding idea behind electron atomic mechanics. Without his theory, Chadwick won't have been able to find neutrons. Wave mechanics is described as an electromagnetic theory of light in terms of a wave equation. Schrödinger proved that electrons have wave properties related to their energy. Which also correlates on how they move around the nucleus.

​

Law of Constant Composition

​

When atoms form it is important that they combine according to their particles forces and mass. The law of constant composition helps correlate this factor. 

​

It states that elements always combine in the same proportion with each other. As such, that compound will be made up of the same elements in the same ratio. For example, let's look at the formula for water. The mass of a water molecule comes from both it's oxygen atoms and it's hydrogen atoms. 94% of the mass comes from the oxygen atoms and the other 6% comes from the mass of the hydrogen. This ratio is consistent with all water molecules. 

​

Law of Conservation of Mass

​

When atoms join and form, a transfer of matter is created. However, any leftover matter from the formation has to go somewhere. This is where the law of conservation of mass happens. It states that mass is neither created nor destroyed in chemical reactions. As well as the mass of one element at the beginning of a reaction will equal the mass of that element at the end of the reaction. 

​

Fusion

​

Now that we have some basic laws understood. Time to talk about some fun stuff. You may have heard of nuclear fusion or atomic fusion. Fusion is the reaction in which two atoms of hydrogen combine together to form an atom of helium. This process gives stars and reactors their source of energy.

​

In order for fusion to happen hydrogen atoms are heated to 100 million degrees so they become ionized, and form plasma. Then, once they have sufficient energy to fuse, they are held together long enough for fusion to occur.

​

Fission

​

Nuclear fission is a process in nuclear physics in which the nucleus of an atom splits into two or more smaller nuclei and some by-product particles. It is a form of elemental transmutation. The by-product particles can include neutrons, photons, gamma rays, beta particles, and alpha particles.

​

Nuclear fission creates energy for nuclear power and nuclear weapons.

​

Nuclear Particles

​

In order for the next chapter to makes sense, we'll need to go over some particles first. Here are some important ones you should know.

​

Alpha Particles

​

These are particles that are made up of two protons and two neutrons. They are emitted from the nucleus when a form of radioactive decay happens. They were the first type of nuclear radiation to be detected, and are also called alpha rays.

​

Beta Particles

​

Beta particles are high speed electrons or positrons that are ejected from the nucleus during a form of radioactive decay. This process can also be called beta-decay. They also have a mass which is half of one thousandth of the mass of a proton and carry a negative charge. They are less ionizing and lose energy quickly when they interact with a material.

​

Neutrons

​

This subatomic particle contains no electric charge, and is one of two particles that make up the nuclei of atoms. It has the mass of one atomic unit. Because it exists inside of an atom, it can also be referred to as a nucleon. 

​

Electrons

​

Electrons are the subatomic particles that orbit the nucleus of an atom. They contain a negative charge, and are smaller than the size of the atom they orbit around. 

​

Protons

​

Protons are positively charged subatomic particles found within atomic nuclei. 

​

Hadrons

​

A hadron is a classification of any particle that is made from quarks, anti-quarks and gluons. Neutrons, protons, pions, and Kaons all fit in this category. 

​

Molecules 

​

A molecule is a group of two or more atoms held together by their chemical bonds. They make up most of the substances and materials on Earth, and help to create compound materials. For example, water contains molecules as it is made up of both oxygen and hydrogen atoms. 

​

Isotopes

​

A isotope is an atom that is missing or has gained an extra neutron. Because of this extra neutron, the isotopes mass is higher than it should be for an atom of that type. Based on how many extra particles it has, the name for that element will also change. For example, Carbon with 12 extra atoms will be called Carbon-12, and so on. In it's process to get rid of the extra neutrons the atom will emit something we call radioactive decay. 

​

Quasi-Particles

​

Quasi particles aren't actually particles. The term describes the motion or movement that exists in matter like spin waves, as particles. Einstein described matter and energy as the same thing. Matter can be converted in energy, and vise versa. Therefore, a natural kinetic energy is abundant in both of them. The study of this kinetic energy would be included under quasi-particles.

​

Atomic-Scale Visualization and Application

​

Working in atomic physics leads to tons of different fields. It doesn't revolve around building or operating nuclear reactors, or weapons. You can work in quantum physics, army research laboratories, heath sciences, astrophysics, and much more. Mostly because these sciences overlap, and their techniques are the same.

 

As you've probably guessed by now, chemistry plays an important role in atomic physics. It also plays a huge role in how scientists visualize atoms and their structures. So let's talk about how you can visualize an atom. 

​

Imaging Hydrogen Atoms

​

In 2013, we were allowed a glimpse at something amazing. We got the first direct observation of an atom’s electron orbital. Why is this important? Well the technology involved and the applications of this observation have completely impacted science for the better. it's also given confirmation that our our current atomic models are proven to exist. 

​

Scientists were able to take images of an atom with something called a quantum microscope. It allows them to literally gaze into the quantum realm. Before this invention we were only able to predict electron movements through wave functions. These functions explain how particles behave in both space and time. They also involved a lot of graph work. 

​

This microscope uses something called photoionization microscopy to to visualize atomic structures. Photoionization involves displacing electrons with high electromagnetic fields, and watching the electron flux back into its original orbit. By making a particle move incorrectly, we can then understand the natural movements that we view through this microscope. This microscope also contains a electrostatic lens that can magnify an outgoing electron wave more than 20,000 times its original size.

​

Spectroscopy

​

Spectroscopy is the study of the interaction between matter and electromagnetic radiation. It originated through the study of visible light dispersed according to its wavelength. For example: a Prism. Spectroscopic data is represented by an emission spectrum. This emission spectrum correlates frequencies from low and high energy states with color. Since this study deals with measuring  frequencies, it also contributes to studying matter and acoustic waves, and the electromagnetic spectrum. 

​

So where does this play apart in atomic studies? Atomic spectroscopy was the first application of this field developed. It measures the absorption and emission of visible and ultraviolet light. These light patterns are called atomic spectral lines. They show the energy outputted the from rise and fall from one electron orbits. Every atom has a different emission spectra, and composition.

​

Electron & Atomic Force Microscopy

​

Atomic Force Microscopy is a high resolution microscopy instrument designed to visualize nano-scale objects. These instruments can output data in three ways. Either through force measurement, topographic imaging, or manipulation of particles. This means these microscopes can not only identify atoms, but view how they can interact with other elements and manipulate their physical state. 

 

These microscopes are used in various fields. Such as solid-state physics, molecular engineering, polymer chemistry, cell biology, and medicinal studies.

​

Nuclear Facilities 

​

This is something I thought would be interesting to talk about for helping the general public understand nuclear power. As well as see exactly what atomic scientists do. It is important to visualize what atoms look like, but it's more important for the public to have access to knowledge they don't understand. Maybe something as an open pit reactor.

​

McMaster University has reacted an app to let people like you and me tour a nuclear facility. They've allowed us to visually see the reactor's core, and where and how they produce isotopes. You can download it from the google play store. It is called McMasterVR: Nuclear Facilities. You can even link it to a VR headset.

​

Visual Effects Application

​

Tutorials and Physically Accurate Creations.

​

From what I could find, there are a few actuate visual effect tutorials to demonstrate atomic structure and physics. The first one being Bogdan Lazar's Houdini tutorial; The Sun. As mentioned before, atomic physics feeds into astrophysics. As well as nuclear fusion, which is the energy source our Sun runs on. In this tutorial he uses VEX, vector calculus, VDB volumes, and particle simulation to form realistic magnetic fields in Houdini. He was also able to replicate solar flares and the solar flames on the surface.You can check out the tutorial HERE.

​

The second example I could find was Surfaced Studio's tutorial on beginner physics. This pretty much covers what you need to know regarding gravity, mechanical laws, and natural states. As well as how to apply these forces in Houdini. However, it doesn't cover atomic physics, or complex theories. Check it out HERE.

​

Quantum Shorts

​

This is a site and organization I stumbled across while researching this article. This site is run by the Center for Quantum Technologies at the National University of Singapore. It promotes the use and research of quantum physics and sciences in films and animated shorts. It also has a contest open every year for artists to develop the most scientifically accurate film. Among these entries you can find multiple visual effects shorts of people visualizing particles, and quantum objects. One being Vladimir Vlasenko's short Triangulation which you can find HERE.

​

The Science of Super Heroes.

​

The superhero genre has really dominated the VFX world in the past few years. There is probably a list of heroes you could count of the top of your head that were created because of nuclear technology. Most of them have been visualized in film, and I think it's worth talking about how we've represented them so far. As well as the science processes taking place in the background. 

​

The Incredible Hulk

​

Now, I'm a bit biased over this hero. I currently work at a studio that helped make the 2008 movie, and the poster sits right above my desk. It was a huge part of their heritage, and in order to not be preachy, or break any NDAs, I'm only going to be using information I can find on this movie on the web. Sorry. Same thing goes with The Fantastic Four. 

​

The Incredible Hulk's backstory starts out with Bruce Banner being exposed to gamma rays during a nuclear blast. These rays gave him the abilities to turn into a huge green giant once his emotions get out of control. So this raises the question, what happens when the human body is exposed to gamma rays? Well it's a clean cut answer, you die from radiation poisoning. Gamma rays are the highest energy form of light in the electromagnetic spectrum. They are also emitted when radiation is released. So realistically, this superhero would never happen.

​

While researching the 2008 movie, there seemed to be less research and development to why the hulk looked the way he did from radiation poisoning, but more towards how can we make him look the right shade of green? This seems like a simple question, but they couldn't have the Hulk the same shade of the grass in every other shot, or give him an unrealistic uranium glow. Instead, they developed a green skin color that would impact every look development for the Hulk in future marvel movies. 

​

The Fantastic Four 

​

These heroes were also formed from a radiation accident. Their space ship was exposed to "cosmic rays" that penetrated their craft, and disfigured them. Now, radiation is radiation. Gamma rays, Beta rays, and other forms exist in space as well as on earth. So as described above, these super heroes probably shouldn't have lived to tell the tale.

​

Now there have been a lot of Fantastic Four films. While writing this, I was unable to find any look dev or reference for the 2015, 2005, and 2007 movies regarding physics. I also found more articles regarding Jessica Alba than interviews with the VFX artists or directors. This disappoints me. It was a different time for superhero movies in the early 2000's, but I kind wish these characters got a bit more love. Silver Surfer is not my favorite super hero, but his 2nd series in 1986 was probably one of my favorite comic plot lines.  

​

Firestorm

​

Now this is one of my families favorite superheroes.  Firestorm is once again the by product of a nuclear experiment gone wrong. Firestorm has the power to rearrange molecular or particle structures of any substance. However, he can only exist if the two people involved in this reactor-gone-wrong experiment fuse together to become a super human. In this comics there have been multiple people and multiple Firestorms. I'll let you look into that.

​

Currently, Firestorm is portrayed on the TV show The Flash. He is shown gaining his powers after a freak particle accelerator accident. Realistically, there are a few problems with this. One being the radiation toxicity, and another being the operation of particle accelerators. I've had the chance to visit the three low energy ones existing on McMaster University's Campus in the past. Which they use for medical diagnosing and experiments. Those you can live from because they are low energy accelerators. You can also learn about the chemical composition of your body. Living through a misfire at a CERN facility on the other hand, would probably be a death sentence.

​

Giving Back to Science

​

Interstellar was a huge movie. It won an Oscar for best visual effects, and was nominated for many others. However, the black-hole featured in the movie was a physically accurate representation of one. What does black-holes have to do with atomic physics? Well, a black-hole has a whole section of science put aside to studying it's atomic structure. Because a black-hole absorbs all matter and energy, and matter can be nether created or destroyed; it has to go somewhere. There is also a theory that a black-hole is not an endless void, but rather has an atomic structure on its insides that are composed of Baryons(a sub-atomic particle). These baryons exist in a rapid unstable state as new matter is added. Then the black-hole grows. So yes, it tackles a huge part of the atomic sciences.

​

Now back to Interstellar's black-hole. This movie had the perfect combination of people to create it. An astrophysicist Kip Thorne was the person behind wanting to create an accurate model of one in a movie. Or at least one that was publicly accessible to view. After befriending the producer behind Interstellar, he was allowed to direct a team of 30 people to create this light sucking void. They then ran into an even bigger issue where they needed to introduce more theories into the film for the plot to make sense. Since the plot of the movie revolved around time dilation, this would need to be represented accurately as well, and also simplified for the viewers watching the film. 

​

Thorne ended up generating equations for the visual effects software and computers to run on, so the effects would appear natural. This included the rendering part as well. Most render engines calculate light as a straight line. But with wormholes and back-holes involved in the movie, that wouldn't be possible either. So while he worked away, the VFX artists started simulating the data. The end result was something that almost ended up not being placed in the film because it was so lifelike. This sounds a bit weird, but the distortion of light around the black-hole was so large and halo-like, the production company thought they rendered it wrong.

​

But they didn't. Instead they created a complete model of a black-hole precisely, so that Kip Thorne was able to reference it in at least two different scientific papers. With this combination of effort, the VFX community created something beautiful. Congratulations to the team at Double Negative.

​

Footnote

​

Finally, on a more somber note. This article is dedicated to may late Grandfather Jim Sharp. He spent the later parts of his years working at the Chalk River Nuclear Reactor as a technician. With out him, I won't have had the chance to be driven up to Ottawa every summer to see the aerospace and technology museums, or gotten lost in the Chalk River sand dunes. I'll miss you grandpa. 

​

References

​

Atomic physics: https://www.britannica.com/science/atomic-physics

​

Introduction to Atomic Physics: http://www.atomicarchive.com/Physics/Physics1.shtml

​

An atomic physics perspective on the kilogram’s new definition: https://physicstoday.scitation.org/doi/10.1063/PT.3.4472

Journals:https://physics.aps.org/articles/v13/29

​

Ultra-cold atomic comagnetometer joins the search for dark matter: https://physicsworld.com/a/ultracold-atomic-comagnetometer-joins-the-search-for-dark-matter/

​

“Light Under Flawless Tutelage Knows No Limits”: Sixty Years Of Lasers Finding New Problems To Solve: https://www.forbes.com/sites/chadorzel/2020/05/15/light-under-flawless-tutelage-knows-no-limits-sixty-years-of-lasers-finding-new-problems-to-solve/#7b1b68e52fcb

​

Physics and chemistry of photocatalytic titanium dioxide: visualization of bactericidal activity using atomic force microscopy: http://repository.ias.ac.in/97987/1/article_id_090_10_1378_1383_0.pdf

 

Atomic-scale visualization of quantum interference on a Weyl semimetal surface by scanning tunneling microscopy: https://pubs.acs.org/doi/abs/10.1021/acsnano.5b06807

 

Visualizing edge states with an atomic Bose gas in the quantum Hall regime: https://science.sciencemag.org/content/349/6255/1514

Four-particle Dalitz plots to visualize atomic break-up processes: https://iopscience.iop.org/article/10.1088/0953-4075/40/15/009/meta

 

Visualization of graphite atomic arrangement by stereo atomscope: https://aip.scitation.org/doi/abs/10.1063/1.1810214

 

Direct visualization of the oscillation of Au (111) surface atoms: https://aip.scitation.org/doi/abs/10.1063/1.118058

 

Atomic-Scale Visualization of Inertial Dynamics: https://science.sciencemag.org/content/308/5720/392

 

See McMaster University’s nuclear reactor through a virtual reality app: https://globalnews.ca/news/6571270/mcmaster-university-nuclear-app/

 

Radiation Basics: https://www.nrc.gov/about-nrc/radiation/health-effects/radiation-basics.html#alpha

​

Chalk River Laboratories: https://www.aecl.ca/environmental-stewardship/chalk-river-laboratories/

​

Einstein and the Incredible Hulk Now Have Their Own Constellations (But You'll Never See Them): https://www.livescience.com/63879-fermi-gamma-ray-constellations-named.html

​

Gamma Rays: The Incredible, Hulking Reality: https://www.livescience.com/2590-gamma-rays-incredible-hulking-reality.html

​

The Incredible Hulk: Curiously Strong: https://www.popsci.com/breakdown/article/2008-05/incredible-hulk-curiously-strong/

​

'The Incredible Hulk': Back to Basics: https://www.awn.com/vfxworld/incredible-hulk-back-basics

​

The Science of Superheroes: https://www.popsci.com/entertainment-gaming/article/2008-01/science-superheroes/

​

The First Image Ever of a Hydrogen Atom's Orbital Structure: https://io9.gizmodo.com/the-first-image-ever-of-a-hydrogen-atoms-orbital-struc-509684901

 

Electron & Atomic Force Microscopy: https://www.microscopemaster.com/atom-under-the-microscope.html

 

Have you ever seen an atom: https://www.youtube.com/watch?v=yqLlgIaz1L0