Halloween is an exciting holiday for many; with its ghost stories and free candy, it is a fun event for people of all ages. Halloween, for me, is my favorite holiday. This article is to take a look at the stories and ghostly legends surrounding Halloween.
If there’s one supernatural being that is the most-well known, it is the ghost. Ghost can be defined as any apparition or soul of a dead person that can appear to be living. Although categorized as a supernatural creature, 45 percent of American believed in ghosts as of 2013. Part of being a physicist is not only asking how, but why as well.So why do so many Americans believe in ghosts? I believe that the main reason why so many people believe in ghosts stems from disliking our own mortality; we love being alive, and it uncomfortable to accept that we all at some point in time will cease to exist. Believing in ghosts reaffirms our belief in the afterlife.Simply enough, repeated research has shown that the people who believe in ghosts are more prone to having a paranormal experience. Do ghosts naturally only seek out people who believe in them? I doubt it; it is rather that when we experience an event that we are unfamiliar with, our brains are wired to taking our existence knowledge of the world to fill in the misses pieces.
But Do Ghost Violate the Laws of Physics?
The short answer is yes. But, nonetheless, we don’t like shortcuts in physics, so let’s dive into some basic physics, more specifically thermodynamics. Thermodynamics is the branch of physics that studies the flow of heat and energy.Ghost hunters love to use thermodynamics to prove that physics has a reasonable explanation for the existence of ghosts, but their lack of understanding of the laws and the big picture of the subject as a whole is their downfall.
Let’s look at the 4 Laws of Thermodynamics:
(Don’t worry if you don’t understand this part yet, we’ll dive into what this all means.)
Zeroth Law: If Object A is in equilibrium with Object B, and Object B is in equilibrium with Object C, then Object A must also be in equilibrium to Object C. In short, this law defines temperature.
First Law: Energy is never created nor destroyed; it only changes forms. This is coined as the ”You can’t win” law because you cannot create something from nothing.
Second Law: The entropy of an isolated system is always increasing. This is coined as the You can’t break even” law because you cannot get the same energy back as you put into it; some is always lost to heat
Third Law: The entropy of a system at absolute zero is a constant number. (Usually zero).This law is coined as ”You can’t get there” law because you cannot take a finite number of steps to reach absolute zero.
Ghost hunters and paranormal enthusiasts love to use the First Law of Thermodynamics to explain how ghosts can exist within the laws of physics by arguing that the energy that makes up our existence has to go somewhere when we died, in other words, ”it cannot be destroyed.” Although this is correct, the energy inside of us after we die gets converted into heat, and food for micro-organisms such as the trillions of bacteria that exists in your gut that get to work digesting your dead cells soon after you die. If you are cremated,the energy is converted into heat and light; kind of in same way an electron releases a photon when it moves from an excited state into a lower-energy orbital.
So the First Law of Thermodynamics doesn’t prove that ghosts exist, but at the same time it doesn’t necessarily disprove the possibility of ghosts despite having an alternative answer to where the energy of a deceased organism travels to.
We need to combine the First Law with the Second Law of Thermodynamics. The Second Law states that the entropy of an isolated system always increases. The term entropy is often described as the measure of disorder of a system, but I do not like to call this disorder, but rather the number of possible ways a system can be arranged. But even that definition can be misleading. I prefer to define entropy as the measurement of the unavailable energy in a system. By unavailable energy, I mean the amount of energy that cannot be used to do mechanical work; this definition is the most useful in our argument.
The Second law of Thermodynamics is coined as the ”You can’t break even” law because not all the energy you put in is converted into mechanical work; some of it is always lost to heat, and although the energy is not destroyed, it can no longer be used to do work. And eventually, all of the available energy will be used up, and there will be no energy to perform work; essentially bring the universe to become ”dead.” This is known as the “heat death of the universe.”
But what does this have to do with ghosts? Ghost, as we understand them, are not made of matter, bur rather pure energy; this creates a difficult situation for ghosts. Because of the Second Law of Thermodynamics, in order for a ghost to move around and interact with then environment, it would need to spend energy. But because energy is always lost to heat and entropy is always increasing, a ghost would need a constant supply of energy to sustain its structure and preventing it from fading out of existence. And because ghosts, unlike living creatures, cannot eat food, they would need to absorb this energy from the environment since ghosts cannot create their own energy according to the first law; if this was the case, this process would be observable. One might argue that this is why cold spots appear when a ghost is present. But if ghosts absorbed heat, they would require mass, and by definition, ghosts are purely energy and have no matter. And by the second law, ghosts should emit heat rather than create cold spots. But we’ll discuss this more in depth when we look at the infrared thermometers used by ghost hunters.
Infrared Radiation thermometers measure the infrared radiation of an object. All objects above absolute zero emit some type of radiation within the infrared spectrum. And if ghosts existed, they would emit this radiation as well since ghosts cannot exist at absolute zero according to the Third Law of Thermodynamics. Ghost hunters love to use this technology for pointing out cold spots in the room; this is not a proper operation of a thermal imaging device such as a IR thermometers.
IR thermometers require that the object not only have mass, but a surface which is why IR thermometers are useful for measuring the temperature gradient of the surface of objects in the room and not so much their internal temperature. You cannot measure the air with a IR thermometer; the only way you would detect the presence of a ghost is if its drawing enough energy to make the walls and floor cold enough to detect. But as mentioned before, ghosts should most likely create hot spots rather than cold ones. In fact, you are more likely to see aspirations of ghosts with your eyes than using an infrared camera; visible light scatters easier than infrared since it has a shorter wavelength. It’s the same phenomenon to why the sky appears blue and not red, given that blue light has a shorter wavelength than that of red light, and is scattered by the Earth’s atmosphere and reflected back into our eyes. This scattering is what would allow you to see the aspiration; otherwise it would penetrate and not reflect back, and our eyes see an object because of an object’s ability to reflect the light back into our eyes. So if you’re looking for an aspiration, thermal imaging using infrared radiation would make it harder to detect ghosts compared to searching for one with your naked eye.
Although ghost stories are fun and spooky; unfortunately the laws of physics don’t allow for our supernatural friends to exists.
Happy Halloween!