Spoiler Alert: It’s a myth.
The Heat Death of the Universe was first proposed by Lord Kelvin in the late 19th century. It is a conjecture that the universe is expanding and will continue to expand until all the thermal energy of the universe is expended causing all physical processes to cease.
This faulty and uninspiring mental image of the universe has been a part of the cultural milieu of the scientific community for so long that it has become a part of the popular culture’s understanding of Reality and is rarely challenged.
This apocalyptic vision originated from the observation of physical and chemical processes under specific, local conditions and then extrapolated to include the fate of the entire universe.
“It’s just the abyss, dear. Try not to gaze into it”
We call this kind of analysis empiricism, which is a bottom-up approach to knowledge. While empiricism is a powerful scientific tool, it has its limitations.
the theory that all knowledge is derived from sense-experience. Stimulated by the rise of experimental science, it developed in the 17th and 18th centuries, expounded in particular by John Locke, George Berkeley, and David Hume.Google definition
Physics gives us knowledge when observing concrete (physical), local systems. We can control and submit these local systems to scientific experimentation. We fail sometimes to realize how little we can observe about the universe. From our tiny perch on this small planet whirling about in the vastness of space what can we really know for certain about the fate of the universe?
Consider the word entropy. It’s a bit confusing terminology because as the total entropy of a system increases, we say the system looses thermal (heat) energy and as entropy decreases we say the system gains thermal energy.
For example, imagine a pot of water on a stove. As you turn up the heat under the pot, the water molecules move faster. Entropy decreases. If you turn off the stove, then the water cools, losing thermal energy. The water molecules slow down. Entropy increases.
1. PHYSICS a thermodynamic quantity representing the unavailability of a system’s thermal energy for conversion into mechanical work, often interpreted as the degree of disorder or randomness in the system.
2. lack of order or predictability; gradual decline into disorder.” a marketplace where entropy reigns supreme”Google definition
In the study of heat energy, a branch of Physics called Thermodynamics, there are 4 laws of Thermodynamics. The two that are necessary to understand the conjecture about the heat death of the Universe involve the first two laws:
The First Law of Thermodynamics states that energy cannot be created or destroyed in an isolated system. This is called the Conservation of Energy.
The Second Law of Thermodynamics states that the entropy of any isolated system always increases.
The key word here is “isolated.” When we speak of an isolated system we mean that the system is separated from its surroundings by a barrier. No energy or matter can enter or leave the system. Sometimes the word isolated is confused with the word closed. A closed system can exchange energy, but not matter.
Is the Universe a Closed System, an Isolated System, or Neither?
By definition, physics is the study of the physical, observable universe.
the branch of science concerned with the nature and properties of matter and energy. The subject matter of physics, distinguished from that of chemistry and biology, includes mechanics, heat, light and other radiation, sound, electricity, magnetism, and the structure of atoms.Google definition
Physicists restrict their observations to energy and matter. There are no physical “surroundings” to interact with the Universe by definition. The argument that the universe contains all the matter and energy that exists and so should behave like an isolated system (leading to the heat death of the universe) is a logical fallacy known as a circular argument. We cannot define the Universe as an isolated physical system and then go on to prove anything based on that definition. The physical universe may or may not be an isolated system with nothing existing outside of it that can affect it, but we have no way of knowing if this is true.
Circular ReasoningFallicies – Internet Encyclopedia of Philosophy
The Fallacy of Circular Reasoning occurs when the reasoner begins with what he or she is trying to end up with.
Some folks at Wikipedia have compiled some controversies concerning this subject under the heading Entropy (arrow of time) While Wikipedia is not the last word on any subject, it can serve as a starting point of fruitful research.
Max Planck wrote that the phrase “entropy of the universe” has no meaning because it admits of no accurate definition.
More recently, Walter Grandy writes: “It is rather presumptuous to speak of the entropy of a universe about which we still understand so little, and we wonder how one might define thermodynamic entropy for a universe and its major constituents that have never been in equilibrium in their entire existence.”
Tiza: “If an isolated system is not in equilibrium, we cannot associate an entropy with it.”
Buchdahl writes of “the entirely unjustifiable assumption that the universe can be treated as a closed thermodynamic system”.
Gallavotti: “… there is no universally accepted notion of entropy for systems out of equilibrium, even when in a stationary state.”
In Landsberg’s opinion: “The third misconception is that thermodynamics, and in particular, the concept of entropy, can without further enquiry be applied to the whole universe. … These questions have a certain fascination, but the answers are speculations, and lie beyond the scope of this book.”Entropy (arrow of time)
If one believes that there is nothing more to Reality beyond the physical world, then this branch of science matches up with that belief system. But it is only a conjecture and not a scientific fact. It is not supported by other scientific observations of the universe and it is built entirely on faulty logic.
Belief makes one resistant to new and/or contradictory information. This is just a part of our human nature and scientists are just as prone to this kind of error as every other human being. And so it is hard to get scientists to think of Reality as something larger than the physical universe. They are constricted by their own mental framework.
There is a way out of that box science has placed Reality in. I am not anti-science. I believe that science can help inform our understanding of the universe and Reality. Through the empirical methodology that science employs, we are led to questions about the boundary of the physical universe. And while looking at that boundary, we can speculate about the possibility of an even greater Reality. In fact, it might open up our minds to the idea that the study of Reality is a subject beyond the scope of the scientific branch of knowledge we call Physics.
Consider, for example, a scientific problem that’s never been solved:
If the Universe is an isolated system, then where did the original low entropy (thermal energy) come from?
You cannot lose thermal energy unless you had it to begin with. So where did it come from? Did something come into the physical universe from the outside? What does it mean to be “outside the physical universe”? And there are many more questions besides these.
In any event, one can see that the fate of the universe is not a settled question, and there is no objective argument that compels us to believe everything will end in the dark cold silence of the abyss.