Chapter 1: Understanding Dark Matter

The pursuit of knowledge about dark matter often leads to the misconception that the lack of experimental findings signifies its non-existence. If we explore the realms of physics, we can see that just because one doesn't find a specific result (like the number 3 between 1 and 2) doesn’t mean it isn’t there.

Imagine you have a theory regarding the fundamental nature of our universe that diverges from conventional understanding. This theory might suggest the presence of additional particles or interactions that could help solve some of the most significant challenges in natural science today. To advance this theory, you would craft a hypothesis, refine it, and then identify observable outcomes that could potentially validate your ideas.

Some of these outcomes are model-independent and would manifest regardless of the correctness of any specific theory, while others are model-dependent, appearing only under certain conditions. When a dark matter experiment yields null results, it primarily tests those model-dependent assumptions, leaving the broader question of dark matter's existence unaddressed.

Section 1.1: The Nature of Particle Collisions

When two particles collide, they provide insights into their internal structures. If one of these is not fundamental but made up of smaller components, experiments can reveal these details. For instance, experiments focused on measuring dark matter/nucleon scattering signals might produce results that could also arise from other mundane interactions. This type of signal is expected to appear in detectors like Germanium, liquid XENON, and liquid ARGON.

Chapter 2: Evidence Supporting Dark Matter's Existence

Although we have yet to observe dark matter through direct interactions with other particles, there is a wealth of indirect evidence suggesting its reality.

The first video titled "Why we have not discovered dark matter: A theorist's apology" discusses the challenges faced in the search for dark matter and the implications of negative findings in experiments.

The particles and antiparticles of the Standard Model have all been directly observed, with the notable exception of dark matter. All known matter, which consists of protons, neutrons, and electrons, along with some radiation, makes up what we perceive in the universe.

We understand that protons and neutrons can be further divided into even more fundamental particles, contributing to the known matter in the cosmos. However, the dark matter hypothesis proposes that there exists an unseen form of matter that significantly influences the total mass of the universe.

The second video, "ANOTHER dark matter experiment finds nothing -- Why keep doing it?" explores the ongoing efforts to uncover dark matter despite repeated failures in direct detection.

The universe is composed predominantly of hydrogen and helium, with other elements present in trace amounts. When we analyze the universe's structure and the gravitational interactions at play, a significant discrepancy arises: the mass calculated from visible matter does not match the mass inferred from gravitational effects, suggesting the presence of dark matter.

The observations from the Cosmic Microwave Background (CMB) also support the existence of dark matter, revealing its ratio in the universe. As we explore the vast cosmic web, we find that gravitational interactions indicate the presence of dark matter surrounding galaxies and clusters.

In conclusion, while direct detection of dark matter remains elusive, the absence of evidence is not evidence of absence. The quest for understanding dark matter continues, driven by a robust body of indirect evidence that affirms its crucial role in the cosmos.

Starts With A Bang is now featured on Forbes and republished on Medium, supported by our Patreon contributors. Ethan has authored two books, "Beyond The Galaxy" and "Treknology: The Science of Star Trek from Tricorders to Warp Drive."