In this latest episode, I discuss the Standard Model of Cosmology, how scientists arrived at it, and how recent discoveries are causing some to question whether or not it is correct. To break it down, it is known as the Lambda Cold Dark Matter (ΛCDM) model, which basically combines the following theories.
- The Big Bang: The theory that the Universe expanded from an initial state in which all matter was in hot, dense state (c’mon, you know the tune!) Evidence for this theory includes the Cosmic Microwave Background (CMB), the abundance of light elements (hydrogen, helium, etc.), the large-scale structure of the Universe, and cosmic expansion (see below).
- Special Relativity: Einstein’s famous theory (E=mc2) that asserts that matter and energy are equivalent and how space and time are part of a four-dimensional framework in which the speed of light is constant and cannot be exceeded.
- General Relativity: The extended generalized version of Einstein’s famous theory, which asserts that mass alters the curvature of spacetime.
- Dark Matter: The theory that the majority of matter in the Universe is made up of a mysterious mass that doesn’t interact with normal matter in visible light.
- Cosmological Constant: Also known as the Hubble-Lemaitre Constant (colloquially referred to as “Dark Energy”), wherein 68% of the cosmos is made up of energy that counteracts the force of gravity.
Over the past 120 years, these theories have come together to create the ΛCDM model of the Universe. For decades, scientists have been hoping to get a look at the very early Universe (less than 1 billion years after the Big Bang) to test this theory. When Webb finally provided the first observations of this period in cosmic history, what astronomers saw challenged many of the assumptions inherent in this model. Check out the episode below to learn more…
Stories by Williams 
I remember reading that shortly before special and general relativity, most scientists thought they had pretty much all the laws of physics figured out. There were just a few minor matters of detail left to work on. Then it turned out the aether didn’t exist, which undermined a bunch of other theories at the time, and then the Einstein revolution began.
I’ve been thinking for a while now that modern cosmology might be in a similar state today, with dark energy being the new aether, and the next Einstein just around the corner.
An astute observation! I’ve often wondered the same thing, and how scientists are once again inferring the existence of forces in order for their theories to make sense. Granted, it’s a perfectly valid method, theorizing what we don’t know based on what we do. But I still wonder..