Episode 7: The Long Fade to Heat Death

I. Cold Open: The Great Reversal**

* **The Objective:** Investigating why the universe's expansion is speeding up and tracing the "unbroken chain of physical necessity" toward the final state of maximum entropy.

II. Dark Energy: The Ghost in the Machine**

* **The 1998 Discovery:** How observations of Type Ia Supernovae ("standard candles") revealed that distant galaxies are farther away than a matter-dominated universe would allow.

* **The Cosmological Constant (Lambda):** Explaining dark energy as the energy intrinsic to empty space itself, exerting negative pressure that drives repulsive gravity.

* **The (Lambda) CDM Model:** Defining the "concordance model" where the universe is composed of ~68% dark energy, ~27% dark matter, and ~5% ordinary matter.

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