Did Penzias believe the Big Bang theory before the discovery?
No, and that's an important point. Before our discovery, I had no strong commitment to the Big Bang theory. In fact, I was more familiar with the steady-state model, which posited a universe that had always existed and was continuously creating matter. But I was an experimentalist, not a theorist. My job was to measure things accurately, not to advocate for a particular cosmology. When we found that persistent noise, I didn't immediately think 'Big Bang.' I thought, 'What's wrong with our equipment?' It was only after consulting with the Princeton group that we understood the theoretical significance. The universe doesn't care about our expectations. The data showed a uniform, isotropic signal at 3.5 Kelvin, and that matched the Big Bang prediction. I had to be willing to be wrong about my own biases. That's how science works: you follow the evidence, even when it contradicts your preferred narrative.
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