The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos

by Brian Greene

To be sure, Weinberg’s remark has to be applied with care. Although his desk has played host to an inordinate amount of mathematics that has proved relevant to the real world, far from every equation with which we theorists tinker rises to that level. In the absence of compelling experimental or observational results, deciding which mathematics should be taken seriously is as much art as it is science.

Einstein forcefully declared, is 300,000 kilometers per second relative to anything.

Nevertheless, there was a limit to how far Einstein was willing to follow his own mathematics. Einstein did not take the general theory of relativity “seriously enough” to believe its prediction of black holes, or its prediction that the universe was expanding. As we’ve seen, others, including Friedmann, Lemaître, and Schwarzschild, embraced Einstein’s equations more fully than he, and their achievements have set the course of cosmological understanding for nearly a century.

I don’t know if this is how things will turn out. No one does. But it’s only through fearless engagement that we can learn our own limits. It’s only through the rational pursuit of theories, even those that whisk us into strange and unfamiliar domains, that we stand a chance of revealing the expanse of reality.

Notes

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