"instant" of the Big-Bang

I'm reading the text "Principles of Physical Cosmology," Peebles, Princeton
University Press (1993). On page 6 Peebles writes

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If there is an instant, at a "big bang," when our universe started
expanding, it is not in the cosmology as now accepted, because no one has
thought of a way to adduce objective physical evidence that such an event
really happened.
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Does anyone agree with this either in part or in whole?

Best regards

Pete


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