Did the Buddha endorse a cyclical cosmology? One of my physics professors implied that Buddhism is false because, unlike the Abrahamic religions, Buddhism claims a cyclical cosmology. He argued that since the universe is expanding and its expansion is speeding up, the universe cannot be cyclical.
I was under the impression that the idea of a cyclical universe was carried over from Hinduism into Buddhism implicitly and that the Buddha never made any claims regarding cosmology.
Did the Buddha suggest a cyclical universe?
DN 1 states:

There comes a time, monks, when after the lapse of a long period
this world contracts (disintegrates) ...
But sooner or later, monks, after the lapse of a long period, there
comes a time when this world begins to expand once again.

This may or may not correspond to the Big Bounce model of physics.
For more info, please read the 2020 Wired article &quot;What If the Big Bang Was Actually a Big Bounce?&quot;, by Charlie Wood.
Despite this, if you look at the whole body of the Buddha's teachings, the Buddha discouraged such speculation.
He preferred the seeker to focus on the Four Noble Truths and the Noble Eightfold Path, the path that leads to the permanent cessation of suffering (dukkha).
Speculating on the origin of the universe is totally unimportant in Buddhism. Whether it was a Big Bang or Big Bounce or an infinitely existing universe, the validity of the Four Noble Truths does not change in any way.
Please read the wikipedia article on the Parable of the Poisoned Arrow.
In AN 4.77, he taught:

&quot;Conjecture about [the origin, etc., of] the world is an
unconjecturable that is not to be conjectured about, that would bring
madness &amp; vexation to anyone who conjectured about it.

In AN 10.70, he taught:

As he was sitting there, he addressed the monks: &quot;For
what topic of conversation are you gathered together here? In the
midst of what topic of conversation have you been interrupted?&quot;
&quot;Just now, lord, after the meal, on returning from our alms round, we
gathered at the meeting hall and got engaged in many kinds of bestial
topics of conversation: conversation about kings, robbers, &amp; ministers
of state; armies, alarms, &amp; battles; food &amp; drink; clothing,
furniture, garlands, &amp; scents; relatives; vehicles; villages, towns,
cities, the countryside; women &amp; heroes; the gossip of the street &amp;
the well; tales of the dead; tales of diversity, the creation of the
world &amp; of the sea; talk of whether things exist or not.&quot;
&quot;It isn't right, monks, that sons of good families, on having gone
forth out of faith from home to the homeless life, should get engaged
in such topics of conversation, i.e., conversation about kings,
robbers, &amp; ministers of state... talk of whether things exist or not.