Not one stone
The discourse begins with a building, not with the end of physics.
And Jesus went out from the temple, and was going on his way; and his disciples came to him to show him the buildings of the temple. But he answered and said unto them, See ye not all these things? verily I say unto you, There shall not be left here one stone upon another, that shall not be thrown down.
And as he went forth out of the temple, one of his disciples saith unto him, Teacher, behold, what manner of stones and what manner of buildings! And Jesus said unto him, Seest thou these great buildings? there shall not be left here one stone upon another, which shall not be thrown down.
And as some spake of the temple, how it was adorned with goodly stones and offerings, he said, As for these things which ye behold, the days will come, in which there shall not be left here one stone upon another, that shall not be thrown down.
What happened
Herod's Temple was one of the wonders of the Roman east — stones Josephus says were enormous. In AD 70 the sanctuary burned; soldiers dismantled the ruin for the melted gold. The prediction is local, architectural, and falsifiable. It was kept.
Josephus, Wars 6.4.7; 7.1.1
Caesar gave orders that they should now demolish the entire city and temple… but leave as many of the towers standing as were of the greatest eminency… in order to demonstrate to posterity what a city it was, and how well fortified, which the Roman valor had subdued.