In Sanhedrin 65b (line 24 and further) Tornosrufus asked same question to R. Akiva. R. Akiva answered that there are three proofs that the day Jew think is Shabbos is a real Shabbos.
River Sebation is very fast on other days and on Shabbos it streams slowly. Baal Ov couldn't be applied on Shabbos. Smoke comes out of the grave of Tornosrufus's father each day except for Shabbos.
So what's the story here? I found about Tonos Rufus and he is a general that put Akiva to death. I thought Akiva is sentenced to death by an emperor.
Anyway, back to the question: Are there verifications for these miracles?
- Where is River Sebation? Is it true that river flow more slowly during Sabbath? If so, does it flow more slowly starting at 18:00 to the next 18:00?
- Not sure what Baal Ov is but perhaps someone can verify this.
- Is that grave still around till now? Do other graves in the area emit smokes?