Wow, it used very intersting vegetables, the very common E shapped cucumber and of course, the commonplace O shapped Tomatoe with a void in the middle. Very usual vegetables, can buy them in any grocery store.
But we are not capable of knowing that anything is true with 100% certainty, we can be very convinced with ample evidence that something is true, but that doesn't make it true. I mean, the whole science shenanigans is based in this principle, that is the reason they talk about theories and not universal truths, because what we call facts or truth is at best very informed interpretations.
We know no truth, so everything has to change and progress.