Scientists can't prove anything for certain but they certainly have much better evidence to say that nothing happens after death than religion which has zero evidence.
Scientists also claimed there was no water on mars based on evidence.
Then they said there might be water, based on evidence.
Then they said there is but its frozen ice caps, based on evidence.
Then they found a canyon longer the East to West Coast of the US, with surface water, based on evidence.
Scientists once thought our solar systems planets where the only planets in the universe, based on evidence.
Then they said there are infact other planets and other stars, much like ours, based on evidence.
Then they said there are 100's of Billions of Stars with planets orbiting them, meaning there are trillions of planets in our galaxy alone, based on evidence.
Now they believe there's microbial life in our own solar system, based on evidence (venus atmosphere)
The point here is, Science becomes more accurate over time as we advance technologically. And something as complex as the afterlife simply cannot be proven/disproven.
RE: Religion.
"
Sure, primitive book written ages ago blah blah..." - Somebody dismissive.
But how do we know the angels and gods depicted and mentioned in ancient writings and artwork weren't actually visitors from another system or galaxy? for all we know Religion/Afterlife/Aliens could all be connected.