A shame it’s only to the medieval times. Had it been to 2000 years ago I’d choose the gun and the bullets. To kill Saul of Tarsus. This would prevent Christianity to exist (and Islam by extension).
Like miracles I would do it in a few times only during my lifetime. The rest would be just me roleplaying/bullshitting my way to becoming a noble. Maybe along the way create a crude battery.
While I definitely recognize the enthusiasm for the model… I would count it as not particularly useful in a medieval context unless you are a ship captain drawing maps. You need multiple people with synchronized time to make them useful for military ir social application.
More or less the same. Sharp or heavy objects were popular. But saying “the attack commences at three o’clock” wasn’t a thing. The idea of a second is about 1000 years old and we couldn’t measure them at all accurately until about 500 years ago.
The very loud noise was the standard of military co-ordination for most of human history.