Why is there a cannon at Hogwarts?

Question

In the Triwizard Tournament in the HP and the Goblet of Fire film, a cannon is used at the start of each of the three tasks. It can be seen e.g. in this video clip:

Having been convinced by @Au101 that the cannon is canon, my question is:

why is there such a thing as a cannon in Hogwarts?

It's easy to make loud bangs with magic, and the Reducto curse can probably do the same amount of damage as a cannonball. We know wizards don't tend to use firearms, so why was an exception made in this case? Why would wizards even know about such Muggle devices, when they can perform all the tasks of a cannon with magic?

Answer 1

• Magical world clearly knows what a cannon is, since Chudley Cannons team is the best Quidditch team ever </Ron>

• A cannon wasn't used in the book. That's a film invention. (Just checked book text for the word "cannon" and it's only used for Quidditch)

• The book used a whistle

  • Task 1: whistle

    'Well, there you are!' said Bagman. 'You have each pulled out the dragon you will face, and the numbers refer to the order in which you are to take on the dragons, do you see? Now, I'm going to have to leave you in a moment, because I'm commentating. Mr Diggory, you're first, just go out into the enclosure when you hear a whistle, all right? Now – Harry – could I have a quick word? Outside?'

    ...

    A whistle had blown somewhere.

    'Good Lord, I've got to run!' said Bagman in alarm, and he hurried off.

    Harry walked back to the tent, and saw Cedric emerging from it, greener than ever. Harry tried to wish him luck as he walked past, but all that came out of his mouth was a sort of hoarse grunt.

    (Chapter 20, The First Task)

  • Task 2: Ludo Bagman and the whistle again

    Bagman gave his shoulder a quick squeeze, and returned to the judges' table; he pointed his wand at his throat as he had done at the World Cup, said 'Sonorus!' and his voice boomed out across the dark water towards the stands.

    'Well, all our champions are ready for the second task, which will start on my whistle. They have precisely an hour to recover what has been taken from them. On the count of three, then. One – two – three!'

    The whistle echoed shrilly in the cold, still air; the stands erupted with cheers and applause; without looking to see what the other champions were doing, Harry pulled off his shoes and socks, pulled the handful of Gillyweed out of his pocket, stuffed it into his mouth, and waded out into the lake.

    (Chapter 26, The Second Task)

  • Task 3: Ludo Bagman and the whistle again

    'So – on my whistle, Harry and Cedric!' said Bagman. 'Three – two – one –'
    He gave a short blast on his whistle, and Harry and Cedric hurried forwards into the maze.

    (Chapter 26, The Third Task)

Answer 2

To elaborate somewhat on points not mentioned in the previous answer, while Hogwarts was indeed founded in the 10th (or 11th) century, the Statute of Secrecy was not established until the late 17th century, by which point cannons were already fairly popular in Muggle use. (Note that the firearms referred to in the question text are from a good deal later than the 17th century.)

That said, it does not appear that the wizards are entirely against copying Muggle technology (at least in shape and function) - Hogwarts Express anyone? (Or the Wizarding Wireless, for that matter.)

Answer 3

There are several instances where the film story does not comply with the logic of the books. One example is in the film Harry Potter and the Order of the Phoenix, as Harry and the Aurors are travelling from the Dursleys' to Grimmauld Place via broomstick, they fly just over the Thames river past several popular London landmarks.

However, the point of the escape by broomstick is to not draw attention to themselves. Which is why, in the book, they fly in the clouds, with Moody asking them to divert their route just because a Muggle is looking up.

If one were to actually see people flying over the Thames as shown in the film, it would cause quite a controversy, would it not? Which defeats the entire purpose of the magic community hiding themselves from Muggles.

NOTE: I understand this answer deviates from the question quite a bit. But the question is related to discrepancies in the films. Just thought I would point out another example to show that one shouldn't scrutinize the films too closely for logic.