Where can I see the current size of the bitcoin blockchain? I am tying to understand the concept of the bitcoin blockchain, from what I understand everybody owns a full copy of the bitcoin blockchain, but is it possible to see the current size somewhere without having "checked it out/cloned it"?

And are there any backups being made? I know it's distributed and everyone owns a full copy - kinda like with a git repository - but is it also backed up on centralized servers?
Yes, you can use this website:

https://blockchain.info/charts/blocks-size