Every day, the cells in your body are dividing like crazy - sometimes too much, which is the definition of cancer. Here you can see breast cancer cells in action, multiplying into what could become a tumorous growth.
Yes, this film is dramatically speeded up - most of these cells would divide about twice in a day. The video below shows us dozens of cells undergoing normal cell division, in real time. I'm not sure why all of them are dividing at once - possibly a chemical has been used to induce it. Mitosis has never looked so much like a lava lamp.