The link explains it further. The point of the chronophone is that you can't just send ideas you already have back. If you want to send the scientific method ba

The link explains it further. The point of the chronophone is that you can't just send ideas you already have back. If you want to send the scientific method back in time, you have to actually do science. If you want to send the printing press, you actually have to think about better ways your present civilization could transmit information.