Answer:
The sugar particles are so small that they have dissolved in the water, and can easily pass through the filter.
During the dark ages-All that wasn't around the christian religion were lost. Knowledge and discoveries before the Dark Ages were mainly in Greek ideas. Biblic scripts however were in Latin. Therefore all inventions up to the dark ages were lost and only religious scripts preserved in the churches. Outside the church, no one knew how to write, read or even communicate.
Alpha decay involves the loss of an alpha particle, aka a helium nucleus. This results in the mass number of the original element decreasing by 4 and the atomic number decreasing by 2. Assuming 23942u is uranium (92), the resulting element's atomic number is 90, making it thorium.