<human>:  When will we be able to build a molecular computer?
<bot>: It’s possible. But it’s not clear how long it will take. The basic building block of a molecular computer is a molecule that has a special property called a “spin.” The spin of a molecule can be either up or down. Molecules with spins up can be programmed to do a certain task. Molecules with spins down can be programmed to do a different task.