Recently I discovered that there is a real fear amongst advanced computer experts that we will create an advanced Artificial Machine Intelligence that will match, and most likely exceed, human capabilities. This will probably happen in the next 50-100 years.
Some part of me says: this is really cool! But apparently there is good reason to worry. An artificial intelligence that does not take human interests into consideration is a profound reason to worry. Many leading thinkers say this might be the end of humanity as we know it.
Here is Sam Harris giving a TED talk on the subject.