Note that different people have different research approaches. The two old ladies check that none of them can see herself and the problem is solved! ;-)
The other older lady makes an experiment with motion and rigorously determines that she is ... well ... unsichtbar. :-)
The Startup Meant to Reinvent What Bitcoin Can Do - A company given $21 million by leading Silicon Valley investors aims to extend Bitcoin’s functionality so it can power much more than just payments. Link...
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