In this lesson, we look at what we mean by overcoming showstoppers. Showstoppers are obstacles to development and widespread adoption of blockchain technology. Showstopper are also risks to the decentralized control and openness of blockchain. If we look back at the history of disruptive technology, we see many examples of innovations gone bad. Their inventors were attempting to solve a problem plaguing humankind. But innovations like big ideas can be twisted or applied in ways their inventors never intended. Consider the work of Lev Sergeyevich Terman, a gifted Russian musician and inventor. He discovered how to make music out of thin air. That reminded us of Satoshi Nakamoto making money out of nothing but clever code. Terman story is a cautionary tale for anyone who wants to see blockchain succeed in the world. Terman was born into Russian aristocracy before the turn of the 20th century. He later joined the Bolsheviks and dismantling the czarist autocracy, it was a political movement. One of this early assignments was to create a device for measuring the electrical conductivity and the capacity of various gases. He tried gas filled lamps, he tried a high frequency oscillator, and he even tried hypnosis. The oscillator ended up working well. So Terman's boss encouraged him to seek other applications for it. The first application is a device that you may be familiar with. It started out as two metal terminals with nothing between them, like a lamp without the glass. Terman discovered if he filled the void with gas, he could gauge the gases electrical properties. He used headphones so he could take acoustic readings of the pitch of the electrical signal each gas produced. To his surprise, Terman could control the pitch by moving his hands carefully. He called his device the ether thong, what is it called today? The theremin, used a lot in Sci-Fi movies of the 1950s, like The Day the Earth Sit Still or the Forbidden Planet. Terman's other apparatus was a larger scale version of this device. It was sensitive to movement within a radius of several meters. It became the first motion detector, a century of the ether. Terman demoed both devices at the Kremlin. And what did comrade Lenin do? He immediately set up the motion detector to guard Soviet stashes of gold. If anyone crossed the electromagnetic line around the gold, they'd set off a silent alarm. Suddenly big brother had electric eyes, chilling stuff. Lenin even co-opted electricity in his propaganda. He created communism with Soviet Power and the electrification of the country. But comrade Stalin took it to a whole new level of bad. Stalin rounded up Terman and his fellow scientists through them in a gulag and forced them to invent more tools of tyranny. The moral of the story is simple, Terman's innovation brought both light and darkness to the world. Web developer, Maciej Ceglowski said as much in his brilliant talk, Our Comrade the Electron". New technology can be used for good and for evil. You probably heard such warnings about the Bitcoin blockchain, beware it's used for drug trafficking, money laundering and Ponzi schemes. Sure, these are real concerns. So, how do we keep dark forces from co-opting or crushing blockchains potential. We already looked at the many promises of this technology. In the coming lessons, we will shine the spotlight on 10 showstopper. Understanding them is half the battle. You may be tempted to dismiss blockchain because of these showstopper. But are these really reasons that blockchain is a bad idea? Or are they implementation challenges to be overcome? We think it's the latter. We encourage you to reframe these as important problems to solve, and you can help solve them. You can collaborate and put your ingenuity to work here as we transition into the second era of the Internet. Up next, we look at the first showstopper, the sheer difficulty of using blockchain right now.