Hydrogen is the most plentiful substance in the universe. Could it also be the fuel of the future? In this episode, we look at the challenges and opportunities related to a hydrogen economy.Learn more about advertising on the HowStuffWorks podcasts at www.howstuffworks.com/advertisers.htmAnd to learn about your ad choices when listening to podcasts, visit https://www.howstuffworks.com/privacy.htm#ad-choices