Transcript: How does the idea of inflation explain some of the problems of the standard big bang model? First, by stretching space by an enormous degree, the universe is predicted to be flat. Imagine a tiny curved balloon that is rapidly inflated to a huge size. Someone observing one small piece of the balloon will see it to be flat or very close to flat. Flatness of space is a prediction of inflation. The same expansion also causes space to be smooth. Regions that we currently observe to be far apart on the sky were once in very close contact. Regions for example twenty or thirty billion lightyears apart now were once only a few meters apart. Thus we can explain the perfect thermal spectrum of the big bang radiation because it reflects the fact that it originated from a region which was in close thermal and causal contact. The expansion also produces a dispersal of defects, topological defects and monopoles, such that we would not expect to observe any in our universe, matching observation. Inflation in a fundamental way predicts that the physical universe must be enormously larger than the observable universe. It could in fact be infinite. The final and staggering implication of the inflationary model is that inflation took regions of space that were quantum fluctuations and inflated them to the size of galaxies where they became the seeds for large scale structure that we observe in the universe. Thus if inflation is correct, when you observe galaxies we are observing quantum fluctuations in the first iotas from the big bang.