All that we really need to plot out the future of our universe arc a few good measurements. This does not mean that we can sit down today and (26) the future course of the universe with anything like certainty. There are still too many things we do not know about the way the universe is put together. But we do know (27) what information we need to fill in our knowledge, and we have a pretty good idea of how to go about getting it. Perhaps the best way to think of our present situation is to (28) a train coming into a switchyard. All of the switches are set before the train arrives, so that its path is completely (29) . Some switches we can see, others we cannot. There is no doubt if we can see the setting of a switch: We can say with (30) that some possible futures will not be realized and others will. At the unseen switches, however, there is no such certainty about it. We know the train will take one of the tracks (31) , but we have no idea which one. The unseen switches are the true decision points in the future, and what happens when we arrive at them determines the entire (32) course of events. When we think about the future of the universe, we can see our "track" (33) years into the future, but after that, there are decision points to be (34) and possible fates to consider. The goal of science is to reduce the (35) at the decision points and find the true road that will be followed. All that we really need to plot out the future of our universe arc a few good measurements. This does not mean that we can sit down today and (26) the future course of the universe with anything like certainty. There are still too many things we do not know about the way the universe is put together. But we do know (27) what information we need to fill in our knowledge, and we have a pretty good idea of how to go about getting it. Perhaps the best way to think of our present situation is to (28) a train coming into a switchyard. All of the switches are set before the train arrives, so that its path is completely (29) . Some switches we can see, others we cannot. There is no doubt if we can see the setting of a switch: We can say with (30) that some possible futures will not be realized and others will. At the unseen switches, however, there is no such certainty about it. We know the train will take one of the tracks (31) , but we have no idea which one. The unseen switches are the true decision points in the future, and what happens when we arrive at them determines the entire (32) course of events. When we think about the future of the universe, we can see our "track" (33) years into the future, but after that, there are decision points to be (34) and possible fates to consider. The goal of science is to reduce the (35) at the decision points and find the true road that will be followed.