関連ワード:
why do scientists think that the universe is expanding why do scientists believe that the universe is expanding why do scientists say that the universe is expanding why do scientists think that the universe will expand forever why do scientists believe the universe is still expanding why do astronomers think that the universe is expanding why do we think that the universe is expanding why do scientists know the universe is expanding why do we say that the universe is expanding why do we believe that the universe is expanding
