Unless you live near the earth's equator, you have no doubt noticed that the weather changes during the year: it is hotter during the summer, colder in winter, and somewhere in between during spring and fall. These are the seasons, a regular change in temperature, that repeat themselves every year, more or less regularly.
What causes these changes? The sun is our main source of heat, and since these changes are the same every year, it surely has something to do with the movement of the earth around the Sun. If we get closer to a fire, we get hotter. Could it be then that the Earth gets closer to the sun during summer, and farther during winter? His idea seems at first to have some merit, until we remember that the seasons get reversed when we cross the equator: when it is summer in the northern hemisphere, it is winter in the southern one, and vice versa. And surely Argentina is at the same distance from the Sun as the USA!
Besides, that the earth's orbit is an ellipse, not a circle, so that at some times the earth is closer to the Sun than at others; but this ellipse is very nearly a circle, and the relatively small differences in distance to the sun cannot account for the changes in temperature. And to make things worse, the earth is closer to the sun during the northern hemisphere winter!