A persuasive speech on "alien exists in the universe"

General purpose:

Alien exists in the universe.

Specific purpose:

                                                To persuade my audience that Alien exists in the universe.

Central idea:

                                                According to the mathematical calculation of galaxies, the crop circles, the pyramids etc. proves that alien exists.

Main points:

                1. The number of galaxies. Approximately 50 billion galaxies are visible with modern telescopes. Let's assume that very few planets among them are suitable for producing life. From this information, science calculated that Ten billion planets in the universe are suitable for producing life. So it is generally possible having aliens.

            2. The pyramids in Egypt. The structure of pyramids seems that we were super advanced thousands of years ago. But human evolution doesn't agree with this. So something besides humans, who made those. We can't think of any other explanation for this.

            3. Crop circle found in crop fields. Most of the crop circles are looks like spaceship, maths and Egyptian hieroglyphics. 80% of the crop circles in England are phoney.