天文学科普（英文版）PPT
The Scale of the UniverseThe universe is a vast and complex system composed ...
The Scale of the UniverseThe universe is a vast and complex system composed of countless stars, galaxies, clusters, and more. It extends billions of light-years across and contains myriad forms of matter and energy. To help us grasp the scale of the universe, let's start with the smallest known unit, the proton.Protons are positively charged particles found in the nucleus of an atom. They have a mass of about 10^21 kilograms. If we compare a proton to the size of a grain of sand, the next step up in scale would be an atom, which would be about the size of a football. The Scale of the UniverseThe universe is a vast and complex system composed of countless stars, galaxies, clusters, and more. It extends billions of light-years across and contains myriad forms of matter and energy. To help us grasp the scale of the universe, let's start with the smallest known unit, the proton.Protons are positively charged particles found in the nucleus of an atom. They have a mass of about 10^21 kilograms. If we compare a proton to the size of a grain of sand, the next step up in scale would be an atom, which would be about the size of a football field. The Scale of the UniverseThe universe is a vast and complex system composed of countless stars, galaxies, clusters, and more. It extends billions of light-years across and contains myriad forms of matter and energy. To help us grasp the scale of the universe, let's start with the smallest known unit, the proton.Protons are positively charged particles found in the nucleus of an atom. They have a mass of about 10^21 kilograms. If we compare a proton to the size of a grain of sand, the next step up in scale would be an atom, which would be about the size of a football field.
