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A telescope and a satellite dish under a starry sky with the Milky Way visible in the background.

How Scientists Study Space

Scientists study space by turning faint signals—mostly light, but also particles and gravitational waves—into data that can be tested, compared, and rechecked. The core workflow is simple: collect photons or other messengers, calibrate instruments, then use physics to infer distance, composition, and motion. Because space is remote, research… How Scientists Study Space

The universe's vast size is shown with numerous stars and galaxies stretching into the distance.

How Big Is the Universe?

Asking how big the Universe is sounds like a single question, but it quietly contains several different ones. Size can mean how far we can see, how far matter is right now, how much space exists in total, or whether space even has an “outside.” Modern cosmology can… How Big Is the Universe?

Spiral galaxy and Earth seen from space, illustrating what is universe.

What Is the Universe?

The universe is the totality of space, time, and everything that can exist within them: matter, energy, the laws of physics, and the evolving patterns that form galaxies, stars, planets, and the space between. It is not just a “place” filled with objects. In modern physics, the universe… What Is the Universe?