Blog

Explore why the universe is mostly empty, from expansion and gravity to cosmic voids, dark matter, and the limits of visible matter.

Explore why cosmic expansion has no central point, how spacetime stretches, and what observations like the CMB reveal.

A clear explanation of why cosmic expansion does not require preexisting space, and what physicists mean by “nothing.”

Learn how dangerous cosmic radiation really is, who faces the highest risk, and how exposure is measured and reduced.

Cosmology explains the origin, structure, and fate of the universe, and it shapes modern science, technology, and our worldview.

Astronauts float because they are in continuous free fall around Earth. Learn the physics, common myths, and how gravity still works in orbit.

Learn what cosmology is, how scientists study the universe, and what major theories explain its origin, structure, and fate.

Artificial gravity would feel familiar at first, but rotation, acceleration, and design details can make it surprisingly strange.

Learn what time dilation is, why it happens in relativity, and how speed and gravity change the passage of time.

Earth’s atmosphere shields life from harmful radiation through absorption, scattering, and magnetic interactions.