This video includes an explanation of density using practical exams. Density is mass per unit volume.

It can be impossible to identify full virus particles from empty ones based on size or shape alone. The particle's buoyant density can help you to distinguish between otherwise identical populations.

This applies to the Shanghai Outer Ring Tunnel: a major travel artery in China’s largest city, which runs for almost 3 km ...

Tunable red to green emissions in upconversion nanoparticles allow precise identification of single particles, enabling ...

Front Cover; Contents; Preface; Acknowledgments; About the Authors; Introduction; Section 1 -- Concept of Matter and Particle Model of Matter; Matter or Not Matter?; Solids, Liquids, and Gases; What ...

For a quarter century, cosmology has leaned on one framework to explain how the universe expands. Known as the ΛCDM model, it assumes about 70 percent of the cosmos is filled with an unseen force ...

A new study suggests that primordial black holes (PBHs)—hypothetical remnants from the early universe—might be on the verge of an unprecedented cosmic event: an explosion observable with current ...