Metals are often confusing. Let’s explore the definition of a metal through chemistry via the Periodic Table of the Elements.
As Condensation Droplets Form and Combine, What Forces are at Work?
Moisture condenses onto glass, forming condensation droplets. What forces are at work in their formation, in their combining, and in their disruption?
Hollow Airtight Sphere With 100% Albedo: Ask the Expert Question
What happens to a light inside a sphere with 100% albedo? Our science experts discuss the results of this theoretical question.
Cane Juice Crystallization to Raw Sugar: A Chemical or a Physical Change?
Sugarcane is harvested, crushed, the juice collected and converted to raw sugar. Is cane juice crystallization to raw sugar a chemical or a physical change?
Can Adjusting the Amount of Helium in a Balloon Affect Its Height?
Physics, Archimedes’ Principle, helium balloons, and air as a liquid – Dr. Paul Heckert answers a reader question in this new Ask the Expert article.
How Astronomers Know the Universe Is Expanding
It’s time for another ‘Ask the Expert’ question from our readers. This reader wants to know how we really know the universe is expanding – Paul Heckert, PhD has the answer.
Methane as a Greenhouse Gas: Ask the Expert Question Answered
Methane is a greenhouse gas more powerful than carbon dioxide. Here we describe the main methane sources and the possible measures to decrease its emissions
Under The Radar: Why It Rains When There Are No Radar Echoes
Radar doesn’t always accurately show precipitation. Sometimes you see what isn’t there — and sometimes you don’t see what’s there.
Suffering From Recurring Nightmares? Practice Happy Dreams Instead
Returning nightmares can make you miserable. Stopping the scary dreams could be as simple as changing your medication, or using a visualization technique.
Sucralose: Possible Risks of a Common Artificial Sweetener
Sucralose is a common artificial sweetener, but according to the research, it may not be very safe to use – either for human health or for the environment.