#physics

visibility Where does light travel to and where does it stop?

Light travels through space in a straight line at a constant speed of 299,792 kilometers per second (or approximately 186,282 miles per second).... Read more

brightness_7 What is the difference between a planetary nebula and an HII region?

Planetary nebulae and HII regions are two types of nebulae found in space. Planetary nebulae are formed by the ejected outer layers of dying low to... Read more

waves Can sound waves travel through space?

Sound is the result of vibrations that propagate through a medium such as air, water, or solid materials. In space, there is no air, and thus no... Read more

scatter_plot If I move at the speed of light and throw a stone forward, would it travel faster than light?

According to Einstein's theory of special relativity, the speed of light is an absolute limit that cannot be exceeded. This means that no matter how... Read more

science How does Einstein's theory of relativity differ from preceding theories?

Einstein's theory of relativity is one of the most significant scientific breakthroughs in history. Prior to Einstein's theory, the prevailing view... Read more

waves What is the difference between a redshift and a blueshift?

Redshift and blueshift are two important concepts in physics and astronomy. They are related to the Doppler effect, which is the change in the... Read more

space_dashboard How big is space?

Space is vast, to say the least. In fact, it is so large that it's difficult for the human mind to comprehend its sheer size. The observable... Read more

insights What is string theory?

String theory is a theoretical framework in physics that attempts to unify all known forces and particles in the universe. It posits that the... Read more

science What is the theory of relativity, and did Einstein ever express doubts about its correctness?

The theory of relativity is a set of two interrelated physical theories proposed by Albert Einstein. The first one, called special relativity, was... Read more

speed Why is the speed of light regarded as the universal speed limit?

According to Einstein's theory of special relativity, the speed of light is the universal speed limit. This means that nothing can travel faster than... Read more