Once matter passes the event horizon of a black hole, it’s torn apart and crushed into a singularity. At the singularity, the laws of physics as we know them no longer apply.
What happens to matter inside a black hole?
Spaghettification: The matter is stretched into long strands, similar to pasta, and ripped apart by the gravitational forces
Superheating: The matter is superheated and emits X-rays
Crushing: The matter is crushed into a singularity, a one-dimensional point at the center of the black hole
What happens to time inside a black hole?
Time dilation: Time passes more slowly near a strong gravitational source
Space-time flow: Space-time flows inward at the speed of light at the event horizon
What happens to the black hole?
Hawking radiation
Black holes may slowly radiate energy away, which could cause them to evaporate over time
Size
The size of the black hole’s event horizon increases as more matter accumulates at the singularity

Cellular respiration is a process that breaks down food molecules to produce energy for cells. It’s a vital process that occurs in the cells of all plants and some animals.
What it is
Cellular respiration is a series of chemical reactions that occur in the mitochondria of cells.
It breaks down glucose and oxygen to produce energy in the form of adenosine triphosphate (ATP).
It also releases carbon dioxide and water as waste products.
Why it’s important
Cellular respiration provides cells with the energy they need to function.
Without cellular respiration, living things would not be able to get the energy they need from food and would eventually die.
How it works
Cellular respiration has three main stages: glycolysis, the citric acid cycle, and oxidative phosphorylation.
The reactions involved in cellular respiration are catabolic, meaning they break down molecules into smaller ones.

The Big Bang theory is a scientific theory that explains the origin and evolution of the universe. It’s important because it:
Explains the universe’s expansion
The theory explains how the universe expanded from an extremely hot and dense state to the cooler and less dense state it is in today.
Explains the presence of matter
The theory explains how the universe came to contain the matter and radiation that make up stars, planets, and galaxies.
Explains the physical laws
The theory explains the physical laws that govern the universe.
Explains the origin of hydrogen and helium
The theory explains where the hydrogen and helium in the universe came from.
The Big Bang theory is based on a combination of observations, mathematical modeling, and experimental evidence. The theory suggests that the universe began about 13.8 billion years ago in a singularity, a point of infinite heat and density. This singularity contained all the matter and energy that would eventually form the universe. The universe then expanded rapidly, faster than the speed of light, in a period known as cosmic inflation.

Telescopes use mirrors or lenses to gather and focus light from distant objects, allowing astronomers to see them:
Light collection
The size of a telescope’s main mirror or lens determines how much light it can collect. Larger mirrors or lenses can collect more light and detect fainter objects.
Light focusing
The shape of the mirror or lens concentrates light into a single point, called the focal point.
Image magnification
When viewed through a telescope’s eyepiece or camera, the concentrated image appears magnified.
There are several types of telescopes, including:
Refracting telescopes
Use lenses to bend, or refract, light. The first telescopes were refracting telescopes, and many backyard telescopes today are still refracting.
Reflecting telescopes
Use mirrors to collect and focus light. Reflecting telescopes are ideal for space because large mirrors can be made lighter and thinner than lenses of the same size.
Catadioptric telescopes
Combine lenses and mirrors to focus light. These telescopes are typically compact and easy to transport and handle.