TWEENS MAGAZINE
Are starfish really fish? Is the earth round? What does the iris do?
INTERESTING FACTS! Enter your best world!
JUNE-JULY 2013
Starfish Watch your steps!
These colorful sea stars make a spiny carpet.
SCIENCE
TWEENS MAGAZINE
The scientific name for the bat sea star, found along the Pacific coast of North America, is Patiria miniata. You probably know sea stars as starfish, the name sea stars are commonly known by. But sea stars aren’t really fish. Sea stars, like sea urchins and sand dollars, do not have backbones, which makes them part of a group called invertebrates. Fish have backbones, which makes them vertebrates. Got it? There are more than 1,600 species (types) of sea stars living in all the world’s oceans. The sea star eats by attaching to prey and extending its stomach out through its mouth. Enzymes from the sea star’s stomach digest the prey. The digested material enters the sea star’s stomach. Tiny organisms can be swallowed whole.
TWEENS MAGAZINE
SCIENCE
3 | JUNE-JULY 2013
Plants Facts
Explore the amazing world of plants. Learn about trees, flowers, photosynthesis, and trivia on weird species such as poison ivy and the venus flytrap. can eventually turn into coal due Tree resin which has been fossilized is known as amber, it sometimes to a process called metamorphosis (changing form). contains plant material or small animals that were trapped inside.
Some plants are carnivores, gaining nutrients by eating various small insects and spiders. A well known example of a carnivorous plant is the Venus Flytrap.
Poison ivy produces a skin irritant called urushiol. Touching poison ivy will cause an allergic reaction, usually in the form of an itchy rash on the skin.
Fertilizers are chemicals added to Bamboo can be a fast growing plant, plants to help them grow. Important elements in fertilizers include nitrosome types can grow almost a gen, phosphorus and potassium. metre (3.28 feet) in just one day! Manure (animal waste) is also used While using energy from sunlight, as a fertilizer. plants turn carbon dioxide into food Around 2000 different types of in a process called photosynthesis. plants are used by humans to make In the agricultural industry, to ensfood. Also, there are over 200,000 ure crops of food grow well water is identified plant species and the list often added to soil in the form is growing all the time. of irrigation. Plant matter found at the bottom of areas with water such as swamps
SCIENCE
TWEENS MAGAZINE
TWEENS MAGAZINE
SCIENCE
5 | JUNE-JULY 2013
Eye Although Although we we can can function function without without sight, sight, we we rely rely heavily heavily on on vision vision to to live live our our everyday everyday lives. lives.
JUNE-JULY 2013 | 6
The information our eyes receive is sent to our brain along the optic nerve. This information is then processed by our brain and helps us make appropriate decisions, for example if you can see an object flying in your direction then you will probably move quickly out of the way. The central opening of your eye is known as the pupil, it changes size depending on the amount of light.
known as the lens, it changes shapes so we can focus on objects at various distances. Human eyes contain a small blind spot where the optic nerve passes through the retina. Our brains use information from the other eye to fill in the vision gap so it is rarely, if ever, noticed.
The cornea is the transparent covering of the iris and pupil, along with the lens it refracts light so it can be The colored area around the pupil is projected onto the retina. called the iris, it controls the size of Glasses and other protective equithe pupil and can be colored brown, pment are often worn by humans blue, green or other colors and to protect the eyes from UV rays or shades depending on the person. during various dangerous activities The light sensitive tissue lining the such as welding. inner surface of your eye is known Glasses and contact lenses are worn as the retina, acting in a similar way to correct common sight conditions to film in a traditional camera. such as short and long sightedness. The part of the eye that allows us to focus on different things in
7 | JUNE-JULY 2013
Earth Planet Interesting Facts About Earth We all live on Earth, but you may not be aware of all the fun and interesting facts about Earth. Now, you can share these facts and surprise your friends and teachers with all your great knowledge!
SCIENCE
TWEENS MAGAZINE
JUNE-JULY 2013 | 8
Earth, our home planet, is the only planet in our solar system known to harbor life. The Earth is Not Round Did you always think the Earth was round? Wrong! The Earth is not completely round, it is actually a little bit flattened at the North and South Poles. Much Of Earth is Water About 70% of Earth is water which means only about 30% of Earth is land. It is kind of like Earth is a huge bath tub or pool and land is the diving board! Earth’s Core Is Steaming Hot The Earth’s core is the center of Earth and the core is hotter than the surface of the sun! You could get no where near the center of Earth or you would burn up, it is a steaming hot place!
TWEENS MAGAZINE
SCIENCE
1 | JUNE-JULY 2013
Water Water is made up of two elements, hydrogen and oxygen. Its chemical formula is H2O. Each molecule of water is made up of two hydrogen atoms bonded to a single oxygen atom.
state. The solid state of water is known as ice while the gas state of water is known as steam.
Water covers around 70% of the Earth’s surface. The three largest oceans on Earth are the Pacific Ocean (largest), the Atlantic Ocean Water has three different states, liquid, solid and gas. The word water (second largest) and the Indian Ocean (third largest). usually refers to water in its liquid
SCIENCE
TWEENS MAGAZINE
JUNE-JULY 2013 | 10
“When the well is dry, we learn the worth of water.”
—Benjamin Franklin
Found in the Pacific Ocean, the Mariana Trench is the deepest known point in the world’s oceans. Ocean tides are caused by the rotation of the Earth and the gravitational pull of the Moon and Sun acting on ocean water. Water from a sea or ocean is known as seawater. On average, every kilogram (2.2lb) of seawater contains 35 grams (1.2oz) of dissolved salt. The freezing point of water lowers as the amount of salt dissolved in at increases. With average levels of salt, seawater freezes at -2 °C (28.4 °F). Pacific Ocean Photography by: Mehulat. The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.
The water cycle involves water evaporating (turning into a gas), rising to the sky, cooling and condensing into tiny drops of water or ice crystals that we see as clouds, falling back to Earth as rain, snow or hail before evaporating again and continuing the cycle. Learn more about the water cycle.
TWEENS MAGAZINE
SCIENCE
Visit our website www.expandingculturalknowledge.com
Postal Information: Expanding Knowledge in USA is published this magazine monthly, by Expanding Inc. Office Of Publication: 500 Bush St, San Francisco, CA 94108. 650-775-0777. Expandingknowledge@yahoo.com.