How do seasons change

But, the Chinese calendar had this transition occurring at a variable time each year, determined partly by the Chinese lunar month, usually in early February. More recently, this thought became fixed to the time of the spring equinox.

The underlying assumption relating to standing eggs on end is that there must exist some special gravitational balance. There are many forces acting on an egg when you try to stand it on end on a flat surface. Some people think that the gravitational pull of the Sun becomes balanced with that of the Earth to allow for this phenomenon to occur. However, the Moon exerts a much stronger gravitational effect on the Earth than the Sun, dominating the ebb and flow of the ocean tides.

The Moon's effects are different at each of the equinoxes however. The most dominant force of gravity on a standing egg is the one between the Earth and the egg itself.

This is determined by the weight of the egg and the force pulling the egg to the counter top. If you want to prove this to yourself, take a fresh, uncooked egg and hold it with the larger end resting on a table or counter top.

Wait for the fluid content of the egg to settle, then carefully test the balance. Be patient as you find the point where you can ever so gently let it go to remain standing on end. Please Contact Us. Please try another search. Multiple locations were found. Please select one of the following:.

Location Help. News Headlines. Customize Your Weather. Privacy Policy. Why Do We Have Seasons? Current Hazards. Local Radar. Rivers and Lakes. Climate and Past Weather. Why Do We have Seasons? Incidentally, that big something that hit Earth also knocked a chunk of it out that became our Moon. At least that is generally accepted theory. So, here we are, orbiting the Sun, but tilted a bit and always with the axis pointed in the same direction.

Hence, the seasons. It is summer in June in the Northern Hemisphere because the Sun's rays hit that part of Earth more directly than at any other point in Earth's orbit - or, in other words, more directly than at any other time of the year.

It is winter in December in the Northern Hemisphere, because that is when it is the South Pole's turn to be tilted toward the Sun. The above clip serves as a helpful follow-up for a longer lesson that makes clear why the Earth has seasons. Get your students to stand up and use their own bodies in an active model! This kinesthetic activity demonstrates to students that the earth's tilt is what is responsible for shifting light patterns and the change in seasons.

After your students have a more solid grasp of this traditionally confusing concept, use the above clip to review and reinforce their understanding. Now that your students understand the reason for the seasons, extend the unit to explore the instrumental role the sun plays in fueling food webs, starting with producers. This clip illustrates the influence of the sun on the seasonal abundance of plant matter produced on land and in our oceans.

How do plants respond to seasonal changes in sunlight? Which areas of land and oceans are most productive at different times of the year, and why? Your class is now comfortable using patterns to identify cause and effect relationships.

Can they extend this one level up the food chain to predators? Track the movement of two migratory birds of prey—ospreys and turkey vultures—as they travel between North and South America over a single calendar year. Assist your students to make connections as to how populations of organisms are dependent on the living things on which they prey.

Have an idea you'd like us to post on this page? Email us. Visualizations based on aggregated data provide the unique opportunity to engage your students in various Science Practices highlighted in the Next Generation Science Standards, including asking questions, analyzing and interpreting data, and constructing explanations. As an example, Academy educators developed sample activities such as this one and this one. Astronomy Activities You'd be surprised by how much astronomy you can learn with a light source, some painter's tape, and a can of play doh.

This collection features nine of our most popular activities. Why do we have seasons? The Reason for the Seasons This website gives background information of why we have seasons and visualizes the angle of sunlight one of the reason of the seasons. Plunge into a California kelp forest and learn about the complex, colorful ecosystems right off our coast.

Travel underground for an up-close look at the ants, amoebas, and bacteria that maintain healthy soil. Browse a rich array of educational resources from the award-winning show, Habitat Earth. Our collection of educational videos will help your students visualize data and understand scientific concepts. Sign up for event updates and exciting announcements. Learn more.