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Showing posts from November, 2022

The Solar Powered Slug

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I've often wondered what it would be like if we could make our food the same way plants do. Could I make glucose for respiration by walking around outside in the sunlight, not that we get much where I live? Of course, I would be green, but perhaps only where my skin is exposed to the sun. Photosynthesis is the chemical reaction plants use to make their food. They take in water from the soil and carbon dioxide from the air and, using sunlight for the energy, they turn this into glucose and oxygen. The name for a reaction that takes in energy is endothermic. Photosynthesis is an exothermic reaction. You may have used a reaction like this if you have ever injured yourself. You can get cool packs which cool down when you mix two chemicals. Chloroplasts in a Cell Plants can collect sunlight for photosynthesis because they have structures in their cells called chloroplasts, (above). Chloroplasts contain a chemical called chlorophyll, which absorbs light energy so that the photosynthesis

Barcoding the Stars

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Looking up at the night sky, you will see dozens of stars. If you live in a very dark place, you may even see hundreds. The thing that people find difficult to grasp is just how far away these stars are. Our sun is 150 million km away from earth. If you could travel at the speed of light, which is as fastest you can go, it would take 8 minutes to get there. To get to the next nearest star at the speed of light, you would be travelling for 4 years (that's without toilet stops). Other objects are much further away. There are billions of galaxies outside of our Milky Way. Light from one of the nearest takes over 2 million years to reach earth. That is truly a galaxy far, far away. This is the Andromeda Galaxy, the farthest object you can see with the naked eye. We can't get to the stars to study them, so how do we find out how they work? The answer is light. We use telescopes to collect light from the stars and watch them move and change. Some telescopes detect light that we can&#