Earth Gravity – Distinguishing the Forest and Trees

Education, Physics
There's no point attempting to explain the precise nature of gravity here. Most of us are aware it is Earth gravity that enables us to remain standing on the planet. Gravitational force operates on all matter.¹ Is Matter the Same as Weight? No, the two are not the same. To illustrate, say a man is seated at the doctor's office and he is invited back. He is requested to stand on a scale. It says he weighs 210 lbs. We write w = 210 lbs. Now say that man is an astronaut. Ah! Next week he is deep in space. If he removes his restraints, he begins to float. He is weightless!² That is, w = 0 lbs. Yet his mass remains the same. That is, m ≠ 0. Weight…
Read More

How Far Can Perfect Eyes See? An Ideal Earthly Scenario

Logic, Mathematics
[caption id="attachment_26540" align="alignright" width="480"] Image by Meg Learner[/caption]I once met a fellow in Virginia who said, 'The human eye is an amazing thing. Why, if there were no mountains in-between, we could see California!' Of course, he was referring to perfect eyes... Of course, that is just plain nuts. Nevertheless, it raised the question, "Just how far away could a person see an object if nothing interfered? Let's consider the answer to that question. Conditions First, we need to set conditions or ground rules. Earth is sufficiently round to call it a sphere, so we treat it as such. In fact, we assume it is perfectly smooth even to an ant. Further, we assume the atmosphere is perfectly clear, and the observer has perfect eyes. When we look out toward…
Read More

Natural Snow Removal – How?

Meteorology, Physics
[caption id="attachment_12185" align="alignright" width="480"] Snow - It's a Natural[/caption] What is natural snow removal? It doesn't involve vitamins or minerals. It doesn't involve mulch or compost. From December to March, throughout the United States, sizable snow falls are no surprise. Some are delighted by snow. Others dread it. Neither speeds up or prevents a snow fall. Except through hard work on streets, sidewalks, and such, snow only goes go away by natural means. Natural Snow Removal One natural factor that removes snow is an increase in outdoor temperature. The greater the temperature, the faster snow melts. Of course it melts from the top down or the outside in. But temperature is not the only factor involved in natural snow removal. Sunlight The sun can shine brightly. Snow disappears more quickly…
Read More