Skip to main content

Why are winters cold?

Winters are cold for two main reasons.  Both of these reasons come about because of the fact that the Earth tilts on its axis.  When the Earth tilts, sun comes to hit one of its hemispheres more directly and the other less directly.  The hemisphere which the sun hits less directly gets colder.


The first reason has to do with the length of the day.  As the Earth tilts, the sun “moves” farther towards the equator.  When this happens, days at higher latitudes get shorter and shorter in terms of how long the sun is above the horizon.  Because the sun spends less and less time above the horizon, it has a much shorter time during which it can heat the atmosphere.


When the Earth tilts on its axis, the angle at which the sun’s rays hit Earth also changes.  During the summer, the sun’s rays hit the Earth at an angle that is close to 90 degrees.  This means that the light points (more or less) straight down at the Earth.  The light does not have to pass through much of the atmosphere before it hits Earth and it does not spread out over very much of the Earth.  By contrast, in the winter, the sun’s light hits Earth at a very oblique angle.  It has to go through much of the atmosphere before hitting the surface, robbing it of some of its energy.  In addition, the light spreads out over a larger surface area, bringing less energy to any particular area.


These factors combine to create a situation in which a particular hemisphere of the Earth gets colder when it is winter in that hemisphere.

Comments

Post a Comment

Popular posts from this blog

Is there a word/phrase for "unperformant"?

As a software engineer, I need to sometimes describe a piece of code as something that lacks performance or was not written with performance in mind. Example: This kind of coding style leads to unmaintainable and unperformant code. Based on my Google searches, this isn't a real word. What is the correct way to describe this? EDIT My usage of "performance" here is in regard to speed and efficiency. For example, the better the performance of code the faster the application runs. My question and example target the negative definition, which is in reference to preventing inefficient coding practices. Answer This kind of coding style leads to unmaintainable and unperformant code. In my opinion, reads more easily as: This coding style leads to unmaintainable and poorly performing code. The key to well-written documentation and reports lies in ease of understanding. Adding poorly understood words such as performant decreases that ease. In addressing the use of such a poorly ...
Post a Comment
Read more

A man has a garden measuring 84 meters by 56 meters. He divides it into the minimum number of square plots. What is the length of the square plots?

We wish to divide this man's garden into the minimum number of square plots possible. A square has all four sides with the same length.Our garden is a rectangle, so the answer is clearly not 1 square plot. If we choose the wrong length for our squares, we may end up with missing holes or we may not be able to fit our squares inside the garden. So we have 84 meters in one direction and 56 meters in the other direction. When we start dividing the garden in square plots, we are "filling" those lengths in their respective directions. At each direction, there must be an integer number of squares (otherwise, we get holes or we leave the garden), so that all the square plots fill up the garden nicely. Thus, our job here is to find the greatest common divisor of 84 and 56. For this, we prime factor both of them: `56 = 2*2*2*7` `84 = 2*2*3*7` We can see that the prime factors and multiplicities in common are `2*2*7 = 28` . This is the desired length of the square plots. If you wi...
Post a Comment
Read more

What warning does Chuchundra issue to Rikki?

Chuchundra, the sniveling, fearful muskrat who creeps around walls because he is too terrified to go into the center of a room, meets Rikki in the middle of the night. He insults Rikki by begging him not to kill him. He then insults him by suggesting that Nag might mistake Chuchundra for Rikki. He says, "Those who kill snakes get killed by snakes."  He issues this warning to Rikki not to help keep Rikki safe but as a way of explaining why Rikki's presence gives him, Chuchundra, more reason to fear.  Chuchundra starts to tell Rikki what Chua the rat told him--but breaks it off when he realizes he might be overheard by Nag. He says, "Nag is everywhere, Rikki-Tikki." Rikki threatens to bite Chuchundra to get him to talk. Even then, Chuchundra won't overtly reveal any information. But he does say, "Can't you hear, Rikki-Tikki?" This is enough of a clue for the clever mongoose. He listens carefully and can just make out the "faintest scratch-s...
Post a Comment
Read more