It’s one of those things that make you wonder. During the winter there can be days of resplendent sunshine, without a cloud in the sky, and yet it will be freezing. If the earth is warmed by the sun, how is it possible that the sun can be shining brightly and yet it’s so cold?

The answer is that the earth is not warmed simply by the sun’s rays coming through the atmosphere. This is clearly demonstrated by the differences between each of the seven different layers in the atmosphere above earth.

The lowest level – the troposphere – is where we live and where all our weather occurs. The higher one travels within the troposphere, the colder it gets. This is why at the top of mountains the temperature drops precipitously, despite the fact that it is “closer to the sun.”

The next level up – the stratosphere – is where the ozone layer is. In this layer, however, the higher one goes the more the temperature increases. At the top of the next level – the mesosphere – are the coldest temperatures on earth, reaching -130° F.

Clearly, it’s not just the sun’s rays that warm the earth. It is also dependent on air pressure. As air pressure drops, less of the heat remains and the colder it becomes. That’s why the mesosphere is so cold; there is almost no air pressure.

Another factor is that the sun does not directly warm the air. Rather the sun warms the earth’s surface, which in turn transmits heat to the air above it. The angle that the sun hits the earth – known as the angle of insolation – determines the amount of heat produced. The lower the angle, the weaker the sun hits the earth. That is why it’s coldest at the North and South Poles. That’s also why it is hottest during midday when the sun is directly overhead.

Why the science lesson, particularly on Chanukah?

The Greek culture posed a formidable threat to the Jewish people. In fact, it was one of the greatest threats our people and our heritage ever faced. Whereas Jews were not at all attracted to Babylonian or Persian culture, Greek culture was a different story. The reason it was such a great danger was because, like Judaism, Greek culture had a deep appreciation for wisdom, depth, and beauty. But the core and vital difference is about what you do with that knowledge.

Judaism believes that it’s not so much what I know as what/who I am! Book knowledge isn’t worth much, if that knowledge doesn’t cause a transformation within the person. It’s one thing to protest against injustices caused to others, it’s another thing to invite the victims to your house for lunch. The Torah outlook on wisdom is that it’s insufficient for knowledge to enter one’s brain if it doesn’t filter down to the rest of his body.

My rebbe, Rabbi Berel Wein, often relates the anecdote about the person who told the Kotzker Rebbe that he had learned through half of Shas. The Rebbe replied, “I am more interested in knowing how much of Shas went through you.”

The sun’s rays alone do not warm the earth. There must also be air pressure and absorption of its rays. So, too, learning words of Torah is only the starting point. We also need to pressure ourselves to absorb the Torah into our very being. Only when we do so, can we radiate spiritual warmth and G-dliness to our surroundings.

Every time we learn Torah, we need to remind ourselves that we are studying and imbibing divine wisdom. That knowledge alone is transformative.

The Jewish people are about to celebrate an incredible milestone: the 13th Siyum HaShas of Daf Yomi, to be celebrated hours after the conclusion of Chanukah.

A Siyum HaShas is not, and cannot, be merely the completion of a study of text and certain pages of ancient knowledge. Rather, it is a completion of a cycle in which its adherents have grown and sought to internalize the timeless words of Gemara. It’s a celebration of absorption, internalization, and transformation. The Daf is not just something to be done; it’s something to be lived. That’s what we are celebrating – not just the spiritual rays of Shas shining through, but, more significantly, their being absorbed and radiated throughout the world.

Rabbi Dani Staum, LMSW, is a rebbe and guidance counselor at Heichal HaTorah in Teaneck, NJ, Principal at Mesivta Ohr Naftoli of New Windsor, and a division head at Camp Dora Golding. He can be reached at This email address is being protected from spambots. You need JavaScript enabled to view it.. Looking for periodic powerful inspiration? Join Rabbi Staum’s new Whatsapp group “Striving Higher.” Email for more info.