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Here you can watch video lectures on astronomy topics. Watch one of 29 individual playlists, or use the Wikimap to find similar topics.

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Articles related to: Sunspot  Read article

1. Sun and Climate Change  Read article

The Sun is the source of all the Earth’s energy, and life could not exist without the Sun. In addition, there’s growing evidence that long term variations in the Sun’s output profoundly affect the Earth’s climate. For example, in the period from 1645 to 1715 sunspots were at a generic minimum call...

2. Rotation of the Sun  Read article

From ancient times Chinese and Indian astronomers noticed and recorded sunspots, blemishes or dark spots on the surface of the Sun. This work improved in the 1600s with the invention of the telescope which allowed the counting and tracking of sunspots. Galileo used such observations to prove that ...

3. Sun Spots  Read article

Galileo was the first to show that sunspots are surface features on the Sun carried around by its rotation. Be very careful ever observing sunspots with the naked eye. Galileo spent the last twenty years of his life blind from careless observations of the Sun. The best procedure is to magnify the...

4. Early Telescopes  Read article

Holland was the center of the craft of glassmaking in Europe. Eyeglasses had been in use since the fourteenth century. Around the year 1600 both the telescope and the microscope were invented in Holland. Almost certainly the telescope was first invented by a Dutch optician called Hans Lippershey....

5. Cause of the Solar Cycle  Read article

The solar cycle is intriguing, but what’s more remarkable is its cause. The Sun’s entire magnetic field reverses every eleven years. This type of behavior is not unprecedented. The Earth’s magnetic field reverses due to liquefaction of the solid core every few hundred thousand to a million years,...

6. Mayan Astronomy  Read article

Some of the most important ancient advances in astronomical knowledge came within Central and South America, in particular from the Mayan culture. Around the year 400 AD, when Europe was slipping into the dark ages, Mayan astronomy was at its peak. Mayan records recorded the phases of the moon, ec...

7. The Solar Cycle  Read article

In 1830 the German astronomer Heinrich Schwabe started observing sunspots as a hobby. He was an amateur astronomer who spent much of his time observing the Sun. After a decade or so he noticed a regular pattern reappearing in the number and placement of sunspots and he proposed the solar cycle. T...

8. The Dark Ages  Read article

In the fourth century with the fall of Rome and the sacking of the great library at Alexandria scientific darkness fell across Europe. Even the language of learning, Latin, splintered as warring tribes took over. The theology of the day was defined by Augustine, and the Christian church was mostly...

9. Galileo  Read article

Galileo was a giant of astronomy and perhaps the first physical scientist. A populist born in Italy, he used the newly discovered telescope to make observations that cemented the Copernican revolution. He made many experiments on the motions of objects. He invented the concepts of inertia, and ma...

10. Prominences and Flares  Read article

The Sun’s photosphere is a plasma, an ionized gas made up of charged particles. The Sun also has a magnetic field. The field is tethered deep within the Sun, but field lines loop out into space. Occasionally eruptions of gas from the surface travel along the field lines. Excitation of the gas cr...