Observations and Questions (GCSE Physics)

Observations and Questions

Observing the Universe

• Astronomy has been used for years. Whilst we may be observing the Universe to learn more about space in Physics, people have closely followed astronomy for centuries for other reasons such as navigation and agriculture.
• The constellation of the stars played a huge role. Following the constellation of stars allowed explorers to navigate their travels. Monuments were also aligned with the position of the Sun and stars to track the time of year.

Telescopes

Throughout much of history, observations of the Universe were only by the human eye. This was until an astronomical telescope was first invented in the 17th century, allowing us to make much more detailed observations.

Optical Telescopes

• Optical telescopes are able to observe visible light from space. Optical telescopes range in size and function, so are used by a variation of people from amateurs to professional astronomers.
• They can only be used under certain conditions. However, they can only be used at night and if the sky is relatively clear.

Space Telescopes

• Some telescopes are located outside the Earth’s atmosphere. For example the infamous Hubble Space Telescope.
• There are limitations to using space telescopes. The Earth’s atmosphere would restrict the images we could produce on Earth, as it would absorb electromagnetic radiation emitted by objects in the Universe. It is also possible that light may reflect off moisture from the Earth’s atmosphere, resulting in air pollution.
• The telescopes must be based on a satellite in space. They can take whole pictures of the sky and work during the day and night.

Forming Theories from Observation

Using Observations for Theories

Through conducting experiments, or simply observing natural phenomena, we can gather evidence. This evidence can be in the form of numbers, graphs or simply descriptions.

Now we know that red-shift provides evidence for the Big Bang theory. This is a real example of how scientific evidence has contributed to the development of theories.

Remaining Question Marks

Sometimes, scientists will come up with theories, such as those involving dark mass and dark energy. However, sufficient evidence may not be found to back up these theories. Currently, we still do not understand very much about the universe.