telescope
an instrument that gathers electromagnetic radiation and concentrates it for better observation
optical telescope
the most common type of telescope that collects and focuses visible light for closer observation. The simplest optical telescope contains an objective lens and a lens in the eyepiece of the telescope
What is the function of the objective lens
to collect light and form an image at the back of the telescope
What is the funtion of the lens in the eyepiece
to magnify the image produced by the objective lens
Refracting Telescopes
uses lenses to gatehr and focus light. Cannot focus images perfectly, distorts images if lens is too large
Reflecting telescope
uses mirrors to gather and focus light. I sused by most professional astronomers. Focuses all colors of light to the same focal point, can use large mirrors to gather light and flaws in the glass don't affect the collected light
2 disadvantages of refracting telescopes
their lenses focus different colors of light at different distances, which means the images cannot be exactly focused. Second, if the objective lens is too big, it will sag and images will be distorted
3 advantages of reflecting telescopes
1. mirrors can be large, which allows reflecting telescopes to gather much light.
2. they use mirrors and light doesn't eneter the glass, so any damages in the glass don't distort the image.
3. their mirrors focus all colors of light to the same focal poi
What do ver large reflecting telescopes use to gather more light and focus it in one spot
they use bigger mirrors to gatehr more light and focus it in on one spot
How does Earth's atmosphere affect the light gathered by telescopes on Earth
it causes starlight to "shimmer and blur" also light pollution in the city makes the sky look bright
Why is a mountaintop a good place on Earth to put a telescope
because the air is thinner and there is less air and light pollution
What is the best place to put a telescope
The best plac eto put a telescope is in space because there is no atmospheric interference
What did James Clerk Macwell prove about visible light
It is part of the electromagnetic spectrum
Each color of light on the electromagnetic spectrum has a..
..different wavelength of electromagnetic radiation
Humans can see radiation from...
..red light to blue light
Radiation in order from shortest wavelength to longest wavelength
Gamma rays, X rays, microwaves, radio waves
Blocked Wavelenths
infared light, X rays
Unblcoked Wavelengths
gamma rays, visible light. microwaves
Why do astronomers study the entired electromagnetic spectrum
because each type of radiation reveals different clues about an object
Radio telescopes
are larger than optical telescopes because radio wavelengths are much longer than optical wavelengths. The surface can also be more flawed than the lenses and mirrors of an optical telescope.
Why can chicken wire be used as the surface of a radio telescope
because the surface doesn't have to be solid
Why have scientists put ultraviolet, infared, gamma-ray, and X ray telescopes in space
because some electromagnetic waves are blocked by Earth's atmosphere
telescope
a tool used for observing and studying the sky
refracting telescope
an optical telescope that uses lenses to focus light
reflecting telescope
an optical telescope that uses mirrors to focus light
electromagnetic spectrum
a scale made up of the wavelengths of electromagnetic radiation