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2/5/2016 BellWork Picture of the day!

Light and Telescopes GRAB YOUR CLICKERS

4. Complex Knowledge: demonstrations of learning that go aboveand above and beyond what was explicitly taught. 3. Knowledge: meeting the learning goals and expectations. 2. Foundational knowledge: simpler procedures, isolated details, vocabulary. 1. Limited knowledge: know very little details but working toward a higher level. understand the electromagnetic spectrum and how it is organized. understand what different types of electromagnetic radiation can reveal about astronomical objects. understand and describe important properties of electromagnetic radiation. understand how technology is used to collect electromagnetic radiation and turn it into images. understand what can be learned from analyzing the light from astronomical objects. understand how different types of telescopes work understand how lenses are used in telescopes.

Learning Goals: What is electromagnetic radiation? What can different types of electromagnetic radiation reveal about astronomical objects? What are the important properties of electromagnetic radiation and how are they typically organized? What can be learned from analyzing the light from astronomical objects? How is technology used to collect electromagnetic radiation and turn it into images?

Coming to Our Senses Today…copy notes Titles Information that’s pink.

Spectroscopes A spectroscope works by breaking light into the wavelengths (or spectra) that make it up. Some spectroscopes are made of diffraction grating- a material that has lots of little parallel lines that are approximately one wavelength apart. There may be 35,000 of these little lines in one inch of the material. When light hits the lines, it bends. Different wavelengths (colors) of light bend by different amounts, so it splits the light into its colors.

What is electromagnetic radiation? Electromagnetic radiation (EM radiation or EMR) Is a form of energy emitted and absorbed by charged particles, which exhibits wave-like behavior as it travels through space. EMR displays both electric and magnetic properties.

Edwin Hubble, 1948 “Equipped with his five senses, man explores the universe around him and calls the adventure science.”

Humans have 5 senses. What are they? Only one of them is good when it comes to observing the universe. Sight.

We have limitations. As a human, you are limited to your 5 senses. You can’t: Feel a magnetic field Feel Ionizing radiation Low level earth tremors See outside of the visible light part of the spectrum.

Our EM Spectrum WE CAN: See Visible light ROY G BIV…Isaac Newton ♥ 7 Feel infrared radiation (heat) Feel Ultraviolet radiation (on a time delay) WE CAN’T SENSE: Microwaves Radio waves Gamma rays X rays

Telescopes! We’ve got telescopes that can sense different types of radiation. If you only observe the sky with your eyes you can’t see… black holes background energy the center of our galaxy

What do you see?

infrared

ultraviolet

visible

radio

infrared

X -ray

ultraviolet

visible

radio

infrared

Visible light

Visible light (zoom)

X - ray

Crab Nebula The Crab Nebula is a supernova remnant and pulsar wind nebula in the constellation of Taurus. The nebula corresponds to a bright supernova recorded by Arab, Chinese and Japanese astronomers in At X-ray and gamma-ray energies the Crab is generally the strongest persistent source in the sky. Located at a distance of about 6,500 light-years from Earth, the nebula has a diameter of 11 ly and expands at a rate of about 1,500 kilometers per second. It is part of the Perseus Arm of the Milky Way Galaxy. At the center of the nebula lies the Crab Pulsar, a neutron star (or spinning ball of neutrons), 28–30 km across, which emits pulses of radiation from gamma rays to radio waves with a spin rate of 30.2 times per second. The nebula was the astronomical object identified with a historical supernova explosion.

Does it “Make Sense?” Before the early 1900s- it was ok to judge science by whether or not things made sense. Now- It’s NOT ok Now we have: Quantum mechanics Atom smashers Telescopes Hubble

The universe doesn’t care about your senses. We are no longer grounded by our senses. And before you celebrate the brilliance of your senses and the technological advances that have come from humans, think about what you DON’T know about the universe and what you CAN’T know using only the tools you have.

Edwin Hubble, 1948 “ Equipped with his five senses, man explores the universe around him and calls the adventure science.”

What Edwin Hubble should have said… “Equipped with our five senses, along with telescopes and microscopes and mass spectrometers and particle accelerators and detectors across the electromagnetic spectrum, we explore the universe around us and call the adventure science.”

Now What do you think? How does seeing images of different types of electromagnetic radiation from an astronomical object help you understand more about the object? How do you feel/what do you think about human capabilities for understanding the universe?

The Electromagnetic Spectrum Tape chart into your notebook