Learning Goals: 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. How do stars differ from moons and planets, and from one another? How does the classification of stars help us understand how they evolve over their lifetimes? What are the different types of stars? What happens when different types of stars die? Why is it important for us to understand stars?

Test this Thursday

My favoritist thing about space! What is it? Why does it happen? What types are there? How big are they? What happens in you fall in? How long do they last?

What are black holes? Star Supernova remnants Black holes have: Large mass Zero volume Infinite density Extreme gravity Black holes have: A region of influence around it determined by mass - Schwarzchild Radius The sphere with the Schwarzchild radius is called the Event Horizon A singularity point – the center of the black hole

Why does it happen? Electron Degeneracy Pressure Electromagnetic Force Neutron Degeneracy Pressure Pauli Exclusion Principle

Anything can be a black hole You just have to squish it enough The Sun – 6 km across The Earth – inside a baseball Me -- .000000000000000000000005847 inches This “size” is called the Schwarzschild Radius It is the size you have to squish a mass down to get it to be a black hole It is ALSO basically telling you where the event horizon is

Does everything get sucked into black holes? No, the popular picture of a black hole as a huge vacuum cleaner sucking in everything around it is inaccurate. Black holes only suck in matter if you get very close to a black hole's event horizon. . Whether black holes have empty space around them or not depends on their environment. There may be objects or gas close enough to fall in, or there may not be. Many black holes have disks of in-falling material around their equators.

How big are black holes? - mass There is no limit to how much or how little mass a black hole can have. In theory, any amount of mass at all can be made to form a black hole if you compress it to the right density. Most black holes are produced by the deaths of massive stars, so scientists believe those black holes weigh about as much as a massive star. A typical one would be about 10 times the mass of the Sun, or about 1031 kilograms. galaxies harbor extremely massive black holes at their centers. These are about a million solar masses.

How big are black holes ? - radius The more massive a black hole is, the more space it takes up. The Schwarzschild radius and the mass are directly proportional to one another: if one black hole weighs ten times as much as another, its radius is ten times as large. A black hole with a mass equal to that of the Sun would have a radius of 3 kilometers. a typical 10-solar-mass black hole would have a radius of 30 kilometers a million-solar-mass black hole at the center of a galaxy would have a radius of 3 million kilometers. 

How do we know black holes are there? Black holes collect matter As material spirals toward the black hole, it speeds up and heats up This releases X-rays We Can see this and call it a quasar Gravitational Lensing

What would you see if you were outside a black hole? http://apod.nasa.gov/htmlt est/gifcity/circbh.mpg Gravitational lensing

How do we know black holes are there? Black holes collect matter As material spirals toward the black hole, it speeds up and heats up This releases X-rays We Can see this and call it a quasar Gravitational Lensing Find mass and orbit by looking at the stars around it

Black Holes Relativity: time and space are relative, not fixed. massive objects can create distortions in space and time. Things can appear different depending on whether you are moving or standing still.

https://www.youtube.com/watch?v=mU04-vJB6gc

Gravity Changes over Distance The gravity on your feet, which are closer to the black hole, will be hundreds of thousands of times stronger than the gravity on your head This will stretch you out until it pulls you apart atom by atom It is called spaghettification

How long do they last? Black Holes actually evaporate! Hawking radiation is energy slowly released by the black hole. Has to do with virtual particles in empty space Can take less than a second for small ones, or a googol years for the largest

Hawking Radiation https://www.youtube.com/watch?v=DC_IfDxXVbE

https://www.youtube.com/watch?v=e-P5IFTqB98

https://www.youtube.com/watch?v=8nHBGFKLHZQ

So…in your own words… What is a black hole? What happens when you fall into a black hole? (at least 3 things)

EdPuzzle 15 points 15 points Web Article Canvas

Test Thursday On info from 2/11 to 3/13 Star Characteristics Sizes Color Temperature Spectral Classes Luminosity Classes Types Magnitude Distances Formation Life Cycle of stars How we learn about stars Luminosity, Size and Temp Apparent and Absolute Magnitude HR Diagram Main Sequence Annie Jump Cannon How a star dies Supernovae Planetary Nebula White Dwarf Neutron Star Black Hole Variable Stars Binary Stars Star Clusters Fusion