by Paola Rebusco Talking about Black Holes

“ Lasciate ogni speranza, o voi ch’entrate.” “ Abandon all hope, you who enter here.” Dante Alighieri (Divina Commedia) Artist impression John Wheeler 1967- Physics Today YOU CAN MIX SCIENCE and THE ARTS =)

“ Lasciate ogni speranza,

o voi ch’entrate.”

“ Abandon all hope,

you who enter here.”

Dante Alighieri

(Divina Commedia)

Some History John Michell (1784) and Pierre-Simon Laplace (1796) propose the existence of “dark stars”…that lock in light Albert Einstein publishes his first paper on GR (1915) Karl Schwarzschild finds black holes as a solution to Einstein’s equations (1916) DID EINSTEIN THINK THAT BLACK HOLES COULD EXIST? Subrahmanyan Chandrasekhar suggests that the a massive star can collapse in a black hole or a neutron star (1930) Roy Kerr finds the solution for rotating black holes (1963)

John Michell (1784) and Pierre-Simon Laplace (1796) propose the existence of “dark stars”…that lock in light

Albert Einstein publishes his first paper on GR (1915)

Karl Schwarzschild finds black holes as a solution to Einstein’s equations (1916)

DID EINSTEIN THINK THAT BLACK HOLES COULD EXIST?

Subrahmanyan Chandrasekhar suggests that the a massive star can collapse in a black hole or a neutron star (1930)

Roy Kerr finds the solution for rotating black holes (1963)

Black Holes have NO HAIR Once they form they are left with ……… Mass Spin We express the mass in solar masses: 1 M sun = 2 × 10 30 Kg= 2 × 10 × 10 × 10…=10 million Earth km QUIZ miles

Black Holes in Theory can have any Sizes!

Death of a Star - Birth of a Black Hole TABLES CAN BE USEFUL

Life Cycle of Massive Stars … after the RED GIANT phase SKETCH ANALOGIES: REMEMBER: gravity against pressure High Temperature and Pressure: successive fusion reactions!

REMEMBER: gravity against pressure

High Temperature and Pressure: successive fusion reactions!

non tutto e’ perduto! What do we Observe??? (BE PROVOCATIVE!)

non tutto e’ perduto!

Black Holes are not Alone! Binaries Motion of Stars Surrounding Gas

Binaries

Motion of Stars

Surrounding Gas

NAMES MEAN A LOT: Low mass X-ray binaries

SURPRISE!! Did you know that… General Relativity in STRONG fields is not observationally confirmed yet!?

More analogies

The ‘Cappuccino Paradigm’

Saggittarius A* Star S2 17 light hours (about 3 times Sun-Pluto) 5000 km/s

Star S2

17 light hours

(about 3 times

Sun-Pluto)

5000 km/s

Let’s make a PODCAST!

Audio editor and recorder: e.g. “AUDACITY”

Conclusions Who is your public? Prepare a sketch on a notebook (How much time do you have?) Don’t be afraid to tell simple stuff Make examples, analogies (be careful!) Try it a few times..in front of someone! (Feedback) Enjoy it!

Who is your public?

Prepare a sketch on a notebook

(How much time do you have?)

Don’t be afraid to tell simple stuff

Make examples, analogies (be careful!)

Try it a few times..in front of someone!

(Feedback)

Enjoy it!

THANK YOU !!!