How do scientists "see" black holes? with Skype A Scientist and MSU SciFest

These slides accompany a virtual presentation I give for middle school and high school science classes through the Skype A Scientist and MSU SciFest programs. I adjust the subset of slides I use based on the audience. There are videos in quite a few of the slides that don't render in the PDF version saved here.

You can read more about me and my background, and get in touch for a talk or creative project, on my website: https://abigailstevens.com/

Transcript

1. Image: NASA/JPL-Caltech How do scientists “see” black holes? Dr. Abbie Stevens
2. First: what is astronomy? • Astronomy: stuff in outer space • Astrophysics: physics of stuff in outer space • Also: astrochemistry, astrobiology, heliophysics, Earth & planetary sciences, near-Earth space physics Image: NASA/ESA/HST Tools: math, computer programming, creative problem-solving, teamwork
3. Black holes • A lot of stuff (mass) in a very small space • Very powerful gravity • Escape velocity faster than the speed of light! Image: J. Provost, ScienceNews.org
4. Black holes Image: Event Horizon Telescope collaboration No limit on how big they can get! Small black holes are formed from the death and collapse of a big star (“stellar” or “stellar mass”) Big black holes have been around since very early in the universe, at the centers of galaxies (“supermassive”)
5. Black holes Image: Event Horizon Telescope collaboration No limit on how big they can get! Small black holes are formed from the death and collapse of a big star (“stellar” or “stellar mass”) Big black holes have been around since very early in the universe, at the centers of galaxies (“supermassive”) Quick interlude: Universe is really big, numbers get really big
6. Black holes Image: Event Horizon Telescope collaboration No limit on how big they can get! Small black holes are formed from the death and collapse of a big star (“stellar” or “stellar mass”) Big black holes have been around since very early in the universe, at the centers of galaxies (“supermassive”) Quick interlude: Universe is really big, numbers get really big 1 thousand seconds ≅ 16 minutes
7. Black holes Image: Event Horizon Telescope collaboration No limit on how big they can get! Small black holes are formed from the death and collapse of a big star (“stellar” or “stellar mass”) Big black holes have been around since very early in the universe, at the centers of galaxies (“supermassive”) Quick interlude: Universe is really big, numbers get really big 1 thousand seconds ≅ 16 minutes 1 million seconds ≅ 11 days
8. Black holes Image: Event Horizon Telescope collaboration No limit on how big they can get! Small black holes are formed from the death and collapse of a big star (“stellar” or “stellar mass”) Big black holes have been around since very early in the universe, at the centers of galaxies (“supermassive”) Quick interlude: Universe is really big, numbers get really big 1 thousand seconds ≅ 16 minutes 1 million seconds ≅ 11 days 1 billion seconds ≅ 32 years
9. Black holes Image: Event Horizon Telescope collaboration Biggest black hole ever seen: 60 Billion times the mass of our Sun Smallest black hole ever seen: 3 times the mass of our Sun No limit on how big they can get! Small black holes are formed from the death and collapse of a big star (“stellar” or “stellar mass”) Big black holes have been around since very early in the universe, at the centers of galaxies (“supermassive”)
10. Can’t just grab one, put it on a table, shine a light on it, and study it Video: NASA/GSFC/J. Schnittman Black holes To see it, need to wait for one to send light in our direction
11. Image: Event Horizon Telescope collaboration How do we see them? taking a picture using radio light
12. Image: Event Horizon Telescope collaboration How do we see them? taking a picture using radio light
13. Image credit: NASA/CXC/M. Weiss How do we see them? eating its star-friend
14. How do we see them? eating its star-friend Video credit: NASA
15. The first black hole we saw is called Cygnus X-1, in 1972. How do we see them? eating its star-friend Image credit: NASA/CXC/M. Weiss
16. Type of light Gets through Earth’s atmosphere? Approx. scale of wavelength? The electro-magnetic spectrum How do we see them? with X-ray telescopes The colors that we see are a very small part of all the types of light that exist! Images: Shutterstock, NASA
17. The electro-magnetic spectrum How do we see them? with X-ray telescopes Type of light Gets through Earth’s atmosphere? Approx. scale of wavelength Images: Shutterstock, NASA X-rays from space can’t get through Earth’s atmosphere, so we put X-ray telescopes on satellites and launch them into space on rockets!
18. Video: NASA/GSFC How do we see them? with X-ray telescopes
19. Black hole as ☆ How do we see them? nearby orbiting stars Sagittarius A-star (Sgr A*) at the center of our Milky Way galaxy! 4.3 million times the mass of the Sun
20. Image credit: NASA/CXC/M. Weiss How do we see them? smashing together Video: S. Ossokine/A. Buonanno/T. Dietrich (MPI for Gravitational Physics)/R. Haas (NCSA)/SXS project
21. Image credit: NASA/CXC/M. Weiss Video: T. Ramirez/G. Lovelace/SXS Collaboration/LIGO-Virgo Collaboration How do we see them? smashing together
22. How do we see them? bending light from behind them
23. Image: HST How do we see them? bending light from behind them The strong gravity of the black hole acts like a lens, bending and distorting the image.
24. Image credit: NASA/CXC/K. Divona
25. Dr. Abbie in school • Middle school and high school: physics, earth science, math, computer programming
26. • Middle school and high school: physics, earth science, math, computer programming • College: small liberal arts college • BA, physics major, math minor Dr. Abbie in school
27. • Middle school and high school: physics, earth science, math, computer programming • College: small liberal arts college • BA, physics major, math minor • Graduate school: large research universities • MSc in physics, in astrophysics group Dr. Abbie in school
28. • Middle school and high school: physics, earth science, math, computer programming • College: small liberal arts college • BA, physics major, math minor • Graduate school: large research universities • MSc in physics, in astrophysics group • PhD in astronomy, in large astronomy research institute Dr. Abbie in school
29. •Middle school and high school: physics, earth science, math, computer programming •College: small liberal arts college •BA, physics major, math minor •Graduate school: large research universities •MSc in physics, in astrophysics group •PhD in astronomy, in large astronomy research institute In high school, I wanted to do architecture and engineering, so I took physics and math. Then in physics I was introduced to astronomy! • Learn about things that interest you, and keep an open mind! Dr. Abbie in school
30. •Middle school and high school: physics, earth science, math, computer programming •College: small liberal arts college •BA, physics major, math minor •Graduate school: large research universities •MSc in physics, in astrophysics group •PhD in astronomy, in large astronomy research institute In high school, I wanted to do architecture and engineering, so I took physics and math. Then in physics I was introduced to astronomy! • Learn about things that interest you, and keep an open mind! In college, I changed majors twice! (environmental policy, theater), nearly added math as a double major • It’s ok to change your mind! Dr. Abbie in school
31. •Middle school and high school: physics, earth science, math, computer programming •College: small liberal arts college •BA, physics major, math minor •Graduate school: large research universities •MSc in physics, in astrophysics group •PhD in astronomy, in large astronomy research institute In high school, I wanted to do architecture and engineering, so I took physics and math. Then in physics I was introduced to astronomy! • Learn about things that interest you, and keep an open mind! In college, I changed majors twice! (environmental policy, theater), nearly added math as a double major • It’s ok to change your mind! • Keep your hobbies! • Mental wellbeing is so important! Dr. Abbie in school
32. Job prospects in astronomy • Academia • Researcher • Professor (research + teaching) • Lecturer/instructor (teaching) • Education and public outreach • Planetarium director • Outreach coordinator • Content at educational nonprofits • Industry • Data science • Quantitative analytics • Software development
33. Image: NASA/JPL-Caltech Q&A time!