By Jedidah Isler
# Background about our speaker
Jedidah Isler studies blazars（耀变天体） — supermassive hyperactive black holes（特大质量、极度活跃的黑洞） that emit powerful jet streams（喷流，喷气流）. They are the universe’s most efficient particle accelerators（粒子加速器）, transferring energy throughout galaxies（星系；银河系）.
# Why you should listen
Jedidah Isler has been staring at the stars since she was 11 or 12. But because neither her undergraduate college or the university where she got her first master’s degree offered astronomy majors（天文学专业）, she threw herself wholeheartedl（全心全意地）y into physics. It wasn’t until she entered a doctoral program that she was able to dedicate her time to the studying the night sky. In 2014, she became the first African-American（指美国黑人） woman to receive a Ph.D in Astrophysics（天体物理学） from Yale.
Isler studies blazars — supermassive hyperactive black holes at the center of galaxies, some of which emit powerful streams of particles. Sometimes these are oriented toward Earth, offering us a unique perspective on the physics of the universe. Isler is a Chancellor（校长（美国某些大学的）’s Faculty Fellow（教职研究员） in Physics at Syracuse University（（美）雪域大学）. She participates in the Future Faculty Leader program at Harvard‘s Center for Astrophysics and was named a 2015 TED Fellow.
Isler is also interested in breaking down barriers that prevent many students — especially women of color — from becoming scienists. She works to make STEM accessible to new communities.
注：STEM代表科学（Science），STEM技术（Technology），工程（Engineering），数学(Mathematics)。STEM教育就是科学，技术，工程，数学的教育。在国家实力的比较中，获得STEM学位的人数成为一个重要的指标。美国政府STEM计划是一项鼓励学生主修科学、技术、工程和数学(STEM)领域的计划，并不断加大科学、技术、工程和数学教育的投入，培养学生的科技理工素养。
# 视频地址
Subtitles and Transcript
My first love was for the night sky. Love is complicated.
You‘re looking at a fly-through（漫游、飞越、行） of the Hubble Space Telescope Ultra-Deep Field, one of the most distant images of our universe ever observed. Everything you see here is a galaxy, comprised of billions of stars each. And the the farthest galaxy is a trillion, trillion kilometers away.
As an astrophysicist, I have the awesome privilege of（有…权限/特权） studying some of the most exotic （外来的；异国情调的；独特的）objects in our universe. The objects that have captivated me from first crush（第一个暗恋对象） throughout my career are supermassive, hyperactive black holes. Weighing one to 10 billion times the mass of our own sun,these galactic（银河的；乳汁的） black holes are devouring（vt. 吞食；毁灭；凝视） material, at a rate of upwards of 1,000 times more than your "average" supermassive black hole. (Laughter)
These two characteristics, with a few others, make them quasars（类星体）. At the same time, the objects I study are producing some of the most powerful particle streams ever observed. These narrow streams, called jets, are moving at 99.99 percent of the speed of light, and are pointed directly at the Earth.
These jetted, Earth-pointed, hyperactive and supermassive black holes are called blazars, or blazing quasars. What makes blazars so special is that they‘re some of the universe‘s most efficient particle accelerators, transporting incredible amounts of energy throughout a galaxy.
Here, I‘m showing an artist‘s conception of a blazar. The dinner plate by which material falls onto the black hole is called the accretion disc（吸积盘）, shown here in blue. Some of that material is slingshotted（弹弓） around the black hole and accelerated to insanely high speeds in the jet, shown here in white.Although the blazar system is rare, the process by which nature pulls in material via a disk, and then flings（掷，抛） some of it out via a jet, is more common. We‘ll eventually zoom out of the blazar system to show its approximate relationship to the larger galactic context.
Beyond the cosmic accounting of what goes in to what goes out（？）, one of the hot topics in blazar astrophysics right now is where the highest-energy jet emission comes from. In this image, I‘m interested in where this white blob（一滴；一抹；难以名状的一团） forms and if, as a result, there‘s any relationship between the jet and the accretion disc material.
Clear answers to this question were almost completely inaccessible until 2008, when NASA launched a new telescope that better detects gamma ray light -- that is, light with energies a million times higher than your standard x-ray scan. I simultaneously compare variations between the gamma ray light data and the visible light data from day to day and year to year, to better localize these gamma ray blobs. My research shows that in some instances, these blobs form much closer to the black hole than we initially thought.
As we more confidently localize where these gamma ray blobs are forming, we can better understand how jets are being accelerated, and ultimately reveal the dynamic processes by which some of the most fascinating objects in our universe are formed.
This all started as a love story. And it still is. This love transformed me from a curious, stargazing（眺望星星；空想） young girl to a professional astrophysicist, hot on the heels of（紧接着） celestial（n. 神仙，天堂里的居民，adj. 天上的，天空的） discovery. Who knew that chasing after the universe would ground（打基础） me so deeply to my mission here on Earth. Then again, when do we ever know where love‘s first flutter will truly take us.
Thank you.
# Comments I like
You didn‘t want to nit-pick（挑剔；吹毛求疵；评头论足）, but you did it anyway!
As an incurable（无可救药的） fellow nit-picker, I would like you to dumb it down（让它更蠢） for me (and for international readers) if you could. I know that the word "billion" means different things on different sides of the Atlantic, so maybe if you used all the zeroes in front of kilometers it could help me nit-pick along with you. And toss in the light-year-to-kilometer conversion too. (I‘d ask you to use exponential notation, but it‘s not needed and it would exclude smart readers who haven‘t learned to read it.)