In fact, I would argue that some of the most interesting things

of the human experience occur at the intersections,

in the liminal space,

where by liminal I mean the space in-between.

There's freedom in that in-between,

freedom to create from the indefiniteness of not-quite-here, not-quite-there,

a new self-definition.

Some of the great intersections of the world come to mind,

like the Arc de Triomphe in Paris,

or Times Square in New York City,

both bustling with the excitement of a seemingly endless stream of people.

Other intersections,

like the Edmund Pettus Bridge in Selma, Alabama,

or Canfield Drive and Copper Creek Court in Ferguson, Missouri, also come to mind

because of the tremendous energy at the intersection of human beings,

ideologies and the ongoing struggle for justice.

Beyond the physical landscape of our planet,

some of the most famous celestial images are of intersections.

Stars are born at the messy intersection of gas and dust,

instigated by gravity's irrevocable pull.

Stars die by this same intersection, this time flung outward

in a violent collision of smaller atoms,

intersecting and efficiently fusing into altogether new and heavier things.

We can all think of intersections that have special meaning to us.

To be intersectional, then,

is to occupy a position at an intersection.

I've lived the entirety of my life in the in-between,

in the liminal space between dreams and reality,

race and gender,

poverty and plenty,

science and society.

I am both black and a woman.

Like the birth of stars in the heavenlies,

this robust combination of knowing results in a shining example

of the explosive fusion of identities.

I am also an astrophysicist.

I study blazars, supermassive, hyperactive black holes

that sit at the centers of massive galaxies

and shoot out jets nearby those black holes

at speeds approaching the speed of light

in a process we are still trying to completely understand.

I have dreamed of becoming an astrophysicist

since I was 12 years old.

I had no idea that at that time,

according to Dr. Jamie Alexander's archive of African-American women in physics,

only 18 black women in the United States had ever earned a PhD

in a physics-related discipline,

and that the first black woman to graduate with a PhD in an astronomy-related field

did so just one year before my birth.

As I journeyed along my path,

I encountered the best and worst of life at an intersection:

the tremendous opportunity to self-define,

the collision of expectation and experience,

the exhilaration of victorious breakthroughs

and, sometimes,

the explosive pain of regeneration.

I began my college experience just after my family had fallen apart.

Our financial situation disintegrated

just after my father's departure from our lives.

This thrust my mother, my sister and I

out of the relative comfort of middle-class life

and into the almost constant struggle to make ends meet.

Thus, I was one of roughly 60 percent of women of color

who find finances to be a major barrier to their educational goals.

Thankfully, Norfolk State University provided me with full funding,

and I was able to achieve my bachelor's in physics.

After graduation, and despite knowing that I wanted a PhD in astrophysics,

I fell through the cracks.

It was a poster that saved my dream,

and some really incredible people and programs.

The American Physical Society had this beautiful poster

encouraging students of color to become physicists.

It was striking to me because it featured a young black girl,

probably around 12 years old,

looking studiously at some physics equations.

I remember thinking

I was looking directly back at the little girl

who first dared to dream this dream.

I immediately wrote to the Society

and requested my personal copy of the poster,

which to this day still hangs in my office.

I described to them in the email my educational path,

and my desire to find myself again in pursuit of the PhD.

They directed me to the Fisk-Vanderbilt University Bridge Program,

itself an intersection of the master's and PhD degrees

at two institutions.

After two years out of school, they accepted me into the program,

and I found myself again on the path to the PhD.

After receiving my master's at Fisk,

I went on to Yale to complete my PhD.

Once I was physically occupying the space that would ultimately give way

to my childhood aspirations,

I anticipated a smooth glide to the PhD.

(Laughter)

It became immediately apparent

that not everyone was thrilled to have that degree of liminality

in their space.

I was ostracized by many of my classmates,

one of whom went so far as to invite me to "do what I really came here to do"

as he pushed all the dirty dishes from our meal in front of me to clean up.

I wish that were an isolated occurrence,

but for many women of color

in science, technology, engineering, and mathematics, or STEM,

this is something they have long endured.

One hundred percent of the 60 women of color

interviewed in a recent study by Joan C. Williams at UC Hastings

reported facing racialized gender bias,

including being mistaken for the janitorial staff.

This mistaken identity was not reported

by any of the white women interviewed for this study,

which comprised 557 women in total.

While there is nothing inherently wrong with a janitorial position,

and in fact my forefathers and foremothers were able to attend college

because many of their parents worked these jobs,

it was a clear attempt to put me in my place.

While there was certainly the acute pain of the encounter,

the real issue is that my appearance

can tell anyone anything about my ability.

Beyond that, though, it underscores

that the women of color in STEM do not experience the same set of barriers

that just women or just people of color face.

That's why today I want to highlight women of color in STEM,

who are inexorably, unapologetically

living as the inseparable sum of identities.

STEM itself is an intersectional term,

such that its true richness cannot be appreciated

without considering the liminal space between disciplines.

Science, the pursuit of understanding the physical world

by way of chemistry, physics, biology,

cannot be accomplished in the absence of mathematics.

Engineering requires the application of basic science and math

to the lived experience.

Technology sits firmly on the foundation of math,

engineering and science.

Math itself serves the critical role of Rosetta Stone,

decoding and encoding the physical principles of the world.

STEM is utterly incomplete without each individual piece.

This is to say nothing of the enrichment that is realized

when STEM is combined with other disciplines.

The purpose for this talk is twofold:

first, to say directly to every black, Latina, indigenous, First Nation

or any other woman or girl

who finds herself resting at the blessed intersection

of race and gender,

that you can be anything you want to be.

My personal hope is that you'll become an astrophysicist,

but beyond that, anything you want.

Do not think for one minute

that because you are who you are,

you cannot be who you imagine yourself to be.

Hold fast to those dreams

and let them carry you into a world you can't even imagine.

Secondly, among the most pressing issues of our time,

most now find their intersection with STEM.

We have as a global society solved

most of the single-faceted issues of our time.

Those that remain require a thorough investigation

of the liminal space between disciplines

to create the multifaceted solutions of tomorrow.

Who better to solve these liminal problems

than those who have faced their whole lives at the intersections.

We as thought leaders and decision makers

must push past the first steps of diversity

and into the richer and more robust territory

of full inclusion and equal opportunity.

One of my favorite examples of liminal excellence

comes from the late Dr. Claudia Alexander,

a black woman plasma physicist,

who passed away this past July after a 10-year bout with breast cancer.

She was a NASA project scientist who spearheaded the NASA side

of the Rosetta mission,

which became famous this year for landing a rover on a comet,

and the 1.5 billion dollar Galileo mission to Jupiter,

two high-profile scientific victories

for NASA, the United States and the world.

Dr. Alexander said it this way:

"I'm used to walking between two cultures.

For me, it's among the purposes of my life

to take us from states of ignorance to states of understanding

with bold exploration that you can't do every day."

This shows exactly the power of a liminal person.

She had the technical ability to spearhead

some of the most ambitious space missions of our time,

and she perfectly understood her place

of being exactly who she was in any place she was.

Jessica Matthews, inventor of the SOCCKET line of sports products,

like soccer balls, that generate renewable energy as you play with them,

said it this way:

"A major part of invention isn't just creating things,

it's understanding people

and understanding the systems that make this world."

The reason I tell my story

and the story of Dr. Alexander and Jessica Matthews

is because they are fundamentally intersectional stories,

the stories of lives lived at the nexus of race, gender and innovation.

Despite implicit and explicit questions of my right to be in an elite space,

I'm proud to report that when I graduated,

I was the first black woman to earn a PhD in astrophysics

in Yale's then 312-year history.

(Applause)

I am now part of a small but growing cadre of women of color in STEM

who are poised to bring new perspectives and new ideas to life

on the most pressing issues of our time:

things like educational inequities,

police brutality, HIV/AIDS, climate change, genetic editing,

artificial intelligence and Mars exploration.

This is to say nothing of the things we haven't even thought of yet.

Women of color in STEM occupy some of the toughest

and most exciting sociotechnological issues of our time.

Thus, we are uniquely positioned

to contribute to and drive these conversations

in ways that are more inclusive of a wider variety of lived experience.

This outlook can be expanded to the many intersectional people

whose experiences, positive and negative,

enrich the conversations in ways that outmatch

even the best-resourced homogenous groups.

This is not a request born out of a desire to fit in.

It's a reminder that we cannot get to the best possible outcomes

for the totality of humanity

without precisely this collaboration,

this bringing together of the liminal,

the differently lived, distinctly experienced

and disparately impacted.

Simply put, we cannot be the most excellent expression

of our collective genius

without the full measure of humanity brought to bear.

Thank you.

(Applause)