This article is the fifth in a series of essays written by Black physicists and co-published with Physics World as part of #BlackInPhysics Week 2022, an event dedicated to celebrating Black physicists and their contributions to the scientific community, and to revealing a more complete picture of what a physicist looks like. This year’s theme is “Joy in the Diverse Black Community.”
As a child, I used to like dot-to-dot drawings. I never really considered myself artistic, but I enjoyed the fact that if I followed the numbers and connected the dots, the “big picture” would ultimately be revealed. This was very rewarding to me. In many ways, it felt like a discovery.
In science, it’s often the big picture that we initially observe. That usually leads us to ask probing questions about its origins, form, and nature, delving ever deeper until we deduce the fundamental building blocks that make up the big picture. It’s a bit like the reverse of a very sophisticated dot-to-dot drawing. At this fundamental level, the building blocks (or elementary particles) often lie within the quantum world. It was quantum theory that propelled my journey into physics.
As an undergraduate studying chemistry, I was mesmerized by spectroscopy, a technique that uses light to probe, characterize, and quantify different types of matter. I was struck by the fact that this technique could take “invisible” light (for example, UV or IR light) and use it to probe the “invisible” air, accurately detecting unseen trace gas particles like carbon monoxide or sulfur dioxide. Through spectroscopy, these trace gases become “visible” in the form of spectral absorption peaks at specific wavelengths, thus providing a unique spectral fingerprint for each gas. With this information we can determine which types of gas are present and their abundance.
The more I asked, “How could this be?,” the more I found myself drawn toward fundamental physics. The idea of making the unseen visible has stayed with me ever since. It’s amazing to think that the principles of quantum mechanics underpin this powerful technique. Not only that, but quantum theory more generally gives rise to many other technologies such as lasers, semiconductors, MRI, GPS, electron microscopy, cryptography, and quantum computing, to name just a few.
A more recent development in quantum mechanics is the rise of quantum dot (QDot) technology. A QDot is a semiconducting particle with optical and electronic properties that are governed by the rules of quantum mechanics due to their size of just a few nanometers, about one ten-thousandth the width of a human hair. These nanoparticles emit light of a specific wavelength when a blue LED shines on them. The wavelength emitted depends on the size of the nanoparticle and determines the color observed.
Not surprisingly, QDot technology has found its way into flat-panel displays for modern television sets due to the high color saturation that can be achieved over a narrow spectral bandwidth. Furthermore, since QDots can be tuned to a determined size to release specific wavelengths, we can use them to achieve high color rendering and overall better color production. Each QDot TV typically contains billions of quantum dots that ultimately make up the big picture.
Connecting the dots
As an early-career Black physicist and the son of Jamaican parents living in the UK, I very much felt like I was a quantum dot—a quantum black dot (QBD), if you will. In my research field, it was rare for me to see someone else who looked like me at a seminar or conference, or even in the same field. Against a backdrop of blue light, I had to find a way to radiate at different wavelengths while knowing that the real powers of QBDs are harnessed when they’re connected and working collectively. In my endeavor to connect, I was fortunate to eventually meet many prominent African American physicists, some when they visited the UK, others when I visited the US. I also attended a conference for Black physicists in the US and connected with scientists from Africa and the Caribbean. These interactions helped strengthen my conviction that from a global perspective, there were plenty of QBDs just like me.
My thoughts then turned to future generations in the UK. I wanted the situation to be different for them, so I engaged heavily with schools and set up several outreach initiatives for young people, trying to do what I could to change their landscape for the future. I also approached the handful of Black undergraduates in my department, asking them to help me in those efforts. It was pleasing to know that they were, in the main, fully on board. Most stayed connected after graduating, and year after year, the group grew in number until it reached a critical mass. A unique identity was emerging for ambitious young Black people with a passion for physics and for positive change within their community.
This effort culminated in the formation of the Blackett Lab Family, the UK’s first national network of Black physicists, in 2020. The group now has visibility and has become a voice for Black physicists in the UK. Furthermore, it provides an accessible means of support to anyone pursuing physics or related fields from high school to the professorial level. More recently, the Blackett Lab Family has received funding to connect Black physicists in the US with UK-based Black physicists through a speaker series in the UK, as well as to send a UK delegation to conferences in the US, further strengthening the global community of Black physicists. Such exciting programs are possible only because the QBDs across the UK are connected and can act collectively.
When I reflect on my career so far, it really has been a case of connecting QBDs in various ways over time and space. Often QBD connections bring a deeper joy and enrichment to the overall discipline and enhance that vital sense of belonging. In many ways, though I am still a QBD, I now know that I’m part of a much larger national and global community of physicists from across the pan-African diaspora. The more we continue to connect, represent, and inspire, the more we will reshape, sharpen, and enrich the big picture showing who physicists are and what we do.
Mark Richards is an atmospheric physicist and senior teaching fellow at Imperial College London and the founder of the Blackett Lab Family. In 2022 he was awarded the inaugural Royal Society Research Culture Award for “dedication and commitment to equity in STEM.”