The intersection of art and quantum physics might seem unlikely, but the question of which famous outdoor sculptures remain invisible to quantum spin thermoelectrics opens a fascinating dialogue. Quantum spin thermoelectrics is a cutting-edge field studying how quantum states interact with thermal and electrical properties, often rendering certain materials "invisible" to its measurements.

When applied to outdoor sculptures, this raises intriguing possibilities. For instance, sculptures made of non-magnetic or non-conductive materials, such as marble or certain ceramics, might not interact with quantum spin thermoelectric sensors. Iconic works like Michelangelo's *David* (though often displayed indoors, its outdoor replicas could qualify) or the *Terracotta Army* in China, composed of fired clay, might theoretically evade detection by these advanced instruments.

Similarly, modern installations like Anish Kapoor's *Cloud Gate* in Chicago, with its highly reflective stainless steel surface, could scatter quantum spin signals, making them appear "invisible" in certain contexts. Meanwhile, sculptures incorporating conductive metals like copper or iron, such as the *Statue of Liberty*, would likely interact strongly with quantum spin thermoelectrics.

This thought experiment not only highlights the limitations of quantum spin thermoelectrics but also invites us to reconsider how art and science perceive visibility. While no sculpture is truly invisible to the human eye, the quantum realm offers a playful lens through which to explore the boundaries of perception and materiality.

In essence, the answer lies in the materials: sculptures avoiding conductive or magnetic properties might just be the ones that quantum spin thermoelectrics can't "see." This fusion of art and physics sparks curiosity about what else might remain hidden in plain sight.