This summer at Harvard University Summer School, I had the chance to study A Short Tour of the Universe Guided by Einstein and Others with Prof. Dr. Arvind Borde. For my project, I chose to focus on white holes, which are one of the most intriguing predictions of Einstein’s equations. A white hole can be thought of as the “opposite” of a black hole. While a black hole pulls everything in and lets nothing escape, a white hole pushes everything out and does not allow anything to enter. They appear naturally as time-reversed solutions in general relativity, even though no one has ever observed one.

White holes become especially interesting when we think about the black hole information paradox. Stephen Hawking showed that black holes emit thermal radiation, now called Hawking radiation. If this process continues until the black

hole disappears completely, all the information about what fell in seems to vanish as well. That would break a key rule of quantum mechanics, which says information cannot be destroyed. One possible solution, explored in recent theories of quantum gravity, is that black holes don’t end in singularities. Instead, when they shrink to the Planck scale, they may undergo a quantum bounce and tunnel into white holes. If this happens, the information thought to be lost could slowly leak back out.

To understand this better, I studied Penrose diagrams and quantum-corrected models that show how black holes can have huge internal volumes, even when their external mass becomes small. In these models, the interior does not collapse into a singularity but instead rebounds into a white hole. This would allow information to re-emerge, preserving the laws of quantum mechanics.

Although white holes are still theoretical, they provide an elegant way of connecting Einstein’s relativity with quantum mechanics. For me, this project was a way to not only learn advanced physics concepts but also to explore how science continues to evolve as we push toward answering some of the universe’s biggest mysteries.