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Quantum Mechanics
For decades, theorists have been cooking up "theories of everything" to explain our Universe. Are all of them completely off-track?
No matter what physical system we consider, nature always obeys the same fundamental laws. Must it be this way, and if so, why?
13mins
Jim Al-Khalili introduces the technologies emerging from the second quantum revolution.
1hr 19mins
Theoretical physicist Jim Al-Khalili explores why our sense of time may be incredibly misleading, including the idea that past, present, and future might all exist at once.
Smashing things together at unprecedented energies sounds dangerous. But it's nothing the Universe hasn't already seen, and survived.
Quantum entanglement links information between particles across space and time. So what happens when one of them falls into a black hole?
The fundamental building blocks of reality are indivisible: quanta that cannot be split or divided. Our understanding remains incomplete.
A century ago, quantum physics overthrew our view of a deterministic Universe. A profound 21st century theorem closes the door even further.
The very word "quantum" makes people's imaginations run wild. But chances are you've fallen for at least one of these myths.
We think of physical reality as what objectively exists, independent of any observer. But relativity and quantum physics say otherwise.
As the lightest baryon in the Universe, the proton is thought by many to be eternally stable. But if it isn't, can we observe it decaying?
From white holes to dark stars and multiverses, James Riordon explores the bizarre exhibits of general relativity's "cryptozoo."
16mins
“The messy reality of it is that all of these very smart people, including Isaac Newton, were talking to other people.”
Quantum mechanics was first discovered on small, microscopic scales. 2025's Nobel Prize brings the quantum and large-scale worlds together.
23mins
"Could black holes be the key to a quantum theory of gravity, a deeper theory of how reality, of how space and time works? Well, I think so."
The Holy Grail of physics is a Theory of Everything: where a single equation describes the whole Universe. But maybe there simply isn't one?
Since even before Einstein, physicists have sought a theory of everything to explain the Universe. Can positive geometry lead us there?
1hr 26mins
“I like to say that physics is hard because physics is easy, by which I mean we actually think about physics as students.”
Parallel universes are among the most profound notions in all of quantum physics. It's a compelling and fascinating idea, but is it true?
Amplifying the energy within a laser, over and over, won't get you an infinite amount of energy. There's a fundamental limit due to physics.
1hr 8mins
“An equation, perhaps no more than one inch long, that would allow us to, quote, 'Read the mind of God.'”
Realizing that matter and energy are quantized is important, but quantum particles aren't the full story; quantum fields are needed, too.
1hr 18mins
“Could black holes be the key to a quantum theory of gravity, a deeper theory of how reality, of how space and time works?”
19mins
"It's a very, very beautiful calculation, but it's the best example I know of the relationship between these rather abstract quantities perhaps and something that you can look at in a telescope."
A meditation on quantum physics, creative endurance, and the unseen forces that shape what lasts.
The ANITA experiment found cosmic rays shooting out of Antarctica. One interpretation claims "parallel Universes," but is that right?
5mins
“When you think about this interconnection of all these tiny causes and effects which add up to the way the world unfolds, it becomes impossible to imagine that we have complete control.”
Here in our Universe, time passes at a fixed rate for all observers: one second-per-second. Before the Big Bang, things were very different.
If it weren't for the intricate rules of quantum physics, we wouldn't have formed neutral atoms "only" ~380,000 years after the Big Bang.
1hr 19mins
“We don't have enough knowledge to precisely calculate what is going to happen, and so we assign probabilities to it, which reflects our ignorance of the situation.”