Why is Quantum Physics and Relativity a Difficult Marriage?

Quantum Physics and Relativity
Why is Quantum Physics and Relativity a difficult marriage? Because it happens everywhere at once!

How can we best understand the basic issue of compatibility between the theories of Quantum Mechanics and General Relativity without having to grapple with equations?

Quantum Mechanics does not deal with gravity, because for most quantum phenomena, the influence of gravity is completely negligible. Starting with the electromagnetic force, it has eventually successfully integrated the weak and the strong nuclear forces. To give it a universal status, however, we need to introduce the fourth type of interaction, gravity. No problem, right, we’ll just quantize gravity! But not so fast! According to General Relativity, gravity isn’t just, like the other three, a force, or a field, acting within spacetime, it’s intimately linked to the fabric of spacetime itself. Quantizing gravity, therefore, means quantizing spacetime as well. OK, now we have a quantum of space, and of time.

Here is the rub, though. Imagine that you are sitting with a ruler of that quantum length, whatever it may turn out to be. By definition, there can’t be a smaller length, anywhere in the universe. Ah, but Special Relativity (Lorentz transformation) tells us that there is a referential, in movement with respect to you, where the observed length of that ruler will be smaller. In fact, we can make it arbirarily smaller by increasing the relative speeds. Well, that doesn’t work, does it?

That is the basic conflict. On the mathematical side, plugging in the equations, we get meaningless infinities all over the place. Many approaches have been tried, but they usually modify special relativity. Is there a way to keep such a beautiful piece of work intact? Well, it turns out that there is. The price to pay: it introduces non-local effects, the notion that physics at a certain point is spacetime can be affected by what happens very far from it. We already know this to be true in the case of entanglement, so why not accept it in a much more general context?

The beauty of this approach, is that it is testable. Scientist are working on an experiment that will tell whether that approach is the right one. Stay tuned!

Once again, our “common sense” cannot be trusted. The laws of the universe may well turn out to be even weirder than we imagined. What an exciting time to be alive!

Journal Reference:

Alessio Belenchia, Dionigi M. T. Benincasa, Stefano Liberati, Francesco Marin, Francesco Marino, Antonello Ortolan. Testing Quantum Gravity Induced Nonlocality via Optomechanical Quantum Oscillators.Physical Review Letters, 2016; 116 (16) DOI:10.1103/PhysRevLett.116.161303


The Dangers of Quantum Tech

Article by ,

The United Nations has proclaimed 2025 as the International Year of Quantum Science and Technology

Indigenous Futurism?

Article by

National Geographic Explorer Keolu Fox says the key to harnessing the technology of tomorrow is centering traditions of the past

Magic Died When Art and Science Split

Article by

Renée Bergland’s 3 greatest revelations while writing Natural Magic: Emily Dickinson, Charles Darwin, and the Dawn of Modern Science

Quantum physics reveals the unity of the universe

Article by

Quantum physics revives the ancient idea of universal oneness that Christianity unjustly excluded from our culture

#77 Regenerative Medicine

Podcast with

Exploring the frontiers of alternative medicine and healing modalities with renowned Cerebral Spiral Fluid expert.

Pixels, Patterns & Perspectives

Video with

Physicist and Author Sky Nelson-Isaacs urges us to see the world differently and consider how pixels and patterns converge to evoke a new perspective.

Time to Support Indigenous Science

Article by

Faced with the profound challenges of a rapidly changing environment, society needs other ways of knowing to illuminate a different way forward

Resonantly Perfect Solar System Found

Article by

Researchers have located "the perfect solar system", forged without the violent collisions that made our own a hotchpotch of different-sized planets

Support SAND with a Donation

Science and Nonduality is a nonprofit organization. Your donation goes towards the development of our vision and the growth of our community.
Thank you for your support!