Episode overview

Inside the Search for Extra Dimensions, with Lara Anderson

StarTalk Radio · 6 October 2026 · 54m · 3 Egleze moments

What happened in this episode?

Neil deGrasse Tyson and comedian Jordan Klepper speak with Virginia Tech string theorist Lara Anderson about what extra dimensions would mean physically and how, in principle, they could be tested. Anderson says the Higgs boson is firmly established experimentally and that current attention is on whether accelerators can reveal physics beyond the Standard Model.

On extra dimensions, Anderson explains that collider experiments such as the Large Hadron Collider can set limits because large additional directions would allow energy or particles to “disappear” from detectors as they propagate into unseen dimensions. She says researchers are also interested in “large extra dimensions” scenarios where gravity could be diluted by leaking into additional directions, potentially offering an explanation for gravity’s relative weakness.

Anderson tells the hosts that string theory’s near-term empirical prospects may be indirect: she argues it could be shown to be wrong if it fails to reproduce features of the Universe that are already measured. She also gives a lay account of why common string-theory constructions require ten dimensions, tying it to quantum anomaly cancellation that makes the theory internally consistent.

The discussion ranges over higher-dimensional visualisation (using “shadows” as an analogy), the holographic principle as a potentially simplifying theoretical tool, and the broader question of whether dimensions are objective features of reality or conceptual structures used to organise physical laws.

What are the key points?

Anderson says the Higgs boson is experimentally secure, while “physics beyond” it remains unconfirmed at the LHC.
She says missing-energy signatures at colliders would have revealed large extra dimensions, placing bounds on their size.
Anderson discusses models where gravity could leak into extra dimensions, potentially explaining why gravity is much weaker than other forces.
She argues string theory might be falsified indirectly if it cannot reproduce known properties of the observed Universe.
Anderson explains the common “D=10” requirement in string theory as a quantum anomaly-cancellation condition for mathematical consistency.
She describes higher-dimensional reasoning via projections and “shadows”, rather than direct visualisation, and notes interest in holography as a simplifying framework.

Who is speaking?

Named speakers identified in Egleze's source-linked moments from this episode.

Lara Anderson

Which topics are covered?

Science

How is this page sourced?

Programme: StarTalk Radio
Published: 6 October 2026
Duration: 54m
Original episode: Open the original source ↗

Egleze verifies the speaker, source and timestamp for each linked moment. Unless a moment is explicitly marked independently verified, statements remain attributed claims by the named speaker rather than established facts.

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3 moments from this episode

Source-linked · editorially selected

Science

Lara Anderson says collider experiments would reveal large extra dimensions via missing energy

Lara Anderson · at 23:40 · Attributed speaker claim

And if there were large extra dimensions that, you know, were the same size as the rest of our universe, things would fly off into them and you'd watch all these pieces just disappear all the time. You'd watch energy and mass disappear.

Guest physicist Lara Anderson says that if large extra spatial dimensions were accessible in particle-collider collisions (such as at the Large Hadron Collider), some collision products could escape into them, showing up as missing mass/energy in detectors. She adds that because experiments largely do not observe this kind of disappearance, physicists can place bounds on how large such dimensions could be.

Read this moment → Check original at 23:40 ↗

Science

Lara Anderson says string theory could be ruled out by observations

Lara Anderson · at 26:28 · Attributed speaker claim

I think it's very possible that we could prove that, you know, string theory is just straight up wrong based on the fact that it just can't get things right about our universe that we already see.

Lara Anderson says string theory may be tested indirectly by comparing its predictions with features of the Universe already observed. She argues that if those predictions do not match existing data, it could show string theory is not a correct description of nature.

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Science

Lara Anderson says anomaly cancellation points string theory to ten dimensions

Lara Anderson · at 32:59 · Attributed speaker claim

And what they found is that all of this quantum uncertainty, this sort of wiggling and violation of these these principles that we think should hold magically cancels out when you have 10 dimensions. Um these quantum anomalies cancel exactly. So the theory becomes really robust and really rigid.

Lara Anderson says early string-theory work found quantum anomalies cancel only in ten dimensions, avoiding mathematical inconsistency. She argues that this makes the framework internally consistent before asking what it predicts about the Universe.

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