Updated

Updated · Ars Technica · Jul 24

Oslo Physicists Find 1 Photon Can Spawn Infinite-State Outcome When Mirror Is Yanked Away

Updated

Updated · Ars Technica · Jul 24

Oslo Physicists Find 1 Photon Can Spawn Infinite-State Outcome When Mirror Is Yanked Away

Q: If cutting a photon in half pulls new light from the vacuum, where does this sudden burst of energy actually originate?

The extra energy would come from the device that changes the boundary condition — the moving mirror or ultrafast optical shutter — not from nowhere. In the Oslo team’s calculation, “splitting” a photon means abruptly changing how the electromagnetic field is constrained. Quantum field theory says the vacuum is not truly empty; it contains fluctuations. When the boundary is changed very quickly, that external action shakes the field and can convert some of those vacuum fluctuations into real photons. This is closely related to the dynamical Casimir effect, where rapidly changing mirrors or circuit boundaries generate light from the vacuum. So the vacuum is the source of the new photons, but not the ultimate energy source. The energy is injected by whatever mechanism removes or shifts the mirror, or switches the shutter, fast enough to disturb the field. In that sense, the apparatus does work on the quantum field, and the field responds by producing a more complicated state with additional photon components. The “infinite” burst appears only in an idealized mathematical limit where the boundary changes instantaneously. Real mirrors and shutters cannot move or switch infinitely fast, so a real experiment would produce only a finite amount of extra light, likely small. The infinity is therefore a sign that a perfectly sharp cutoff would require unbounded energy, not a prediction of a physically achievable infinite flash.

2 articles · Updated · Ars Technica · Jul 24

Three University of Oslo theorists calculated that removing a mirror while a single photon is still reflecting does not simply split the light packet, but generates a far more complex quantum state.
Their analysis models an optical shutter that truncates the photon's wave packet, turning the interruption into a nonlinear event even though ordinary reflection itself is usually treated as linear.
The resulting state contains contributions from photon numbers extending up to infinity, according to the Physical Review Letters paper "Truncated Photon."
Local measurements of either separated part would still look like a single-photon state or vacuum, highlighting how counterintuitive the effect is and why it probes little-explored quantum field behavior.

Sources

Ars Technica2h ago

Norwegian Physicists Discover Complex Outcome of Removing Mirror During Photon Reflection

Gizmodo2h ago

Physicists Calculate "Cutting" a Photon Creates Infinite Photon State

Could rapidly chopping a single particle of light rewrite our fundamental understanding of quantum reality and vacuum fluctuations?

If cutting a photon in half pulls new light from the vacuum, where does this sudden burst of energy actually originate?

How will superconducting circuits prove that severing a photon's wave packet spawns a hidden infinity of new particles?

Sources

2 total

Ars Technica2h ago

Norwegian Physicists Discover Complex Outcome of Removing Mirror During Photon Reflection

Gizmodo2h ago

Physicists Calculate "Cutting" a Photon Creates Infinite Photon State

Oslo Physicists Find 1 Photon Can Spawn Infinite-State Outcome When Mirror Is Yanked Away

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