Scientists Tried to Cut a Photon in Half—and Broke the Rules of Physics 5%
By Caroline Delbert45%
8/4/2026, 11:15:00 AM
Keywords: Photon, Scientist, State, Single Photon, Part, Light, Infinite Trailing Tail, Team, Truncation, Shutter, Half, Photon Number, Oslo, Case, Truncated Photon
BS Summary: This article contains 23 faulty reasoning types, including Biased Writer Voice, Hasty Generalization, and Unattributed Quote, with Ambiguity (Equivocation) as the most egregious example at 30.7% saturation with 189 hits. Analysis detected 978 faulty-reasoning hits from 616 analyzed words, generating a BS Score of 11.6% and a BS Rank of 5% (29,344 of 30,584 articles). This article is better (less manipulative) than 95.90% of the article peer group.
Here’s what you’ll learn when you read this story:
When you try to clip a photon using a barrier, it becomes more photons than before.
Photons are inherently asymmetrical because one side has an infinite trailing tail.
We now know photons are like worms—they can regrow from either half.
In newly published research, three physicists from the University of Oslo in Norway posed an interesting dinner-party question for fellow particle nerds: What happens when you “truncate” a photon?
After all, a photon can’t be split the way non-elementary particles can be split, but it can be smushed into various quantum phenomena and combinations thereof.
The new research appears now in the peer-reviewed journal Physical Review Letters.
“A photon, being an elementary particle, cannot be cut in two halves.
Still, it is clearly possible to remove a part of an optical pulse, e.g., using an optical shutter,” the team explained in their introduction.
In other words, the light is almost like a stream, and it can be cut off and then released.
“If a photon is truncated in this way, what is the resulting state?
Despite being a simple question, it appears that it has not been asked before.”
Optical pulses are like tiny, extremely precise lasers.
Just a few photons pass through at once, released during an infinitesimal opening.
Clipping this stream with an optical shutter is not as simple as it sounds, partly because single photons “have infinite tails.”
As the team explained, “Surprisingly, we will find that a truncated photon is a complicated state involving photon numbers up to infinity.
In other words, by ‘cutting away part of the photon’ with a shutter, we effectively create a bunch of new photons.
In principle, this is the case even if the shutter is turned off slowly.”
Maybe it’s now clear why nobody had ever bothered to ask this seemingly simple question: the answer defies common sense.
Cut off the “head” of a photon, and—like the mythical hydra—it doesn’t die or shrink.
It multiplies, erupting into a swarm of brand-new photons.
That strange outcome is possible in part because a photon isn’t a neat, symmetrical packet of light; its “infinite tail” trails off in only one direction, meaning where you make the cut matters enormously.
To pin down exactly what happens at that moment of truncation, the Oslo team built a pristine hypothetical scenario—following a single photon through the shutter—and crunched the numbers.
Their scenario is what scientists call a toy model—a deliberately stripped-down version of a complex phenomenon that makes it possible to isolate the variables that matter.
In this case, the team pared reality down to “one dimension, and a single polarization,” then sent “an exact single photon” toward a mirror-like shutter that clipped it mid-flight.
What emerged was genuinely odd.
Rather than producing two damaged fragments of light, the truncation yielded two clean, self-contained pieces: one “half” registered as pure vacuum—no photon at all—while the other “half” registered as a complete single photon.
Neither piece carried any trace of ever having been part of something larger.
Photons are unusual, and the researchers stressed that this is a really specific setup that they made in order to study how the photons respond to truncation.
That said, they concluded with a comparison to perturbed states that act on photons, and explained how their formulation could help scientists who study those states of causality.
These setups may be easier to represent with classical physics interactions, as opposed to quantum or exotic approaches.
But future scientists could still use the information that their truncated photons are going infinite quantum when they hit the barrier.
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Analysis
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