"There are more things in Heaven and Earth, Horatio, than are dreamt of in your philosophy."
So wrote William Shakespeare in Hamlet, and if anything, it's a significant understatement. If Shakespeare were writing today, considering recent discoveries in science, he might phrase it as, "Horatio, you seriously have no idea how weird it is out there. I mean, literally," which gains in accuracy but does lose something in poetic diction.
To take just one example, consider the paper that appeared in Astrophysical Journal Letters this week, about a gamma ray burst that was discovered by the amusingly-named Very Large Telescope (they're currently building a bigger one down in Chile which will be called, I shit you not, the Extremely Large Telescope). Gamma ray bursts are already pretty astonishing; NASA describes them as "second only to the Big Bang as the most energetic and luminous phenomena known." There are several possible causes of these enormous releases of high-frequency electromagnetic radiation -- supernovae, the catastrophic merger of neutron stars, and flares from magnetars amongst them. (You would not want to be looking down the gun barrel of one of these when it went off. There is some suspicion that the Late Ordovician Mass Extinction -- one of the "Big Five" mass extinctions, and second only to the Permian-Triassic "Great Dying" event in terms of magnitude -- was caused by a nearby gamma ray burst.)
Most of these events are one-offs, and considering the energy they involve (most of them release more energy in a few seconds than the Sun will in its entire lifetime) you can understand why. After one flare-up of that size, it's unsurprising that it wouldn't do it again any time soon. So the astrophysicists were puzzled when they found a gamma-ray burster (GRB 250702B) that seems to recur -- it produced a sequence of five flares, and did that entire sequence three times. Weirdest still, each time, the interval between the second and third flare in the sequence was an integer multiple of the interval between the first two!
What in the hell could cause that?
The gamma-ray burst seems to be extragalactic -- to be coming from a source outside the Milky Way. The source is near a known galaxy, but whether the burst is coming from within the galaxy, or simply from a source that happens to be lined up with it, hasn't been determined yet. The galaxy is one of the thousands that have been located by the Hubble and James Webb Space Telescopes but have yet to be studied; they don't even know what its red shift is (which would tell you how far away it is). But because the red shift of gamma ray bursts is impossible to determine -- to calculate red shift, you need identifiable spectral lines, and those don't occur in something as massive and chaotic as a burst -- this still wouldn't tell you whether the source was actually inside the galaxy or not.
In fact, there's more that's unknown than known about this phenomena. The periodicity led the researchers to suggest one possibility, that it was some unfortunate massive star in an elliptical orbit around a massive black hole, and having pieces torn off it every time it gets to perihelion. Another possibility is an "atypical stellar core collapse," which is astrophysics-speak for "a collapsing star where we really have no idea why it's acting like it does." A third is that the detected periodicity is an artifact caused by "dust echoes" -- reflection of the original gamma-ray burst from concentric shells of dust surrounding the remains of an exploded star. The final possibility -- at least of the ones the authors came up with -- is that it's an example of gravitational lensing, where light emitted by a star (or other astronomical object) travels close to a black hole, the curved space around the black hole causes the light beam to split along more than one path, and different parts of it arrive at different times.
The upshot is that we simply don't know what's going on here. The authors write:
We have... new, multiwavelength observations of a superlative series of associated GRB triggers, GRB 250702B. Our observations reveal a rapidly fading, multiwavelength counterpart likely to be embedded in a galaxy with a complex and asymmetric morphology. We... conclude that GRB 250702B is an extragalactic event. The relatively bright and extended host suggest the redshift is moderate (z < 1).
GRB 250702B is observationally unprecedented in its timescale, morphology, and the onset of X-ray photons prior to the initial GRB trigger. In addition, we find a striking, near-integer time step between the GRB outbursts, suggesting (although not proving) possible periodicity in the events.
All of this is absolutely fascinating to the astronomers, because it opens up the perennial question of "Is this a phenomenon we've already seen and know how to explain, or is it actually new physics?" At present, there's no way to answer this with any certainty. All that's known is something really weird is going on out there, and we're going to have to do a lot more observation before we'll be able to figure out what the explanation is.
So like I said, Shakespeare was spot-on. And the more we look out into the skies, the more we find that is Not Dreamt Of In Our Philosophy. Only now we have astrophysicists working on actually explaining these phenomena -- so perhaps this very peculiar flash-in-the-pan won't remain a mystery forever.
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