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Science Journaling Club

Volume 1, Issue 4June 2025

Summer 2025

Organisms doing things they are not supposed to be able to do, plus a boiled egg that secretly wants two different temperatures at once and what a trained nose can tell you about a body three thousand years dead.

This issueSJC 1.4
Published
June 2025
Articles
8
Research
3
Field notes
5
With code
6

Contents

8 articles, in the order the club meant them to be read.

  1. ResearchOriginal Research

    Spots, Stripes and the Two Chemicals That Might Explain Both

    In 1952 Alan Turing proposed that two substances reacting and diffusing at different rates could turn a uniform sheet into a patterned one with no template anywhere. We tested the mechanism by integrating the Gray-Scott system on a periodic 256 × 256 grid, and nothing here was observed in an organism or a beaker, because the club has no laboratory and the computation is the experiment. We derived the Turing conditions in closed form and evaluated them at F=0.0740F = 0.0740, k=0.0620k = 0.0620, Du/Dv=2D_u/D_v = 2, where the uniform state is stable without diffusion (tr J=−0.014209\mathrm{tr}\,J = -0.014209, det⁡J=+0.000300\det J = +0.000300) and unstable with it (B=+0.009743>0B = +0.009743 > 0). Growth rates measured mode by mode matched the analysis to a worst relative error of 1.08 × 10−5 over twelve modes, and during growth the pattern's wavelength came out at 13.6371 ± 0.1372 cells against a predicted 13.5612, a gap of +0.56% and z = +0.55 over 24 replicates. After the pattern stopped moving it had drifted to 13.8870 ± 0.0877 cells against the fastest-mode prediction of 12.7207, +9.17% and z = +13.30; a 512 × 512 control put the same number at 13.8186 ± 0.1150, ruling out the grid. Setting Du=DvD_u = D_v annihilated the pattern exactly as the theory requires: the surviving amplitude after 3000 steps was 6.47 × 10−14 against 0.1553 for the unequal case, and the measured decay rates sat within 2.78% of the analytic ones. A 169-point sweep of (F,k)(F, k) produced 123 uniform, 14 spots, 18 maze, 14 chaotic and zero aligned-stripe outcomes; stripes are stable when seeded but are never chosen out of isotropic noise. Wavelength fell with diffusion ratio as r−0.678±0.036r^{-0.678 \pm 0.036} against a predicted r−0.687r^{-0.687}, a gap of 0.26 standard errors, and at the low end of that sweep the pattern grew exactly on schedule and then collapsed to nothing at all. Seed 20250621.

    Summer 2025Read 35 minSections 13

  2. ResearchOriginal Research

    Why Frost, Coral and Copper Deposits All Grow the Same Shape

    Branched, feathery growth turns up in places that share almost no physics, and the club wanted to know whether the family resemblance survives being measured rather than merely admired. We implemented diffusion-limited aggregation on a square lattice and grew six independent clusters of 50,000 particles, plus 192,000 further particles in a sticking-probability sweep and an algorithmic control, for 492,000 particles in total. Nothing here was observed, because the computation is itself the experiment, and two estimators turned loose on the same six clusters were asked to hand back the same number. Radius-of-gyration scaling gave D = 1.6992 ± 0.0172, which sits 0.63 of our own standard errors below the accepted value of 1.71, while box counting on those identical clusters gave D = 1.6420 ± 0.0015, which is 46.9 standard errors below it. The two rulers therefore disagree with each other by +0.0572 ± 0.0172, a paired z of +3.32, and we spent most of this study on that gap rather than on the number that flattered us. Running that same box counter on three shapes whose dimension is known exactly showed it reading low in every case, by −0.119 on average. The radius-of-gyration exponent refuses to hold still either: its local value falls from 1.824 at a few hundred particles to 1.669 over the last half-decade, while a four-fold anisotropy grows from 0.041 to 0.416, the known signature of the square lattice rather than of the growth process. Dropping the sticking probability from 1.00 to 0.05 raised the apparent dimension at fixed size from 1.7006 ± 0.0259 to 1.9595 ± 0.0171 and shrank the mean radius of gyration by 43.6%. An algorithmic control found no detectable bias from our long-jump acceleration, −0.0251 ± 0.0262. Seed 20250704, runtime 365 s.

    Summer 2025Read 36 minSections 12

  3. ResearchReplication

    A Planet of Daisies That Regulates Its Own Temperature

    In 1983 Andrew Watson and James Lovelock published a planet made of black and white daisies, to answer the charge that Gaia required the biosphere to plan ahead [3]. We re-implemented their model, swept the solar luminosity from 0.6 to 1.6 times present in 501 steps, integrated to steady state at each, and observed nothing whatever, since the computation is the experiment and no planet, daisy, or physical measurement appears anywhere in this study. The daisies hold the planetary temperature inside a band of 10.421 °C across L = 0.704 to 1.556, which is 85.2 per cent of the swept range, while an identical bare planet moves through 60.236 °C over the same interval: a suppression factor of 5.78, rising to 8.30 across the middle 90 per cent of the interval and 6.65 inside the band where temperature stays within 2 °C of the growth optimum. Three checks make this a measurement rather than a picture. The three surface areas, integrated as independent variables, sum to one to within 8.882×10−15, or 40 machine epsilons, at every one of 1,162,915 integration steps, and the daisy-free control reproduces the Stefan–Boltzmann temperature exactly, to 0.000×100 K at all 501 luminosities. Setting both daisy albedos equal to bare ground, which leaves the ecology untouched and removes only the radiative channel, collapses the temperature curve onto the bare control to 2.842×10−13 K while daisies still cover up to 70 per cent of the surface. An independent closed-form prediction we derived and did not impose, that the bare-ground fraction is pinned at γ/(1−(d/h)2) = 0.326530786 throughout the coexistence band, is reproduced by the integrator to 1.7×10−9. A Monte Carlo over 2,000 randomly drawn parameter sets gives a regulated width of 0.8066 ± 0.0025 and a suppression factor of 6.403 ± 0.051, with every drawn planet regulating to some degree. Against that, one bookkeeping choice we did not measure, whether dead daisies can re-seed, moves the hot edge of the regulated range from 1.556 to 1.212 and removes 40.4 per cent of the result. Seed 20250621.

    Summer 2025Read 36 minSections 12

  4. Field notePaper Analysis

    The Tree That Wants to Be Struck by Lightning

    For a century, lightning has been filed under damage. In March 2025 a team working in central Panama filed it under strategy. A custom lightning-location array pinned down 93 struck trees, and the crews then went and looked at every one of them, which is how ten strikes on Dipteryx oleifera, the tonka bean, came to be recorded as doing negligible damage while 64% of struck trees of other species were dead within two years. The same bolts killed 78% of the vines strangling the Dipteryx crowns, along with roughly 2.1 tonnes of neighbouring competitor biomass per strike, and the authors estimate that surviving lightning multiplies lifetime seed output about 14-fold [1]. This Field Note asks something the paper does not. Does the physics even permit that asymmetry? We build our own crude two-resistor model of a struck trunk and its lianas, the club's own simplified model rather than the paper's analysis, and the answer turns out to depend violently on one modelling choice. Share a voltage between trunk and vine and the vine heats 0.75× as fast per kilogram as the trunk, so nothing burns anywhere; let the vine carry the current itself and it heats 271,205× faster, boiling dry in 243 microseconds. Our 300-year Monte Carlo returns a fitness advantage of 7.23×. Large and real, and still only half the paper's 14×. We show exactly which assumptions we would have to bend to close that gap. We do not bend them.

    Tropical EcologyRead 33 minSections 12

  5. Field notePaper Analysis

    Clownfish Shrink to Survive Heatwaves, Actually Shorter, Not Just Thinner

    A bony vertebrate is supposed to get longer, or hold still. Reversing is not on the menu. During the marine heatwave that hit Kimbe Bay, Papua New Guinea in 2023, Melissa Versteeg and colleagues measured 134 wild clown anemonefish six times over five lunar months. A hundred of them got shorter. Shrinking raised an individual's survival probability by as much as 78 percent. Pairs where both partners shrank did better than pairs where only one did [1]. We rebuilt the physiological argument ourselves, from oxygen solubility tables and scaling exponents, and the club did not expect what came out. Under the gill-limitation account, a typical 1.4 percent shrink offsets 0.0248 °C of warming, against a 4 °C anomaly. Change the accounting to count total energy demand instead of supply per unit demand, and the same shrink is worth 0.4577 °C, eighteen times more. Our simulated survival model recovers an odds ratio of 1.73, and tandem shrinking beats solo shrinking by 7.65 percentage points. Everything past §5 is the club's own simplified calculation, kept clearly separate from what Versteeg and colleagues measured, and one of its inputs can flip the sign of the whole geometric argument.

    Marine PhysiologyRead 33 minSections 12

  6. Field notePaper Analysis

    Eight Thousand Kilometres on a Raft of Weeds: How Iguanas Reached Fiji

    Fiji has iguanas. Nothing else in the Pacific does, and the family is otherwise an American one, so for a century the four Fijian species were explained away as leftovers from a vanished southern supercontinent or as the end of a long chain of island hops from South America. In March 2025 a team led by Simon Scarpetta sequenced more than four thousand genetic loci and found the closest living relative of the Fijian iguanas sitting in the Mojave and the Sonoran, the desert iguana, with the two lineages parting somewhere near 34 million years ago [1]. The implied journey is a drift of more than 8,000 km across open ocean, the longest crossing ever documented for a land vertebrate, and we wanted to know whether an animal could physically survive it, so we built our own water and energy budget for a 70 g lizard on a floating mat of vegetation. Our simplified model gives 179 to 833 days at sea depending on the current, a fasting limit of 73.7 days, and a dehydration limit of 27.3 days with no fresh water at all, both of them far shorter than the voyage. The trip only closes if the raft is edible and it rains. On our numbers it needs rain on roughly 15% of days to give a coin-flip chance of arrival, which the tropical Pacific supplies easily along the whole route, then and now. Everything after the second section is the club's own arithmetic rather than the paper's analysis, and one of our parameters could move the answer by two orders of magnitude, which we name and flag rather than bury.

    BiogeographyRead 34 minSections 12

  7. Field notePaper Analysis

    What Nine Egyptian Mummies Actually Smell Like

    A smell has never had a fixed procedure. In February 2025 a team led by Emma Paolin, working across University College London, the University of Ljubljana, Kraków University of Economics, and the Egyptian Museum in Cairo, gave it one anyway. They put nine mummified human bodies — five held in storage, four standing in gallery cases, spanning the New Kingdom to the Byzantine period — through non-invasive headspace sampling, gas chromatography-mass spectrometry with olfactometry, and a trained sensory panel scoring thirteen fixed descriptor words [1]. The three words that came back most often were woody (in 78 percent of the bodies), spicy (67 percent), and sweet (56 percent) — a chemical signature of cedar and juniper resin, myrrh, and beeswax that has been sitting in these bodies for roughly three thousand years. Underneath that signature the instrument also found compounds nobody embalmed on purpose: a botanical pest-control oil the museum itself applies to display cases, unexplained synthetic pesticide residues, and volatile by-products of active mould and bacteria still living on the wrappings. This field note is a close read of the method — how you turn a subjective sensation into a chemical identity two people can agree on — the compound list, and the paper's own ethics section on what it means to study, and publish, the smell of a human body that cannot consent to being smelled. The arithmetic converting one of the paper's reported odor thresholds into an everyday volume of air is ours, done from their published numbers, and flagged as such where it appears.

    Heritage ScienceRead 18 minSections 13

  8. Field notePaper Analysis

    How to Cook an Egg That Cannot Be Cooked at One Temperature

    An egg is a boundary-value problem disguised as breakfast. Its white sets properly around 85°C and its yolk wants to stop cooking near 65°C [1], and a single bath cannot deliver both numbers to a single object at the same time: hold it at 100°C and the white sets while the yolk turns to paste, hold it at 65°C and the yolk is perfect while the white never fully sets, because only one of its proteins, ovotransferrin, is capable of gelling that cool [1]. A 2025 paper in Communications Engineering stops trying to pick one temperature and instead moves the boundary condition itself: the egg spends 2 minutes in a 100°C bath, then 2 minutes in a 30°C bath, repeated 8 times for a total of 32 minutes [1]. Their heat-conduction and reaction-kinetics model finds that the yolk, buried at the centre of the egg, barely notices the swing and settles near a constant 67°C, while the albumen, sitting right against the water, rides the full oscillation and accumulates enough time above its own threshold to set completely [1]. They then cooked real eggs this way and checked the claim with texture analysis, sensory panels, FT-IR spectroscopy and untargeted metabolomics, finding a texture partway between soft-boiled and sous-vide and, unexpectedly, more of several polyphenols retained in the yolk than any conventional method produced [1]. Below we work through the physics ourselves, using nothing but the paper's own reported numbers: why 67°C beats the naive halfway point of 65°C by more than arithmetic averaging would suggest, roughly how far a four-minute thermal cycle reaches into a shell before it fades out, and the fact that the periodic egg spends four more minutes submerged near boiling than a conventional hard-boiled egg does — and still comes out soft.

    Heat TransferRead 20 minSections 14