What entropy actually means
Entropy, in physics, describes the universe's slow drift toward disorder. Left to themselves, organized systems break down. Heat disperses. Structure loosens. Things tend, over time, toward randomness rather than coherence. I cannot describe how much I have always loved this concept. I love the idea that disorder is not a failure of the system but the natural direction of things. That falling apart is, in some fundamental sense, what everything is doing all the time. I encountered it first in a physics class and have been quietly returning to it ever since, the way you return to a sentence that keeps meaning something new. So when researchers at Edith Cowan University asked whether that same principle could describe what happens inside the human body as it ages, I was already paying attention. The paper, published in the Journal of Travel Research and led by PhD candidate Fangli Hu, proposed exactly that. Aging, from an entropy perspective, is the body's gradual movement toward biological disorder — declining metabolic efficiency, weakening immune function, reduced capacity for self-repair. The authors proposed that positive travel experiences might help the body resist that drift by supporting self-organising systems. The paper is theoretical rather than clinical: it offers a conceptual framework, does not test travellers or measure ageing biomarkers, and should be read as a set of hypotheses for future research rather than evidence that travel slows ageing. "Ageing, as a process, is irreversible," Hu noted. "While it can't be stopped, it can be slowed down."Three reasons travel works as a counter-entropy force
The authors discuss several possible mechanisms through which travel might affect health; these are proposed pathways, not effects demonstrated by this paper. The first is novelty. New environments expose a traveller to unfamiliar sensory input and, sometimes, different patterns of physical activity and social contact. The paper proposes that these experiences could engage adaptive systems. It did not measure immune responses, metabolic rates, nervous-system flexibility or entropy in travellers. The second mechanism is physical activity. Most travel involves more movement than ordinary life — walking unfamiliar streets, hiking, swimming, navigating new cities on foot. This kind of incidental, embodied movement has well-established effects on metabolic health and immune function. The body staying in motion is the body resisting stasis. The third is the low-entropy effect of genuine rest. Leisurely travel may provide opportunities for rest, but it does not automatically move a person out of chronic stress, reduce cortisol or change immune activity. Those are plausible pathways discussed by the authors and would need direct empirical testing. What fascinates me about this triad is how closely it maps onto what people actually describe when they talk about feeling alive on a trip. The movement. The novelty. The particular quality of rest that only seems to arrive when you have genuinely left your ordinary life behind.What this means for the brain, specifically
The entropy framework connects naturally to what neuroscience has been finding separately about novelty and the ageing brain. Brain entropy — the complexity and variability of neural activity — decreases with age. A younger brain generates more varied, flexible signal patterns. An older brain, left unstimulated, tends toward less complex, more repetitive activity. This neural dedifferentiation is linked to cognitive decline and reduced emotional flexibility. Novel environments counteract this. New places, new social configurations, new sensory landscapes force the brain to generate new patterns rather than defaulting to familiar ones. The brain that keeps encountering the unfamiliar is a brain that keeps working at full complexity. This is part of why travel can feel so cognitively clarifying. It is not only rest. It is a particular kind of activation — the kind that comes from a nervous system being asked to do something genuinely new.The honest caveat
The paper's limits are important, and it is worth being explicit about them. The 2024 paper is conceptual rather than clinical. It proposes a framework without enrolling participants or measuring biological markers. Follow-up work published in 2025 described travel therapy as promising but still emerging, and called for clearer methodologies before the field draws firm conclusions. The same researchers also noted that not all travel is restorative — stressful itineraries, unsafe conditions, illness abroad, and exhausting schedules can increase entropy rather than reduce it. The kind of travel that seems to support health is not the kind that involves seventeen flights in ten days with zero downtime. It is the kind that includes real rest alongside novelty, physical engagement alongside stillness, social connection alongside solitude. Most people who travel thoughtfully already know the difference intuitively. The paper gives that intuition a hypothetical structure to be tested.What we actually miss when we come home
I keep returning to the novelty piece, because I think it explains something that post-travel flatness research has only partially captured. When I am away, my nervous system is genuinely busy. Not anxiously busy — the opposite of that. Alert, present, engaged with the immediate. The body is warm or tired from walking. The day is full of small decisions about where to eat and which street to take. Nothing is automatic. Coming home means returning to a life the brain has already largely mapped. The commute, the routine, the apartment organized exactly as expected. There is comfort in that. But there is also a kind of neural quieting that can feel like flatness, especially in the first days back. The entropy framework offers one possible way to think about this feeling. It does not establish that my biological systems were activated on the trip or returned to a measured baseline at home. This does not mean ordinary life is unhealthy. Travel may have physiological as well as emotional correlates, but this paper did not measure them.The rationalization I was looking for
I want to be transparent: I came to this research with an agenda. I travel more than is strictly defensible on an academic salary, and I have been quietly looking for peer-reviewed support for this decision for some time. I have found a useful hypothesis, not a prescription. The paper proposes that novelty, movement, rest and social connection could influence systems relevant to health. It does not show that travel slows biological ageing, keeps a nervous system flexible or gives post-trip aliveness a measurable biological basis. I am choosing to enjoy the idea without treating my next flight as a health intervention. I recognize this is exactly the kind of motivated reasoning a psychologist should not engage in. I am engaging in it anyway. The entropy paper gives me a metaphor, not medical clearance.Correction (14 September 2026): This article previously described a conceptual paper as evidence that travel slows ageing. It now clearly distinguishes the authors' hypotheses from findings tested in travellers.
