Large Scale Volcanism: an explanation for the heat-death of Venus like worlds

<p class="p1"><span class="s1">Large scale volcanism has played a critical role in the long-term habitability </span><span class="s1">of Earth and possibly Venus.<span class="Apple-converted-space">  </span>We examine the timing of Large Igneous Provinces </span><span class="s1">(LIPs) through Earth’s history [1] to estimate the likelihood of nearly simultaneous </span><span class="s1">events that could drive a planet into an extreme moist or runaway greenhouse, </span><span class="s1">quenching subductive plate tectonics. Such events would end volatile cycling </span>and may have caused the heat-death of Venus. Using the Earth's LIP record <span class="s1">a conservative estimate of the rate of LIPs in a random history statistically </span>the same as Earth’s, pairs and triplets of LIPs closer in time <span class="s1">than 0.1-1 Myrs are likely. This simultaneity threshold is significant to the </span><span class="s1">extent that it is less than the time over which environmental effects </span><span class="s1">have been shown to persist, for example in the Siberian Traps record [2,3].</span></p> <p class="p1"><span class="s1">[1] Ernst, R.E. et al. (2021). Large Igneous Province Record Through Time and </span><span class="s1">Implications for Secular Environmental Changes and Geological Time-Scale </span>Boundaries. In: Ernst, R.E., Dickson, A.J., Bekker, A. (eds.) Large Igneous <span class="s1">Provinces: A Driver of Global Environmental and Biotic Changes. AGU Geophysical </span><span class="s1">Monograph 255 (pp. 3-26).</span></p> <p class="p1"><span class="s1">[2] Burgess, S.D. et al. (2014). High-precision timeline for Earth’s most </span><span class="s1">severe extinction. Proceedings of the National Academy of Sciences, 111:</span></p> <p class="p1"><span class="s1">3316–3321 [correction 2014, 111: 5050]. </span></p> <p class="p1"><span class="s1">[3] Burgess, S.D. & Bowring, S.A. (2015). High-precision geochronology confirms </span><span class="s1">voluminous magmatism before, during and after Earth's most severe extinction. </span><span class="s1">Sci. Adv. 1 (7), e1500470. http://dx.doi.org/10.1126/sciadv.1500470. </span></p>

Frederic Leighton's Flaming June, Thermodynamics, and the Heat Death of the Sun

At the close of the nineteenth century, amid pervasive fears of decadence and widespread pessimism, Frederic Leighton (1830–96) completed Flaming June (1895). Taking as its starting point Victorian responses to the work that seem incomprehensible to viewers today, this paper examines the possible meaning behind Flaming June's more impenetrable iconography. The following discussion highlights the significance of thermodynamics in the work's cultural context. It examines the impact of an implication of the second law of thermodynamics, known as the Sun's heat death – a fated apocalyptic event – and suggests that this resonated with late Victorian audiences plagued by concerns of degeneration and decadence. Considered within this context, this paper reveals further layers of meaning embedded within the imagery of Flaming June available to a Victorian audience, but which have since been eclipsed by a dominant focus on other aspects of the painting's cultural milieu.

A preliminary study about gravitational wave radiation and cosmic heat death

ABSTRACT We study the role of gravitational waves (GW) in the heat death of the Universe. Due to the GW emission, in a very long period, dynamical systems in the universe suffer from persistent mechanical energy dissipation, evolving to a state of universal rest and death. With N-body simulations, we adopt a simple yet representative scheme to calculate the energy loss due to the GW emission. For current dark matter systems with mass ∼1012−1015 M⊙, we estimate their GW emission time-scale as ∼1019−1025 yr. This time-scale is significantly larger than any baryon processes in the Universe, but still ∼1080 times shorter than that of the Hawking radiation. We stress that our analysis could be invalid due to many unknowns such as the dynamical chaos, the quadrupole momentum of haloes, the angular momentum loss, the dynamic friction, the central black hole accretion, the dark matter decays or annihilations, the property of dark energy, and the future evolution of the Universe.

The Heat Death Line: Proposed Heat Index Alert Threshold for Preventing Heat-Related Fatalities in the Civilian Workforce

A threshold Heat Index (HI) can serve as the basis for advising the civilian workforce about the risk of heat-related illnesses. We conducted a systematic review and compiled reports of work-related fatalities from heat-related illnesses. We calculated the HI for each fatality. Our objective was to expand upon the military’s concept of a “heat death line” and identify an HI alert threshold for the civilian workforce. We identified 14 publications totaling 570 heat-related deaths. In the meta-analysis, the median HI was 101 with a range of 62 to 137. Almost all deaths (96 percent and 99 percent of civilian and military fatalities, respectively) occurred when HI ≥80, which is our proposed heat death line. Some existing HI-based heat advisories are set at a higher temperature value. However, many occupational heat-related illnesses occur below these thresholds, resulting in low sensitivity and a false sense of security. In at-risk outdoor industries, HI ≥80 should trigger hazard awareness and protective actions.