The Universe Is Always Looking | The Atlantic

Source: The Universe Is Always Looking | The Atlantic, by Philip Ball

[Schrödinger’s] cat is still hauled out today as if to imply that we’re as puzzled as ever by the mere fact that the quantum world at small scales turns into the world of classical physics at human scales. The fact is, however, that this so-called quantum-classical transition is now largely understood. … quantum physics is not replaced by another sort of physics at large scales. It actually gives rise to classical physics.

At the root of the distinction, though, lies the fact that quantum objects have a wave nature—which is to say, the equation Schrödinger devised in 1924 to quantify their behavior tells us that they should be described as if they were waves, albeit waves of a peculiar, abstract sort that are indicative only of probabilities. It is this waviness that gives rise to distinctly quantum phenomena like interference, superposition, and entanglement. These behaviors become possible when there is a well-defined relationship between the quantum “waves”: in effect, when they are in step. This coordination is called “coherence.”

Macroscopic, classical objects don’t display quantum interference or exist in superpositions of states because their wave functions are not coherent. … Every real system in the universe sits somewhere, surrounded by other stuff and interacting with it. … Quantum superpositions of states … are highly contagious and apt to spread out rapidly. And that is what seems to destroy them. … As time passes, the initial quantum system becomes more and more entangled with its environment. In effect, we then no longer have a well-defined quantum system embedded in an environment. Rather, system and environment have merged into a single superposition. … This spreading is the very thing that destroys the manifestation of a superposition in the original quantum system. Because the superposition is now a shared property of the system and its environment, we can no longer “see” the superposition just by looking at the little part of it. What we understand to be decoherence is not actually a loss of superposition but a loss of our ability to detect it in the original system.

And this has nothing to do with observation in the normal sense: We don’t need a conscious mind to “look” in order to “collapse the wave function.” All we need is for the environment to disperse the quantum coherence. We obtain classical uniqueness from quantum multiplicity when decoherence has taken its toll. … All of the photons of sunlight that bounce off the moon are agents of decoherence, and are more than adequate to fix its position in space and give it a sharp outline. The universe is always looking.

Scientists Have Uncovered a Climate Change Precedent | The Atlantic

Source: Scientists Have Uncovered a Disturbing Climate Change Precedent

Looking at evidence about the environments on earth 50 million years ago, it is likely that the earth then had 1,000 parts per million (ppm) of atmospheric carbon dioxide (CO2), arctic and antarctic environments similar to today’s tropics (e.g. the Sahara desert and Amazon rainforest), and possibly dead zones with temperatures above 50 degrees Celsius (122 degrees Fahrenheit) in the tropics.

You can also see a rendering of the earth [here].

Why a Typical Home Solar Setup Does Not Work With the Grid Down – And What You Can Do About It | Syonyk’s Project

Source: Why a Typical Home Solar Setup Does Not Work With the Grid Down – And What You Can Do About It | Syonyk’s Project, by Russell Graves

The biggest problem is that they’re very easy to drive into voltage collapse (and therefore power collapse) if you draw beyond the peak power they can produce at the current temperature and illumination. This is an example IV (current/voltage) curve out of the datasheet from my panels – it’s one I had laying around. The numbers don’t matter, because all solar panels work this way – just with different numbers on the scales.

The peak power (maximum power point) on the panel comes slightly past the start of the drop in voltage, and the available power drops very rapidly as you go past that point into the voltage collapse. At both the short circuit point (0V, plenty of amps) and the open circuit voltage (0 amps, plenty of volts), the panels are producing zero usable power. …

You need batteries in an off grid system for two reasons: Energy storage is the obvious reason, but they also cover peak power demands. … Worth noting on batteries: They suffer age related degradation as well as as cycle based degradation. You cannot keep any battery alive forever, even if you don’t use it. … Let me offer a general guideline on batteries: Any time you put any sort of battery into a power system, the system will never “pay for itself.” There may be specialty cases where this isn’t true, but it’s a solid first order approximation you should be aware of.

Why have I written all this? To explain (hopefully) that the reason most solar power systems won’t work off grid has literally nothing to do with power companies being evil and demanding that you buy their power. It has everything to do with the system not being designed to run off grid. Why are they designed that way? Because it’s cheaper. Period. A microinverter based system is substantially cheaper than anything with batteries (which will need regular replacement), and that’s what people get installed when they want a reasonably priced bit of rooftop solar to save money on their power bill.

The biomass distribution on Earth | PNAS

Source: The biomass distribution on Earth | PNAS, by Yinon M. Bar-On, Rob Phillips, and Ron Milo

A census of the biomass on Earth is key for understanding the structure and dynamics of the biosphere. However, a global, quantitative view of how the biomass of different taxa compare with one another is still lacking. Here, we assemble the overall biomass composition of the biosphere, establishing a census of the ≈550 gigatons of carbon (Gt C) of biomass distributed among all of the kingdoms of life. We find that the kingdoms of life concentrate at different locations on the planet; plants (≈450 Gt C, the dominant kingdom) are primarily terrestrial, whereas animals (≈2 Gt C) are mainly marine, and bacteria (≈70 Gt C) and archaea (≈7 Gt C) are predominantly located in deep subsurface environments. We show that terrestrial biomass is about two orders of magnitude higher than marine biomass and estimate a total of ≈6 Gt C of marine biota, doubling the previous estimated quantity. Our analysis reveals that the global marine biomass pyramid contains more consumers than producers, thus increasing the scope of previous observations on inverse food pyramids. Finally, we highlight that the mass of humans is an order of magnitude higher than that of all wild mammals combined and report the historical impact of humanity on the global biomass of prominent taxa, including mammals, fish, and plants.