Tag: science

Superwhite Paint

Superwhite paint will cool the earth

This paint would be both cheaper to produce than its commercial alternative and could save $1 per day that would have been spent on air conditioning for a 1-story house of 100m2. It would take 37 liters to paint a 100m2 house. The world makes 55m tons of paint a year. Saving $1 a day would mean a payback for 37 liters of paint in 6-12 months. If paint production was doubled and the new production was used for this superwhite paint then 100K square kilometers could be painted every year.

2023-04-04: Rethinking how paint works can get us even farther

Unlike pigments, which require a different base molecule—like cobalt or purple snail slime—for each color, the base molecule for this process is always aluminum, just cut into different-size bits that oscillate to light at different wavelengths. It’s the lightest paint in the world— both in terms of weight and temperature. The paint consists of aluminum flakes dotted with aluminum nanoparticles. A Boeing 747 needs 500kg of paint. This paint could cover the same area with 1.3kg. Unlike conventional paint, structural paint doesn’t absorb infrared radiation, so it doesn’t trap heat. It can keep surfaces 10 degrees Celsius cooler than conventional paint.

Black hole info paradox

The most famous paradox in physics nears its end

In a landmark series of calculations, physicists have proved that black holes can shed information, which seems impossible by definition. The work appears to resolve a paradox that Stephen Hawking first described 50 years ago. All this reinforces many physicists’ hunch that space-time is not the root level of nature, but instead emerges from some underlying mechanism that is not spatial or temporal. To many, that was the main lesson of the AdS/CFT duality. The new calculations say much the same thing, but without committing to the duality or to string theory. Wormholes crop up because they are the only language the path integral can use to convey that space is breaking down. They are geometry’s way of saying the universe is ultimately nongeometric.

2023-02-12: More on Feynman Path Integrals

The most powerful formula in physics starts with a slender S, the symbol for a sort of sum known as an integral. Further along comes a second S, representing a quantity known as action. Together, these twin S’s form the essence of an equation that is arguably the most effective diviner of the future yet devised.

The oracular formula is known as the Feynman path integral. As far as physicists can tell, it precisely predicts the behavior of any quantum system — an electron, a light ray or even a black hole. The path integral has racked up so many successes that many physicists believe it to be a direct window into the heart of reality.

Medicinal chemists uplevel

Are medicinal chemists taking it too easy?

In medicinal chemistry, we have now reached a state where millions of building blocks have previously been engineered and can now be used in molecular design and synthesis. In addition to the increase in the number of new amines, boronic acids have been another fast-expanding reagent class since the introduction of the Suzuki coupling method. And if we can get our work done via such easy reactions – plenty of experience in doing the reactions, relatively easy purifications, existing scaleup expertise, and so on – then why shouldn’t we?

320 ka behavior leap

10s of collaborators at institutions worldwide worked to analyze the environmental record they had obtained, which is now the most precisely dated African environmental record of the past 1 ma. early humans at Olorgesailie relied on the same tools, stone handaxes, for 700 ka. Their way of life during this period was remarkably stable, with no major changes in their behaviors and strategies for survival. Then, beginning around 320 ka ago, people living there entered the Middle Stone Age, crafting smaller, more sophisticated weapons, including projectiles. At the same time, they began to trade resources with distant groups and to use coloring materials, suggesting symbolic communication.

RNA Memory

Eventually, the worms recoiled to the light alone. Then something interesting happened when he cut the worms in half. The head of one half of the worm grew a tail and, understandably, retained the memory of its training. Surprisingly, however, the tail, which grew a head and a brain, also retained the memory of its training. If a headless worm can regrow a memory, then where is the memory stored, McConnell wondered. And, if a memory can regenerate, could he transfer it? They had transferred a memory, vaguely but surely, from one animal to another, and they had strong evidence that RNA was the memory-transferring agent. Glanzman now believes that synapses are necessary for the activation of a memory, but that the memory is encoded in the nucleus of the neuron through epigenetic changes.

Earlier research had shown that these epigenetic changes can be inherited. Perhaps phobias are epigenetic?

Memories can be passed down to later generations through genetic switches that allow offspring to inherit the experience of their ancestors.

TCA cycle origins

Instead of trying to find the precursor to the TCA cycle by swapping in simpler versions of its components, they started by asking what versatile reactants might have been present in the prebiotic world and then looked at how much they could do under various circumstances. Astonishingly, they found that the glyoxylate and pyruvate reacted to make a range of compounds that included chemical analogues to all the intermediary products in the TCA cycle except for citric acid. Comparatively, the chemistry we discovered here was a dream to run: All you really needed to do to get the pathway started was to drop 2 stable reactants into buffered water and stick it on a warm hotplate. The chemistry was extremely robust.

Multi-species community assembly

Early on, Mehta thought Gore was ignoring important details about microbial environments, but Mehta concedes that these details have proved less important than he believed. “What’s interesting and impressive about the work is that they show that many, many different phenomena — pH changes, competition for nutrients — can all be captured using these simple phenomenological models, at least in systems where you have a few species. This is a true and tried reductionism of the sort that’s served well in physics.”