Month: October 2020

DL generalize to brains

Last year, DiCarlo’s team published results that took on both the opacity of deep nets and their alleged inability to generalize. The researchers used a version of AlexNet to model the ventral visual stream of macaques and figured out the correspondences between the artificial neuron units and neural sites in the monkeys’ V4 area. Then, using the computational model, they synthesized images that they predicted would elicit unnaturally high levels of activity in the monkey neurons. In one experiment, when these “unnatural” images were shown to monkeys, they elevated the activity of 68% of the neural sites beyond their usual levels; in another, the images drove up activity in one neuron while suppressing it in nearby neurons. Both results were predicted by the neural-net model.

To the researchers, these results suggest that the deep nets do generalize to brains and are not entirely unfathomable. “However, we acknowledge that … many other notions of ‘understanding’ remain to be explored to see whether and how these models add value,” they wrote.

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.

Waymo Superhuman Safety

The gauntlet is down. If Cruise, Zoox, Argo, Tesla and others want to say they are in the game, they need to show the same data. If they won’t show it, we should presume they are afraid of releasing it for a reason. No proprietary secrets are disclosed. A few useful lessons are revealed but everybody should be sharing those lessons anyway, for the good of the industry.

Will Waymo be as bold in deploying as suggested above? Probably not. It’s a quirk of humanity that “people don’t like being killed by robots.” We would rather be killed by drunks. We expect perfection from machines that they can’t deliver, and which we don’t expect from other human drivers. The risk to the public of Waymo deploying today are not just low, they are much lower than the risk which will be created by the people who drive themselves rather than taking a ride in a Waymo. And I don’t just mean the people today. If we assume that Waymo grows in a similar way depending on when they launch, and that if they launch a month later they get big a month later, then the math tells us the risk they prevent is actually all the people who didn’t ride with Waymo in that whole period before they got big, and it’s equal to all the people who ride in a month when they do get big. If Waymo can grow in the distant future to be 10% of trips in the USA, that means delaying a month causes 80000 accidents and over 250 deaths due to people who drove themselves rather than rode in a Waymo. For each and every month of delay.

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.

Boomer Brains

What ss the internet doing to boomers’ brains? A naive generation gets sucked in.

“They were indoors for 6 months with nothing to do but watch Fox News and go on Facebook. And now they’re telling me, ‘Oh well, the weak just need to die and then we’ll be over this thing.’”

Randomize Judges Widely

But in fact it is common wisdom that if you have an important case in some area, you must hire not only a local lawyer but one from the top of that local pecking order. Getting an even better lawyer from elsewhere just won’t do. So these effects must be strong. But these 2 affects being strong seems quite a damning fact about the neutrality and fairness of our law. You should be able to get a fair trial without your lawyer pandering to individual judge biases, or having socialized with your judge for years. There seems to be an obvious fix: randomize judges over a wide area, perhaps even nationwide.

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?