621–630 of 839 posts
Why tardigrades are so hardy, how their biology is so different? How immune system and medications work. Why some plastics are recyclable and others are not.
I've been mulling making a youtube channel with ten minute videos on immunology; what would be a good starter video that might interest someone like you? I thought I'll do something about antibodies as drugs!
Earlier quoted context omitted.
I have seen the example with the polarized lenses in a few places, but they dont explain why (imo) the simplest explanation does not apply. Namely that the lens itself might disturb the phase of the light, which would then mean it can pass through the next lens.
But if you take away the third lens, there is no light of any polarization. How is it that by adding a filter, you create light where there was none?
Here's what I would have thought happens: After the first lens, you get polarized light, 90deg offset from the last lens, so no light passes. Then you introduce a 3rd lens in the middle, 45deg offset. This could alter the polarization (maybe it widens the band, or introduce some greater variance, shifts it who knows), and this is why now some light will pass through number 3. No need to create any light
Crypto and practical security. I get tired of the circular “don’t roll your own crypto unless you’re qualified”. How does one become qualified? I don’t feel like I know how to evaluate many of the arguments people make for or against technologies people argue about on HN, such as Signal or different password managers. I feel like “security through obscurity” is a bad thing, and “layers of security” are a good thing,…
The reason people say not to roll your own crypto is that there is no secret answer to making things secure, we just have smart and creative people bash their heads against a crypto protocol/implement for a long time and hope we found all the problems. So unless you have a good reason to do something else, and the budget to pay experienced people to bash their heads against it, you should stick to an implementation t…
How did Mendeleev and his peers knew something was the final indivisible element and not just another molecule?
The idea that some some compounds didn't just contain some fire was still common when the first list of elements was put together. A big leap forward was realizing air had two principle components, burn-y air and not burn-y air.
They figured out water wasn't an element when the burn-y air and some mystery gas burned to make it.
Basically, everything was maybe an element until they either broke it into pieces, or made it out of other stuff.
Macroeconomics. Central banks are "creating" a trillion here, a trillion there, like nobody's business. But what are the consequences? What is the thought process that central bankers have gone through to make these decisions? Also why, exactly, are they buying the exact assets that they are buying (govt. debt, high-yield bonds, etc..) and why not others (e.g. stocks or put money into startups)? And then, what happen…
> Macroeconomics. Central banks are "creating" a trillion here, a trillion there, like nobody's business. What is the thought process that central bankers have gone through to make these decisions?
The general consensus is that central banks should stay passive and keep prices stable. However, in periods of crisis, like the one we live in, the central bank could support economy. In ordinary times, creating trillions would lead to inflation. But here the idea is more to save the economy in the short term because it's always cheaper than reparing it. Central bankers agreed to create trillions such that banks do not go bankrupt like they did in 1929. By creating trillions, they also keep interest rates low for government such that they can still borrow.
> But what are the consequences?
Some inflation. Another consequence is that investors will invest in riskier assets afterward to keep their profitability target. (Again, because lending trillions will lower the interest rates)
> Also why, exactly, are they buying the exact assets that they are buying (govt. debt, high-yield bonds, etc..)?
They usually buy low risk, higly liquid assets. Putting trillions in startups is infinitely infinitely complicated for a central bank because it implies high monitoring costs, and it also takes a lot of time to create those kind of contracts. Remind that the goal is to provide lot of liquidity to the economy as fast as possible. There is also an academic debate about giving money directly to the general public (known as "helicopter money"), but with little attention from central bankers.
> And then, what happens if a debtor pays back its debt? Is that money consequently getting "erased" again ?
Yep, pretty much... Appart from fiat money, money is constantly created and destroyed. It is mostly created by private banks when they grant loans. And it is destroyed when you repay it. Of course they cannot do whatever they like and create at will, but remember that "Deposits DO NOT make the credits (but in some way it defines how much you could create)"
> What percentage of the debt is expected to default and how much is expected to be paid back? What would happen if a country defaults on a loan given by a central bank?
Central banks buy bonds, and bonds are pretty much always paid back. And if not, the central bank will not suffer much. Cases of countries not reimbursing are very scarce and exceptional (I can just think of Argentina). Anyway, a country CANNOT go bankrupt like a person. And in general, comparing countries with individuals or companies is not a good idea. Countries are here pretty much forever (in a financial sense), you don't. Countries can waive taxes, individuals cannot.
Macroeconomics. Central banks are "creating" a trillion here, a trillion there, like nobody's business. But what are the consequences? What is the thought process that central bankers have gone through to make these decisions? Also why, exactly, are they buying the exact assets that they are buying (govt. debt, high-yield bonds, etc..) and why not others (e.g. stocks or put money into startups)? And then, what happen…
Not sure I'd class it as a science, but here's my take... though I'm no expert and certainly agree this stuff could be better explained! > Macroeconomics. Central banks are "creating" a trillion here, a trillion there, like nobody's business. But what are the consequences? Nobody quite knows; it's still hotly contested between left wing lovers of Keynes and right wing believers in austerity. > What is the thought pro…
A lot of these things are kind on unknowable because they depend on future human behaviour in ways you can't really predict. A lot of George Soros's theory of reflexivity is along those lines. People think they are calculating on the basis of fundamentals but the things that look like fundamentals are actually functions of human behaviour so the system is inherently unstable. He's made a few bob from that.
I have wondered if heat and photons impart a partial charge on atoms and molecules which causes several phenomena. Faster Brownian motion due to the increased repelling action of stronger charges which cause pressure/volume changes in gasses. Also are these charges responsible for some weather effects such as the jet stream. In a tornado is the negative charges on the dry side of the dry line interacting with the moi…
Spin aka intrinsic angular momentum
At the subatomic level, we observe that electrons have some extra angular momentum, beyond what we'd expect from their "orbits". We call that spin, because it's intrinsic, like the spinning of a macroscale object.
The mathematics of training a neural network. I understand how they work once trained, but that you can train them almost seems too good to be true.
On the contrary, it is pretty simple, it is just the same process of "a little bit to the left, a little bit to the right" when you are trying to hang a poster.
Quantum Computers. Not like I'm five, but like I'm a software engineer who has a pretty decent understanding of how a classical turing machine works. I can't tell you how many times I've heard someone say "qubits are like bits except they don't have to be just 1 or 0" without providing any coherent explanation of how that's useful. I've also heard that they can try every possible solution to a problem. What I don't u…
https://metacpan.org/pod/Quantum::Superpositions
As far as I can tell this one still outperforms all existing "hardware implementations".