antognini (u/antognini)

antognini commented on Ask HN: Does anyone understand how Hacker News works? · Posted by u/jannesblobel

antognini · an hour ago

I've found that there can be a lot of randomness for what makes the front page. Not too many people read the "New" page and articles drop off it pretty quickly, so it can be hard for a niche article to attract the handful of votes it needs to appear on the front page. (Though there is a "second chance" feature which helps to ameliorate this issue.) So there's a lot of randomness to what makes it onto the front page.

For instance I submitted an article three times (spaced a year apart). The first two times the article got no upvotes. The third time it got 600+ and hit the top of the front page. It's just a matter of who happens to be looking at the New page at the time.

antognini commented on Why do commercial spaces sit vacant? archive.strongtowns.org/j... · Posted by u/NaOH

lordnacho · 11 hours ago

It always bothered me that certain things are not marked to market. It's pretty much the point of financializing the economy, that you can then get a current value for things, instead of being able to pretend everything is fine.

The problem is that if you don't update values continuously, you are surprised when you finally are forced to. Some stock on the public market that isn't doing well goes from 100 to 90, 80, 70... etc, and people thinking about the stock have to make decisions accordingly.

A private loan against that business can sit at 100 until the company decides it can't pay, and suddenly the loan is worth 20.

antognini · 10 hours ago

Mark-to-market can create liquidity crises when coupled with capitalization requirements, though. This can happen in, e.g., bond markets.

Say a bank is sitting on a pile of very safe bonds. If the interest rate suddenly increases, the mark-to-market value of the bonds goes way down. The bank would still expect to get the full value of all the bonds at maturity. But if the bank has to mark-to-market, the current value may be low enough that capitalization requirements force the bank to sell all the bonds in a fire sale. So even though the bank in theory could have held onto the assets and gotten exactly what it had expected from the start, it instead ends up taking a big loss.

antognini commented on Why do commercial spaces sit vacant? archive.strongtowns.org/j... · Posted by u/NaOH

LgWoodenBadger · 11 hours ago

Pricing something based on what you project to make over 20 years seems like an insane way to go about it. Nobody can predict that far in the future.

It's a no-lose scenario for banks though, which is why it's done that way I guess.

antognini · 11 hours ago

This article probably omitted it for simplicity, but you would discount the income stream over time. Projected income at the 20 year mark is valued much less than income next year. That helps to account for the uncertainty.

antognini commented on Why do commercial spaces sit vacant? archive.strongtowns.org/j... · Posted by u/NaOH

bell-cot · 11 hours ago

One "Simple Fix" for cities, albeit with limited scope: Force your Planning Commission, Zoning Board, etc. to keep track of the vacancy rates for commercial space. Then use their powers to strongly discourage the construction of yet more vacant commercial space. And/or renovation of such space to other uses.

EDIT:

- Please do not assume some trivial straw-man implementation of this idea. That includes City organization being hopelessly corrupt or incompetent.

antognini · 11 hours ago

How would this help? If the existing operators refuse to lower rents and leave their spaces vacant then under this scheme no one else can build new spaces which rent at lower rates. You would just be stuck with vacant properties at above-market rates.

antognini commented on String theory inspires a brilliant, baffling new math proof quantamagazine.org/string... · Posted by u/ArmageddonIt

rhdunn · 6 days ago

The testable predictions would be at the places where QM and GR meet. Some examples:

1. interactions at the event horizon of a black hole -- could the theory describe Hawking radiation?

2. large elements -- these are where special relativity influences the electrons [1]

It's also possible (and worth checking) that a unified theory would provide explanations for phenomena and observed data we are ascribing to Dark Matter and Dark Energy.

I wonder if there are other phenomena such as effects on electronics (i.e. QM electrons) in GR environments (such as geostationary satellites). Or possibly things like testing the double slit experiment in those conditions.

[1] https://physics.stackexchange.com/questions/646114/why-do-re...

antognini · 5 days ago

You don't need a full fledged theory of quantum gravity to describe Hawking radiation. Quantization of the gravitational field isn't relevant for that phenomenon. Similarly you don't need quantum gravity to describe large elements. Special relativity is already integrated into quantum field theory.

In some ways saying that we don't have a theory of quantum gravity is overblown. It is perfectly possible to quantize gravity in QFT the same way we quantize the electromagnetic field. This approach is applicable in almost all circumstances. But unlike in the case of QED, the equations blow up at high energies which implies that the theory breaks down in that regime. But the only places we know of where the energies are high enough that the quantization of the gravitational field would be relevant would be near the singularity of a black hole or right at the beginning of the Big Bang.

antognini commented on Tides are weirder than you think signoregalilei.com/2025/1... · Posted by u/surprisetalk

antognini · 12 days ago

You may have seen diagrams of the tidal force of the Moon on the earth (like this one: https://www.oc.nps.edu/nom/day1/tide_force_diagram.gif).

Intuitively you would think that the tide is being formed because the Moon is "lifting up" the water at the point closest to the Moon. But this contribution is actually very miniscule to the tidal effect. Instead the bulk of the tides are produced about 45 degrees away where the tidal force is parallel to the Earth's surface. This has the effect of dragging the water closer to the tidal bulge.

antognini commented on Brain has five 'eras' with adult mode not starting until early 30s theguardian.com/science/2... · Posted by u/hackernj

antognini · 22 days ago

It's kind of interesting to compare this to Ptolemy's eras. In the Tetrabiblios, Ptolemy argued that man went through seven ages in his life, each associated with a different celestial object.

1. Infancy --- The Moon. Since the Moon waxes and wanes more rapidly than any other celestial object, this period is characterized by the fastest development.

2. Childhood --- Mercury. As Mercury is the fastest of the planets, at this age children have the short attention spans and flit from one thing to the next.

3. Youth --- Venus. Starting around puberty, a man's mind starts to become focused on love.

4. Young Adulthood --- The Sun. A man comes of age, he starts to think about his work and people begin to take him seriously.

5. Middle Adulthood --- Mars. In his mid 30s a man's demeanor becomes more severe. He realizes he has certain goals he would like to accomplish and there is not much time left to achieve them.

6. Maturity --- Jupiter. By his mid 50s, having achieved what he can in his life, he has arrived at a position of authority in the community. He has gravitas and respect.

7. Old Age --- Saturn. By his late 60s, he starts to decline physically and mentally.

antognini commented on Angel Investors, a Field Guide jeanyang.com/posts/angel-... · Posted by u/azhenley

meagher · a month ago

> Martin and Mike both advised strategic angels instead of friends and family to fill out the round, so that’s what we did.

How is Kevin Durant (pro basketball player) a strategic angel for a monitoring/observability company?

antognini · a month ago

Later on it looks like he classifies him as a "vanity angel" rather than a "strategic angel." It sounds like it can be useful to have someone with name recognition as an investor when you're talking to people who aren't very familiar with the space.

antognini commented on Analysis indicates that the universe’s expansion is not accelerating ras.ac.uk/news-and-press/... · Posted by u/chrka

shomp · a month ago

Noether's theorem tells us when symmetry guarantees conservation, but it says nothing about conservation in the absence of that symmetry - it's not a biconditional statement. Talking about endless expansion is like observing 1 second of a pendulum's swing and concluding there's no time symmetry because it's only moving in one direction. The symmetry exists at the full cycle scale, not the snapshot scale.

antognini · a month ago

It's true that it leaves open the possibility of a conserved quantity that is not associated with a symmetry. But the kinds of conservation laws we are thinking about, like conservation of energy, do originate from a symmetry. So if the symmetry is broken it is very reasonable to assume that the conservation law would be broken as well.