HNHacker News
TopNewBestAskShowJobs

tamcap

315 karma · joined April 19, 2016

submissionscomments
tamcap··on US will overhaul childhood vaccine schedule to recommend fewer shots
This clarification is missing from many others sources (such as the AP one I saw from a local news source): https://www.wral.com/news/ap/9b8df-us-drops-the-number-of-va... .

What you are describing is a somewhat routine adjustment and if it's non-inferior... sure. But it sure reads differently in different sources...

tamcap··on US will overhaul childhood vaccine schedule to recommend fewer shots
The thesis was known from the very beginning. The rest is just window dressing to justify the outcome.

I still scratch my head about some no-brainer vaccines such as HPV. All upsides, prevents the literal cancer. No downsides.

tamcap··on Ryanair flight landed at Manchester airport with six minutes of fuel left
> It has a cruise speed of about 200 km/h (\(124\) mph), a payload of \(350\) kg (\(770\) lbs), and a range of approximately 300 km (\(186\) miles)

While it’s a real plane, I think we can both agree this is more of a prototype than what the general public would consider to be a passenger plane.

Yes, energy recovery is possible. It’s not happening currently in commercial aviation.

tamcap··on Ryanair flight landed at Manchester airport with six minutes of fuel left
You can use a turbine to generate electricity, so yes, you are converting potential energy into electrical potential. However, no real mass produced passenger plane today can use that electricity for flight (thrust).

RAT is only used when sh*t hits the fan. Even then, it can help you power some hydraulics / electrical, not “store” energy for further flight.

The OP asked - in a low fuel situation, can the energy spent on a climb get effectively recovered - and the answer is not really. We convert as much as we can into unpowered (low-powered) descent. But once you are at a spot where you make a final decision to land or not, you are by design low and slow - and all that energy you had 15m ago is gone.

If you need to keep flying, those engines need to spool back up. And that takes fuel.

tamcap··on Ryanair flight landed at Manchester airport with six minutes of fuel left
Not really. While you have a large potential energy buildup at a higher altitude, you cannot "bank it" / "save it" on descent. There is no way to store it in batteries or convert it back into fuel.

One of the challenges of aeronautics is the efficient disposition of the potential energy without converting it all into kinetic energy (ie speed) so that the landing happens at an optimally low speed - thus giving you a chance to brake and slow down at the end.

tamcap··on Why hasn't commercial air travel gotten any faster since the 1960s? (2009)
Many airports (in the US, at least) make much more money from parking fees than everything else. On top of that, at least some operate their retail in a royalties model too (ie 20% of all sales goes to the airport, before any costs).

Thus, there is very little incentive to keep you in the airport less, and multiple incentives to keep you there longer.

tamcap··on Elsevier may wish they had checked the revision a bit more carefully
> Reviewers can be professors, PhD students, etc. and are paid by the journal for their time.

Most journals do not pay for reviewers time. There are some experiments that allow for this, but I would say 99% of the reviews out there are done... "out of the goodness of the reviewer's heart".

There are indirect benefits to being a reviewer, such as early access to unpublished work, "goodwill" with the editor, etc.

tamcap··on TACF is no longer supporting development of D58 American chestnut trees
It's possible they checked before (and the article suggests they had an inclination where the gene should be) but the resultant backcrosses involved a spontaneous recombination of the relevant fragment. It's possible someone checked the wrong vial in lab, or mislabeled results. It's possible something funny "just happened".

Wet lab is hard, and everyone is chasing the eureka moment.

tamcap··on Finding that lead emissions from aircraft engines contribute to air pollution
https://en.m.wikipedia.org/wiki/Thomas_Midgley_Jr. He was a fascinating man, relatively non-famous. Probably singlehandedly contributed to more environmental damage than you can imagine. Died in a strange way too.
tamcap··on ArXiv receives $10M for upgrades
* overhead - people cost a lot of money: this includes ongoing maintenance of the tech stack, including rewrites of obsolete parts, but also ops cost - preprinting can include more than one human touchpoint

* converting PDFs to HTML is an annoying problem

* searchability of the repo is likely an annoying problem

* any new features that stakeholders want added (commenting, annotations, etc) * ongoing hosting / CDN cost

tamcap··on Yellen says government will help SVB depositors but rules out bailout
Magically using billions of federal money to hold assets to maturity is a bailout. If hypothetical JPMorgan is willing to pay for the (ie) bonds $20B, but they "support" $25B of deposits... that $5B is a bailout. Even if in 10 years those bonds would be worth $25B.
tamcap··on Twitter to employees: all office buildings closed, badge access suspended
Happy to report that it actually has happened in the end.
tamcap··on Twitter to employees: all office buildings closed, badge access suspended
In their defense, if the backup requires accessing archive tape drive records, long processing queues in non-scalable systems, etc - this could easily take 24 "physical" hours of things getting lined up correctly.

It's one thing to show you the last 24hr of tweets. Another to get a complete twitter history for given uid.

tamcap··on Twitter to employees: all office buildings closed, badge access suspended
I've been waiting for an archive of my data for 3 days now. And my activity on Twitter is probably bottom 25%.
tamcap··on France's senate votes that large parking lots have to be covered by solar panels
I think the US needs an honest assessment about the cost of such high degree of car centricity. There are layers of laws and regulations establishing car as a dominant method of transport, and actively discriminating against everything else.

In this current case, large surface parking lots are a terrible use of space. They generate very little taxes, contribute towards the heat island effect, and make the general area surrounding them less walkable.

The example you provided is definitely believable. I don't know a single modern (new) location that successfully changed the habits of residents from "more-car" to "less-car". And I don't necessarily have an answer what's a good solution. Having regulation like the French do at least helps nudge the outcomes somewhat.

tamcap··on France's senate votes that large parking lots have to be covered by solar panels
Then you end up with a problem of clear cutting "useless woods" in order to install solar panels. While I don't think the French solution is flawless, it introduces an interesting dynamic.

Generally, I am against large surface lots (American style). So seeing someone introduce a simple incentive that both a) introduces a limit to their size AND b) offsets some of the blight for larger ones...

I am willing to see how well it works.

tamcap··on Crazy crypto mining story from 2013
Did he?

> I paid off all my debts, bills and rent, and the cold realization hit me: I had nothing left over to show for it.

tamcap··on GPSJam: Daily Maps of GPS Interference
That's SBAS/WAAS! another cool thing

This is trying to measure ionosphere disturbances which affect signal propagation rates via ground reference stations. The real-time model is then calculated and distributed using ground stations and geostationary satellites.

GPS is way, way cool, and it's a pity the extent of its engineering is not better known.

tamcap··on GPSJam: Daily Maps of GPS Interference
> how do you measure your own gps “accuracy”?

Because GPS is way cool. First, there is the official site: https://www.gps.gov/systems/gps/performance/accuracy/ I am far from being an expert, but being a flying nerd, that's what I can tell you:

The more satellites in sight you have access to, the cooler stuff you can do with GPS. Minimum to establish 2D (on globe projection 2D) location is 3 sats, minimum for altitude is 4 sats. There are mathematical simulations you can do to see if, and when, a given aircraft will have access to 4 sats (or more), called RAIM: https://www.mygdc.com/new/static/usermanuals/web_help/RAIM_P...

Now, things get even better if you use 4+ sats, or sats from different constellations (I am not sure how mature is cross-constellation data validation, however, so let's pretend 1 constellation for now). With 5 sats, the receiver can calculate the position even more precisely, determine the level of URE, etc. You can even detect that one source is unreliable, and discard it (effectively falling back to 4 sats). With even more sats you can (theoretically) do cool data analysis, where you can determine those factors even more precisely.

Now, add the inertial factors. Many passenger have either in-software (history of previous positions) or in-hardware (think accelerometers, magnetometers) inertial data sources. A sophisticated flight management software (FMS) can cross-corelate the inertial data with GNSS data and determine when the latter becomes unreliable.

All of those measurements and factors can subsequently be reported via ADS-B or ACARS, to help with fleet management, and general predictive maintenance. While aviation technology might sometimes look way out of date at a first glance, the modern airplanes have some really cool technology hiding in it.

tamcap··on SpaceX said to fire employees involved in letter rebuking Elon Musk
quoting: "A few examples of protected concerted activities are:

Two or more employees addressing their employer about improving their pay. Two or more employees discussing work-related issues beyond pay, such as safety concerns, with each other. An employee speaking to an employer on behalf of one or more co-workers about improving workplace conditions."

Would that letter fall under that? I think there is at least a somewhat credible claim it could (and also a credible opposing counterclaim that the form of speech was meant to be defamatory/disparaging, and not a protected activity), but I am not a lawyer.

tamcap··on Costly SOFIA telescope faces termination after years of problems
It's easy to agree that number of papers published is a poor indicator of "quality" or "quantity" of raw science generated... but we hardly have anything better. Publication record is the currency at the moment.

And for every cancelled experiment / unfunded grant - there is someone else getting that money instead. I want to believe that savings from the operations of the SOFIA will be channeled into another scientific project. I am pretty sure there is a lot of smart folks out there that will happily convert newly available budget into interesting observations.

tamcap··on Union Pacific to buy 20 battery-electric locomotives for yard service
"another major beneficiary would be the environment, specifically when operating in urban centers"

But you see, they don't care. If there is no incentive for them to do it, why would they? Good neighborhood-will will pay for a donation to a local charity cause, etc, but will not make meaningful expensive changes to the SOP.

Ideally this is the point where a regulator (of some kind) steps in and nudges the change. We all know what the political problems behind that are - despite mounting evidence of how damaging diesel exhaust particles are to us, and our children.

tamcap··on Moderna’s HIV vaccine has officially begun human trials
This is a valid point, but I think ignores amount of public health resources "spent" on trying to address vaccine hesitancy and healthcare resources addressing "unnecessary" hospitalization and complications.

Now imagine we could cut the above in half, and then use some fraction of those savings (as a nation) promoting wider adoption of vaccines globally. If we've reached higher levels of vaccination earlier (in the USA), more people without access to the vaccine currently would've been able to get it.

tamcap··on Renault Zoe NCAP crash rating: zero stars [pdf]
I think you just answered your own question ;-) .
tamcap··on Covid-19 Mortality Risk Correlates Inversely with Vitamin D3 Status
RE: your last sentence. High dose supplementation of vitamin D should be done after consulting with your doctor (like you did). As a fat soluble vitamin, our bodies sometimes struggle to dispose of the excess. Therefore a person with "normal" vitamin D levels who begins supplementing at high levels is potentially risking some side effects. It's always good to be monitored in situations like those.

It seems you are doing exactly that, which is great.

tamcap··on Airbnb removes 80% of advertisements in Amsterdam after registration obligation
https://en.wiktionary.org/wiki/avis#Old_French Wiktionary says it comes from Latin.

In English "advise", alas, not used in the common language in regards to mail, like it is used in Polish (and Czech?).

tamcap··on American parents are sending their kids to 'Russian math' (2017)
As an immigrant in the US from Central Europe, I am blown away by how much time American children spend on extracurriculars vs academics (at least based on what I see around me). My extracurriculars in high school were maaaybe 5 hours a week. Some kids in the US spend 5 hours a day, every day. And don't get me started on varsity sports - that starts to resemble a job!
tamcap··on Amazon ending IE11 support on Management Console and Documentation
Said it is the company policy to not use certain competitor's products, and it was neither time not place to drill down further. How it's enforced, I have no idea.
tamcap··on Amazon ending IE11 support on Management Console and Documentation
From an outsider's perspective: AWS has a strong anti-google-tools policy. I appreciate Chrome is listed at all ;-)

One time I tried to have a video call with someone higher up in AWS, and they were unable to join a Google Meet call we have scheduled for that meeting (and only realized at t+2m).

tamcap··on In Response to Oversight Board, Trump Suspended for Two Years
He got a "at least 2 years" ban, to be exact. The 2 years is the punishment for the post. Then, at the end of those 2 years, fb will evaluate the restrictions you quoted, and re-assess if further ban is necessary.
Page 1 of 3Next →