This is very cool, thanks for sharing. There are many industries and academic fields where Matlab has gone out of fashion (I work in one), and my experience has been that there's a lot of over the top negativity about Mathworks products, centering mostly on the license and business model. But I think there's a lack of awareness of just how superior Matlab and Simulink are to all alternatives in some domains. All that to say: don't let the Matlab hate get to you, you're using the right tool for the job.
There really is no alternative to Simulink. When you add Simulink Compiler and Embedded Coder, you can do some amazing things. If I am doing anything else, I use Python.
The complaints about licensing seem a bit weird given that the company actually accommodates hobbyists. They have a $100-something perpetual home license that doesn't require internet access.
Most other vendors of niche "pro" software just give the middle finger to hobbyists and want you to pony up thousands of dollars for an annual subscription.
I think it's perfectly OK to say "I don't need this, open-source tools work for me". Just like you can use KiCad instead of Cadence for PCB design. But getting angry at Mathworks for wanting money from commercial users seems weird.
I'm frustrated that they push their product on undergrad engineering classes so heavily. Except for a few poorly taught weeks of C++, most of my classmates never leaned anything else. Admittedly, Matlab is a very good product for modeling and learning about controls, but they use this advantage to make sure all the fresh undergrads only know how to program in their product.
This is a fun dataset. The paper leaves a slight misimpression about channel statistics: IIUC, they do not correct for sampling propensity to reweight when looking at subscriber counts (it should be weighted ~1/# of videos per channel since the probability of a given channel appearing is proportional to the number of public videos that channel has, as long as the sample is a small fraction of the population).
It also includes the Apple One bundle. I wonder if the bundles complicate that breakdown — I certainly never use Apple Music or Arcade, and almost never TV+.
Anecdotally, I cannot figure out how to cancel One without losing my iCloud photo library. As soon as I do figure that out, I'll be iCloud only.
Why is the Navy obligated to say something before the wreck is found? Coast Guard was still going to do a search anyway, and it’s not as if tiktokers were sailing out to help with the search.
The US government did reject the OceanGate’s and Explorer’s Group request for military airlifts, so it’s possible the Navy intel played a part in saving those resources from being pointlessly expended
Probably a mixture of declassification procedures, no imminent danger to the public and a desire to confirm the incident visually before giving up hope.
They heard the implosion at the same time they lost contact with the sub. Why not say that? There is neither added nor diminished risk to life by revealing or concealing that.
As for what the point of informing the public is - the government serves the public and the public was interested. Without a compelling reason to keep information secret the government should share.
The government shouldn't conceal information to mislead the public without some compelling reason. Since no reason exists here, the government shouldn't have done that.
What's the point in telling the public any of this anyway? Was there any reason for these people's deaths to be in the news? It has no effect on people's lives.
"Hey, we're pretty sure your family is dead, because we heard them die, but we're going to give you a few days of thinking they're suffocating to death in a cold dark can because..."
This is just reasoning after the fact. It doesn't make sense to conceal evidence. If this used some secret technology, okay, why say it publicly now? If it's okay to be public, why not a few days ago?
"Hey we heard a loud boom that may or may not mean your family is dead, and we have no other source of confirmation at this point but just stew on that for a few days while we try to confirm."
Do you have NO empathy? Why would they tell the family they think everyone is dead without verifiable proof and within the window in which they could still be alive? (4 days of oxygen). What is the benefit beyond a bunch of virtual gawkers getting slightly more information slightly quicker?
I'm rolling my eyes at the "Do you have NO empathy" bit. Is it empathy that drives one to lie by omission to obfuscate the death of others? Is that the word for it?
You don't have to tell the family you're certain they are dead, if you aren't, but you should tell the family "We heard a sound consistent with implosion at the same time we simultaneously lost communications and telemetry from the sub. The most rational explanation is that they are all dead." Once you've told the family, you should tell the public.
What people are engaging in here, you included, is some kind of baffling Just World bias. That is, this unusual circumstance has happened - the sub imploded, the government knew, the government waited days to tell the public, and now you and others are defending the government's actions - as if, because it happened this way it must be justified in happening this way. In reality, of course, it's completely irrational - that's why you don't even bother to defend the course of events rather than imply I lack empathy (which, again, backwards because you are defending lying to the bereaved for no gain, in order to deceive them into believing their loved ones are huddled in the cold and dark and slowly suffocating when you know they are not).
There is absolutely no reason to temporarily conceal the deaths. The government should have notified the families with their information, and then the public.
Because dealing with it internally and informing the public are two entirely different things.
They may well have told the families some things, but not the public. Afterall this is a privately funded venture and the rescue effort isn't going to be paid for by the public either. They owe us nothing.
We seem, as a culture, to feel we're owed, or entitled, to everything nowaways.
By releasing this information, there would have possible been a massive outcry by the (unconcerned) public and the families involved that the parties involved weren't doing enough. Everyone would have hopped on the "you're too slow to act" bandwagon. This despite not having any knowledge or expertise in the area.
They may have created some headaches at this point, but saved themselves a lot of undeserved headaches and media criticism by not releasing info earlier.
They do, but what they owe differs by what part of the government one is dealing with. You’ll find that, with regards to the military, one thing they do not owe to citizens is real-time, unfettered access to intelligence.
They certainly told the family about the implosion noise, because I heard one of the expert commentators remark on how he knew about it prior to the news about the knocking noises. If he knew, the family knew.
I think they were just holding out hope that it wasn’t an implosion noise.
It's worth knowing just how unregulated the whole "adventure tourism" industry is. You might be not in the wealth bracket for Titanic tours, but there are more reasonably priced "adventurous" things you could do and it is worth being aware that nobody seems to be checking if these things are safe.
Why does the public need to know now if that is the case?
I think it's likely the news articles are making it sound more definitive than the Navy was thinking, or maybe the person leaking it to the press was trying to make themselves seem more important or make the Navy seem more omniscient.
It does sound like the Navy reviewed their data they had already collected and discovered the implosion and informed people on site that they likely had a termination event.
Hydrophones don't need to be nearby or even at a similar depth. The SOFAR channel acts as a waveguide and will duct sources from other depths as long as the bottom is below the critical depth. As others have said, this part of the North Atlantic is one of the most heavily monitored parts of the ocean as well. No sci-fi physics necessary — this has been done continuously since the 1950s.
I fail to see the analogy between "aliens must exist" (a statement for which there is no evidence) and "the submersible imploded" (which is substantiated by debris). The syllogism is simple:
* submarines make loud noises when they implode
* the navy can hear loud noises underwater
* the submersible is thought to have imploded based on debris
Maybe there's a miscommunication here; detecting underwater sound from hundreds, even thousands of kilometers away, is made possible via the publicly known laws of physics.
Detecting extraterrestrial aliens requires technology that is not publicly known. Therefore, it is not at all logical to compare "hearing an imploding submersible in the Atlantic" to "detecting aliens/UFOs"
I don't believe I said that. You can draw your own conclusion from the fact that it is within their capabilities to detect, localize, and to some extent classify a wide range of sources in this region of the ocean.
What you won't find is a lot of information about those capabilities in the public domain. Just consider that what _is_ known tells us that we had these capabilities in the 1950s, and that they were continuously improved upon throughout the cold war. This is not Area 51 conspiracy speculation; it is bread-and-butter NRL stuff that is more than half a century old at this point and is classified for good reasons.
> Also that assumes the scientists are completely accurate and don't make any mistakes. As recently as 5 years ago they discovered that the measured rise for almost all of the 90s was wrong and revised it by 3mm/year +- 1.7mm/year - the error was the same amount as the imputed level of rise!
Citation for this? There are always improvements to our understanding of past data, but you seem to be implying that the uncertainty exceeds the signal. That's simply not the case [1].
Ablain, "Uncertainty in Satellite estimate of Global Mean Sea Level
changes, trend and acceleration", p4
They have shown that there was a drift in the GMSL record over the period 1993-1998. This drift is caused by an erroneous on-board calibration correction on TOPEX altimeter side-A (noted TOPEX-A). TOPEX-A was operated from launch in
October 1992 to the end of January 1999. Then TOPEX side-B altimeter (noted TOPEX-B) took over in February 1999 (Beckley et al., 2017). The impact on the GMSL changes is -1.0 mm/yr between January 1993 and July 1995, 120 and +3.0 mm/yr between August 1995 and February 1999, with an uncertainty of ±1.7 mm/yr (within a 90%CL, (Ablain, 2017)).
Figure 1 from that paper didn't convince you that it was a minor issue? Their correction is about 7% of the 1993-2018 signal, and it resolves the discrepancy with respect to other estimates, including non-satellite ones. Nobody relies on estimates from a single satellite alone.
> The six main groups that provide satellite-altimetry-based GMSL estimates ...
1) You're restricting your attention to groups producing satellite-derived estimates.
2) Several of those groups, e.g. CSIRO, are using data assimilation to combine satellite estimates with gauges [1].
3) There are multiple satellites, often overlapping in time, often of totally different design/orbit/etc... [2]
4) Up to the most recent IPCC report (AR6), assessments were based on tide gauges alone [3]. For many of the reasons that you bring up. Hence "Nobody relies on estimates from a single satellite alone." Reconstruction of historical sea level is a huge scientific discipline and you would benefit from doing some more reading before beating a dead horse. The estimated uncertainty is large for a reason, but it does not encapsulate any scenarios where the observed change has been insignificant. If you think otherwise, I'd be happy to take your money for 2100 options on coastal real estate in about 90% of the world's coastline.
- Uncertainty exceeding signal in satellite data is "simply not the case"
to
- OK maybe it was the case but it doesn't matter and nobody relies on one satellite anyway
to
- OK maybe some groups relied on one satellite but this is flogging a dead horse everyone already knows about
That's a big distance in a short thread! Also, note that you said "nobody relies" and now you're arguing "not everyone relies", which is different.
I won't be alive in 2100 but if you've got some nice seafront property you'd like to sell me below market price I'd definitely consider it. Maybe in Tuvalu? (see other post).
>> Nobody relies on estimates from a single satellite alone.
Yes they did. From the paper I just cited:
The six main groups that provide satellite-altimetry-based GMSL estimates (AVISO/CNES, SL_cci/ESA, University of Colorado, CSIRO, NASA/GSFC, NOAA) use 1 Hz altimetry measurements from the T/P, Jason-1, Jason-2 and Jason-3 missions from 1993 to 2018 (1993–2015 for SL_cci/ESA). The differences among the GMSL estimates from several groups arise from data editing, from differences in the geophysical corrections and from differences in the used method to spatially average individual measurements during the orbital cycles
The apparently independent time series are actually computed from the same raw data sources, as there isn't an abundance of redundant satellites measuring sea level.
But isn't this goalpost shifting? At first you said I was wrong that uncertainty has been the same size as the measurements in the past, citing the IPCC as proof which of course doesn't mention any of this, saying only that they have high confidence in these numbers (the IPCC is not trustworthy). Then it became that the error isn't big enough for you, and nobody relied on a single satellite. Now I show that they did indeed rely on a single satellite.
The core issue here remains the same: how do they know they're getting it right now? A calibration error so large it invalidated their entire time-series lasted for the entire lifetime of the TOPEX-1 mission, and it then took 20 years for the problem to actually be detected and corrected for. They've only been measuring sea level with satellites for 30 years, and the discrepancy between tide gauges and satellites has never been properly reconciled even though they theoretically measure the same thing.
Archimedes would like a word. There are some small effects due mostly to salinity differences, but sea ice isn't a major contributor because it is already floating and thus displacing an equivalent volume of water:
This article only briefly touches on what I think is the most interesting aspect of sea level rise: gravitational adjustment. Even though I never worked seriously on sea level research, it was by far my favorite course in graduate school. For anyone who would like to learn more, I highly recommend listening to Jerry Mitrovica expound on the subject [1]. I guarantee that you will learn a few things that will stick with you.
In my experience, the first order adjustment effects are not widely known even among physical oceanographers. I remember describing it to a preeminent expert on El Nino, and him being incredulous that local sea level fall near the source of meltwater could be the first-order effect beyond accounting for rebound. "The first-order response is a Kelvin wave — you've surely been misinformed."
I've been very impressed with sqlglot, and am looking forward to trying this feature. The only issue I've had with sqlglot is transpiling for use with a specific spark version: in my experience Spark is not great about surfacing obvious 'not registered' errors when a function isn't supported (especially in >=2.4). I ran into this with width_bucket, which is only in the most recent release. I am curious whether there's a straightforward way to write with a specific release and catch the error in transpilation rather than execution.
Side note: Iaroslav (post author) and Toby (sqlglot creator) are both amazing, and I'm so glad that they're working on open source projects like this.
It's easy to add errors for dialects by calling #unsupported when a function is used.
In terms of versioning of engines, I haven't implemented that yet, but presumably it could be done by adding a dialect subclass and having versioning route to it, so we could do something like parse(sql, dialect="spark", version=...) which could then route to a 2.3 version of spark.
Happy to chat more about this and we can see about adding it (or feel free to make a pr). You can DM me on twitter or some other avenue as well if you want to dive in deep.
A cautionary tale from personal experience: My parents retired to a rural area and wanted to ensure that their area would remain a healthy old growth forest. They have been actively involved in a land trust that has successfully created large, continuous corridors throughout the area. One of their contributions was a continuous strip of about 20 acres. Their community has stitched these together to create wonderful cycling/walking paths through the woods, linking up different areas.
At the start of the pandemic, a developer bought up a large (~200 acre) tract neighboring them and the corridor. They immediately clearcut the whole thing, and are building hundreds of tract houses, cheek by jowl, and have consequently forced the local government to build additional roads. Guess the big selling point they use in their website and listings? 'Neighbors a wilderness trust with extensive woodland paths.'
Knowing all of this, I'm not sure whether I'd still go through with the land trust purchases or not. They couldn't have afforded the 200 acre parcel, and who knows if the developer would have bought the other 50 acres. All I can say is that it is dispiriting to see people doing the right thing and having a net increase in clearcutting at their doorstep.
> a developer bought up a large (~200 acre) tract neighboring them and the corridor. They immediately clearcut the whole thing
Make the land private and only allow access to conservation workers, volunteers and financially contributing members. The less joggers disrupting the ecosystem the better, and it's a way to fund more purchases of land, and encourage people to volunteer.
I know this may not help now, but to approve such a development, many counties would require that it is not down range from a historical or even prospective shooting range. You might offer every new resident subsidized membership because they live downrange.
You do know that this is essentially what Henry Geroge was warning about? People invest in their community and then some private land owners capture all those public benefits and turn them into cold, hard, emotionless cash.
Well rural living and by extension preservation has to be joined with land ownership maps. First thing to check with a rural purchase must be what it borders. The more BLM/federal/state/county land, the more likely stuff like the above doesn’t happen. Same issue for building trusts.
