1. Taking a shot in the dark - Maybe check your ethernet cables? Not all ethernet cables are the same. If it's a cheap / old ethernet cable then it might not be rated for the same kinds of speed as your wifi. There is a chart on this page labeled "Ethernet Cable Performance Summary" with some stats for different ethernet cables.
2. Yes, although in my experience this is very minor. On my network - good wifi has a 3ms latency and good ethernet has a .3ms latency. While that is a 10x improvement, in the scheme of things I don't notice 3ms of latency. I live in a high rise condo with lots of interference in a major city and can't say it's caused me any issues.
Just curious, what would it take for you to get on a 737-Max?
European and American regulators have gone over it with a fine tooth comb at this point and allow it to fly. There is always gonna be people that will say the plane shouldn't fly. Arguably the amount of attention this plane has gotten will probably make it one of the safest in the industry going forward.
Nothing more than approval by relevant authorities. Once I use a different treshold than that, it becomes very difficult to fly at all.
I mean all else being equal (Two planes to London leaving at almost exactly the same time and exactly the same cost) then perhaps I'd prefer the A32X. But the point is all else isn't equal. It becomes a matter of how many hundred you want to spend to fly the Airbus. Or how many hours you want to spend at the airport waiting for the non-Max flight. And I'll happily take the MAX if it saves me 30 minutes or $20. And I'll take my family along too without hesitation.
The whole thing has been badly handled. The FAA/EU agencies should have declared at the very outset that airlines will need to bear the cost of retraining the pilots who will be flying this. It was the attraction of not having to retrain pilots that was the biggest incentive for Boeing to pull the shortcuts they did. At a bare minimum the aviation agencies should have pulled that benefit away.
No it is not. No regulators has yet been prepared to certify a fixed-wing aircraft that is intrinsically unstable, even after decades of proven fly-by-wire development.
The 737 Max has different yoke force during pitch-up than predecessor 737 models, such that at higher angles of attack it does not natively require increasing yoke force to continue to pitch up. That doesn't mean it would pitch up uncontrollably. MCAS was designed to provide pitch-down force in these high-AoA cases so that yoke forces would be equivalent to 737 NG models and minimal training would be necessary to fly both.
https://en.wikipedia.org/wiki/Relaxed_stability#Unstable_air... indicates that the MD-11 (which regulators certified) is aerodynamically unstable. (That plane has a compensation system, similar to the 737-MAX.) Is "intrinsically unstable" different from "relaxed stability" in some subtle way?
And while military planes are quite different from commercial planes, many (most at this point?) military jets are aerodynamically unstable.
There are different kinds of "relaxed stability", largely depending on which axes of the aircraft are affected, and the magnitude of the instability.
Longitudinal stability is something of a special case, in that essentially all swept-wing aircraft are vulnerable to "Dutch roll" instability and are generally fitted with yaw dampers. Since such stabilizers are, practically-speaking, omnipresent, regulators are OK with using them in what is now a well-understood domain. While it can be unpleasant, all of these aircraft can be flown with a failed yaw damper - notably the 707 family has a particular proclivity for yaw instability, and while almost all civilian users opted for the yaw damper, the largest fleet user, the USAF, did not fit their KC-135s with dampers until well into their service life.
For good reason, pitch instability is a much more serious issue, and there has been very little interest in trying to bring to market a transport aircraft that required active pitch stabilization. Many, if not all, modern clean-sheet airliner designs are fly-by-wire due the the safety, performance, and efficiency improvements to be had, but they are all safely flyable in an "alternate law" (or equivalent) fallback mode.
Combat aircraft, generally speaking, aren't certified aircraft (they have no need be), for good reason - if you're flying a modern fighter and the FBW computers die on you, it's over, you eject. Understandably, that's not an option in a transport aircraft.
Aerospace controls engineer here - while the airframe might not be passively stable (as is common for civilian aircraft), dynamically unstable aircraft have been stabilized with control software since the 70s [0]. If you've flown on an MD-11, you've flown on an 'aerodynamically flawed' aircraft. Most real systems are dynamically unstable without some kind of controller (implying software) in the loop.
Ah - I didn't say Boeing's ability to write and test that control software was particularly good (in fact, I think their current track record says exactly the opposite.) I just hate when non-domain experts make judgements about things being 'fundamentally flawed.'
Insufficiently tested and documented? Sure. Bad UI/UX? Most definitely. Irredeemable 'because of aerodynamics' according to some private pilot that flew a 737 once in sim? Absolutely not.
But yes. MCAS was put in place due to concerns over aero. If that was just to avoid the need for extra pilot training then it should have been scrapped since new training will be required now anyway. But since great effort has been made to fix MCAS we can conclude that the root problem is aerodynamic.
Can aerodynamic issues be compensated for with software? Sure. I need to read up on the final hardware/software/instruction solution before passing Judgement.
You're completely ignoring that flying the 737 MAX without MCAS is not an automatic death sentence. Meanwhile a malfunctioning MCAS is actually an automatic death sentence.
The big flaws are in the software, not in the hardware. So stop focusing on that.
It’s “atypical” because it’s a 30+ year old superseded model and there are more efficient designs available. KLM, a flag carrier, was flying them up until just a few years ago. If it’s certified for carrying passengers, it’s certified. There are no special concessions made to airworthiness regulations for aircraft that sell few in number.
The MD-11 has been certified for air transport since it was introduced, was flying in revenue service until 2014, and as far as I know, that certification has never been revoked.
I don't think the flight safety record of the MD-11 bears that out[0] - most crashes of significance were either cargo flights (which are much more prone to dynamical issues than passenger flights) or flights in conditions that exceeded design specs (landing in typhoons). It sounds like most airlines sold it because it missed range/fuel burn targets, not because of safety issues.
My Dad was a frequent business traveller in the 1980s and 90's and I remember him commenting on the MD-11 and saying that he hated them because they were noisy and had lot of vibrations at the back from the center engine.
He said that was the the reason airlines switched to using them as cargo planes.
>Travis is unequivocal in his assessment of the Boeing 737 MAX. “It’s a faulty airframe. You’ve got to fix the airframe [and] you can’t fix the airframe without moving the engines” back and away from their current position.
>The root problem with the engine-forward design is “once this thing pitches up, it wants to keep pitching up,” said Travis. “That’s a big no-no,” he continued, because pitch-up on an aircraft increases angle of attack.
"Gregory Travis, a veteran software engineer and experienced, instrument-rated pilot who has flown aircraft simulators as large as the Boeing 757"
I know a few veteran software engineers that are instrument-rated and frankly I'm not sure I would listen to any of them over the FAA or aeronautical engineers. Probably good for some perspective, but not exactly a great source for determining if an airplane is "aerodynamically flawed by design".
That article, and Gregory Travis' assessment, offer zero actual evidence that the design is unstable. Lot of hand waving and "the engines are different so it must be dynamically unstable" but no actual evidence, which is obvious because no independent engineer/pilot is going to be able to effectively assess the upset aerodynamics of an airliner and come to a different conclusion than both the FAA and EASA about whether or not the aircraft is dynamically unstable.
He's somewhat right on other details, but that doesn't make his assessment of the aerodynamic issues correct.
I suppose it boils down to whether you have confidence in the FAA of 2020 to make a decision that would be strongly against the financial interests of Boeing and many US carriers.
I think the Max will crash again. Excuse me, the 737-8 will crash again.
If pilots can disable the malfunctioning MCAS during emergencies then this type of accident won't happen again. The 737 max might suffer from more emergency landings than usual though.
Different aerodynamics probably had a little impact but it's mostly just a much better power to weight ratio. It helps that you didn't launch a raspberry pi and battery :)
That's exactly it. This thing was pretty heavy with a battery, Pi, sensors, mounting components, etc. I used an Estes D12-5 engine, which is fairly powerful but there are wayyy more powerful model rocket motors out there that I'd like to try in the future with this.
If you’d like inspiration for something larger, check out a rocket[0] a friend and I designed/built/launched earlier this year. Basically a combination of a drone and a rocket, rocket part takes it up, drone part handles the landing. I can share a lot more photos, videos, and design characteristics if interested (contact info on my profile page).
Thanks for clarifying.
As a total noob I was staggered by those little sugar rockets, as soon as the thing left the ground I thought "uh oh, what have I done?"
Just curious, what would you have liked to see the U.S. do about Hong Kong? Arguably if anyone was gonna do something it should probably be the British being their agreement was broken. I'm sure the British would have U.S. backing them if they wanted to retaliate.
The U.S. started removing the extra trade agreements from Hong Kong (which arguably is a large part of what made Hong Kong what it is today) and sanctioned individuals in the Chinese government [1]. While this seems to be a "weak" response, I'm not sure what else I would like to see short of getting the military involved.
Given that agreement on Hong Kong independance was set to expire relatively soon, is difficult to justify serious intervention from a cost/ benefit perspective.
The original seisure of Hong Kong was an act of gunboat displomacy, and not exactly an exemplar of justice and law. Consider how its seen in donestic politics in China.
This does not mean that I approve of China's activity, just putting things in perspective.
>if anyone was gonna do something it should probably be the British
Except the UK has much bigger issues ATM like dealing with the social, political and economical fallout of Brexit and Covid-19.
To put it mildly, even if they wanted to, it's tough for them to help put out a fire in a far away village when they have a huge dumpster fire in their own back yard to deal with first.
Building relationships with our allies in the area (TPP), State Department diplomacy, etc. to pressure China effectively. I think TPP was dead regardless of who won, but that State is impaired right now.
It is hard to see what the US should do, but I think the west has a moral obligation to do something (even though it is technically an Anglo-sino agreement).
The UK is trying to welcome people from Hong Kong to the UK (passports left over from before the handover) which could hurt them where it actually matters if lucky.
The article talks about the airline focusing on shorter routes and cutting the longer routes that they were losing money on. Even if the airline doesn't go through bankruptcy the long haul routes at the same price will probably no longer be around.
"However, with the scheduled flights gradually resuming, the airline is restructuring its fleet and focusing on short- and medium-range destinations. Europe’s fourth-largest low-cost carrier will likely completely discontinue the long-haul flights that sank the company into debt."
I'm still working through the paper which is fascinating and have only had a chance to glance it over so forgive me if I ask any questions that are answered in the paper.
I see lots of large timeframes of the data (20 years), but nothing about how much data that actually is. I'm not very familiar with this kind of data, but am curious about the software side and how much data was needed, timeframes for processing the data, any special hardware required, etc....
How much data did you start with (gigabytes? terabytes?)?
What does this data actually look like? csv, custom binary format, some open spec maybe?
How much did you end up filtering out for the various reasons in the paper?
Was there anything that surprised you personally while working on this paper? It seems like most of this is confirming existing theory which is great, but curious if you had any new take aways.
Does the team want to continue to pursue this? If so, what do they hope to accomplish or maybe there's some odd data / behavior that you would like to continue to look at?
Software wise, we use a standard pipeline that reduces the data from the space observatory into the standard astronomy format (FITS), provided by the European Space Agency. The output is in the form of events - X-ray photons which landed on a detector at a particular time. This can then be turned into spectra with the standard software, extracting from particular spatial regions. The spectra can be fit with a standard tool in X-ray astronomy (Xspec), but this also relies on spectral models (some standard, some I made for this project). However, a lot of the hard work is in the form of Python code I made for running the pipeline, extracting spectra, collating the spectra, adding them together, fitting them, collating the results and doing fits. There are also some scripts in tcl for controlling Xspec. The plots and things were done with Veusz (which I wrote) and ds9 (a standard astronomy image GUI).
Yes - we analysed a lot of observations to do the calibration work - that's the advantage of a big public archive. After processing it takes several hundred gigabytes. It probably would take a few times more, but I threw away quite a lot of it which we don't use for this analysis (flared time periods and low energies). That doesn't included the input raw datasets, which might be a few TB - I've not checked, as they're on a different system.
The data, as I say above, is in FITS format, which is standard binary table format. The processed data are these event files (lists of photons), spectra (tables of energy vs number of photons), and detector responses (matrices to turn a model spectrum into an observed spectrum). Along the way there are lots of intermediate text and FITS files. I even used HDF5 for part of the code, but that's mainly because it's so easy to use from Python.
How much was filtered? Usually we need to filter around 40% of the time periods for an average observation due to flares caused by soft protons hitting the detector. In this analysis we also threw away a lot of the data at lower energies, as we were only interested in the high energy emission lines, where we can calibrate the detector. I don't know the number there - maybe we threw away 80% of the total events by filtering the low energies. Finally, we also throw away half of the events, to retain those with the best energy resolution (those where a photon hits a single pixel on the detector).
Surprises? For the Perseus cluster, it was nice when I made a map of the motions and ended up with something that looked like the simulations of sloshing. For Coma, I was surprised that the gas in the cluster still has the same velocity as the central galaxies - I would have thought that it should have slowed down - it will be interesting to discuss this further with theorists. I was also surprised by the complexity of the detector on the instrument. It seemed a simple idea when I started, but turned out to be rather tricky.
We're planning to pursue this further. We have new deep observations of two other nearby clusters. The aim is study "feedback" by active galactic nuclei - active black holes affecting their surroundings - in the centre of these clusters. They should be disturbing the gas/plasma and we hope to measure that, as that hasn't been done before. There are also some things we could do to improve the calibration technique if we have time. For example, we could also use photons which land on multiple pixels.
This is misleading to most people. The US census counts the suburbs as urban. I don't believe most people referring to urban areas are referring to people in the suburbs.
"To qualify as an urban area, the territory identified according to criteria must encompass at least 2,500 people, at least 1,500 of which reside outside institutional group quarters."
As I tell people, together with my two neighbors I live in the middle of about 100 acres on a road with no sidewalks. This counts as urban as far as the census is concerned.
The US is big. That the above is urban makes sense in the context that I'm only about a 15 minute drive from a small city and am only about an hour drive from a large city. There are lots of places in the US that are 100+ miles from the nearest Walmart.
Lots to read over, but this stuck out to me so far.
"gross emissions of biogenic methane in a calendar year are 10% less than 2017 emissions by the calendar year beginning on 1 January 2030; and are at least 24% to 47% less than 2017 emissions by the calendar year beginning on 1 January 2050 and for each subsequent calendar year"
"no remedy or relief is available for failure to meet the 2050 target or an emissions budget, and the 2050 target and emissions budgets are not enforceable in a court of law, except that if the 2050 target or an emissions budget is not met, a court may make a declaration to that effect, together with an award of costs"
Unless they plan to ban the consumption of meat, the biogenic methane cap seems like it would result in more emissions. If Kiwis don't grow their own beef, they will just have it shipped from abroad. Same consumption pattern, no global change in gross biogenic methane, but now there is the added emissions of shipping the beef across an ocean.
Also, I can scarcely think of a more Orwellian idea than that Kiwis may soon be required to hold a (scarce) methane permit in order to raise livestock on their own land. Your sow had a litter, ey? Hope your permits are in order!
There are other approaches to livestock methane reduction being actively investigated (and I’d suggest more promising than perennial unicorns such as carbon sequestration).
I think corn feed is more of a US thing due to the over abundance of subsidised corn production (I’m amazed at how much of the human and animal food chain in the US is corn derived).
In Australia and NZ, it’s mainly grass/hay.
There is a third option, which you have not considered - tariffs on non-conforming importers.
> Also, I can scarcely think of a more Orwellian idea than that Kiwis may soon be required to hold a (scarce) methane permit in order to raise livestock on their own land. Your sow had a litter, ey? Hope your permits are in order!
Canada operates this exact way with dairy licenses, and last time I dropped by, it wasn't an Orwellian nightmare. It's got a bit of a cronyism problem, but I've yet to see a country that doesn't.
The US census counts the suburbs as urban. I don't believe most people referring to "city-folk" are referring to people in the suburbs.
"To qualify as an urban area, the territory identified according to criteria must encompass at least 2,500 people, at least 1,500 of which reside outside institutional group quarters."
I use a Thinkpad t480s (last years model). This laptop has done a great job "getting out my way". It has one of the best keyboards on any laptop I have used. It runs ubuntu great out of the box. 14in screen happens to be be a very nice size for me. I have the touchscreen model which has been nice for testing mobile sites. The screen could be a little brighter / more vibrant, but I do prefer the matte display for when I setup outside when the weather is nice. A brighter glossy version is available if you prefer that.
It has great port selection:
- 2 usb-c ports (1 thunderbolt)
- 2 usb-b
- 1 hdmi port
- 1 ethernet port
- 1 sd card reader
Overall I'd say it's a very good well rounded laptop that I don't have any major complaints about.
I am using the same device and it's also a clear recommendation from my side. Another plus to add is the support: When I called the support because I had these vertical stripes showing up in the panel from time to time, they sent a replacement mainboard and a technician who replaced it at my place in about an hour. I was 0 days without the device which is quite valuable if you are using it professionally, I'd say... This sort of support does of course not only apply to this exact model but I think it is constrained to the T and X series.
Did a lot of research on my last purchase and it came down to a Thinkpad T480s or Thinkpad Carbon X1 and I ended up going with the Carbon because it's so much lighter and thinner while still having an i7, 16 GB of RAM and SSD.
And I bought it from Costco which was a great price and doubled the factory warranty for free, gives free tech support for a year and a ridiculous 90 day return policy.
I disagree. I have had a T480 for some time, the 1440p one. I regret getting th is screen and wish I had gone for the 1080p. While I hear HiDPI may work OK for displays that are scaled up in integer ratios, I basically expect that fractional scaling is never really going to work that well unless all the software you use written in the latest frameworks. (Based on experiences with Arch, Debian 10, Fedora 31 beta)
I was pretty happy using an HP x360 UHD display on Fedora. It also drove two 4K external displays.
What makes the different is wayland. Fractural scaling is working fine. However, we also were using Airtame for over-the-air desktop mirroring, which supports x.org only. Thus, I needed to switch sometimes, which caused „WTF is not working again?!? Oh forgot to switch x.org session back to wayland.“.
No seriously, if you need HiDPI and could omit proprietary nvidia drivers, give wayland a serious try.
https://www.electronics-notes.com/articles/connectivity/ethe...
2. Yes, although in my experience this is very minor. On my network - good wifi has a 3ms latency and good ethernet has a .3ms latency. While that is a 10x improvement, in the scheme of things I don't notice 3ms of latency. I live in a high rise condo with lots of interference in a major city and can't say it's caused me any issues.