I harvested about a third of my mustard plants today. The stack of plants is currently on a bed sheet, on my back porch, drying.
Not sure if this was smart, but it looks like heavy rains for the next two days, and I figured I’d roll the dice on part of the crop. I may have been a bit early. Continue reading G23-036: Mus-stakes?
Increasingly, over the past few years, we’ve been hearing some sort of frog or toad calling in mid-summer, in our neighborhood.
This year, we seem to have those amphibians in our back yard, judging from the noise they’re making. Continue reading Post #1806: Frog calling.
To save you some time, it’s a stupid idea to plant russet potatoes in the South. That’s all this post is about. Thus showing, once again, that the most important step in gardening is growing the right varieties of plants.
Edit: Also see also Post G23-041, on the poor yield of all varieties with this method.
Continue reading G23-035: Russet potatoes, southern garden, poor yield.
I used to think I had a great e-rapport with my daughter. I would frequently write her lengthy emails, and she would respond almost immediately. How nice, I thought, that she’d always send back this little abbreviation, just to let me know that she’d gotten my email.
Then I found out what TLDR meant.
With that as background, let me keep this one brief. Continue reading Post #1805: The best deal at the farmers’ market.
Source: WTOP.
There was an article today on the local news-radio website (WTOP) regarding speeding in school zones. I took note, because I routinely drive through one of those zones where Fairfax County VA operates speed cameras. The zone is clearly marked, and you’d have to be blind to miss it, as shown above.
And yet:
In total, 23,431 cars were caught going 10 or more miles per hour above the speed limit in April, May and June combined.
I supposed I should be impressed by the sheer numbers. But instead, a completely different figure caught my eye: They only ticketed folks for going at least 10 MPH over the limit.
First, I thought it was intemperate of the reporter to note that exact figure. Anybody reading the article realizes that there’s no risk of a ticket at anything up to the posted speed plus 9 MPH. So, presumably, if generally known, that now becomes the de facto speed limit.
But second, I’d heard that same figure before, a few years back, in a discussion of red-light cameras and speeding cameras in Vienna, a town in Fairfax County. There it was phrased as “we don’t ticket unless they are going at least 11 MPH over the posted limit.” The explanation given at the time was that Fairfax County courts would not accept cases for any infraction less than that.
Short answer is, yes and no.
In theory, by Virginia statute, you can get ticketed for traveling one mile an hour over the speed limit in a residential area. This is my interpretation of § 46.2-878.2 of Virginia statute, which says :
Operation of any motor vehicle in excess of a maximum speed limit ... in a residence district of a county, city, or town ... shall be unlawful and constitute a traffic infraction punishable by a fine of $200, in addition to other penalties provided by law.
The black-letter law provides no slack. If you’re in a residential district, on a highway (meaning, in Virginia, any public alley, street, road, or highway), and you’re going a mile over the limit, you can, in theory, be ticketed and will owe a minimum of $200.
Except that the law spells out a different set of penalties for drivers caught by speed cameras in school zones. My interpretation is that because the process is, in effect, automated, they cut drivers a lot more slack than they would if they’d been pulled over, in person, by a uniformed officer.
In the case of speed cameras in a school zone (§ 46.2-882.1), emphasis mine:
1. The operator ... shall be liable for a monetary civil penalty ... if such vehicle is found ... to be traveling at speeds of at least 10 miles per hour above the posted ... speed limit ... . Such civil penalty shall not exceed $100 ... ... 4. Imposition of a penalty pursuant to this section ... shall not be made part of the operating record of the person upon whom such liability is imposed, nor shall it be used for insurance purposes in the provision of motor vehicle insurance coverage.
There appears to be no hard-and-fast rule regarding ticketing for how much “slack” you get, speeding in a residential area in Virginia. The plain language of State law in Virginia law says that if you exceed the posted limit, you can be ticketed. I believe that pre-empts any local law, as we are a Dillon Rule state. That is, local governments can only make their own rules where the Commonwealth grants them permission to do so. And nothing in Commonwealth statute appears to do that, with a few limited and explicit exceptions spelled out in the law.
Except that “ten miles over the limit” is written into law, in Virginia, for speed-zone cameras. There, the Commonwealth leans heavily in the direction of protecting drivers’ rights, and avoiding Big Brother information harvesting. So, in exchange for what is basically an automated process, you face a small fine. There’s a monetary penalty, but (as I read it) no points on the license.
First, if you are speeding, in Virginia, you lose any claim to having right-of-way. So if some bonehead does something to get you in a car accident, where you had the right of way, but you were speeding at the time … tough luck. You cannot claim right-of-way while you are speeding.
§ 46.2-823. Unlawful speed forfeits right-of-way. The driver of any vehicle traveling at an unlawful speed shall forfeit any right-of-way which he might otherwise have under this article.
The reason for that is pretty clear. Traveling at excess speed makes it difficult for other drivers to judge whether or not an accident will occur.
We had a horrific accident in this area, last year, that is a classic illustration of that. The culprit was a bozo who was driving a BMW about 80 MPH in a 35 MPH zone. His car got struck by a car turning left, and his car subsequently jumped the sidewalk and killed two high school student who were on the sidewalk, walking home from school.
Normally, the car going straight has the right of way. Should the car turning left have therefore been charged with the accident, for failure to yield right-of-way? I don’t think any sane person would suggest that. If nothing else, on a curved road, excessive speed of that magnitude more-or-less prevents drivers from seeing you coming in time. The accident was entirely the fault of the speeding driver.
Second, if you speed significantly in areas with red lights, you will run red lights.
Not may, will.
This point is courtesy of Road Guy Rob on YouTube. Yellow light duration is set based on expected traffic speed. (Plus regional variation, I guess). High-speed roads have long yellow lights, low speed roads have short yellow lights. In both cases, the length of the yellow allows drivers that are far from the intersection to stop before the light turns red.
If you drive at high speed, on a low speed road, there will be a stretch of pavement, and a rage of excess speeds, so that if you see the yellow light while you’re in that zone, you will literally be unable to avoid running the red. That’s because, between your reaction time and the car’s stopping distance, your car will travel much further than the engineers who set up the light expected. If you are within just the right range of excess speeds, if you see the light turn yellow, you both a) can’t make it through the intersection before the light turns red, and b) can’t stop before entering the intersection. No matter what you do — hit the brakes, hit the gas — you go through the red light.
And so, at some level, excessive speeding and running red lights go hand-in-hand. There’s a certain pleasing symmetry to that. My guess is, the folks who don’t care about the first, don’t much care about the second either.
One thing I’ve noticed about the AQI for particulates is how variable it is. On any given day, my local hourly estimate from Accuweather will differ significantly from the EPA’s Airnow map. Which, in turn, differs from readings just a few miles away. For example, above, my AQI for particulates (as of 1 PM 7/6/2023 is either 63 (Airnow) or 33 (Accuweather). Or somewhere between.
And readings within a few miles go as low as 13. At the same time, the seemingly accurate meter I just bought shows “9”, sitting on my back screen porch.
At first, I chalked that up to instrumentation. Maybe particulates are hard to measure, and what I’m looking at is more-or-less instrumentation error.
Because, serious, how could the air be so different, just a few miles away? If I were to take some other measure of the atmosphere — temperature, humidity, pressure — it would vary smoothly over vast areas. E.g., if it’s 90 degrees here in Vienna, VA, there isn’t going to be a pocket of 45 degree air five miles away in the City of Fairfax. Yet you see that sort of apparent PM 2.5 disparity all the time.
So I thought, it must be poor instrumentation. Then I bought a cheap air quality meter, noted above. Not only are the readings stable from hour to hour, they are frequently in good agreement with the Accuweather numbers. They clearly respond to ambient conditions in a hurry. (The 4th of July fireworks briefly sent the meter into the “purple” AQI range, consistent with predictions from the Airnow map.) The stated accuracy of the PM 2.5 measurement is +/- 10%. All that, from a device that measures all five of the key air pollutants and costs under $75.
So, this isn’t due to instrumentation error. Or shouldn’t be. You can get reasonably reliable PM 2.5 measurements with a cheap off-the-shelf device.
Maybe my local variation is due to the presence of large local point-sources of PM 2.5. But, to a large degree, we have no large point sources of particulate emissions in this area. Largely because we are almost devoid of industry, in the DC area, and our power plants are (mostly) located outside of the metro area.
Which also matches my observation, because it’s not as if one area is consistently dirty. It’s that the readings consistently vary a lot from place-to-place in this region.
So why do the PM2.5 readings in my area appear to be so highly localized? Is there really that little mixing of the air between PM2.5 emitters, and local air?
After about an hour of looking, I’m going to say that short of getting a graduate degree in atmospheric science, this ain’t gonna happen.
It’s surprisingly complicated, but the joker in the deck is “turbulent mixing”? Once I found out about that, I realized it was time to call it quits on trying to understand this.
First, physicists distinguish “bulk flow” (e.g., a breeze) from “diffusion processes” (molecules or particles moving through still air). In this case, the latter would be the movement of water molecules or fine particulates through still air.
So, smoke spreads out because it 1) blows smoothly downwind, and because 2) the particles diffuse outward into surrounding clean air.
That said, it also spreads due to 3) turbulent mixing. Any time the flow of air is not smooth (laminar, or layered), turbulent mixing is said to occur. This sort of mixing can apparently distribute that smoke fully and more-or-less uniformly in the adjacent clean air.
Turbulent mixing occurs a lot in the atmosphere. I’m pretty sure that it occurs at the level at which clouds form above the ground. It occurs within clouds. I occurs if sufficiently strong wind sweeps past fixed objects, e.g., tree branches. And so on. Anything sufficient energetic will kick the flow of the atmosphere from laminar flow to turbulent flow and turbulent mixing.
The bottom line is that there is no back-of-the-envelope way to determine how well PM 2.5 (including smoke) typically mixes into the surrounding atmosphere. In the end, it’s all empirical, and depends on how hard the wind is blowing horizontally, how turbulent the atmosphere is in vertical profile, and so on.
Presumably, both water vapor and PM 2.5 move at the same speed, and mix at the same rate, when it comes to bulk transport and to turbulent mixing. In both those cases, they are merely being carried along by the surrounding air.
But PM 2.5 diffuses a lot less rapidly than (say) water vapor. A theoretical rule (via Einstein and Stokes) is that rate of diffusion is inversely proportional to the radius of the particle trying to diffuse. Getting hold of some data (but not showing the calculation), that suggest that PM 2.5 diffuses about a thousand times more slowly than water vapor.
Diameter of a water molecule seems to be given as 2.75 Angstrom, where an Angstrom is 1/(10^10) meters. Ah, round down to 2.5. But PM 2.5 is in microns, or 1/(10^6) meters. This means PM2.5 particle is about 10^4 = 1000 times larger than a water molecule. Thus under this simple theory, water (humidity) diffuses through still air roughly a thousand times faster than a PM 2.5 particle would.
At the end of the day, I have no clue whether that matters or not, with regard to widely varying PM 2.5 readings across my area.
All I know is that even without big local point-sources of PM 2.5, it’s common to see big difference in (what appears to be) actual PM 2.5, across different locations in my area. Whereas for other parameters of the atmosphere — temperature, pressure, humidity — true local variation in those quantities is tiny.
Seems kind of crazy to worry about it, but there has to be some good reason why this aspect of the atmosphere is so qualitatively different from others.
Maybe my only clue comes from the Keeling curve (above) and how that is measured. When Keeling started measuring atmospheric C02 in the late 1950s, he established his laboratory on the windward side of Mauna Loa.
And found average atmospheric C02 around 315 PPM. Currently, it’s around 422 PPM.
But the point is why he chose that locale. His goal was to get “well mixed” atmospheric gasses, and, apparently, having circa 6000 (?) miles of open ocean to windward was just the ticket for getting that.
By contrast, you can frequently find city air with C02 levels in the 1000-PPM range, near congested roads (reference). That air hadn’t had a chance to get mixed with the rest of the atmosphere.
So, maybe Keeling located there for some reason other than it’s being a nice place. Maybe you really need that much distance to ensure uniform mixing. And maybe the mere 500 miles or so between me and the nearest Canadian mega-fire isn’t enough to ensure uniform mixing of the air.
So I’m guessing that the atmosphere doesn’t mix all that uniformly. For whatever reason. And that the small-area variation in PM 2.5 is true. And that I should not expect it to get any smaller as the summer progresses.
Well, finally.
The package clearly implied that I’d have ripe tomatoes by the 4th of July. And here it is the 6th, and I’m just now seeing some ripening (above). Easily week behind schedule, maybe more. And that may not even be the 4th of July’s that are ripening.
I know that gardening is supposed to be a relaxing hobby, an appreciation of the ebb and flow of the natural forces of blah blah blah.
But some people are just wired a little differently. Sometimes you just gotta go with what God gave you. If you swing toward “Type A” on the gardening scale, run with it.
Source: Source: Ripening Tomatoes, Marita Cantwell, Dept. Plant Sciences, UC Davis, Fruit Ripening and Retail Handling Workshop, Postharvest Technology Center, UC Davis, March 18-19, 2013
That’s what I do. Among other things, I check my tomatoes for signs of ripeness, every day. I get out of my chair and walk the back 40 (square yards). Finally, today I was rewarded by the first blush of color. That’s the stage professionals call “turning” (above), and that means that ripe tomatoes are somewhere around a week away.
I could, in theory, pick that tomato now, and in a week, it would be as ripe as if I’d left it on the vine. As I learned in Post G21-038. Some say that. Others disagree. But if pests are a problem, it’s nice to know that I have the option of picking now, and … maybe it’ll still be a pretty good tomato.
Once upon a time, ripe tomatoes by the 4th of July would have been cause for bragging rights. But now, with all kinds of “cold season” varieties, it’s more a matter of picking the right variety than of having any particular gardening skill.
But that’s OK. I still look forward to that first ripe tomato of the year. Just wish it would hurry up.
As a gardener, I try to keep an eye on the thievin’ varmints wonderful creatures of nature passing through my back yard.
As a retiree, I have nothing better to do.
But my eyesight ain’t what it used to be.
Keep that in mind when I say that I’m fairly sure I saw my first backyard coyote yesterday.
The pictures you might typically see — making the coyote look like some noble offshoot of the wolf — don’t match reality of the eastern Coyote. Around here, if you see something about the size of an adult fox, but without the good looks, chance are, that’s a coyote. If you see an ugly brown dog with a mottled coat and a long tail, not acting like a domesticated dog, chances are good that you’ve spotted an eastern coyote.
This was not unexpected. Coyotes are native to the western U.S., and have been expanding eastward for the better part of a century. The predominant theory is that we invited them in by killing off bigger predators (wolf, bear), and converting forest into open areas.
I got my first-hand introduction to the Eastern coyote about five years ago, camping at Sky Meadows State Park. That sits adjacent to the ridge of the Blue Ridge.
Just at dusk, the coyotes had themselves a howl. At first, you hear a few individuals starting it off. You think, oh, cute, that must be a coyote. A minute later the entire ridge is ringing with the sound of howling coyotes. Three minutes later they wind it down, and silence returns.
It was chilling. There aren’t a few coyotes in those woods. Like bear, or foxes. There were hundreds within earshot of where I was camping. At least by the sound of them.
In short, the Blue Ridge Mountains are infested with coyotes. Given how few bear and foxes there are left, I’m guessing coyotes are now the dominant predator species in this area. That’s a complete change from my youth, where there were no coyotes in this area, period.
And they are here in the ‘burbs. There have been sporadic reports of pets being eaten by coyotes, here in the D.C. area. I think I spotted one crossing a construction site a few years back.
But it’s a different thing entirely to find one eyeballing your back yard. It skedaddled as soon as I opened my back porch door.
I would like to think I’m not the sort of person to form an opinion about animals based on cuteness. For example, I loathe deer, for the destruction they bring. Despite being handsome creatures. Foxes, I like for the fact that they eat squirrels, and not just because they are really elegant-looking beautiful animals.
Eastern coyote? My gut reaction is, one step up from rat. They may be noble wolf-like creatures in the western climate. And most photos you’ll see of them make them look the part. But around here, they look like mangy stray dogs. As in this view, from Wikipedia:
Looks aside, near as I can tell, this newest invasive species brings along only one good attribute: They kill deer.
Better yet, they kill baby deer. More specifically, in many areas, coyotes are the number one cause of death for fawns. (See, e.g., this random reference).
Much of the literature on this topic comes from the deer-hunting community, which of course tut-tuts over these premature deer losses. The deer hunters have a valid point of view. For them, coyotes are competition. Having eliminated wolves and nearly eliminated bear in this area, the deer hunter is the only native carnivore that’s in competition with the coyote.
By contrast, as a back-yard gardener, I’m am definitely on Team Coyote on this one.
However.
However, coyotes are omnivores. Sure they eat fawns. They also eat poodles. And squirrels. And garbage. And fruits and berries, if there’s nothing else around.
Oh, and they are known to attack small children occasionally. Just thought you might want to know, in case you were still harboring some sympathy for coyotes.
This invasive species is definitely going to put some pressure on our local fox population. And that’s a pity, because the foxes in my neighborhood don’t go around hunting down my neighbor’s cats. Or kids.
So if the coyote succeeds in pushing out foxes, we’ll have replaced a relatively benign and good-looking wild creature with one that’s far more of a nuisance. And ugly to boot. But one that is capable of reducing the deer population.
If Fluffy goes missing out of your backyard any time soon, you’ll know whom to suspect.
Coyotes aren’t advertising their presence. They aren’t howling, here, yet. (I think that’s a large-group activity for them and they aren’t yet that numerous.) They are stealthy, and they are hard to spot. They are easy to mistake for a fox or a stray dog.
But they are here. As in, prowling the suburban back-yards of Vienna VA.
In the grand scheme of ongoing slow-mo environmental apocalypse — (reference insect loss, reference global warming) — I guess this hardly even registers. Just another nuisance invasive species to deal with.
Currently our AQI is a mere 87, for fine particulates (PM 2.5). That’s a relief. Just a normal amount of air pollution.
Or is it? I’ve kind of lost track of what was normal for my area. It’s not like I paid attention to the AQI for most of the past decade.
So here, for Fairfax County, VA, I’m posting a table of AQI statistics, for PM 2.5. based on the period 2010-2022. Just so that I can refer to it as needed. Briefly, only 1% of days exceed the 99th percentile. Half of days exceed the 50th percentile. And so on. Continue reading Post #1803: What’s normal for PM 2.5 in my area?
There’s little in the way of hard data available for car air filters themselves.
That said, the clear consensus of informed opinion is that in newer vehicles, setting the AC to recirculate will remove most of the fine particulates (PM 2.5) from the cabin air in a matter of minutes. Continue reading Post #1802: How good is my car’s interior (cabin) air filter?
