If we don't count minor ones and vehicle/object on the tracks, yeah. I want it to be just the news being extra jumpy, but I'm not convinced.

It was a headline a few days ago, it should still pop up near the top of you search your normal news source

Derailment is fairly common, but usually not major ones like this. There are several a week nationwide but most are just one or two wheel sets skipping and having to be set back on the track with a special crane truck. Not sure where this one falls on the scale.

You know how a sidewalk, driveway, etc will get grass and trees in the cracks that you have to clip? And how the edge of the grass can creep over the edge of the concrete, meaning the sidewalk occasionally has to be edged to keep it clear? Same thing, but with a lot more time.

Worth adding that cultures would often knock down old buildings and just level the remnants, then put the replacement building right on top of the older one just a foot or two higher than the predecessor. Many of these are the big mounds you see that are listed as archeological sites.

Combine these two for generation upon generation, and you end up with ruins buried anywhere from a few centimeters up to several meters under what we now call ground-level.

Of course, wind and water can move dirt in -- and they can remove or erode it as well.

"Zoonotic" is generally a term for a disease readily transmissible to humans or a disease that has a very similar human counterpart, and often that does not transmit readily from person to person -- though obviously there are a lot of exceptions, my definition is only a generalization.

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That said H5N1 does seem to be general enough that it can infect a wide variety of warm-blooded organisms, and to spread between many (though not all) of those species without birds - and that is very disturbing, because we know only one of two critical facts about H5N1 in people:

• We know we can get it, a number of people in close contact with birds have come down with it. I'm talking people who clean coops (read: barns) in chicken farms and that kind of thing, not a person with a bird feeder on their balcony.
• We don't know what keeps it from spreading from person to person. It can get you sick enough to need a hospital, if not kill you, but for whatever reason an ill person is not (yet) contagious to other humans. But it can spread in other mammals, eg. from one mink to another. Are we just not dense enough (population wise), the mink farm was loads of them all in an enclosure in constant close contact. Or a time factor, like it takes hours to acquire the load needed to trigger an infection, and the few minutes of contact human to human is not enough? Or is it biological, eg. it can't hijack the reproduction mechanics necessary to reach the level where it would be contagious? Or something else? We don't know, and considering how severe of a disease this is that is very troubling.

edit: to be clear, there are some solid information/fact-based hypotheses that posit why it may not be human-human transmissable (see the rest of this thread), but we don't know which one or perhaps some/all the possible reasons are the 'correct' ones; this is ELI5 not ELIdoctor

How old? If a city had gas streetlights in the evening, those lights may have been extinguished once evening traffic slowed down.

It's also possible they used a different sequence of names for the hours and/or daylight savings.

[It is probably due to a combination of different definitions of time-setting, our modern lack of familiarity with night vision, and a little astronomy]

And there is also the different grades of darkness. A sunset at 5pm will have useful light until 6 or 7 depending on your latitude, though it's less obvious today with modern electric lights being ubiquitous. Where I am, you can make out trees against the sky for an hour or so after the sun goes behind the horizon, but you have to actively be looking for it in order to notice it. The presence of so many electric lights and headlights means your night-vision never has the chance to grow into it because those opsins are always being knocked back. Given time to properly form, your dark-vision can pick out a trail in an open area even a couple of hours (or more!) after sunset.

Combine this with a sense of how quickly the sun moves, and you can work out useful light after dark fairly easily. The sun moves through about 15 degrees of arc in an hour, and there are discernible amounts of useful light up to at least 18 degrees of arc below the horizon, sometimes more depending on weather -- and you can have well in excess of an hour before/after the sun is visible. Perhaps two hours or even more. And if the area has an open tree canopy, stars provide a fair amount of light if they are visible.

This page illustrates the different shades of twilight in a way that may be useful. https://www.timeanddate.com/astronomy/different-types-twilight.html

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[Note: keep in mind that both latitude and season will affect how long it takes to have the sun position itself 18-20 degrees below the horizon, as the sun rarely crosses at precisely 90 degrees. The sun moves along the hypotenuse of a right triangle, not the short leg. This means reaching 18 degrees of arc below the horizon means traveling *more* than 18 degrees of arc along its [apparent] path of motion, or more than the 1.2 hours it would need if it were travelling at a right-angle to the horizon. In mid-summer, you can experience twilight all night if you are a few miles from the Arctic/Antarctic Circle; while at the Equator twilight will short and relatively equal all year]

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edit: timezones are also a consideration. Until the railroads, all time was local time based on local solar noon. If you live at the far western or eastern edge of a modern time zone , you could be offset by up to two full clock-hours from someone living in your town 200 years ago -- one hour for the ~15 degrees of longitude comprising an average time zone, and one hour if your area practices daylight-savings. Time zones are measured from their theoretical central longitude, for instance where I live in Denver the 105th line of longitude literally runs through the middle of downtown (there is even a mark in the pavement where it lies). 105/15 = 7, and what do you know but Mountain Time is GMT - 7 (and we are roughly center of the Mountain Time Zone, local noon and clock noon are fairly close).

But if you live in New York, you are on the very east edge of Eastern Time and your local noon is a full hour offset from someone living in Indianapolis on the far west edge of the same time zone. If you live in northwest Indiana (Gary area) you may even be TWO hours off due to some of those counties following Chicago time (Central Time) due to their proximity to that city -- add to this that Indiana as a state does not universally do daylight savings and...you can easily find one to three hours where your modern clock could vary from the historical clock of someone living there in the early 1800s. (The new American government opened Indiana Territory to settlement by non-Native people in 1791, and by the late 1820s it was approaching its modern form from a perspective of demographics and rough political boundaries - think the world of Mark Twain and Abraham Lincoln.)

Brief is relative. For a kingdom over 3,000 years old, 'brief' takes on a different definition.

A round of applause or ten!

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And, what kind of lens? With a 600 on a crop body (900 equivalent) I can *just* begin to make out banding on Jupiter and get Saturn to look lumpy. I've toyed with a bit of astro- but it's been a lot of thinking and only a little dabbling. Before I invest more it's worth asking how big to go.

edit: also on a tripod or other stable surface; I can do the Moon unsupported but nothing else obviously! and the sun @ 150 is fine, but I don't buy it for the others, that or you are REALLY talented!