For Questions That Don't Merit Their Own Thread

[mikegarrison]

If you look closely at that pix you see little holes on the combustor liner. I helped contribute to those, back in the day.

I was working combustor design. At the time, we used "film cooling". But there was this idea to use laser-drilled holes to replace film nuggets. Not my idea, but I was testing whether you could have some gaps and only replace film air in places rather than all over.

What I figured out is that yes, you could do that, BUT it was not a good idea. Because more cooling actually happens inside the holes than happens because the film of cool air is protecting the combustor wall. So better to have the holes nice and evenly spaced, to take advantage of the heat transfer happening inside the holes.

All such liners have evenly spaced holes now, so apparently I was right. (Not saying I was the only one who figured this out, but I *was* the one who figured this out where I was working at the time.)

[JoeSchmuckatelli]

For those interested - Clovis may not be the earliest evidence of human migration to the Americas:

https://www.google.com/amp/s/www.sciencenews.org/article/footprints-ghost-tracks-prehistoric-humans-americas/amp

 

[magnemoe]

10 hours ago, wumpus said:

There was an awfully long time while cavalry often used lance and saber, while infantry used musket.  So they weren't exactly "mounted infantry" then.  Some cavalry units in the American Civil War tried to use saber against other cavalry using rifles, it didn't go well.  There were even some elite French cavalry wearing armor at the time (no idea if they tried it during the  Franco-Prussian war.  Judging by attitudes at the start of the Great War, I'd assume they brought it to the first battle and likely didn't survive  long enough to change tactics).

On the other hand, "riding infantry" is as old as riding horses.  Quite a few battles (especially in the War of the Roses) involved English knights dismounted and fighting on foot.

Fighting on horseback like cavalry an specials skill who require lots of practice. Giving infantrymen horses give them the strategic mobility of cavalry and just require them to be able to ride. 
And before repeating firearms you has at max two shots unless you had multiple guns.  

[kerbiloid]

4 hours ago, JoeSchmuckatelli said:

For those interested - Clovis may not be the earliest evidence of human migration to the Americas:

https://www.google.com/amp/s/www.sciencenews.org/article/footprints-ghost-tracks-prehistoric-humans-americas/amp

 

https://ria-ru.translate.goog/20200628/1573537120.html?_x_tr_sl=ru&_x_tr_tl=en&_x_tr_hl=ru&_x_tr_pto=nui,elem

https://ria-ru.translate.goog/20120711/697208284.html?in=t&_x_tr_sl=ru&_x_tr_tl=en&_x_tr_hl=ru&_x_tr_pto=nui,elem

https://ria-ru.translate.goog/20190605/1555296329.html?_x_tr_sl=ru&_x_tr_tl=en&_x_tr_hl=ru&_x_tr_pto=nui,elem

Anyways, Americas were first inhabited by the emigrants (émigré ? emigrees?) from Russia (somewhere from Kyakhta near Baikal)., they didn't know it's another continent, so technically America is Far Transbaikalia.

Edited September 24, 2021 by kerbiloid

[DDE]

1 hour ago, kerbiloid said:

Anyways, Americas were first inhabited by the emigrants (émigré ? emigrees?) from Russia (somewhere from Kyakhta near Baikal)., they didn't know it's another continent, so technically America is Far Transbaikalia.

Look, the Indians still haven't gotten over that they were conquered by ancient Kazakhs.

https://en.wikipedia.org/wiki/Indigenous_Aryanism

Give Americans some slack.

[kerbiloid]

8 minutes ago, DDE said:

ancient Kazakhs.

Ancient Kyrgyz.

Kyrgyz are mostly R1a. while Kazakh are mostly C.

So, Kyrgyz are paternally Indoeuropeans, while Kazakh are Altayans.

Edited September 24, 2021 by kerbiloid

[DDE]

Early Yersenia Pestris was much less virulent.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4644222/

(light reading before getting an S-V booster shot)

[kerbiloid]

54 minutes ago, DDE said:

S-V booster

Saturn V?

P.S.
A proper game to sit in a queue.

Edited September 24, 2021 by kerbiloid

[DDE]

4 hours ago, kerbiloid said:

Saturn V?

P.S.
A proper game to sit in a queue.

I don't like it.

Which is why they kicked me out without giving me the jab.

Spoiler

The real reason is that the Moscow mayor's office has e-mailed me when it was six months from my first jab, and the doctors disagreed with this health advice.

So, a dry run.

 

Also, there wasn't a queue at all.

[JoeSchmuckatelli]

9 hours ago, kerbiloid said:

https://ria-ru.translate.goog/20200628/1573537120.html?_x_tr_sl=ru&_x_tr_tl=en&_x_tr_hl=ru&_x_tr_pto=nui,elem

https://ria-ru.translate.goog/20120711/697208284.html?in=t&_x_tr_sl=ru&_x_tr_tl=en&_x_tr_hl=ru&_x_tr_pto=nui,elem

https://ria-ru.translate.goog/20190605/1555296329.html?_x_tr_sl=ru&_x_tr_tl=en&_x_tr_hl=ru&_x_tr_pto=nui,elem

Anyways, Americas were first inhabited by the emigrants (émigré ? emigrees?) from Russia (somewhere from Kyakhta near Baikal)., they didn't know it's another continent, so technically America is Far Transbaikalia.

There is also a strong emotive relationship between the American indigenous of the Plains people and the Siberian and Mongolian folks.  I know that there are studies linking (or at least looking into links) between the populations. Land Bridge hypothesis is strong - as is coastal canoe transport.

Aren't there also similarities between the indigenous of Kamchatka and those of Canada? 

Likelihood is strong that the first people who populated the ice-age riparian and coastal areas of Northern East Asia did spread out both to the Americas and Steppes / Taiga. 

Interestingly - the Denisovan population predating them seems to have actually moved south and spread through Malaysia into the archipelago north of Australia. 

[kerbiloid]

28 minutes ago, JoeSchmuckatelli said:

Aren't there also similarities between the indigenous of Kamchatka and those of Canada? 

Inuits came from the Eurasian Far North as well, so it's expectable.

Now the Siberians live on both coasts of the Pacific Gulf.

30 minutes ago, JoeSchmuckatelli said:

Interestingly - the Denisovan population predating them seems to have actually moved south and spread through Malaysia into the archipelago north of Australia. 

Afair, there were two waves of migration from the Central Asia to Papua and so, 20kya and earlier.

[DDE]

With the ridiculous density of marine traffic today, and the apparent ease of at least screwing around with AIS (e.g. warships declaring themselves pleasure craft or switching codes around, including, IIRC the suddenly famous HMS Defender broadcasting the codes of Queen Elizabeth as it passed through the Straits), is it possible to conduct merchant raiding via auxiliary cruisers in times of war (or casual corsairing)?

Asking for a friend.

Edited September 24, 2021 by DDE

[JoeSchmuckatelli]

Question for you maths guys:

If, for a lark, Intrepid Spaceman Jeremiah Altmacher took a quill pen up to the ISS so he could scrawl his name on the outside, and did, but dropped the quill - how much kinetic energy would a goose quill 8" in length, but

weighing only

.00125 pounds be able to deliver to the next spaceship crossing perpendicular to its orbit that it hits? 

Is the pen actually mightier than the sword? 

[razark]

2 hours ago, JoeSchmuckatelli said:

Is the pen actually mightier than the sword? 

As any sword deserving of the name would have a much higher mass, no.

To answer the other part of your question: No idea, I don't feel like doing math today.

[SunlitZelkova]

7 hours ago, DDE said:

With the ridiculous density of marine traffic today, and the apparent ease of at least screwing around with AIS (e.g. warships declaring themselves pleasure craft or switching codes around, including, IIRC the suddenly famous HMS Defender broadcasting the codes of Queen Elizabeth as it passed through the Straits), is it possible to conduct merchant raiding via auxiliary cruisers in times of war (or casual corsairing)?

Asking for a friend.

Yes for the latter (corsairing), not sure about the cost effectiveness of the former (auxiliary cruisers). https://www.sandboxx.us/blog/american-pirates-us-privateers-could-help-win-a-war-with-china/

A couple problems with this though- 1. In either case of the two possible great power conflicts for the US, the "enemy" has a land route for trade with the presumably neutral third great power, and 2. Most merchant ships can probably be expected to flee the area(s) if war were to break out. Obviously, trade is going to end between the participants of the war, and commercial shipping companies would be reluctant to have their ships sunk by stray radar guided AShMs. There wasn't exactly a lot of Argentine shipping for the UK to prey on in the Falklands War because everybody obeyed the British blockade of it. Also, because most of the modern wars are going to be *a* Western coalition vs. effectively one geographical bloc of nations or a nation, it won't be like WWII where you had the global Axis trying to get merchant ships to and fro and thus vulnerable to attack. And in the case of the nations they can continue trade with, there is a land route for that for the most part.

So if it is a 100 million dollar auxiliary cruiser (random cost estimate, could be higher) vs. another 80 million dollar Light Amphibious Warship to actually contribute to combat ops, they will probably go with the latter.

Now in the case of China and Russia, as far as I can tell their naval strategies are A2AD over a very limited area- for China it is the South and East China Seas, not sure about Russia but presumably the Baltic + the SSBN bastion in the north. Not "nation killing"/power projection as was the objective of both the Axis and Allies in WWII, so I don't think they have much use for auxiliary cruisers or commerce raiding for that matter. It wouldn't work on a NATO convoy reinforcing Europe across the Atlantic either- those will all be under heavy escort. And in the case of Taiwan, a simple blockade with existing assets is all that is needed to achieve the same effect.

Edited September 24, 2021 by SunlitZelkova

[AHHans]

18 hours ago, DDE said:

With the ridiculous density of marine traffic today, and the apparent ease of at least screwing around with AIS (e.g. warships declaring themselves pleasure craft or switching codes around, including, IIRC the suddenly famous HMS Defender broadcasting the codes of Queen Elizabeth as it passed through the Straits), is it possible to conduct merchant raiding via auxiliary cruisers in times of war (or casual corsairing)?

AIS is meant for collision avoidance and works - like all traffic laws - because nobody is intentionally trying to break the system. There is no skill involved in faking an AIS transmission, so anyone could spend a few hundred bucks and declare their 12m yacht to be a Nimitz class aircraft carrier on AIS. So nobody uses AIS to identify military vessels or for IFF or something similar. You could probably cause more chaos by sending out fake AIS signals claiming to be loads of sailing yachts (== too small to show up on radar, but under sails so motor ships (even large ones) are supposed to make way) on collision courses with the regular traffic.

Also: I just was on a sailing trip on the Baltic sea (https://track.alex-2.info/track_map.php?trip=19121), and as far as I can tell all navy ships we saw had their AIS switched off. (*Bleep*ing annoing, but not my problem as my job was only to pull on ropes after being told to.)

So AIS or not has no influence on merchant raiding! But if you want to do that, then the civilian side of seafaring wouldn't pose an obstacle to that. Just take a ship that can take you where you want to raid, bring some fast RIBs and some grunts with assault rifles, and off you go. If you want to capture the ships then bring spare crew for prize crews, if you want to sink them then bring plenty of scuttling charges. The real risk to such an operation is the response of the navies.

 

[kerbiloid]

9 minutes ago, AHHans said:

anyone could spend a few hundred bucks and declare their 12m yacht to be a Nimitz class aircraft carrier on AIS.

Spoiler

"Just imagine, Karl... Thanks to AIS, in XXI century we could just declare our U-Boot as a 12 m yacht and have a nice sea voyage, and have a bath with clean water."

 

[magnemoe]

6 hours ago, AHHans said:

AIS is meant for collision avoidance and works - like all traffic laws - because nobody is intentionally trying to break the system. There is no skill involved in faking an AIS transmission, so anyone could spend a few hundred bucks and declare their 12m yacht to be a Nimitz class aircraft carrier on AIS. So nobody uses AIS to identify military vessels or for IFF or something similar. You could probably cause more chaos by sending out fake AIS signals claiming to be loads of sailing yachts (== too small to show up on radar, but under sails so motor ships (even large ones) are supposed to make way) on collision courses with the regular traffic.

Also: I just was on a sailing trip on the Baltic sea (https://track.alex-2.info/track_map.php?trip=19121), and as far as I can tell all navy ships we saw had their AIS switched off. (*Bleep*ing annoing, but not my problem as my job was only to pull on ropes after being told to.)

So AIS or not has no influence on merchant raiding! But if you want to do that, then the civilian side of seafaring wouldn't pose an obstacle to that. Just take a ship that can take you where you want to raid, bring some fast RIBs and some grunts with assault rifles, and off you go. If you want to capture the ships then bring spare crew for prize crews, if you want to sink them then bring plenty of scuttling charges. The real risk to such an operation is the response of the navies.

 

Could see navy ships might want to use an fake AIS if they has to use it, not only does it give away your position but it also give it over time so some could learn it patterns. 

And the ribs would be an high tech version of that the Somali pirates did, it was also an area AIS was not used for obvious reason. And here an AIS q-ship might had worked. 
But the ribs would not work during WW 1 and WW 2 as ships was armed then, stuff up to a couple 40 mm bofors was common, therefore you needed the merchant cruisers who tended to have 3-4 5" guns on each side.
This was an setup you could hide unlike turrets who is pretty obvious  \

[DDE]

https://www.pewresearch.org/fact-tank/2021/09/21/who-doesnt-read-books-in-america/

...define "part of a book"?

[JoeSchmuckatelli]

3 minutes ago, DDE said:

define "part of a book

Go to any 'book club' in suburban America and find out.  

 

Hint: it's all anyone but Nancy reads (and everyone is pretty much over her, anyway) 

[kerbiloid]

17 minutes ago, DDE said:

...define "part of a book"?

The pack of pages used at once.

[sevenperforce]

Hey, so I was in DC watching the sky lazily and spotted an aircraft making an extremely wide turn at around 35,000 feet. It was heading west towards DC but performed a full loop headed back out toward the Atlantic. Kept watching and saw two planes basically making one single loop with the western edge over the Chesapeake and the eastern edge over the Atlantic.

Both aircraft were white and generally appeared to be commercial, but I suppose they could have been AWACS or something. They both did two full loops before disappearing over the horizon for good. Any idea what this could have been and why?

[Staticalliam7]

How do we make a wormhole

[mikegarrison]

8 minutes ago, Staticalliam7 said:

How do we make a wormhole

Place a worm on an apple and let it do its thing.

41 minutes ago, sevenperforce said:

Hey, so I was in DC watching the sky lazily and spotted an aircraft making an extremely wide turn at around 35,000 feet. It was heading west towards DC but performed a full loop headed back out toward the Atlantic. Kept watching and saw two planes basically making one single loop with the western edge over the Chesapeake and the eastern edge over the Atlantic.

Both aircraft were white and generally appeared to be commercial, but I suppose they could have been AWACS or something. They both did two full loops before disappearing over the horizon for good. Any idea what this could have been and why?

Probably in a holding pattern for a non-DC airport. Lot of airports around there.

[Admiral Fluffy]

29 minutes ago, Staticalliam7 said:

How do we make a wormhole

Get a point in space, put lots of energy in it, and then yeet one end somewhere else.