Wikipedia:Reference desk/Archives/Science/2023 August 18

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August 18

Crossing the desert

What survival equipment does one need when crossing the Sahara Desert? (Not planning to try this at home -- this has to do with a fictional scenario.) 2601:646:9882:46E0:C990:4871:79E0:D481 (talk) 08:47, 18 August 2023 (UTC)

By what method? (Otherwise I'd advise an aircraft as a sensible piece of equipment to use.) Bazza (talk) 09:35, 18 August 2023 (UTC)

I'm wondering how one would accomplish crossing the Sahara "at home". ←Baseball Bugs ^{What's up, Doc?} carrots→ 09:55, 18 August 2023 (UTC)

As far as method of transportation I have in mind, the answer is, by camel caravan -- and the route is roughly from Tangier to Adrar, Algeria and thence to Tunis, so the total journey time would be about 2 months, give or take (same time as Google Maps theoretically gives for making the journey on foot -- but going on foot would be purely theoretical, because it's impossible to carry the amount of water one needs to survive that journey). 2601:646:9882:46E0:C990:4871:79E0:D481 (talk) 11:01, 18 August 2023 (UTC)

Whatever the mode of transportation, for ground travel one need not carry more than needed for each segment from one water source to the next. I know people who have crossed the Sahara in a Deux Chevaux, following the route from Algiers to Tamanrasset to Agadez (see route 2 in Trans-Sahara Highway) and then to Niamey. They travelled in "car caravans" – a row of cars travelling together so that assistance can be offered in case of a car breaking down – but the whole trip was not particularly challenging. On foot this is indeed not feasible; although the longest stretch without water sources is perhaps only 500 kilometres (310 mi), this will take close to two weeks and one needs to drink at least 2 litres (0.53 US gal) a day to keep hydrated, so one would need to cart some 25–30 kilograms (55–66 lb) of water.  --Lambiam 20:56, 18 August 2023 (UTC)

So, lots of water (obviously) -- what else? 2601:646:9882:46E0:CDC2:4F04:96FF:A0FE (talk) 01:59, 19 August 2023 (UTC)

Food. Travelling through the desert requires a lot of energy, both to enable one's metabolism to counteract the heat (and cold at night), and for the sheer effort of walking on rough or sandy footing.

One adventure thriller I recall reading hinged on discrepancies in an account of an earlier wartime escape across the Sahara. The protagonist realised that the account had been falsified to obscure the escapees apparent lack of sufficient food to make the actual journey, and deduced what their food source must have been. {The poster formerly known as 87.81.230.195} 51.198.140.169 (talk) 03:21, 19 August 2023 (UTC)

Survival Kit for Desert Travel. Alansplodge (talk) 09:17, 19 August 2023 (UTC)

All of these appear to be good ideas as far as basic survival (well, except that on one hand, fishing hooks and line are probably not necessary, because there are no fishing holes in the Sahara, and on the other hand, the supply of water purification tablets would have to be increased by a factor of at least 5, on account of the journey will take up to 2 months) -- but what about personal defense? Because in the Sahara (as opposed to, say, the Arizona desert), at least for a foreigner (like the characters I'm thinking of), dying of thirst is only the second-biggest danger! 2601:646:9882:46E0:A4C4:8081:B88D:5509 (talk) 01:53, 20 August 2023 (UTC)

Dying of thirst can only cease to be the worst risk if the traveller has a sufficient supply of water. Do you have a source for your implied claim that the local Bedouin pose a significant risk to the life of ill-prepared desert hikers?  --Lambiam 08:02, 20 August 2023 (UTC)

I thought I already said the travellers would be taking lots of water and a 2-month supply of purification tablets??? And as for the locals being a bigger danger than dehydration (at least to foreigners), how about this? 2601:646:9882:46E0:5D23:E078:A946:673 (talk) 08:35, 20 August 2023 (UTC)

The killers were not Bedouin. They were city dwellers. The place of the murders was hundreds of kilometres away from the desert.  --Lambiam 03:06, 21 August 2023 (UTC)

It was still a remote area within the same region, so the same principle would apply in the desert (only more so, given that if anything, law enforcement becomes less effective the farther away you go from the coastal areas!) 2601:646:9882:46E0:FCF1:5148:45CE:E9B3 (talk) 03:25, 21 August 2023 (UTC)

Considering the many things that could still go wrong, even with taking a supply of water and purification tablets (which don't help if you can't find water), I can't imagine many scenarios where the greatest danger is the risk of intentional harm from "locals". While there is some risk from "locals" where ever you are e.g. Murder of Ahmaud Arbery, with some places being more dangerous than others, we shouldn't overplay the risks either. Notably in the case of an actual ill-prepared desert hiker, it's quite likely an encounter with the Bedouin is more likely to save their life than end it. Nil Einne (talk) 12:38, 21 August 2023 (UTC)

And if (as in my scenario) they are going into the desert specifically to pursue a local who not only had committed murder, but is also inciting other locals to become terrorists??? You haven't thought of that scenario, have you??? (Not to mention that, obviously, the locals in different parts of the world are not alike in how friendly or hostile they might be, and in some parts of the world, like Afghanistan for example, attacks by the locals are in fact the biggest danger -- although admittedly, the Sahara is not quite as dangerous as Afghanistan in that sense, but still much more dangerous than Savannah, GA! 2601:646:9882:46E0:7C19:FF2A:2EEF:9C07 (talk) 09:24, 23 August 2023 (UTC)

Condition of road after plane crash

How did the road and street furniture in https://ichef-bbci-co-uk.cdn.ampproject.org/ii/AW/s/ichef.bbci.co.uk/news/800/cpsprodpb/500C/production/_130829402_malaysia2.png survive undamaged except for charring or soot after having a small plane directly crash into them? Thanks, cmɢʟee⎆τaʟκ 10:10, 18 August 2023 (UTC)

I'm not so sure the photo is sufficiently hi-def to draw that conclusion. ←Baseball Bugs ^{What's up, Doc?} carrots→ 10:28, 18 August 2023 (UTC)

Did a small plane crash here? The location is close to Rawang in Selangor state, Malaysia, looking south on the Guthrie Corridor Expressway that leads to the state capital Shah Alam and further south to the Kuala Lumpur International Airport. The photograph shows that emergency services have cordoned off a junction where we see widely spread debris. I cannot identify much but there are 7-8 crash responders gathered around what may be interesting (human?) remains at right where they have placed a red marker. It looks like the crash impacted somewhere off to the left of the scene and cast burning fuel over the whole scorched area. However the flare was too brief to leave other trace than to singe the grass at the road fork. Northbound traffic and crowds have collected at the incident on which we have no other information. Philvoids (talk) 17:36, 18 August 2023 (UTC)

There are plenty of news reports on the plane crash, which killed all eight people on board the plane, a Beechcraft Premier I, and two motorists on the ground. The opening shot of the video in this news report, taken from a side opposite to that for the photo in the BBC's article, shows still burning debris on the road as well as a significant smoke trail to the east. The latter is an area not visible in the BBC photo – although the charred ground can be seen up to where the left edge of the frame cuts it off and can be surmised to extend much further.  --Lambiam 20:10, 18 August 2023 (UTC)

A small plane isn't a missile or bomb. It doesn't have a warhead or explosives in it. Weapons designed to do things like crater runways or roads are actually rather specialized for the task. --OuroborosCobra (talk) 19:49, 18 August 2023 (UTC)

Now that you mention it, small planes are rather light and fragile. A paved road would likely do a lot more damage to a small plane than vice versa. ←Baseball Bugs ^{What's up, Doc?} carrots→ 10:50, 19 August 2023 (UTC)

Thanks, everyone. That makes sense! cmɢʟee⎆τaʟκ 16:40, 19 August 2023 (UTC)

P.S. Though that may trigger some 9/11 conspiracy theorists! cmɢʟee⎆τaʟκ 16:41, 19 August 2023 (UTC)

Had the terrorists flown small planes, they might have bounced off. ←Baseball Bugs ^{What's up, Doc?} carrots→ 17:35, 19 August 2023 (UTC)

The main damage was caused by all the fuel in the planes burning. they had taken off soon before. NadVolum (talk) 18:56, 19 August 2023 (UTC)

Yes. Essentially self-contained bombs. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:14, 19 August 2023 (UTC)

The plane was actually minutes from landing and crashed about 8.5 km (5.3 mi) from the runway of Sultan Abdul Aziz Shah Airport where it was headed, after more than an hour's flight from Langkawi.  --Lambiam 07:51, 20 August 2023 (UTC)

Don't know where I got they idea they were near the start of their flights. It still was the fires they caused which caused the iron to weaken leading to the collapse. The article says the impact and explosion of the fuel removed a lot of the fireproofing and started multiple fires. So worryingly the implication is that a smaller plane full of fuel might have the same effect on a similar building. NadVolum (talk) 08:59, 20 August 2023 (UTC)

American Airlines Flight 11 left the runway at 07:59 and crashed into WTC 1 at 08:46. It was headed from Boston to LA so was indeed fairly early on in its flight. (Our article doesn't give an expected flight time or landing time that I noticed, but Google suggests the normal time for such a flight is ~6 hours 10 minutes.) United Airlines Flight 175 took off at 08:14 (about the time AA 11 was being hijacked) and crashed into WTC 2 at 09:03. It too was headed from Boston to LA, so could also be said to be fairly early in its flight. The Beechcraft Premier I which crashed in Malaysia a few days ago was nearing the end of its flight as mention by Lambian. Nil Einne (talk) 12:05, 21 August 2023 (UTC)

Note that a plane near the end of its scheduled flight is nowhere near empty. ICAO fuel reserve requirements require extra fuel for at least 30 minutes' flight. cmɢʟee⎆τaʟκ 08:16, 22 August 2023 (UTC)