Wikipedia:Reference desk/Archives/Science/2015 April 30

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April 30

Amazon

The amazonian jungle is one of the most underexplored parts of the world. Is it likely or unlikely to have huge oil fields? Why? Jartgina (talk) 12:22, 30 April 2015 (UTC)

Here's an image of deforestation in the Amazon basin [1] - all those red and yellow areas are accessible by logging roads. The Sugar Loaf field, and the Santos Basin are relatively recently discovered and development is actively planned. I'm pretty sure if they thought that they could get oil from under the ground without having to do offshore drilling, they would be doing that instead. See also Oil reserves, List of oil fields, hydrocarbon exploration and peak oil. There isn't too much of the world that hasn't been prospected for hydrocarbons. You will probably find this interactive map very useful [2], and also might like some of these maps [3]. SemanticMantis (talk) 12:59, 30 April 2015 (UTC)

There is already discussion of this in the thread over on WP:RD/M...SteveBaker (talk) 13:06, 30 April 2015 (UTC)

Well, the Amazon basin is huge, so there's a lot of room for variability; but you might want to read up on geology to learn where we expect oil to be found. Among the important prerequisite items for a lucrative hydrocarbon (oil) deposit:

• there must be a source rock. This is usually an ancient shale or similar rock layer.
• there must be a reservoir rock. This is usually a porous material like sandstone.
• there must be a sufficient trap (or cap) rock. This is an overburden layer on top of the reservoir that caps in the hydrocarbon (so it can not escape over geological timescales).

These geological conditions usually form in special cases: for example, when ancient sea beds, lakes, rivers, or marshes get covered with new sediment, trapping massive amounts of organic source carbon; and this needs to have happened at the correct time in geological history so that the correct type of organic matter has "cooked" at exactly the right temperature and pressure to produce petroleum (as opposed to, say, coal or natural gas).

A 2013 Assessment of 137 Shale Formations in 41 Countries Outside the United States by the United States Energy Information Agency assessed the Amazon basin; you should interpret their results for Amazonas and other basins for yourself. Brazil ranked #10 of all worldwide reserves assessed. This report focused on shale oil, but there are many other types of geological plays.

You can read about the Amazon basin and its superbly underrepresented geology. You can also read about Petrobras, the most major Brazilian energy corporation, (although many other supermajors operate in the region). You may also want to read this 2011 Economist article, The drilling edge, to learn why Petrobras chooses invests so much in unconventional oil (and computer science!)

Speaking as a former card-carrying exploration geophysicist, let me say this much: lots of money is staked, won, and lost, on knowing whether valuable mineral and hydrocarbon deposits will be somewhere. This means that there are lots of opinions about whether a specific find is "likely" or "unlikely."

If you engage in this industry, you will find people who buy into the science - and study geology, geophysics, and petroleum engineering. You will also find people who do not subscribe to the science - who happily drill wildcat wells on the off-chance that there might be some resource, even if the prevailing scientific theory contraindicates this decision. Some people even believe in abiotic petroleum. I have even heard a Young Earth Creationist tell me that the geological theories (to which most educated members of the industry subscribe) are incompatible with several of their very lucrative exploration results. We, as scientists, may tell them they are unlikely to find success; but when they do find success, it is surprisingly difficult to argue with them on factual grounds (the rigorous mathematical methods of statistics leave a lot of room for shot noise and observer bias). On the statistical average, however, major energy exploration companies are more successful when they rely on scientific method to locate resources. This means understanding geology first and foremost; it means understanding rock physics and geophysics, petroleum engineering, biology, economics (and politics).

This week's issue of Oil and Gas Journal reports one major find in the Amazon, with majority ownership by Petrobras, and a 40% minority stake owned by Petrogal. If you want perspective on whether this is "significant," I highly recommend subscribing to OGJ: it publishes one of the most factual, unbiased, quantitative representations of the state of the petroleum industry.

Nimur (talk) 15:12, 30 April 2015 (UTC)

Is e-diesel/blue crude a feasible fuel?

At least, this is not a nutty guy claiming on Youtube that he produces fuel from water and thin air, but big corporations don't want you to know. Anyway, did Audi discovered a process for producing a a new fuel which is compatible with modern cars and is indeed made of water and thin air (+energy)? Is mass production at least theoretically possible? All the information that I find just explains how great this breakthrough is. --Llaanngg (talk) 13:07, 30 April 2015 (UTC)

The fuel seems fine, it's the life cycle analysis that's killer. By that I mean, if we had abundance of renewable or at least clean-ish electricity, whether from fusion or solar or whatever, then this fuel would probably be a nice way to get the energy density that we need for liquid fuels to be worthwhile in transportation. To make a hydrocarbon out of water and CO2, you will always need to put in more energy than you get out, even if you are using carbon neutral sources of energy. In some applications, it makes sense to lose energy in exchange for a more easily usable form of energy storage, but in others it doesn't. Deciding if/when it is practical in the real world is far too subtle for us to handle on this desk. SemanticMantis (talk) 13:30, 30 April 2015 (UTC)

The Fischer–Tropsch process was discovered in the interbellum. It takes hydrogen and carbon dioxide and forms an alkanes. Either petrol or diesel can be targeted. The major stumbling block is generating the feed hydrogen; hydrogen is normally created by controlled partial combustion of methane. Electrolysis of water is currently energy-inefficient. If there is a large surplus of electricity, then it may be worth while to create fuel. 62.56.51.155 (talk) 18:05, 30 April 2015 (UTC)

Of course, breaking apart a perfectly combustible alkane (Methane) to make additional combustible alkanes seems like taking three left turns where one right one would do. Just burn the methane. CNG vehicles are on the road now. Making, say, gasoline via the method you describe seems far less efficient than just converting to natural gas powered vehicles. --Jayron32 18:47, 30 April 2015 (UTC)

As I understand it, the point of doing this isn't to get more energy, it's to get a carbon neutral methodology for making liquid fuel for transportation. Methane can never be that. I agree that burning methane to get hydrogen is a bit off, but that's not what Audi wants to do. In principle, if we can work out plenty of carbon neutral electrical power, then this could potentially be a way to fuel our current fleets, without the hassles of infrastructure and battery technology that make electric cars difficult. SemanticMantis (talk) 18:56, 30 April 2015 (UTC)

Well, again, it's all in what ends up being more efficient. For example, if we use solar power to create a carbon-neutral combustible fuel, is developing that technology more efficient than developing better solar powered cars? The entire addiction to combustion is one of the "If all you have is a hammer, every problem looks like a nail" issues: Every solution to producing a combustible fuel via carbon neutral methods is ultimately less efficient than seeking out combustionless alternatives to begin with. Instead of "lets create a carbon-neutral gasoline" why aren't people thinking "lets just create vehicles that don't burn things". --Jayron32 19:14, 30 April 2015 (UTC)

Because of energy density and weight issues, mostly -- nothing comes close to hydrocarbons, except for nuclear fuels and pure hydrogen. I mean sure, we have Compressed_air_car and Tesla motors, but neither of those is really poised to take over the major automobile markets. I guess the point is, nobody knows which technologies will be successful, and there's already a lot of sunk costs in the way we've designed most of our cities and suburbs around cars (at least in the USA). Not to mention the cultural fixation (e.g. many people find it normal and reasonable to drive themselves 50 miles to work each day in a 3 ton Escalade). So various industry leaders sink their R&D into a variety of projects, in part to hedge their bets. In related news, British Petroleum has pulled out of the liquid cellulosic biofuel game [4], after entering it with much fanfare ~10 years ago. I'd be personally happy to pay more for gas/diesel that had a reliable claim to carbon neutral production, but that doesn't mean I won't also be happy to see affordable electric cars for the common citizen -- they both have pros and cons, and companies can research both at the same time. I'd be happier yet if we could have decent public transit and more room for human-powered vehicles in the USA, but I know that's a pipe dream. Sorry if this is seen as too far off-topic, but it's interesting stuff, good discussion, and it can only help the more that we learn and share about these things. SemanticMantis (talk) 21:51, 30 April 2015 (UTC)

See also synthetic fuel and Gas to liquids ---- 62.56.51.155 (talk) 18:21, 30 April 2015 (UTC)

The theoretical issue with synthetic diesel from hydrogen is that electricity can be converted at high efficiency to mechanical work, but heat energy cannot be. When you use electricity to split water into hydrogen and oxygen, the theoretical maximum efficiency of combining those in a fuel cell (according to our article) already drops to 83%, but it is still more efficient than 58% that it gives as the theoretical maximum for an internal combustion engine. I'll admit, I'm not sure at the moment why the one form of tapping chemical energy is more efficient than the other - I only know of the Carnot cycle. But in any case, once you have hot burning diesel in your engine, much of the energy that was in your original electricity is now waste heat going out your exhaust pipe. Wnt (talk) 23:53, 30 April 2015 (UTC)

A Carnot cycle is only going to exploit the temperature difference, it won't be able to use the difference in chemical potential of the exhaust gasses and the atmosphere. E.g. in principle a lot of work can be extracted from a cup of water at room temperature, simply due to the fact that in equilibrium, it should all have been evaporated. The work is enough to be able to lift it up about 8 kilometers high. But since it is at room temperature, you cannot run a Carnot machine to extract that work. Count Iblis (talk) 15:54, 1 May 2015 (UTC)

Scientific studies on good diets to gain a lot of weight?

Most of what we can read in the literature deals with calorie restrictive diets to make overweight people lose weight. However, there are people like me who would benefit from eating a lot more calories to gain weight, the problem is then to eat healthy a foods such that 5000 Kcal wil still fit in your stomach. There have been overeating experiment studies, but in these studies the people were basically given a diet of Big Macs and ice creams, the goal of these studies was not to study how one can gain weight in a healthy way.

There are many suggestions that one can find online e.g. the GOMAD diet, or this suggestion but nothing reliable based on rigorous scientific research, particularly w.r.t. the health of the diet. Obviously, if you just eat 6000 Kcal per day you will likely gain weight, but the problem is to do this while still eating a healthy diet. Count Iblis (talk) 19:46, 30 April 2015 (UTC)

Try Chankonabe. It is delicious. No scientific studies that I know of but proven by generations practice.Don't forget to included lots of rice as a compliment.--Aspro (talk) 20:47, 30 April 2015 (UTC)

For whom is the rice a compliment?--Llaanngg (talk) 23:57, 30 April 2015 (UTC)

Well, that settles it. I'm naiver going two use microsoft's spilling chequer ever a gain! Its LibreOffice from here on in – and its free – as in bier.--Aspro (talk) 11:39, 1 May 2015 (UTC)

Take a look at a sumo wrestler diet tips: [5]. --Llaanngg (talk) 20:55, 30 April 2015 (UTC)

When actors gain or lose a lot of weight for a role, they consult a doctor. You should do likewise. ←Baseball Bugs ^{What's up, Doc?} carrots→ 00:30, 1 May 2015 (UTC)

• Count Iblis knows this is a request for professional advice, he also has utter contempt for our rules, per his user page, and his question is absurd button-pushing that should simply be removed without further comment. μηδείς (talk) 04:32, 1 May 2015 (UTC)

• Clearly a request for medical advice, and thus we cannot help, other than to direct the questioner to his doctor. RomanSpa (talk) 09:43, 1 May 2015 (UTC)

And the big joke (which RomanSpa omits to add) is that 50% of the time he will consult.... You guessed it Doctors’ #1 Source for Healthcare Information: Wikipedia. P.S. For dietary advice you need a nutritionist not a MD. They only know what they were taught in med skool and that wouldn’t fill up the back of a post-card.--Aspro (talk) 15:07, 1 May 2015 (UTC)

Thanks, I'll read up on the diet Sumo wrestlers eat.

About medical advice, this is no the case as I'm currently not going to do some diet to increase my weight, but I may have to do that in the future if I'm to exercise a lot harder than I do now (increase it to well beyond one hour per day of hard exercise). Now, where I live, you don't go to the doctor if you are healthy and no illness is suspected or you don't want to rule that out. Doctors are not allowed to help such people because that would amount to public spending on things other than helping the people in need for medical attention. Healthy people are expected to be able to care for themselves, which includes consulting the available sources to find the information they need.

So, you go to the doctor because you suspect something is wrong with you or because you already don't feel well. You don't go to the doctor just because you want to run even faster and longer than you already can. Count Iblis (talk) 15:40, 1 May 2015 (UTC)

Well put Count Iblis. Some comments here -I think- are good examples of political correctness gone overboard. In the past I have refused to answer questions because they were asking (and sometimes subtlety) for medical advice. This question does not fall into that category. If others disagree, they can post a complaint on ANI.--Aspro (talk) 16:18, 1 May 2015 (UTC)

Aspro, read both the policy at the top of the page, and the disclaimer at the bottom of the page. This has nothing to do with political correctness. (I can't even imagine how political correctness would apply to any of the statements above, and I am personally in favor of a totally laissez faire medical policy, entirely unregulated except for fraud, but that's not the law in the US.)

The issue is civil liability for us and the wikimedia foundation. Disclaimers are void if the disclaimant regularly violates them. You can't put up a sign saying we do not give medical advice and then routinely dispence medical advice and expect the sign you ignored to indemnify you from civil damages any more than you can put up a sign that says "I am not a prostitute, but I give strangers blowjobs for $10 a piece" and expect exepct John Cleese in a bobby outfit to walk by and say "Well, that's all right then."

I'll also suggest you read the disclaimers at the top of Count Iblis's user page. μηδείς (talk) 16:45, 1 May 2015 (UTC)

Right. Now read it all. Both forwards, backwards, up and down. So..?--Aspro (talk) 00:05, 2 May 2015 (UTC)

Aspro, here's the point from Count Iblis's page (it was blue, so maybe you missed it): "Count Iblis rejects most of Wikipedia's policies and guidelines. He just edits in any way he sees fit to improve Wikipedia. Whether such edits violate Wikipedia's policies is neither here nor there."

The issue here is not whether nutritional advice is medical advice, but that nutritionists and dietitians are licensed professionals in the state of Florida where the Wikimedia Foundation is incorporated. Wikipedia doesn't give any sort of professional advice, and medical and legal advice are just examples, not a limiting qualification. 17:34, 2 May 2015 (UTC)

Which is to be interpreted as saying that whatever information is to be found on Wikimedia pages, none of it is to be interpreted as professional advice. Otherwise, almost nothing could be written here as for almost any subject there are licenced professionals. The language Ref Desk, the Math Ref Deask and this Science Ref Desk would need to be closed because there are licenced public and private teachers, schools and universities. Count Iblis (talk) 19:47, 2 May 2015 (UTC)

Except that when such disclaimers are routinely and willfully violated, "We don't give professional advice, so here's some professional advice" they become void. That's alright though, since there's no actual advice anywhere in this waist of a thread.

Nutritional advice is not medical advice. If it was, most people who write a diet book or work at Weight Watchers, etc., would be arrested for practicing medicine without a license. We've repeated this many times but some people never seem to learn. And the Ref Desk talk page is the place for this, not AN/I. StuRat (talk) 16:52, 1 May 2015 (UTC)

For what it's worth, I tried searching the scientific literature, but also had problems finding anything appropriate. Seeing a general practitioner might not be useful, but seeing a dietician or nutritionist would probably help. You could also ask this question at a different forum, perhaps reddit's /r/fitness. The /r/gainit subreddit seems to be a whole forum devoted to discussing healthy weight gain. SemanticMantis (talk) 16:02, 1 May 2015 (UTC)

Thanks, I'll take a look at reddit. Count Iblis (talk) 19:49, 2 May 2015 (UTC)

The weight gain diet would depend on the reason weight gain is needed. If the person was a body-builder, for example, then a high protein diet would be in order to help build up muscle.

For a more general case of somebody who is just underweight, perhaps some appetite stimulants like MSG might help (as long as that individual didn't have an MSG sensitivity). Also, the general advice of "don't drink your calories" would be reversed in the case of somebody seeking to gain weight. The usual problem, but in this case benefit, of drinking calories is that they are very easy to digest, allowing the rapid consumption of many calories. Fruit and vegetable juices or blends are a good source of nutrition, but also calories.

Then there's the case of somebody underweight due to a disease, such as cancer with chemotherapy and vomiting. In that case a doctor's advice actually would be in order. StuRat (talk) 16:57, 1 May 2015 (UTC)

MSG just enhances the flavour. It wont encourage one to eat more. All one has to do is pile on an extra 20% to breakfast and lunch (eat supper like a church mouse). Then remember to exercise so that it becomes muscle mass rather than flab. --Aspro (talk) 19:45, 1 May 2015 (UTC)

The point is that we don't know what the cause of the OP's being underweight is, and therefore shouldn't be giving advice on how to "fix" the "problem". AndrewWTaylor (talk) 19:30, 1 May 2015 (UTC)

? No where did the OP say he was 'underweight'. He is just asking about gaining more weight. Maybe, in order to feel closer to his morbidly obese neighbors but his motive are a different question. Personally, if he views himself as a skinny-bean-pole then that maybe the best body shape for him - but he did not ask this. This might be the antithesis of Pyecraft but that was fiction.--Aspro (talk) 19:45, 1 May 2015 (UTC)

That's a good point. He might want to have his Body mass index calculated. These days, it's possible, especially for a man, to think a healthy weight is actually underweight, by comparing with other "role models" such as American football players. (Less so for a woman, because of all those anorexic supermodels.) StuRat (talk) 19:59, 1 May 2015 (UTC)

"There are people like me who would benefit from eating a lot more calories to gain weight" (emphasis added) seems to imply he thinks he's underweight. AndrewWTaylor (talk) 13:25, 2 May 2015 (UTC)

My BMI is about 20, which is well above the limit of 18 for being underweight. But I'm a bit too fat, my body fat percentage is about 14% while 10% or lower would be better. Just getting rid of the excess fat I have to become fitter would reduce my BMI to 19.2%. But the whole point of all this is to gain muscle mass, so the BMI would actually increase not decrease. The power to weight ratio should then increase, allowing me to do all of these 44 exercises (the first few are not much of a challenge, but they become increasingly harder). Count Iblis (talk) 20:05, 2 May 2015 (UTC)