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Wikipedia:Reference desk/Archives/Science/2016 August 2

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August 2

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FTIR, again

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Does anyone happen to know which company makes the Mattson/Satellite brand of FTIR machines? Thanks in advance! 2601:646:8E01:7E0B:F88D:DE34:7772:8E5B (talk) 02:09, 2 August 2016 (UTC)[reply]

Thermo Scientific acquired Mattson Instruments in 1995. DMacks (talk) 02:17, 2 August 2016 (UTC)[reply]
You mean Thermo-Fisher Scientific? 2601:646:8E01:7E0B:68B9:B9AE:F3EB:CDDF (talk) 04:23, 2 August 2016 (UTC)[reply]
Yes, that's where my link leads:) Thermo Fisher Scientific being their current name. DMacks (talk) 05:42, 2 August 2016 (UTC)[reply]
Thanks! 2601:646:8E01:7E0B:68B9:B9AE:F3EB:CDDF (talk) 06:54, 2 August 2016 (UTC)[reply]

Free metabolism

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Hi I’ve been looking at human metabolism and the processes struck me as wasteful. Why couldn’t I just eat those electrons rather than the sugars? Surely we could find some way. — Preceding unsigned comment added by 130.102.82.124 (talk) 03:45, 2 August 2016 (UTC)[reply]

You could try plugging a live electrical wire into yourself and report back to us on how it worked out. ←Baseball Bugs What's up, Doc? carrots→ 04:00, 2 August 2016 (UTC)[reply]
Struck out exceedingly dangerous suggestion. Although it was made facetiously, the editor has no idea how responsive to suggestion the OP might be, or how capable of misunderstanding he/she might be. Do not attempt the advice given. Akld guy (talk) 05:07, 2 August 2016 (UTC)[reply]
If you have a better idea on how to ingest electrons, let us know. ←Baseball Bugs What's up, Doc? carrots→ 10:09, 2 August 2016 (UTC)[reply]
An apple has some. Or anything, actually, so there is no real need to kill yourself. TigraanClick here to contact me 10:40, 2 August 2016 (UTC)[reply]
I was thinking more in terms of hooking himself to a transistor radio battery. ←Baseball Bugs What's up, Doc? carrots→ 10:51, 2 August 2016 (UTC)[reply]

Thank you for your concern, but never mind. I’m serious. I expect I could swallow ATP or NADH and get the energy/electrons, but they’re large molecules for so little and would make awkward pills. Mightn’t there be another more condensed way, a smaller ion/molecule that might be unstable enough to unload its’ electrons and inducible to deliver them to the ETC? — Preceding unsigned comment added by 130.102.82.124 (talk) 05:18, 2 August 2016 (UTC)[reply]

Cellular respiration did not evolve for speed. In fact, having the electrons slowly migrate to lower potentials allows for more hydrogen ion transfers to occur during the transition, which ultimately increases efficiency. Someguy1221 (talk) 08:00, 2 August 2016 (UTC)[reply]
  • With all due respect, it seems you have not very clear ideas of what you are talking about. For example, you seem to think of electrons as "energitrons", i.e. quanta of energy - which they are not.
You will need to explain why you think metabolism is "wasteful". If your benchmary is the amount of stones a pyramid-builder can carry per day vs. the Gibbs free energy in what they eat, then yes, the efficiency is awful compared to (say) a steam engine. But, as opposed to a steam engine, you can eat a lot of different things without short-term disfunction (and things that are easily found in the wild, not highly refined fuels) and your temperature self-regulates (which means the "lost" heat is not completely useless). TigraanClick here to contact me 08:46, 2 August 2016 (UTC)[reply]
The bigger issue (one which is a problem at large) is the problem that people don't understand what energy is in general. They think of energy like some kind of substance, which one uses like a fuel to do things. That's so very very wrong. Energy is simply a way to quantize change. When something about the world changes, like when I lift my arm up in the air, we need a universal way to indicate how much the world has changed. That's because it turns out those changes are conserved; if I define energy in some way (usually defined as the amount of change done to the world necessary to move an arbitrary object using a force of 1 newton a distance of 1 meter); then I can figure out what caused that change (for example, burning some bit of wood to generate steam to provide the force necessary to move the object), and say that the change to the world from moving the object is equivalent to the change to the world to burn that bit of wood. Every one of these changes is conserved. Now that we've defined energy (quantifying change); we have really 2 reasons why something may change:
1) Another object in motion smashes into it, and causes it to move
2) There's a force on the object which is currently being resisted (that is, it's under a force, but not currently in motion).
That's it, that's the only reason anything moves; either a collision or some tension caused by a force which lets go. The first kind of energy we call kinetic energy and the second kind we call potential energy. You can think of potential energy as "stored up energy" that can be converted later to kinetic energy; that is we can use it to move something around later if we can relieve the pent-up forces. When we say energy is "stored" in the body in compounds like ATP and NADP and the like, what we mean is that the chemical bonds holding those molecules together are like little tightly wound springs: under great force, but not moving. But rearranging the atoms so the bonds have less potential energy (that is, releasing some of the force in the "springs") we can use that potential energy to then move things around, making happen all of the changes necessary to keep your body running. The reason we use these molecules to store and then release energy is a) they are very efficient in being able to store up a LOT of energy and hold it until the proper chemical reaction releases it and, most importantly, they are made up of bits of other molecules which your body can construct simply by using parts it already uses to do other things. Thus, it doesn't have to use a molecule from scratch it isn't already using. In the case of ATP; the bits that make it up are adenine (which is also used in DNA and RNA), a sugar called ribose, which your body also uses in other ways, and phosphate, a simple ubiquitous ion which has dozens of other uses in the body. Super efficient to use parts in that way. --Jayron32 18:11, 2 August 2016 (UTC)[reply]
Jay,
  • You appear to have meant quantify when you said quantize.
  • The simile that energy is "used like a fuel" is not a bad one. You use it yourself later on when you talk about energy being stored.
--69.159.9.219 (talk) 19:34, 2 August 2016 (UTC)[reply]
Sugar or other carbohydrate is a reasonably good way to store energy, but fat is better - 4000 vs. 9000 kcal/kg. Lipid catabolism illustrates that the size of a molecule doesn't matter much - every two carbons is a separate run through a cycle that puts out energy when the fat is effectively burned with oxygen (via the cofactors, of course). Now you can picture eating "more concentrated energy" than this, but the question is, what do you put it in? You wouldn't like eating lithium, for example, which is a way to provide sort of free electrons.
Now to be sure, plug-in organisms are neat and I think there are some that accomplish something like this - look in the melanin and humic acid aisle for some interesting soil fungi or microbes that seem to put out a network of molecules that can route in electrons. I can't think of anything that quite matches what you have in mind. For fictional purposes, rigging the mitochondrial proton gradient to nanowires is my favored way of implementing zombies. Wnt (talk) 19:33, 2 August 2016 (UTC)[reply]
Chemicals that want to "give away" electrons tend to not care very much what they give them away to. Consequently, you don't find much of them lying around, because they react with other chemicals. See redox. Also, as some others have touched on, the issue with biological systems is not just releasing energy, but doing so in a controlled fashion so the organism can use said energy to do useful work. You could release a whole lot of energy really quickly by setting yourself on fire, but you won't be able to accomplish much with the energy. --71.110.8.102 (talk) 21:06, 2 August 2016 (UTC)[reply]

Houseflies

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I'm spending a few days in a central London flat I know well. I have never seen any flies here on previous visits. This morning I woke up to about a score - medium-sized, silent houseflies, on or near the windows, quite easy to kill. What might have caused this phenomenon? No food has been left out. Carbon Caryatid (talk) 11:46, 2 August 2016 (UTC)[reply]

Sounds like one got in through an open window and laid eggs somewhere near the window, and they've hatched. You wouldn't necessarily have been able to find the food source for the eggs, it could have been a dead mouse or rat under the floorboards or somewhere similar. --TammyMoet (talk) 12:42, 2 August 2016 (UTC)[reply]
I'd expect to have difficulty not noticing a dead rat under the floorboards. :) HenryFlower 20:01, 2 August 2016 (UTC)[reply]
I had a similar incident, and also never found the source. I did indeed find a dead mouse in a corner of a storage area some time later, but I don't know if that was the "food source". The dead mouse smell was only noticeable within a yard/meter, and I have an excellent sense of smell. StuRat (talk) 20:42, 2 August 2016 (UTC)[reply]
They've all gone now. No dead rodents, as far as I can tell. Carbon Caryatid (talk) 20:47, 3 August 2016 (UTC)[reply]

Ocean Exploration

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I'm an intern at the Aquarium of the Pacific. What have been the 5-10 biggest OE stories of the past 5 years? I'm finding it hard to collect specific ones. Thanks NicoARicoA (talk) 19:59, 2 August 2016 (UTC)[reply]

  • MH370 ... it's not much fun but it sure involved a lot of exploration.
  • Ocean acidification keeps getting worse; also see corals e.g. the ones in the Great Barrier Reef that are dying.
Wnt (talk) 19:43, 2 August 2016 (UTC)[reply]
Surely the recent Ghost Fish found by NOAA's Okeanos Explorer has to rank supreme! This amazing life-form was found at a depth of 2500 meters in the Marianas Trench.
If you are not already a regular subscriber to Ocean Explorer, you ought to sign up for their email updates, or review their archives!
I also find the Marine Fisheries newsletters to be pretty informative: the NOAA Fisheries Service website has great news and information of general interest to explorers and ocean enthusiasts of all walks.
Another amazing website is operated by the Woods Hole Oceanographic Institute affiliated with MIT. They build great stuff and conduct incredible research missions. A brief glance at any of their top news stories is also surely worth your time. I've always been a fan of their cool toys for underwater cameras, which they deploy to amazing and extreme environments.
And since you're in Southern California, you might as well check out the cool stuff they do at Scripps, which is arguably the West coast's counter-argument to Woods Hole. Here's their online magazine, "explorations now".
If you're into the Hawai'i thing, the best place for explorers to start is at the University of Hawaii: here's their live feed from their support station for the most recent NOAA Okeanos mission.
Nimur (talk) 20:00, 2 August 2016 (UTC)[reply]

How to make concrete resistance against water damage

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When you have no way of isolating a concrete structure from sea or fresh water, how can you make a concrete structure resistance against water damage? Hofhof (talk) 21:57, 2 August 2016 (UTC)[reply]

Use a hydraulic-setting cement in the concrete. See, for instance, roman concrete, portland cement and more generally, cement. --Tagishsimon (talk) 22:01, 2 August 2016 (UTC)[reply]
And why aren't all buildings made with this? What's the disadvantage here? Hofhof (talk) 23:18, 2 August 2016 (UTC)[reply]
Most of the concrete I can think of is rained on, buried in wet ground, etc. I'm not sure I understand the drift of your question. That's not to say that water and metal reinforced concrete is always a good mix, as spalling can occur if the rebar is corroded. --Tagishsimon (talk) 23:24, 2 August 2016 (UTC)[reply]
I do not mean big outdoor structures like bridges or canals, but pipe leaks, flood or water damage in a home. Why it's such a big deal? Wouldn't the concrete isolate the rebar? Is the concrete directly affected? Hofhof (talk) 23:59, 2 August 2016 (UTC)[reply]
In homes with which I'm familiar, damage to concrete does not arise out of such circumstances. Flooding tends to affect plaster and especially plasterboard, so that's your wall finishes and ceilings gone; wood (by warping & staining), so joists, floorboards, etc are affected; and electrical systems. Concrete (typically foundations) and brickwork tends to be unaffected unless undermined by a water channel or void, or abnormally loaded by large volumes of water, in which case structural damage can occur. In, for instance, prefabricated concrete structures - think 60s tower blocks - water damage tends to arise out of poor seals between prefab blocks and, especially, the expansion of ice as water freezes, which can extert sufficient pressure to fracture concrete. --Tagishsimon (talk) 00:07, 3 August 2016 (UTC)[reply]
This might be of some interest Alkali–silica reaction. Vespine (talk) 04:38, 3 August 2016 (UTC)[reply]
Note that there are many ways water can damage concrete:
1) It can dissolve components of the concrete, especially with prolonged exposure. The pH of the water may be important here.
2) There's the frost/freeze cycle, mentioned above. Obviously only a problem if the water freezes and thaws.
3) There's the slow erosion of water dripping on an object. If the concrete is completely submerged all the time, this won't occur.
4) It can carry rocks or sand that scour the concrete. Physically isolating the concrete, say by burying it under rocks, is a good way to prevent this, but the rocks will need to be periodically replaced.
5) It can carry organisms that attach to the concrete, like coral. Some of these organisms might be protective of the concrete, while others might tend to break it down.
6) As mentioned previously, if water, especially salt-water, finds it's way to the rebar, it can quickly rust away. StuRat (talk) 20:53, 3 August 2016 (UTC)[reply]
  Resolved
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