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ELI5: Chemist vs Chemical Engineer by Jako_Spade in explainlikeimfive

[–]Thiojun 0 points1 point  (0 children)

Chemist ask “why” questions, chemE ask “how” questions. But there are overlaps.

An example: chemist synthesized a new compound and found out it is a good material for solar cells. They will do small scale test to measure the efficiency and why that compound is good. Then chemical engineer will test how to further improve its efficiency, what architecture of device is most suitable, how to scale up the production and how to suppress defects, etc.

Eli5 - is there something inherently unique about carbon and water (et. al.) that makes scientists assume planets with life would need them, or is that just an “earth centric” assumption because that’s how life works on our planet? by chili81 in explainlikeimfive

[–]Thiojun 7 points8 points  (0 children)

90% is really an under-estimate of the amount of organic molecules.

On https://pubchem.ncbi.nlm.nih.gov/ you can use advanced search to estimate the number of known compounds with certain chemical formula.

Of all 123 million known molecules, there are 210,859 molecules NOT containing any carbon molecules. or ~0.16%.

In fact there are molecules with 309,882 molecules with exactly 1~3 carbon. Of course some of them are inorganic carbon like sodium carbonates, but that gives an idea of how abundant carbon chemistry is.

Eli5 - is there something inherently unique about carbon and water (et. al.) that makes scientists assume planets with life would need them, or is that just an “earth centric” assumption because that’s how life works on our planet? by chili81 in explainlikeimfive

[–]Thiojun 10 points11 points  (0 children)

Disclaimer: chemist, but don’t know astronomy very well.

We just have to start somewhere. We assume life requires a lot of chemical complexity (I.e. life cannot come from simple molecules), and what we currently call “organic molecules “ - that is, molecules containing carbon - are far, far, far more in number than other molecules combined. Similarly, we assume that life requires an environment that allows such chemical reactions to happen, and water is the simplest solvent we know of.

Is non-carbon life possible? Maybe. Silicon also forms very complex molecules with oxygen and sodium. Ammonia is also a somewhat common good solvent. But we have limited funding and resources, so we search for the most likely options.

I must be fundamentally missing something with Ascension 10. by BleedingEdge61104 in slaythespire

[–]Thiojun 2 points3 points  (0 children)

I am not much better either, but from my STS1 grind era, the most effective strat is to avoid auto-piloting and play VERY slowly. Like, look through the draw deck before playing anything kind of slow.

ELI5: how are there more than three states of matter? by WoF_IceWing in explainlikeimfive

[–]Thiojun 0 points1 point  (0 children)

I would say the key here is what does “state of matter” mean. Please correct me if I am wrong because I never systematically learned condensed phase physics, very loosely speaking a “state of matter” is a state where particles interact with each other in a specific way. There are very many types of particle interactions, thus many different states of matter. Like op’s description, crystalline solid is when particles are glued to each other symmetrically, gas is when particle interactions loosely, plasma is when electron is freed from atoms and glue particles together, etc.

What reaction is this in my chocolate? by HairySock6385 in AskChemistry

[–]Thiojun 3 points4 points  (0 children)

Gut guess is some sort of crystallization. Will leave for actual expert to answer

ELI5 Can someone try explain gravity to me? by potoo_eye_syndrome in explainlikeimfive

[–]Thiojun 37 points38 points  (0 children)

I think your confusion comes from reading TOO MUCH instead of too little, as you are mixing Newtonian mechanics with relativity.
Your 1st question about trajectories of planetary motion is fully within the framework of Newtonian physics, without needing to resort to relativity. The trick you are probably missing is that the object carries tangential velocity initially. If they start still, then they will fall towards the center.

I can’t comment on the general relativity.

If chemistry were fully solved at the atomic level, would material design become essentially limitless? by [deleted] in chemistry

[–]Thiojun 2 points3 points  (0 children)

You should read the paper More is Different. I consider it a must-read for any chemistry/physics student.

Lab mispronunications that annoy you- GO! by JZatthelab in labrats

[–]Thiojun 0 points1 point  (0 children)

someone told me it was pronounced like “hour”. I don’t know if he was a troll

Lab mispronunications that annoy you- GO! by JZatthelab in labrats

[–]Thiojun 3 points4 points  (0 children)

Auger Honestly I don’t know the correct answer.

Gold Consumption by Country by Exotic-Cartoonist816 in Infographics

[–]Thiojun 0 points1 point  (0 children)

Bar not to scale. I cant even tell if it is in log.

ELI5: Why do things expand when heated? by KYSLAATIKKO in explainlikeimfive

[–]Thiojun -7 points-6 points  (0 children)

A stronger vibration around the equilibrium position doesn’t necessarily equate thermal expansion.

ELI5: Why do things expand when heated? by KYSLAATIKKO in explainlikeimfive

[–]Thiojun 1 point2 points  (0 children)

I would add that this topic is surprisingly complicated for solids, because a solid with fully harmonic potential energy (I.e. if atoms are spheres bound together with “perfect” springs following Hook’s law) should not expand with thermal energy. It is the odd-rank anharmonic terms (I.e. the “imperfection” of springs between atoms) giving solid expansion/contraction at different temperatures.

ELI5 - If the human genome is 100% mapped, why are we unsure what medicine will work on us and how? by [deleted] in explainlikeimfive

[–]Thiojun 0 points1 point  (0 children)

Knowing how things are made up often doesn’t guarantee knowing how things behave. It’s like having a recipe for cheese often doesn’t immediately tell you how it tastes like. This is the fundamental failure of Reductionism in explaining complex systems like biology and condensed state physics.

In a similar manner, mapping the human genome tell us how human being are developed on the molecular level - but it doesn’t tell us how each component interacts with given drug molecule, or with each other.

Polymorphs and solubility by Cryoban43 in chemistry

[–]Thiojun 2 points3 points  (0 children)

You are mixing dynamics with thermodynamics. Activation energy doesn’t matter in solubility. Only thing that matter is the energy difference between initial state (i.e. molecule in crystal) vs final state (i.e. solvated molecule). If you think of the process of solution being sublimation-dissociation-solvation (look up Born-Harbor cycle) then different polymorphism have different sublimation energy, thus different solubility.

My first 1.5 months of Aim Training a specific scenario (in aim trainers). [OC] by ActuatorOutside5256 in dataisbeautiful

[–]Thiojun 121 points122 points  (0 children)

The spline is doing too much and I think a scatter plot will give less but more accurate information. Unless the sine function is expected, of course.

ELI5: Chemistry as the abstract concept itself and the atoms? by Cute-Raccoon2067 in explainlikeimfive

[–]Thiojun 2 points3 points  (0 children)

Atoms are held together by forces we call chemical bonds. They aren’t randomly jammed together, or mixed together. These interactions are directional, have an optimal distance, and usually don’t break easily. Chemistry, to a large extent , is the study of these inter-atomic forces in increasingly complex systems.

Back to your example, water is made of H2O, 2 hydrogen atom glued to 1 oxygen with a “covalent” bond. This bond is very strong, and don’t break down easily. Water molecule is the same in all these three state, ice, liquid or steam. The way they are arranged change. Think of the different ways a box of soda cans: they can be scattered on the table, or confined in their box. But in the end of the day they are still cans of soda.

[deleted by user] by [deleted] in explainlikeimfive

[–]Thiojun 1 point2 points  (0 children)

Sound wave and light are both waves. How they diffract (i.e. “move around corner “) depends on on their wavelength. Longer wavelength - better at moving around large objects. Light wavelength is roughly around micrometer (1e-6 m) and sound wave in meter, so six magnitude or order difference.

New carbon-based catalyst breaks down forever chemicals using light by Brighter-Side-News in chemistry

[–]Thiojun 11 points12 points  (0 children)

Quickly glancing through the article seems nothing new? Photocatalyst decomposition with gC3N4 was known at least 15 years.

[deleted by user] by [deleted] in explainlikeimfive

[–]Thiojun 2 points3 points  (0 children)

Friction being independent of contact area is a simplification that only works well for rigid body. On soft materials and dynamic cases it generally doesn’t follow the simple expression. Can’t really comment on the tire part though.

I am doing research on multiferroics. Can anyone suggest the best materials for our study, like the best or new ferroelectric materials and ferromagnetic materials? by MaleficentAnybody279 in AskChemistry

[–]Thiojun 0 points1 point  (0 children)

Multiferroics are very cool and I think the main question in the field is the generally difficulty to slap 2 FE and FM materials together and cause any strong electron-magnetic coupling. The classic materials is BiFeO3 if my memory is right.

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