OldChemE

A very interesting development, but it raised a question in my mind. As you all know, superconductivity was originally achieved by cooling to a very low temperature. Now it has been achieved by applying a very, very high pressure. It occurs to me that these two approaches have a common element-- they both involve moving the atoms closer together than they normally would be at room temperature and one atmosphere pressure. I have no knowledge as to whether distance between atoms is a factor in producing superconductivity-- but I wonder about it. If atomic distances are a factor, this achievement may not bring us closer to practical room-temperature conductivity.

It depends a lot on what you know and how much you are in the habit of using what you know. People who have a solid grounding in math and science often apply their knowledge without ever consciously thinking "now I will do science." When I go to clean the bathroom and look at the available cleaning products my wife has accumulated I find myself considering the ingredients and their possible chemical interactions. 10 years ago a tall pine in our back yard died and looked like it would fall, but I was just packing for a vacation. So I quickly used the similar triangles method to estimate how tall it was and decided that if it did fall it would be just short enough not to touch our glass back door. Sure enough we got back from the trip and it was down, and the tip was three feet from the door. It's just a automatic sort of thought process for people who are accustomed to applying math and science.

Alas, there are many different types of work in Chemical Engineering and I never spent much time on pipe systems, but its nice to get a mention. I, too, was thinking that perhaps the goal was to create a vortex action, but have not been able to come up with a proof that it would work. It wold be interesting to know if anyone has ever actually done an experiment on this.

First, let me say that "simply being creative" is very much more valuable than you make it seem. But, aside from that, There are undoubtedly many novel ideas that a hobby inventor might discover and patent thereby becoming rich and/or famous. The difficulty is that the things that have value depend on what is going on in society and the current state of both technology and the needs of society. To successfully invent you need to be attuned to the needs of society and where those needs are either not being fulfilled or may not even have been yet recognized. A good example is the invention of the tiny plastic clips that are used to close plastic bags (such as in the bread section of the market, at least in the US). Invention has a great deal to do with recognizing needs and being at the right place at the right time.

Oxidation states relate to the electron structure of the given atom, generally taking into account the octet rule. The Octet rule basically says that atoms "prefer" to have 8 electrons in their outer shells (there are exceptions and it is not very rigorous-- but it works). The outer shells of Sulfur are 3s2 3p4, for a total of 6 electrons. By 'sharing' 2 more electrons (from the hydrogen atoms) the atom fulfills the octet rule, but that gives it an electric charge of -2 (2 extra electrons). As these two electrons are from the two Hydrogen atoms, they are now are each +1. The extent to which the electrons are only shared, as opposed to one atom taking and varies. There is a lot more technical detail to that. You should note that the arrangement of the Periodic Table is ties into this, as elements that usually have the same oxidation states are all in the same column.

You might want to approach this differently. How many half lives would it take to get to 30%? If you knew how many half lives, you would then know how many half lives equals 300,000 years.

Not much of a paradox. The definitions of Won and Lost imply a contest, which implies two or more contestants. Your example was not a contest. Therefore the words do not apply. M(ore) S(lippery)C(oncepts}? 🙂

Some religions, fundamentally, aim to teach moral principles and give guidance on how to live a useful, productive and happy life. Some dress that up with lots of improbable features in order to connect with people who need that sort of thing. One need not believe the improbable to believe in the value.

I love this post! Very often we solve problems ourselves simply through the thought process of describing the problem. I cannot count the number of times my batter math students have begun to describe the problem they were trying to solve, only to end the conversation with "oh!... nevermind" Well done!

The element hidden in several of the replies is creativity, or the lack thereof. In my experience, collaborative teams where several members are very creative, especially if they have different skill sets, produce amazing results (because they tend to build on each other's inspirations). But-- one good engineer, if sufficiently creative, can outperform a group that lacks creativity.

Yes-- frustrating-- but not without purpose. It facilitates part numbering. For example, 787ST-24 is a model 787 hose, super tough cover, 24/16 ID. Virtually every industry over the years has faced the issue of creating meaningful part numbers primarily intended to be intelligible to professionals in their industry. This is just one example.

By now I presume you will have already found your answer. But-- if you are still struggling with dimensional analysis maybe a teacher's perspective will help. 1.. You have two pieces of information: liters used and km traveled, but the question asks for efficiency in km/L So, step 1: you need numbers arranged in a ratio that matches the desired answer. It wants km/L (a ratio), so the ratio has to match: 100100100 km/88 L Here, we made a ratio using the actual numbers making it so that the km's are on top and the L's on the bottom so that it matches the units in the required answer. Step 2, do the math (100100100 divided by 88) Step 3: you now have a number that has the units of km/L this is your answer. Think about this: We look at the dimensions that the answer is supposed to have, and form our ratio so that the arrangement of the dimensions we have matches the arrangement of the required answer (that is, km on top of the fraction and liters on the bottom). Then, we put in the numbers in the same arrangement and do the math. This is what Dimensional Analysis is all about: Using the dimensions of the answer we want to decide where to put the numbers in the math.

If you want a 'real' answer I'm not sure it can be done very easily. It will depend on the friction losses in the tube, which depends on configuration, length, surface roughness and even the shape of the exit in the end of the tube. Sorry to not be very helpful.

And the remarkable thing in my view is that the sequence in the periodic table correlates so well to both the number of neutrons and protons in the nucleus and the sequence of available valence electrons, and to the actual energy levels of electrons (s, p, d, f, etc), even though this information was unknown at the time. The real value of the Periodic Table is that it groups the elements in ways that reflect their chemical behaviors--a very valuable 'shorthand' way of understanding the elements. Perhaps there are a few places in the table that minor 'tweaks' might be of value, but I don't know off hand where those might be. For a while after retiring from Chemical Engineering I taught High School chemistry. The Periodic Table proved to be an excellent way to give students the "Big Picture" of Chemistry.

This is difficult to interpret-- but I notice the heading says 'Expands the least expensive node first.' So-- my interpretation is that the red dashed lines are intended only to indicate the order in which the pathways are tested-- not the actual path used. The dashed line from A indicates that the first path examined is from A to C, because the cost from A to C is less than from A to B. The red line from C to B is only to indicate that the next pathway examined is the one that leads to B (from A). The next path examined is the one that leads to D from C, the next is the one that leads form B to D. The next is from D back to B (pathway ACDB - which fails) and finally the next pathway examined is ACDE, a success. In other words, I'm postulating that the red dashed lines show the order in which the algorithm tests destinations, not the path taken to test them. Summarizing, the system keeps testing paths starting with the least values until it finds the solution. The paths tested, in order, are AC, AB, ACD. ABD. ACDB, and finally ACDE.

There is a difference. The arguments about heavier than air flying machines, like may similar arguments, were arguments based on ignorance of the science. The theory with regard to light speed has implications that have been tested and found to be correct, even though nobody has propelled a rocket to light speed. Einstein's predictions have been tested in so many ways and found to be correct to such an extent that the preponderance of evidence suggests he was right.

Being alive is dangerous. What value is there in living if one cannot enjoy life in the manner they prefer, within the bounds of behavior permitted by society?? Total Deaths in 2018 were over 2 million. Motor vehicles are a minor component of the risk of living.

Speaking as a licensed HIgh School math teacher I would say no-- not something we should teach in High School. Benford's law is indeed very interesting, but the High School math curriculum is focused on continuing the development of math skills started in lower grades, in a building block fashion, in order to prepare the student for post-HS education. Pre-Algebra, Algebra, Geometry, Algebra 2, pre-calc and sometimes early stages of Calculus. That is, we are still in the process of building connected competencies-- one topic building on the previous. Benford's law and its implications is pretty much outside the things that have to get done in High School. The amount of material to be mastered is very large and difficult to do as is-- I would not want to add more.

"The theory claims, and the article deduces from empirical knowledge", which is stated in the link, involves scientific thought, but does not prove anything, particularly since the authors have no proof for the timelessness they theorize occurs at death. It might be true, and might be of some benefit in understanding what a person goes through at death, but it is not proven. As such, its a significant stretch to say it is supported by science. The idea that a person might experience some feeling attributable to heaven or hell at death is not new (pleasure or regret about how one lived one's life)

Pure vegetable oil is usable in diesel engines. That does require oxygen (as noted by Sensei). Ignition under those conditions is achieved a t 15-120 atm. For ignition or decomposition without oxygen it will depend on temperature as well as pressure-- so there is no single correct answer. While I do not know for certain. I suspect that since the oil is essentially not compressible, it will not significantly heat up as it is compressed and therefore high pressure alone will neither cause it to ignite nor decompose.

Color codes for resistors: Bad Boys rape....... Totally out of place today and I would not repeat it now-- but it got me through my EE courses 54 years ago.

I don't think the number of people represented is a direct issue. That is, I don;t think it matters if a district is 750k or 120 k as long as they are all the same population. But-- the disparity in district populations and the gerrymandering are issues. I would love to see some simple-minded criterion for districts that would minimize gerrymandering, but I'm not sure what it should be. "All districts shall consist of a single rectangle of sufficient size to encompass x people?" I suspect this might be like th famous problem of how to draw a map in different colors without having two adjacent areas the same color.

I must have worded things badly. What I meant was that they have NOT been seeking to solve the problems, whereas, they probably know the technology best.

I very much agree the leadership of the NRA should be held accountable for any provable acts along the lines of those charged. As a gun owner, I want the Second Amendment to remain, but have long felt that the organizations that know gun technology best (Manufacturers and the NRA) should have been working with government to solve the problems instead of blindly fighting everything. So-- I hope this lawsuit will lead to some positive results.

Good summary. Having just recently retired from teaching I see many challenges here. Certainly, until now, online learning has been underutilized, but in some areas where it is used it is not used well. Case in point is Math. Quite a number of schools now do online instruction in Math, but the success rate has been uneven. I suspect the issue is that online systems cannot always detect why a student gets a wrong answer and provide the correct guidance (making students do math on paper and reviewing the actual paper is a very important part of math instruction). But-- there are efforts to overcome these type of issues and COVID has given us the impetus to take on the challenges. More to the point of the OP-- I think the answer is that education is being changed. We are very, very, lucky that the development of online learning was already well underway before the virus arose. I do not, however, think we will do away altogether with physical schools. Socialization is an important part of education, along with activities like art, music, performing arts, and similar things that do not so easily lend themselves to online studies.