aka grade 11 of 12

they call grade 11 "junior", grade 12 "senior"

just like 3rd year uni and 4th year uni

Hi @heather welcome back

does your high school offer advanced placement courses for university during those years?

@heather Oh hey, how've ya been

@heather Woah. Feels like last time we spoke you were a freshman

I guess middle school could have the "freshman" to "senior" labels also?

not to mention primary elementary school :P

fresh men ---> freshers

@skullpetrol yep

@SirCumference good, and yourself?

calling a 9 year old a "senior" in elementary school seems a bit silly, imho

yeah, i've never heard 'senior' used to refer to anyone other than a senior in highschool or a senior in college.

@skullpetrol technically 12 of 13 because of kindergarten, but yeah.

basically: 2 years before college.

@PM2Ring So then my idea proposal is a good idea then. Since asking questions on the chat in 2 different rooms is an issue. Having 1 room dedicated to answering these questions will solve this problem.

@PM2Ring I was talking about questions asked in the chat rooms. Not on the questions site.

@PM2Ring So I guess we can both agree that having 1 chat room dedicated to answering these types of questions having to do with both Physics and Electrical Engineering would be beneficial. Since the cross-posting is a problem and is discouraged. This chat room would solve that problem.

@PM2Ring We would have two different but yet very similar worlds of interest in 1 place. Creating the best learning opportunity for the members and others asking the questions.

@heather but isn't kindergarten optional?

for 5 year olds

some home schoolers start right after the child settles down after the "terrible twos"

that^ would put them two years ahead of other kindergarteners

@dmckee what do you think of the above strategy that some home schoolers are using?

@skullpetrol you know, i actually don't know

i thought it was required, but i could be wrong.

i know preschool is a thing, but isn't required.

in some states it is required

some high schools offer AP for first and second year STEM university courses @heather

@skullpetrol yeah, mine does - lots of AP courses, and not just for STEM, for humanities as well.

If we have two 1d potential Wells with one of the boundaries of one overlapping the others what do we get?

|_|_| something like this where the middle line is overlapping of boundaries

Mood Gorning.

About how much grams of NaOH should I put it 150ml of baby oil? 6 grams?

@NovaliumCompany sodium hydroxide isn't soluble in baby oil, so you can't use it to create a charge on the particles.

I don't know how the charge is created in an e-Ink device.

Wikipedia says

In the simplest implementation of an electrophoretic display, titanium dioxide(titania) particles approximately one micrometer in diameter are dispersed in a hydrocarbon oil. A dark-colored dye is also added to the oil, along with surfactants and charging agents that cause the particles to take on an electric charge. This mixture is placed between two parallel, conductive plates separated by a gap of 10 to 100 micrometres.

@NovaliumCompany So maybe dissolve the NaOH in the surfactant, eg washing-up liquid detergent. You already have TiO2 + NaOH in water at the correct pH, so maybe let most of the water evaporate & add a small amount of detergent.

charging agents - that's not too helpful. Though it's possible the details have been kept secret because they're commercially sensitive.

Probably. It's really hard to find definite details for this stuff. I suppose some of it isn't too hard to reverse engineer, with the right equipment, but people who've done that are hardly likely to spread the info around.

Where is the pirate's gold

@GarimanSingh Probably on a biology site or chatroom.

Hey Guys! Question: Is it possible to replicate the exact behavior of the potential of a spherical distribution both within the sphere (as a constant) and outside the sphere (which falls off as 1/r) by rearranging the charge distribution on the boundary? This implies that the source is now at the boundary and solutions to the Laplace equation must yield only the boundary integral.

@PM2Ring After some time, in the current solution that I have of water and charged TiO2 particles, the TiO2 particles seem to sink at the bottom and I can carefully remove the water at the top. Will that work instead of boiling it?

Then I can put some kind of dark paint in the baby oil, then the charged TiO2 particles (with very little water).

@NovaliumCompany You definitely don't want to boil the water off. That would increase the pH too much. So yes, let it settle, then remove most of the water, and then let most of the remaining water evaporate away.

You also need a surfactant. A little bit of detergent added to the TiO2 sludge while it's evaporating will probably work. John Rennie may have better suggestions.

If I prepare photon to be in a definite state with an appropriate device, and then measure some observable (sorry for being vague) of the photon, won't we know the observable deterministically before measuring it?

Maybe not...due to Heisenberg's principle.

If photons are too tricky to work with, replace them with something else...

say and electron.

So, we can prepare an electron to have a definite momentum, right? And if we measure the momentum (an observable), we will know its value deterministically.

But if we had chosen to measure a different observable, say its position, then Heisenberg says that we can't know it deterministically.

So, just because we prepare a quantum system to be in a certain state, doesn't mean that all of its associated observables will be known deterministically; it may be that we only know one deterministically...

Does this sound right?

If you know momentum of a particle at a particular time you cannot measure it's position accurately, simultaneously

That's what the uncertainty principle mean in the most simplest form

If you prepare a particle say an electron in a particular state say particular momentum, you may not have it's correct position and vice versa

@NaveenBalaji do you mean in a hollowed sphere or a solid one?

Because in a hollow sphere, the charges are only at the boundary, which in turn gives the electric field inside to be zero and potential to be constant

@Korra Okay. It sounds like you are confirming what I'm saying. Is that right?

@user193319 Yes but only in the case of position, if you choose to measure the energy by preparing the electron in a certain state of momentum, you can measure it (upto a certain error in observations, of course)

What you can and cannot measure is given by the commutators.

P and x do not commute i.e. Px=/xP

For a quantum system

@PM2Ring How would I let the rest of the water evaporate away? Can I open the bottle and put in in the sun for a day?

@PM2Ring Why do I need a surfactant? (e.g soap?) I mean, putting it in the solution while the water evaporates will wrap the TiO2 particles in micelle which will stop the particles to go up with the water?

Also does that mean that if I add a surfactant to the TiO2 particles they will not be covered by the black dye?

@NovaliumCompany I'm guessing here that you don't want them to be covered by the dye so that they actually stay white

@NovaliumCompany The Wikipedia article on e-paper says they use a surfactant, but it doesn't go into details. But I like ACM's theory. It may also reduce the tendency of the TiO2 particles to form clumps.

@NovaliumCompany Pour the sludge into a shallow dish, to increase the surface area, and to make it easier to get at once it dries out. Maybe cover the dish with thin cloth or paper so it doesn't get contaminated with dust.

@ACuriousMind Ye

@PM2Ring Does it mean that after I have the sludge of TiO2 particles and very little water, the TiO2 particles will be covered in surfactant and will not mix with the black dye? (which I will put in the baby oil together with the sludge of TiO2)

@NovaliumCompany I think so. And remember, you're going to do this first without the black dye, so you can see more easily what the TiO2 particles do when you apply the field.

@PM2Ring Yep, ok.

Hello to all. Anyone possibly knows a mailing service called @freenet.de ? Is it a usual mailing service in Germany?

@ConstantineBlack it is.

@Loong Alright, thank you.

But why do they use a service like that? I mean why not use the already big names like Google and Microsoft?

@ConstantineBlack Because they saw ads for it here in Germany and just signed up?

We don't have such services in Greece and I am wondering what they offer as an alternative to the other services, or how exactly are they competitive.

I don't think they really offer anything, I think they're usually just the offerings from ISPs who offer email services to their clients anyways (e.g. gmx.de is just the "in-house" mailing service for 1&1)

OK.