exchemist

15 hours ago, CharonY said:

It should also noted that the paper uses "whiteness" to refer to a organizational structure whereas race as itself is actually not a factor in the observation (it is only based on the observation of three students). The paper also seems to be in a fairly low impact journal focused on teaching science (rather than a science journal) so it looks to me that that the fuss is disproportionate.

Fair point. You have inspired me to look up the paper too. Here is a link: https://journals.aps.org/prper/abstract/10.1103/PhysRevPhysEducRes.18.010119

I have to agree the argument about whiteboards is not that they are physically white in colour, but the way a whiteboard (or potentially a blackboard, or a flipchart, I imagine)  is used in teaching, to focus discussion of a topic.

But I did find the paper shocking. I think it is worth reproducing a part of it. The authors analyse a recorded discussion about heat capacity. I quote an extract from their analysis (an "EID" is an Energy Interaction Diagram):

QUOTE

In the episode we analyzed in this paper, we observe an interaction in which Drake and the representation he is constructing are centered, and Gail and Paris’ sense making and contributions are marginalized, both in their interactions within their (small) group and in the larger-group discourse. This social organization is co-constructed and co-maintained by at least five mechanisms of control: the EID representation, physics values, the use of whiteboards, gendered social norms, and the structure of schooling. Importantly, we would suggest that these mechanisms operate mostly invisibly; actors’ participation in them is sensible and normal. At the same time, actors are (consciously or unconsciously) renegotiating their relationship to the center or expressing aspirations to change whiteness as social organization [51,53,64]. For example, Iris expresses a wish for her class to reflect nonhierarchical social structure, and has made a number of pedagogical choices that make this more possible, even if not actualized in this episode. Paris describes herself as “making sure that me and Gail had a say” in interactions with Drake, and Gail challenged Drake’s assertions and made moves toward the center. Drake seeks Gail’s approval at the end of the episode and makes discursive moves to distribute the credit for the construction of the representation (using “we” pronouns). That these aspirations and microchallenges did not fundamentally change the nature of the interaction or the social organization of the classroom in this episode points to the power and the institutionalization of whiteness. Even our notions of what collaboration means are shaped, epistemically, by whiteness.

Our goal in this paper has been to “make whiteness visible,” in the tradition of Critical Whiteness Studies. In particular, we have sought to make visible how everyday physics classroom interactions reproduce whiteness as social organization, and how physics representations, values, and pedagogical tools play a role in this reproduction. That whiteness is “ordinary” in physics classrooms is not surprising, given critical race theory’s assertion that whiteness is endemic to every aspect of U.S. society [7]. The ordinariness of whiteness’ reproduction is not surprising either, given critical scholarship’s emphasis on the invisibility and hegemony of whiteness.

UNQUOTE

This strikes me as verging on parody. The authors clearly have a preconceived ideological conviction that any form of steering of a discussion is - culturally - "white" and, ipso facto, A Bad Thing. Well, good luck with trying to keep any form of discussion on-topic, then! These people would obviously accuse the moderation on this forum of "whiteness", for a start. 

It's nuts. 

But actually, the point Krauss was objecting to was not so much the article, daft though it is, but the impossibility of responding to its claims, due to the Catch 22 attitude of the editors of the journal. There will always be contentious papers published, but refusing to accept a critique of them is more alarming, academically. 

18 minutes ago, toucana said:

A few years ago I took part in a public tour of the newly opened Bristol Center for Nanoscience and Quantum Information (NSQI) - a new research centre constructed by Bristol University next to the main HHW Physics building in BS6.

https://www.bristol.ac.uk/physics/facilities/nsqi//

One of the many fascinating features that caught my eye was that there was one, and only one room in the entire building equipped with old-fashioned blackboards and chalk - and those blackboards were in fact not black, but a deep emerald green !

Our guide explained that the presence of those atavistic blackboards had only been sanctioned after a prolonged argument with the theoretical physicists who insisted that they could not possibly function and perform ground-breaking research into Quantum Mechanics without the comforting squeak of a stick of chalk scratching its way across a ‘blackboard’.

Left to their own devices, the building committee would have apparently vetoed the presence of blackboards in their new research centre, because even microscopic particles of chalk dust are an unwelcome headache when creating climate-controlled, vibration free, and electromagnetically shielded laboratory spaces for nanoscale engineering research.

Yes we had dark green ones at both school and university, which were some kind of flexible rubber material, in a loop on rollers at top and bottom, so one could scroll them up or down. Handy for long mathematical derivations that took up more than could be written on one panel. But you still wrote on them with chalk.

1 hour ago, Phi for All said:

Except that it's use began about the same time that the US slave trade ramped up for tobacco cultivation (1610 or so), to indicate that people on the list were undesirables, troublemakers, and deserved some form of punishment for it. 

There is no evidence of any connection, so far as I can see. Troublemakers were logged in a black book, sure (from the 2nd link below, Henry VIII is the first documented case of someone who did this) , but there's no evidence that it had anything to do with slavery or skin colour. Black and white have been contrasted for hundreds, if not thousands, of years, due to light being associated with goodness and reason and dark with danger and evil. It probably goes right back to when we lived in caves. https://en.wikipedia.org/wiki/Black-and-white_dualism.  

 https://en.wikipedia.org/wiki/Blacklisting

21 minutes ago, edwardrius said:

I have a general grasp on the function and "existence" of bosons and such, but I'm struggling to find any sources that provide a helpful explanation of what virtual particles are in a way that I feel I'm really able to conceptualize it.  Can someone please help?  Mostly just looking for an explanation of what force carriers really are (as in if they do not technically physically exist as particles but rather are just representative terms used in the math discussion of quantum field theory, what are the fields made up of and how do they exist if they do not involve any "real" particles).

Also, sorry if any of that was wrong, please correct me if so.  I'm pretty confused so apologies in advance if any of what I explained as my understanding was false.

Being a mere chemist by training, I had the same difficulty for many years. I found this article by Matt Strassler very helpful: 

https://profmattstrassler.com/articles-and-posts/particle-physics-basics/virtual-particles-what-are-they/

One key takeaway for me was that the term virtual particle is a bit unfortunate, as these disturbances in the relevant field are not particles, but just disturbances that can modelled using much of the same mathematics.

However, as a chemist, I have never studied QFT. Some of the real physicists here may be able to comment with far more authority. 

37 minutes ago, Phi for All said:

OTOH, I don't mind some over-sensitivity when it comes to racism. There are so many words and phrases that have inherent biases in them, or have racist origins, or help perpetuate stereotypes. Should you use white paper to blacklist someone for being the black sheep of the physics journal?

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6148600/#b39-jmla-106-527

I thought folks were being overly sensitive by correcting my use of the term "master bedroom" until I thought about how gender and racially offensive it was. It took me about three tries to learn to use "main" instead of "master". 

I think it's pretty obvious to most people that there's nothing remotely racist about the term "blacklist". 

Black sheep is obviously not racist in origin, though one can definitely sympathise with the idea that the concept of separating sheep by colour and denigrating black ones is not a comfortable metaphor in a multiracial society. So that's a metaphor that is probably past its sell-by date.

Re master bedroom, I was actually brought up short yesterday in a Hi-Fi shop, where I was getting advice about stereo bluetooth speakers.  These are sold as a pair, with one having the bluetooth receiver and power supply and the other running from it by a wire. So I said something like "Aha I see, so it's a master and slave setup. The shop assistant slightly uncomfortably replied "Well we call them primary and secondary".  So there we are. The "master" and "slave" metaphor has been standard in engineering throughout my life (e.g. the cylinders in hydraulic brakes on a car), but no longer, it seems. I suppose that's fair enough: when I was growing up, Britain was nothing like as multiracial as it is now, so now there will be different sensitivities to step around.     

But, assuming the article is not a spoof, I am sort of intrigued as to what they would say about a blackboard. 

35 minutes ago, MigL said:

Those of you who publish original research may find the following interesting, and suggesting of an 'agenda' not backed up by science
( wish BeeCee was still here; he was passionate about this sort of thing, and had great respect for L Krauss )

Lawrence Krauss: Whiteboards are racist because woke physics journal says so (msn.com)

What do you guys think; tempest in a teapot, or the unravelling of society as we know it ?

How funny. I’m old enough to remember when all our teachers used a blackboard. Would that be seen now as “cultural appropriation”, perhaps?

And what about the universal prevalence of white paper for writing and printing? Pretty shocking, eh? Something Must Be Done! 🤪

24 minutes ago, PrimalMinister said:

We have oceans, land and an atmosphere, is it any surprise that we have things swimming in the water, walking on the land and flying in the air? I mean the design of a wing comes from the aerodynamics of the air, wasn't it inevitable wings ended up the way they did? I mean there is light, we end up with eyes, there is sound, we end up with ears, what else was going to happen?

It's not a surprise that organisms adapt to make use of their environment, if that is what you mean. That's what evolution does, after all.  

2 hours ago, Baron d'Holbach said:

Best take on it 😊 

Let me take a spin at it...
Gravity has no origins or beginnings; it is the “emergent phenomenon” that arises from its functions, actions, and motions of itself—a one-directional wave flux. It is itself; Gravity is an indefinite motion toward the equilibrium point, the center. 
As an orientational acceleration system that fluxes, drags, and decays, leaving stored information behind, a trail of past information imprints can clump together, creating blocks of stored matter, constants, and properties. All the constants and properties (Fundamental and Dimensional Constants) are collected to build a smooth structure. This process is the continuation process until Aether (Big Bang aka the physical universe) is created. A negative response takes place and the expansion outwards into the creation of the 4 dimension we currently live in. 

LOL! I know… this is why I kept on telling to debunk it and attack it. I can’t get this out of my head. 😊
 

I watermarked it. Just a understanding. I use Naiver Stroke to explain Laminar flow for Aether and use it for my chip and applications. 

Is a Naiver Stroke a medical condition you suffer from? 

1 hour ago, Baron d'Holbach said:

@exchemist

Now we back to silly games. Can you debunk my theory or what. A fully dead on stop to it? If not? Just lurker around 1960s...

You haven’t bunked it yet. 😁

8 minutes ago, Baron d'Holbach said:

Serious, after 20 post now you brought a made up a lie?

Oh, jeez

 

My 1st post here. After a masterpiece diagram that you can even comprehend. 

At the bottom I wrote:

S_phi = ∫ d^11x √|g| [(1/2) g^{ij} ∂_i phi ∂_j phi - V(phi)]
where:

S_phi is the action for the scalar field phi in 11-dimensional spacetime
∫ d^11x denotes the 11-dimensional integral over all spacetime coordinates
√|g| is the square root of the determinant of the 11-dimensional metric tensor g_{ij}, which 
describes the geometry of spacetime

g^{ij} is the inverse of the 11-dimensional metric tensor g_{ij}
∂_i phi is the partial derivative of the scalar field phi with respect to the i-th coordinate
V(phi) is the potential energy function of the scalar field phi
This action describes the dynamics of a scalar field in 11-dimensional spacetime, including its 
kinetic energy and potential energy. The equations of motion for the scalar field can be derived by 
varying this action with respect to the scalar field phi.

The action is a scalar quantity that describes the dynamics of the scalar field phi in 11-dimensional 
spacetime, taking into account the effects of Gravity, Dark Matter, and Dark Energy through the 
11-dimensional metric tensor g^{ij}. The action is used to derive the equations of motion for the 
scalar field phi, which describes how the field evolves in time and space.

This is 100% correct. Dont lie now

A lie is an intentionally false statement.

Are you really accusing @Mordred of that? 

2 hours ago, openlyfescience said:

The reaction between one another. To determine what may happen if you combine them.

Can you give an example to show how this would work?

1 hour ago, Paulwilliam said:

is there a way to make some thing out of house hold stuff to make a absorbent powder 

Probably. 

2 hours ago, TheVat said:

Thanks.  That had completely escaped my attention.   😜

 

The transposition, you mean?…..

14 hours ago, TheVat said:

Video unavailable in US.  I found (on our golden coast) this unblocked version.

(sighs)(wipes steam from spectacles)

Yes it seems Emma Kirkby's version can't be seen in the US, for some arcane copyright reason I presume.

But the singer in your version has slightly screwed it up by failing to use the flattened note in the last line (when pitched in G, as Kirkby sings it, some of the F#s are flattened to natural) which gives it its sexy bittersweetness.

Here's another, more authentic version (transposed down to E♭ -  sung by someone who has chosen, in view of the subject matter, not to wear a bra, by the look of it.......

38 minutes ago, Externet said:

Greetings.  If deserves moving to science news, well, go ahead.

Seems rosy.  Perhaps too rosy.  Any opinions for the inconvenient sides if any; of hurdles against ?   Aimed mostly to large scale storage (which is not wrong at all) , at least for now.  I understand the manufacturing/production started already. 🤨

A link, just a link ---> https://www.youtube.com/watch?v=cHNELRnJ_4Y     There should be others, better or worse.

 

I can't claim expertise in this area but it is certainly interesting. Thanks for posting.

The Li ion battery exploits the very small size of the Li+ ion, which is isoelectronic with helium and will be even smaller, due to the higher nuclear charge. This can fit into interstitial sites in cobalt oxide reversibly, i.e. the ions can flow in and out without disrupting the crystal structure, due to their small size.

I would assume one of the challenges of trying to do the same thing with the far larger Na+ ion is to find crystal structures sufficiently open to allow the same thing to happen with a larger cation. This appears to be what lies behind the choice of Prussian White. This is is a mixed-cation ionic compound with ferrocyanide (Fe(CN)6)4- anions, Fe2+ cations plus a second metal cation to make it electrically neutral - which can be Na. It has large interstitial sites due to the large size of the ferrocyanide anion.

The other electrode, which is carbon, also has to be able to accept the cations reversibly into its structure - easy for the tiny Li+ ion, but more of a challenge for Na+. From what I read, there is however one particular, amorphous type of carbon that can do this.

So that's what I have been able to pick up so far on this topic. Comments, additions or corrections welcome.

I would guess there will be not insignificant commercial manufacturing challenges,  but from an environmental and geopolitical point of view, getting away from dependence on lithium and cobalt would seem to be a very good idea indeed. 

It's years since I listened to this CD. I was inspired by seeing Westminster Abbey at the coronation to play some of Purcell's music (he was the Abbey organist as one stage in his life), and was rather captivated by this song. It's in 6/4 time and in G major but with some flattened F#s, which give it some minor/modal bittersweet character. It's about the seduction of a maid:

When first Amintas sued for a kiss,
My innocent heart was tender,
That though I push'd him away from the bliss,
My eyes declar'd my heart was won.
I fain an artful coyness would use,
Before I the fort did surrender,
But love would suffer no more such abuse
And soon, alas! my cheat was known.
He'd sit all day, and laugh and play,
A thousand pretty things would say;
My hand he squeeze, and press my knees,
'Till further on he got by degrees.

My heart, just like a vessel at sea,
Would toss when Amintas came near me,
But ah! so cunning a pilot was he,
Through doubts and fears he'd still sail on.
I thought in him no danger could be,
So wisely he knew how to steer me,
And soon, alas! was brought to agree
To taste of joys before unknown.
Well might he boast his pain not lost,
For soon he found the golden coast,
Enjoyed the ore, and touched the shore
Where never merchant went before. 

1 hour ago, graybear13 said:

I am an old retired land surveyor in middle America. I am not a scientist or an engineer.  I cannot provide any scientific evidence or proof that this machine will be able to produce a vortex with over 1,000 mph wind speed.  That is what the experiment is for.  I have presented a logical speculation of a unified theory.  Logic and a little common sense is all that is needed to understand the concept.  I don't hear anyone disputing the logic.  All that is left to do is gather up some money and perform the experiment.  

Yes I have been raked over the coals through the years for daring to challenge the 'hairbrained theory" big bang.  I don't disagree with big bang from the time the stars lit up until now, it is just the question of what caused those clouds of hydrogen cloud to collapse and condense into star ignition. I think it is important to understand how that happened; what was the process. I am sorry that pyramids and vortexes are key to understanding this last puzzle piece.  It does make it harder for folks to take me seriously because of myths and legends about pyramid power, and tornados destructive power; how can a destructive power lead to a creative power?  

The problem is that "in science", as a fellow chemist and schoolteacher on another forum likes to remind people, "you can't just make shit up". Contrary to what you say, there does not seem to be any discernible "logic" to what you have posted here, nor have you offered any observational support for any of it. The fact that you are not familiar with the relevant science ought - at least if you are a sensible person -  to make you cautious in how you put forward  novel ideas, especially in a science forum. You should be checking the logic at each stage with people who know the science that you do not.  

As for how clouds of gas condenses into stars, the answer is simple and explanations are widely available on the internet. It's gravity that does it. If you have a gravitational field whose escape velocity exceeds the speed of the gas atoms or molecules, the cloud will condense. Gravity on Earth is strong enough to stop the atmosphere flying off into space, after all. So if you have a much bigger mass, like that of the sun, it should not be hard to see that it can pull gases in very powerfully.

12 hours ago, FRAGMASTER2023 said:

 

No priest preaches to me....

 

Haha you sound a bit like the late Ian Paisley: "Naow Paopereaigh!"😁 

Here is an example I found on line to illustrate how it is done:

7 hours ago, Brainee said:

How do you know how much light has redshifted?

The spectrometer tells you the wavelength or frequency of each line. So you just compare the reading for hydrogen in the star with the standard reading for the same spectral line in a lab here on Earth.

4 minutes ago, Brainee said:

Sorry, I meant when light from distant body red shifts, how can use spectrography to determine what its made of?

That's what I'm talking about. Here is an article with a picture of some of the lines from hydrogen: https://en.wikipedia.org/wiki/Balmer_series 

Now, if the star emitting these lines is red shifted, the whole set of these lines will be moved a bit from their normal positions towards the red (lower frequency, longer wavelength) end of the spectrum. But they are all still there and so is the spacing between them. So you can still identify that it is hydrogen emission you are looking at.  

14 minutes ago, Brainee said:

When space body travels far it red shifts, how can one then see what it is made of using spectgraphy?

Because the lines in the spectrum, which are characteristic of the elements of which it is composed, are all still there, just moved along a bit, to lower frequency. So you get the same pattern of lines, which can easily be recognised by a spectroscopist. Once you have found one element and determined from that how big the red shift is for that object, you then immediately know by how much all the lines for other elements will be shifted, and so you can assign them to the elements responsible.

P.S. One thing you may possibly not be aware of is that each element emits (or absorbs) not just a single line but a whole series, corresponding to electrons making transitions between different atomic orbitals in the atoms of that element. So it's a whole pattern you are looking for, not just a single line. I agree that if it were only a single line per element, you would not be able to do it. 

38 minutes ago, Phi for All said:

!

Moderator Note

I really wish you'd stop responding to them, or if you feel you must, please stop reposting their spam links.

 

OK, generally I don’t, but I admit I did find this one funny so I made an exception. Point taken about the link - I hadn’t thought about that.

3 hours ago, ivan.novak said:

Hello,
I have a question or two that I need help with:
What happens when you put magnesium bisglycinate and citric acid into water solution?
Does magnesium change form here?

Kind regards,
IN

 At neutral pH, glycine in solution is mainly present as a zwitterion: NH3⁺-COO⁻. So I think what will happen when you dissolve the glycinate: NH2-COO⁻, is it will pick up 2 protons from citric acid to form NH3⁺-COOH, leaving you with citrate and/or hydrogen citrates, depending on the relative amounts of citrate and glycinate (Citric acid is tribasic so it can release up to 3 protons, depending on the relative pKa s - or pKb s if you prefer - of both it and the other species around.) 

Mg²⁺ in solution will be present as a solvated cation anyway, so it won't be affected by any of this.  

6 hours ago, Randal E. Molloy said:

It's great to hear that you're interested in chemistry! Here are answers for your queries:

1. Creating elements in a laboratory typically involves processes such as nuclear fusion, which require extremely high temperatures and pressures and specialized equipment.

2. The equipment and materials needed to make basic elements would depend on the element being created and the process being used.

3. This includes wearing appropriate personal protective equipment (PPE) such as goggles and gloves, ensuring proper ventilation in the laboratory, and following proper handling and storage procedures for chemicals.

Also you can visit here to get more information: reposted link removed by moderator

This is quite funny. The spambot correctly says you need nuclear fusion to create elements - but then goes on, serenely, to warn you to use appropriate PPE and ensure lab ventilation when doing so!