exchemist

There are several misconceptions in what you have written. Firstly the shift in wavelength as one looks at more distant objects is a red shift. You are describing a blue shift. What happens is that the wavelengths get longer (=lower frequency) at longer distances, which shifts the yellow to the red and the blue to the green etc. Secondly, the cosmological red shift is not actually a Doppler shift but is caused by the expansion of space itself stretching out the waves. Thirdly, dark matter is so-called because it appears neither to emit nor absorb radiation at any wavelength. Astronomers are not so silly as to have only looked at the visible range of the spectrum. So dark matter really is dark. It is not just something to do with emission being red-shifted.

What transition state, in what process? And what do you mean by an open or "exploded" transition state? It's a bit hard to comment without any information about this .

Yes, I think the term "neck" is used for the extinct eroded form, whereas a plug may be either extinct or just a blockage in an active volcanic conduit, as you say.

Close to the surface of a large body of water, it is very common to have an inversion, whereby the cool water cools the air immediately above. So then it would not be true that the temperature decreases upwards within the layer. The opposite would be the case. For example this explains why Chicago is sometimes visible from a point 60 miles way on the far side of Lake Michigan. It is what is called a superior mirage, and its cause is the bending of light in an inversion layer above the lake: https://www.abc57.com/news/mirage-of-chicago-skyline-seen-from-michigan-shoreline

Domes would be the most dangerous. A dome signifies extremely viscous magma, typically "acid", with lots of silica. Volcanoes with this feature are notorious for eruptions in the form of pyroclastic flows (nuees ardentes). La Montagne Pelee is a classic, as is La Soufriere, currently going off in St Vincent. In the terminology I am used to, a volcanic neck is the exposed solidified magma plug (a sort of dyke) left after the erosion of an extinct volcano. So that would be 100% safe. But I admit my terminology may be out of date.

This article seems to be from mid-2019. Is what sense is it "new", then? And what is troubling about the discrepancies? Aren't they just intriguing? To the right sort of person, I mean.

Duplicate of thread started by @joigus last Friday: https://www.scienceforums.net/topic/124936-billion-year-old-fossil-reveals-missing-link-in-the-evolution-of-animals/

Can you cite examples?

Hmm, I see. In that case we may want to be careful how responses are dealt with, so as not to provide, inadvertently, ammunition for a disinformation video later, as apparently happened last time.

It's the same group, by the look of it, including some person called Bob Knodel. They seem to have a glossy website called FECORE on which various "projects" are described, connected with investigating the curvature of the Earth. Knodel was I think involved in the Lake Balaton caper. But, be that as it may, I have my own evidence the Earth is flat. If it were round, people in New Zealand would be upside down. Well, I've been there, and I can tell you they are the right way up. So there.

Then the question becomes a different one, viz. what limits are there to the rate of pressure change the human body can withstand, or something like that. So far as I know, the most sensitive part of the body from the point of view of pressure changes is the ear. The middle ear equalises pressure with the environment via the eustachian tube, which is linked to the nasal sinuses and is very narrow, with a sort of semi non-return valve in it, to encourage the removal of any mucus discharges etc. To pressurise the middle ear, air must go the "wrong way" through this non-return valve, leading to the sensation of deafness, relieved by swallowing, that we are all familiar with in a descending aircraft. Swallowing allows the non-return valve to open and allow air in "the wrong way". If you increases the pressure too fast, you experience deafness, as the eardrum becomes stretched by the pressure difference, followed by pain as it is further stretched. The eardrum can easily rupture if enough time is not allowed for the ears to "pop" and thus transfer the increased pressure via the eustachian tube to the other side of the eardrum. Some people have difficulty equalising the pressure, especially if they have a cold or other inflammation of the sinuses. To you have to go carefully or you can inflict considerable pain and make people go deaf.

OK, then I can't answer that for sure. But seeing as borate is sold as a buffering agent, it looks to me as if using it may make use of HCl unnecessary. But you would need to check with a supplier of borate, I guess.

This is a silly question.

How long is a piece of string? The time will depend on the pressure differential, the size of the valve aperture, the viscosity of the fluid passing through and the size of the space the fluid has to fill.

It has already been patented for that purpose, but unfortunately it is so expensive to make that it has never been commercialised.https://en.wikipedia.org/wiki/L-Glucose

Meaningless question. Unless this "shape" has observable consequences, in the way the photon interacts, it is simply not real as far as QM is concerned. One could just as well hypothesise that there are pixies dancing round it on its way.

Yes, this is how it is possible for divers to go down so far, as long as the gas mixture they breathe is at the pressure of the surrounding water.

Eh? No. A photon is not split in two by a semi-transparent mirror. It is either reflected or transmitted, with 50% probability of each outcome.

If the pressure is equalised throughout the object, i.e. with no spaces at a different pressure, then merely a bit of compression of the materials of which it is made.

Agree. The hearing of these sounds, and the rather improbable persecution scenario, put me in mind of schizophrenia.

This is not so much a question about chemistry as about the shelf life of specific manufactured items. I found this link, which may point you in the direction of an answer: https://electronics.stackexchange.com/questions/8794/do-electrolytic-capacitors-have-a-limited-shelf-life From this it rather looks as though trying to put into service a 30yr old component may not be a good idea.

I don't know about a formula, but this link: https://www.borax.com/BoraxCorp/media/Borax-Main/Resources/Brochures/borates-swimming-pools.pdf seems to contain a lot of information about the use of borates in swimming pools. It seems to act as a buffer, enabling the chlorine to work in its best regime and also to soften the water by binding calcium. If it acts as a buffer, it may be that by using borates you can fully control the pH with them alone and can dispense with the hydrochloric acid entirely, but I stress I am learning all this as I go in response to your queries, so you might want to do some further checking.

It is not strictly true that water is non-compressible. Liquids are about as compressible as solids, which is to say hardly at all by comparison with gases. But they still compress a bit. If you suddenly expose the water in a torpedo tube to 100atm, you exert that pressure on the water inside and thus on the walls of the tube as well. The water will compress a tiny bit and the walls of the tube will stretch and expand a tiny bit as well. (Because it is only a tiny bit, very little work is done, so there will be very little stored energy in the compressed and stretched materials.) Water hammer is a shockwave caused by abruptly blocking the path of a moving mass of water, thereby causing rapid change in momentum. This change of momentum requires a certain impulse (F x t) and because t is so small (because it happens fast), F has to be great. So that means water hammer creates large forces and hence pressures - a pressure wave. When you open a torpedo tube that is full of water, you do not have this, because the water on both sides of the opening is static and no change of momentum occurs. So it won't cause water hammer, just a bit of stretching of the walls of the tube. As for the equalising valve, I suspect that will be because when you flood a torpedo tube in practice you most certainly do have trapped air, which will compress to 1% of its volume, storing a lot of energy and causing water to flood in as it is compressed - with momentum. So there can be large forces and energies created in that scenario, which you do not want for safety reasons. So you flood it progressively rather than instantaneously. At least, that would be my best guess as to what is going on.

Yes I suspect you touch on something important here. I'm halfway through Carlo Rovelli's book "Helgoland" at the moment. He points out that Heisenberg's approach to QM was based on deliberately restricting the model to accounting for the behaviour of systems in interactions - and not making any assumptions about what goes on in between. It is the classical mindset that assumes something goes on in between that can be defined and tracked. QM gives up that assumption. Or so I am led to understand. I feel it is not a coincidence that @Duda Jarek's posts and links continually refer to classical or semi-classical models. I suspect this is all an exercise in semi-classical modelling and should not be taken seriously as the way nature really behaves.

I'm still struggling to see what the "dimensions" of a photon, or even expectation values for a set of dimensions for an ensemble of them, can mean. According to my understanding, QM only describes how quantum objects are expected to interact (usually expressed in terms of probability distributions) and is deliberately silent on what they "do" in between. Do any of these authors suggest that the "shape" or "dimensions" of a photon predict how it will interact with other QM objects? If not, then it seems to me to be just building castles in the air.