Leaderboard

My understanding of the process is that each time we revisit a memory we also slightly rewrite it. It gets slightly edited every single time we think about it. Basically, the more we think about it over time, the less likely it is to remain accurate and maintain fidelity to the actual experience. This is a result of how recall works, not some intentional manipulation or conscious attempt to embellish.

I experienced this a few times when I was younger and especially in high stress / trauma situations. You’re description of it as a forecast resonates with me. The things in my dreams were directionally correct and vague enough to allow different details to fit into it when they were experienced in waking life. When I got to college, I noticed similar feelings when under the influence of THC, but I chalked those up more to flawed transition from short term to long term memory... basically an encoding error or a retrieval / recall error. Similar, but obviously different from the first... the thing you’re describing here. An intuitive forecast based on lots of variables and inputs, not all of which were conscious of. Interesting idea. ✌️

They aren't. The spin of the proton is aligned with the magnetic field in MRI - pointing in that dierection. That doesn't mean the atoms are lined up in a line. Spin is quantized. You can't reduce the spin. You reduce the CoM motion. Spin is quantized. All you can do is change the orientation of the spin. Yes, there is a field, but the force is optical, not magnetic. The function of the field is to Zeeman shift the resonance of the atom. Without the magnetic field you have what is called optical molasses. Cold atoms where the lasers overlap, but not confined. You don't get as many atoms in a molasses, but you can get them colder by letting the cloud expand (in a BEC, the next step is a magnetic trap, and then evaporative cooling)

Apologies, I should have qualified my use of "precognitive dream" as a reference distinguishable from some unproven psychic phenomena. It is not a suggestion that I or anyone possesses some extraordinary perceptual ability. As I perceive and use this reference, it describes the predictive nature of a dream type and content that isn't anymore extraordinary that weather forecasting. Meteorologists, for example, can forecast atmospheric occurrences within a relative degree of certainty with sufficient data. Likewise, there's a significant amount of sensory experiences that escape our conscious perception but not necessarily our unconscious awareness. As I understand, precognitive dreaming is about the unconscious nature of brain function and how that function accumulates, processes and accesses huge amounts of sensory data to produce predictive outcomes. Using my muddy shoe dream as a example, it's likely that I was unconsciously aware of the potential for someone stepping in some muddy area near my parent's home and that anyone leaving or entering that resident might muddy their shoes if not particularly attentive. Unfortunately, my sister was that person and my dream appeared to forecast that she would muddy her shoe. Further, it may be that I was unconsciously aware that the shoe she muddied was one of a pair she might have worn frequently at the time and that if she were to step in some mud puddle, that pair would be the ones soiled. I cannot now know for certain, given the number of years that have past since that dream, what I did or didn't know about the grounds of my parent's home or my sister's foot apparel preferences at that time. What I do know is that this dream experience compelled my many years of interests in the extraordinary nature of our unconscious--which is the focus of my interests here in these discussions. Amusing and yes, coincidence does indeed appear to be the most reasonable and applicable explanation as it relates to the general nature of real life experiences; however, coincidence is not a word that apply to the nature of dreaming and dream content in brain function. Empirically, the science suggests that dreaming is not a coincidental act of brain function in sleep and neither is dream content. On average occurring at 90 minute intervals, dreaming initiates as a consequence of atonia near the end of the deepest stages of NREM glymphatic cleansing. Dreaming emerge as a response to the increase sensitivity of brain function to stimuli in sleep due to the partial removal of sensory suppressing interstitial cell waste (adenosine) and brain chemistry (melatonin). Dream content is an interpretive response to the stimuli our brain experiences in sleep. The elements of my dream suggest something deeper, which I cannot now confirm given how long ago it occurred. Nevertheless, I appreciate your perspective.

On a minor note, how are we all identifying "the least number of assumptions"? A Theory in Biology can use a small number of words and what appears to be a small number of assumptions. However, the moment any of that is something like "and this keys to the recptor site", there are actually a thousand-and-one small assumptions attached. There are assumptions that microscopic objects like molecules behave like macroscopic objects. That ping-pong ball models of molecules actually convey information about shape. Within each molecule the inter-atomic bonding is also represented by some generalised theory of bonding. In particular, it was never assumed necessary to find exact solutions to any Schrodinger's equation for the molecule. If Ockham's razor is applied as a judgement tool for science then Chemistry isn't far removed from wishful thinking and Biology is something akin to superstition. However, Biology is obviously an extremely valuable science. That is the one that has developed vaccines for the Covid-19 virus. It has demonstrability of predictions and utility for human beings "in spades" and that is what makes it a high value science. If we had been determined to make the least number of assumptions, then computers would still be trying to find numerical solutions to wave equations today and human beings would not yet have had the understanding that molecules in the Pfizzer or AstraZeneca vaccine could even hold together.

Archimedes is supposed to have said "Give me long enough lever and a place to stand and I can move the earth". The "place to stand" is crucial! When your strong man is pushing against the wagon what are his feet pushing against? When he is standing on the ground, outside the wagon, His arms are pushing the wagon one way while his feet are pushing the ground in the opposite direction. Of course the earth is so large it isn't going to move so it is just the wagon that moves. When he is standing in the wagon his arms are pushing the wagon one way and his feet are pushing the wagon the opposite way. it is a stalemate! Nothing moves.

The transition that you use in MRI is not the same as you use in laser cooling. In MRI you cause Larmor precession at a frequency that's resonant because you have put on a magnetic field to match the frequency of the RF. The emission pattern of the radiation is laser cooling is isotropic, which is why the force from emission averages out to zero. As far as I know this is not the case for MRI interactions. If the incoming and outgoing photon are in opposite direction, so net momentum change occurs — the atom doesn't slow down. Cooling and trapping requires that you scatter enough photons before the atom has passed through the interaction region. If you don't do this, the atom will not be trapped. If it passes through it then hots the vacuum chamber wall or, since the "dark vacuum" still has background gas, some other atom, and re-thermalizes. Even if you managed to trap an atom or two, these collisions will liberate them from the trap. You use the optical frequency of the D2 transition (which minimizes the optical pumping I mentioned earlier) which for Rb is at ~780 nm The 500 MHz they mention in the wikipedia article is ∆w, which is the Doppler-broadened width (FWHM = full width at half-maximum) of the transition, not the transition frequency. IOW, the laser has to be within about 500 MHz of the center to be resonant with one of the atoms in the thermal distribution (the Maxwell-Boltzmann distribution that is mentioned). They mention the natural line width of 6 MHz, which is true for any Rb atom at rest. That's how closely you have to tune the 780 nm light to be most likely to be absorbed by a particular atom. Here is a trace from this paper https://advancedlab.physics.gatech.edu/labs/SaturationSpectroscopy/SatSpecManual.pdf It shows the saturated absorption signal of the D2 transitions in Rb for both isotopes (around 500 MHz FWHM) and the individual structure because they are doing Doppler-free saturated absorption, which can show the transitions for the atoms with v=0 in the ensemble. Those are nominally 6 MHz wide, but broadened by other effects, like laser power.

Any model selection process which uses AIC or BIC (or any other variable penalisation method) is explicitly using Ockham's razor to prevent over-fitting of models. I'd wager their use is increasing not decreasing.

@studiot I actually was not online at the time you posted this. I just saw this Now. Usually I keep these type of tabs open in the device and so that's why probably it was showing. I am now gradually getting a feel of it. I have tried to draw the diagram of your scenario as elaborately as possible . Though I did not understand this analogy clearly. It would be helpful if you elaborate a little more. But I have climbed up to the nodes of the branches of the tree , I just need to climb to the apex of the shoot.😁 If you elaborate the diagram of my case (with your explanation) a little more, I will feel like a book. I can't describe anything in words but thanks for the help

While this thread is closed and (I think) being the only person who identifies as female in this thread, I just wanted to provide a little food for thought. Of all the women in my life with whom I am close to, I can't think of a single one who hasn't been sexually assaulted or raped by a man at some point in her life. I cannot say the same about the men I know wrt to false accusations. Anecdotal I know, but something to think about.

Hmm, first of all, thanks for the explanation. I thought I can have the rubidium gas atoms flying around so it can be cooled by radio wave, but it seems a magnetic field line is needed to line up the molecules so they go into precession(rotation). This is in contrast to the laser cooling in which the molecules are "confined" in a region, to me it seems like the laser needs enough strength so that it produces a 500MHz frequency at the "center" of the magneto-trap. But since I have the molecules lined up with a magnetic field, all I need to worry about is the rotational frequency. As you can see below in the article that the water molecule rotational transition is at the microwave region 200 cm−1. But I do not know the rotational transition frequency for rubidium = =. https://en.wikipedia.org/wiki/Electromagnetic_absorption_by_water Of course I cannot think of a way to line up the rubidium gas atoms with the magnetic field line = =. So I will work on that(if someone knows feel free to let me know). P.S. Many thanks for Dr. Swansnot's on the explanation on laser cooling. If I made a mistake I will go back and look into them

No you are trying to cool down the precession with atom's rotational frequency absorption of electromagnetic radiation, IOW make the atom spin slower. Laser cooling does not cause confinement, but your magneto-trap does, it exhibits zero magnetic field at the center, so the atoms are not lined up but confined. A lion in a cage can move around. A lion lined up in a cage cannot move around. Ya well professor Swansnot @@. Well the point a about a 2-D magneto-optic trap is I am gonna use a magnetic coils, not lasers, so it has a wider coverage. But ya maybe opposite polarity so they stay at the center, good funnel