Science desk
< October 22	<< Sep \| October \| Nov >>	October 24 >

Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is a transcluded archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

October 23[edit]

Extrasensory perception and quantum entanglement[edit]

I wonder if there is a connection? I think it was Eugene Wigner who made a statement about it. He essentially said that consciousness is impossible without a quantum operation and that is the wave function collapse. There had been so many talks recently about quantum entanglement and quantum communications that it rekindled a long forgotten episode in my life. I was in a medical school at that time and a group of us got interested in "supernatural." We did Zener's cards and all the experiments failed. There had also been a talk about spontaneous extrasensory perception. I had a personal contact wish a person who claimed such experience. I don't remember his name and will call him Mr. X. The event happened decades before I met him, he published a skinny book, an account of what happened, and this is how we found out about him. This is what he said. As a young student he lived in a large metropolitan city away from his family. His father, a sick man, lived two thousand miles away in their family home. There was a caregiver involved, a young female. One day, at appointed time to give him a medication, she approached him with a glass with the medicine and a silver spoon. When she looked at him she realized he passed away. Startled she dropped the spoon in the glass which made a distinct sound of a bell ring. Mr. X claimed that he heard that sound at exactly that time.

It's important to give a characteristic of this man. He spent some years after that, trying to promote the possible research in the issue with no result since nobody wanted to deal with it. My understanding is that he never made a nickel out of his experience. He presented to us as an old, humble individual without much ambition or show off tendency. For him our visit was a chance to go down a memory lane once more since he lost interest in the problem long before we came. I am certain he told us the truth.

I lost interest in extrasensory perceptions long ago also but what if there is a connection between the two phenomena in the title? Thanks, AboutFace 22 (talk) 16:54, 23 October 2019 (UTC)[reply]

NO. Good god no. Extrasensory perception, in the sense of "magical powers to sense things no one else can" is unmitigated bullshit. Physicists even have a derogatory name for the "magic can be explained by quantum!" and it's quantum woo. Magical powers are not caused by quantum effects. Just no. --Jayron 32 17:46, 23 October 2019 (UTC)[reply]

See our Articles Extrasensory perception and Quantum entanglement for an overview. I am not a professional in this but id guess the Hidden-variable theory seems the closest answer for the moment. --Kharon (talk) 17:52, 23 October 2019 (UTC)[reply]

No, its not. The closest answer for the moment is "it's bullshit". Hidden-variable theory is part of the discourse among scientists to explain what was (at the time) some of the unexplained phenomena associated with Quantum physics. It is decidedly not "how quantum causes magic". --Jayron 32 18:07, 23 October 2019 (UTC)[reply]

As they've said on the TV series "Brain Games", our brains try to make sense of things. Pattern recognition, whether real or coincidental. A gentle term for it is "superstition". There's also the matter of "intuition", which some folks (especially con artists) are pretty good at. ←Baseball Bugs ^{What's up, Doc?} carrots→ 18:26, 23 October 2019 (UTC)[reply]

How much information can be stored in a single atom?[edit]

How many bits of data could be realistically stored in a atom, assuming optimal storage method(s)? — Preceding unsigned comment added by MoonyTheDwarf (talk • contribs) 23:57, 23 October 2019 (UTC)[reply]

One. ←Baseball Bugs ^{What's up, Doc?} carrots→ 00:11, 24 October 2019 (UTC)[reply]

Baseball Bugs, Even assuming more unusual data storage/retreival methods? MoonyTheDwarf (Braden N.) (talk) 00:23, 24 October 2019 (UTC)[reply]

You can store information by exciting the atom into a different electronic state. This will store more information. This will be in addition to a direction of spin for the nucleus. Most states will not be long lasting though. You may also get information from where the atom is. Graeme Bartlett (talk) 02:20, 24 October 2019 (UTC)[reply]

Wikipedia has an article entitled Entropy in thermodynamics and information theory. Specifically, Landauer's principle allows us to relate information storage to the entropy of the physical system: particularly, if we have a method to store information embedded in some degree of freedom of the atom - like its position, or its quantum state, or its electron energy levels, or whatever, then we impose a minimum requirement for additional degrees of freedom. Since we can enumerate the number of degrees of freedom for a simple atom, we can put a hard boundary on the number of bits that can be theoretically stored.

Theoretically, this means that the absolute maximum number of bits is about equal to half the degrees of freedom available to the atom. As it turns out, it's a bit subtle and tricky to actually count how many degrees of freedom there really are; but this is actually less important than it seems, because of a much bigger practical problem.

Practically, the limit is much more constrained: real machines that we know how to build have poor signal-to-noise ratios, and we need to use many atoms to store a single bit, relying on statistical coherency to keep the information retrieval above the noise-floor. So, for example, a modern semiconductor storage device might use, say, a simple bit storage circuit with memory cells built out of a single transistor and a single capacitor. Even on our smallest, most microscopic processes, these parts are composed of hundreds of atoms per device. Since we need a few of these devices to build the standard circuit that stores one single bit, that means that we average at least several thousand atoms per bit (or, less than one fractional part of a bit per atom). This bit is essentially stored in the ensemble, coherent, deterministic placement of many individual electrons, on many individual atoms, connected to each other in the form of a micro-circuit; and we can store the information by placing electrons in specific places - applying a voltage; and we can read the information by checking where the electrons are - measuring a voltage; and we normally do these tasks using standard circuits. The limiting factor is that we demand reliable information storage: these circuits use many individual atoms and many individual electrons for redundancy against the very real tendency of electrons to ... not stay where we put them. That tendency is a hard fact of our universe and is never going to change. If we could tolerate more errors per unit of time - in other words, if we could accept an incorrect readback, or more formally - if we could accept the occasional loss of the information - we could pack more bits into fewer atoms.

Experimental physicists have built smaller devices - the famous single-atom transistor made the news a few years ago - but it's a very poor-quality transistor, and we don't use devices like that if we care about storing information.

And of course, nothing constrains us to using the electrons. We could store information on atoms in a manner other than the construction of electronic circuits: for example, by manipulating the spinstate of its nuclear magnetic moment, as some qubit researchers have attempted - but again, that would be a less reliable information storage device than what we have today. So far, no reliable researcher has shown any advantage to storing information in these esoteric fashions; every effort to store bits on atoms in weird ways - no matter how scientifically interesting - has so far yielded devices which are worse at storing data than conventional electronic circuits.

Now, just this morning, a major corporate researcher has published claims in a major peer reviewed journal - Quantum supremacy using a programmable superconducting processor ... so, maybe the new era is upon us... but at least a few dissenting opinions are already hitting back against what has been claimed. This is still pretty fresh stuff, and we'll see where it lands after the research community has a few years to digest it all.

Nimur (talk) 03:20, 24 October 2019 (UTC)[reply]

One proposed method of data storage is to substitute one atom for another in a crystal lattice, where the two atoms behave similarly, such as carbon and silicon. You could use more than 2 elements in each spot, but assuming you only select between 2 elements, that would mean one bit per atom in the crystal. Note, however, that only the surface is reachable, so that the surface atoms could be read non-destructively, while atoms at a depth could only be examined by removing the layers on top. SinisterLefty (talk) 20:37, 30 October 2019 (UTC)[reply]