The more you save on a flash drive, the lighter it gets?
sciencefocus.com
sciencefocus.com
Take a 2 TiB flash drive. That’s 1e13 bytes or 1e16 bits. Suppose it’s one electron per bit. That’s approaching 1% of a Coulomb! So you take two flash drives, charge them up, and hold them 1cm apart, and they fly apart with several hundred meganewtons of force! The electrostatic force is strong!
This is, of course, completely wrong. When you write to flash, you are moving electrons around, not adding net electrons. The whole device stays electrically neutral (on average), and any mass change is due solely to minuscule relativistic effects if you add or remove energy.
> I worked on all sorts of problems that involved the Coulomb interaction, and occasionally my proposed solution would be very wrong. The worst kind of wrong was the one that made my advisor remark “What you just created is a Coulomb bomb,” which meant that I had proposed something that wasn’t neutral on the large scale.
This is similar to what it means to "charge" a capacitor. It doesn't mean injecting or removing electrons from it, because that would cause a net charge. It actually means shifting electrons from one electrode to the other, separated by an insulated gap. http://amasci.com/emotor/cap1.html
Ironically, that makes a Dunning-Kruger Effect effect.
https://gwern.net/doc/iq/2020-gignac.pdf
Do you think a physicist would be less certain that OP is wrong, than how certain OP is that he is right?
This is not the correct application of the effect.
A physicist would have been sure about this particular case being wrong, but would likely be a lot more careful and concise about what he's talking about. Also a physicist is supposed to be more confident, as they are on the far right side of the curve.
Being at the bottom of that curve is reserved for folks like me who rely on common sense but cannot be certain outside of extremely basic cases like knowing that electrons are not leaving the USB en masse.
(Also, 2 TiB is just 2e12 bytes, and 2e12 bytes only equals 1.6e13 bits, it’s log2(8) that’s 3, but that doesn’t really affect your conclusion.)
$ units -t 'coulombconst * (2 TiB * atomiccharge/bit / cm) ** 2'
714.00592 kg m / s^2
In reality, much more than 1 electron is required to store a 0 or 1 with any level of reliability. On the order of 10s to 100s of electrons per bit even on leading processes.
What about the mechanical strain caused by the charges? Would the device be more compressed due to the attraction between the opposite charges associated with charged bits? Since the device is in air, it would then displace less air. Even though the device mass would be the same, the weight would be more.
They were amazed and delighted when I compared the weight of my iPhone to the weight of one of the store iPods and showed them how much more music was on my iPhone compared to the store iPod.
Teaching people about how technology can improve their lives can really be rewarding.
Of course once they were gone the staff ended up in a debate about the actual technical scientific answer. I don't think we ever came to an agreement on it.
This raises an interesting point. It's very undesirable to have long sequences of all 0 or 1 in a digital stream that is being read subject to a lot of analog effects. You want the line to return to a known state. This is why simple serial communication protocol like RS-232 uses a mark bit, to synchronize the clock repeatedly to protect against drift.
It's possible -- and usually preferable -- to implement a digital coding in a way such that the average signal intensity is 50% and there are an approximately equal number of 0s and 1s physically speaking, with frequent crossings, regardless of the actual signal contents. Unsurprisingly, CDs do this on several levels, first permutating the stream into blocks with error correction, and then into a line coding that has regular transitions even if the stream is all 0/1. Though they're not guaranteed to literally have the exact same number of 0 and 1 bits across any content.
The iPod has a tiny notebook inside that it uses to remember your songs.
In any case, the charge on the device would be negligible in any direction. It's a ridiculously small amount of charge when compared to the overall device, or even the substrate material of the flash memory cells.
Would be fun to do an experiment though. Maybe in 100 years we'll be able to do that.
Core memory (ferrite bead), SRAM (4 transistors/bit) and DRAM (1 transistor with a pseudo capacitor/bit) would increase in relativistic weight depending on their state.
The same is true of batteries, ultracaps, or anything that consumes or stores large amounts of energy. m = E/c^2. 1e17 J weighs about 1 kg. That's about the energy of 2 of the large nuclear weapons ever tested.
Let's suppose we have an average largish lake, 100 km^3 or 1e14 kg of water, and we store it at average height of 60 m above a generator. PE=m*g*h. That 6e16 J of potential energy weighs 651g.
https://pubs.aip.org/aip/sci/article/2022/9/091111/2849001/A...
How intuitive is the mass-energy equivalence? Before Einstein's era, people might have said that such an idea clashes with the intuition that is a completely separate thing from energy.
Physicists are always looking for equivalences and conserved quantities. They are the basis for modern physics. It's how we discovered that 3 of the 4 known forces were all based on the same equivalent principle. You find a conserved quantity that unifies the two forces.
Possibly one of the greatest feats of this was Maxwell when he unified electrical and magnetic forces by discovering an equivalence between the two that allowed energy to be conserved. This helped us to discover the underlying principles of light itself and describe it as an electromagnetic wave.
Information conservation could prove to unify gravity with the remaining forces. Or not! Or it could break them all apart again. That's just what scientific inquiry is all about.
It's an active area of research because of this because it may point to a way to reconcile the incompatibilities between QM and Relativity to get a Grand Unified Theory. I believe Loop Quantum Gravity ends up with effects around this mass-energy-information/entropy equivalence idea as an emergent property of how it's trying to reconcile QM and Relativity.
Intuition hasn't been a good guide for physics since newton. It's not clear to me that anything physical is separate from the information that describes it though.
To be more concrete, bmacho equation, E = mc^2 + q*6*10^23 J/e holds for every experiment, every theory (standard model, GR). It states that energy is equivalent to mass and charge.
Unfortunately, your argument here is implausible. There have been tens of thousands of experiments demonstrating mass to energy conversion. It is the basic principle behind nuclear energy production. Mass energy equivalence is necessary to maintain conservation laws and has been proven by empirical observation. The total mass/energy in the system will not change, however the two can be exchanged for each other.
> Information having energy is well known since Boltzmann
Information having mass/energy has not been proven. There have been no experiments to support this argument. It is merely a theory.
> ..as entropy is measured in J/K
Entropy is not a conserved quantity since it will increase within a closed system. The Joules/Kelvin unit comes from statistical mechanics where temperature is defined as a change in entropy per increase in total energy. The entropy used in information theory is different, although related. Entropy in information theory is measured in bits.
And if you ascribed meaning to random data it would gain weight...
Possibly.
> And if you ascribed meaning to random data it would gain weight...
You would have to create a dictionary with that meaning which would be more information that would add that theorized weight. This is a common problem in compression.
For instance, if you have the state "H" and want to add a meaning to it "High Temperature" you need to create a third piece of information "H" -> "High Temperature"
You are not changing the information in "H" or "High Temperature" you are merely creating a third piece of information which is the lambda.
Take for instance the word "Red." To a computer this means: 52, 65, 64
The there is a mapping to letters call an ASCII table or UTF-8 encoding. Then there is a mapping from character data to a bitmap containing the letters projection on a screen. Then there is a mapping in your brain that associates that sequence of letters to a neural structure that encodes your memory of the color red. That mapping was created by a teacher that showed you the color red next to those letters.
But in the end, the numbers 52, 65, 64 haven't gained any information. They could still mean anything based on which system interacts with them. An RGB color picker will interpret it as a nice teal color. Without knowing what system to use to interpret their meaning, they are meaningless aside from the numbers themselves. You need the key to find the difference which is information itself.
A lot of "Ifs" though.
Which suggests that one way to decide is to take two USB drives, one full of information and the other empty and throw each into a separate black hole of identical mass.
Then wait until both black holes evaporate and check if there is any black hole hair left.
[1] https://en.wikipedia.org/wiki/Black_hole_information_paradox
Re GP: It's a closed system, with a constant number of neutrons, protons, and electrons (electrons flow in and out, but protons don't, so the number of electrons has to stay the same).
The mass being added and removed is the mass created and destroyed when you destroy/create a chemical bond. Bonds store energy, and that energy is converted to mass following e=mc^2.
If bonds don't store energy, how does breaking hydrocarbon bonds release energy? It doesn't - it's just that the new bonds formed in CO2 and H2O release more energy than it took to break the hydrocarbon bonds.
Energy is not not a substance. Is a meaure of an entire configuration of states. Forms of energy is an "interpretation", a metpahor.
C02 + H20 has less energy than CH3 + O2, because C02 + H20 are more stable (= lower energy) bonds.
You can say the energy is in the electron, released as it falls into a lower energy state (bond).
If I walk up a hill to a cliff, am I then in a more energetic state?
No, because it takes energy to push me off the cliff, the ground is a more stable position than the top of the ledge and the appparent energy released by me turning a windmill I hit on the way down is because more energy is released by freefalling off a cliff than by sitting down on top of the ledge?
or Yes, for exactly the same reason?
> However, you would need to weigh more USB drives than exist on the planet together at once before the difference in weight became easily measurable.
Scales precisions limits are not absolute, but relative to their measuring range, so if a weight change is too small to measure, the solution is better scales, not more stuff.
Disclaimer, only a fun thought exercise, I know very little about these things.
Regardless of what you call the states, what makes flash flash (as opposed to EEPROM) is that it's erased in large blocks. So the chips should come out of the factory erased. Whether that means all ones or all zeros is up to the manufacturer.
They were fixated on much storage in bytes it must have to store the music
The amount of audio stored on a vinyl record depends on the amplitude of the signal. Loud sounds and thumping bass will increase the spacing between tracks, thus reducing the recording time.
Good encryption algos will have an average of 50% 1s and 0s regardless of the plaintext data.
How the cell presents "voltage" has to do with exactly the wiring of the source and drain on the flash cell, not the basic structure.
The weight of the drive varies with the sum of the charged cells.