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Posted (edited)

Hi,

 

there´s an awesome experiment trending right now:

it shows the change of weight of sd cards when they are full of data. My question: is it necessary to use big sd cards like in the video or will it work with for example 64 gb cards?

 

best regards

 

Edited by HawkingA
Posted
51 minutes ago, HawkingA said:

My question: is it necessary to use big sd cards like in the video or will it work with for example 64 gb cards?

I assume the only reason for using a large number of large capacity cards is to make the difference large enough to be measurable. It would work with a 64GB card but you would need a much more precise scale to measure the effect.

Posted (edited)

Is this an April fool gag or something?

There is, in principle, a tiny change in mass due to a change in the stored energy. It would be impossible to measure it directly in this way.

Edited by John Cuthber
Posted

Some reading that you might find interesting:

https://www.scientificamerican.com/article/black-hole-computers-2007-04/ (I first read about this concept years ago it may have changed but I cannot find anything more recent).

https://arxiv.org/abs/1309.7889 does information have made? The answer is situation dependent it seems. I've only read the abstract so it might be dross. 

I did wonder about this as the SD card is already full of data, it's just not useful? This might be my missunderstanding of how we cards work. I'm far more comfortable with hard disk physics. 

 

Posted
1 hour ago, John Cuthber said:

Is this an April fool gag or something?

There is, in principle, a tiny change in mass due to a change in the stored energy. It would be impossible to measure it directly in this way.

It does seem implausible. I haven't watched the video and I don't know where it is from.

Posted
1 hour ago, Klaynos said:

I did wonder about this as the SD card is already full of data, it's just not useful? This might be my missunderstanding of how we cards work. I'm far more comfortable with hard disk physics. 

 

There is a physical difference between "erased" and data stored. Storing data means injecting electrons through an insulator onto an isolated conductor. So there will be a difference in energy (and, presumably, the number of electrons). I haven't done any calculations yet but it seems surprising that it would be easy to measure...

Posted

They assert that the mass change is 0.186 mg  or 1.86E-7 Kg

Equivalent  to a stored energy of 16 GJ or about 4 tonnes of TNT

That's just silly.

It's fake.

Posted
3 hours ago, Strange said:

I assume the only reason for using a large number of large capacity cards is to make the difference large enough to be measurable. It would work with a 64GB card but you would need a much more precise scale to measure the effect.

Would you like to calculate roughly how sensitive the balance would need to be.
:)

Posted
1 hour ago, Strange said:

There is a physical difference between "erased" and data stored. Storing data means injecting electrons through an insulator onto an isolated conductor. So there will be a difference in energy (and, presumably, the number of electrons). I haven't done any calculations yet but it seems surprising that it would be easy to measure...

Thank you for filling in some of my unknowns. Flash memory is something that seems to have fallen through things I've learnt about over the years. 

Posted

Perhaps it would be a better experiment to handle the cards and put them in and out of the equipment without changing the information on the cards at all, to check if the change in weight is due to skin cells and oil and any residue picked up in the slot.   Also if it were true, removing the data and weighing it again would return the cards to their original weight.  I think it not likely to be true, as has been mentioned, there is data, 1s and 0s even on a blank card, so the test would be to load the card with all 0s and weigh it, load with maximum number of 1s and weigh it, and then load with equal number of 1s and 0s and weigh it.  The difference between the heavier condition and the lighter condition should be x and the weight of the half and half condition should be light, plus 1/2x.  Otherwise, 1s and 0s probably are not different weights.

Posted

Certainly a careful control should have been run at the same time. Along with careful handling (gloves as a minimum). 

Also reversing by completely removing the data would have been a sensible step. 

Posted (edited)

Also the tester could have weighed the cards 5 times placing them in the exact same manner on the scale, and seen what the range of weights were to test the accuracy and repeatability of the instrument (and then tested the scale with the same 12 cards place all together, spread out on the corners, and other random alignments to see if the scale always reported the same weight regardless of placement).  Also, I was thinking, if you are talking minute differences in weight, the temperature of the cards might make a difference, as a warm card could act like a tiny hot air balloon, and have a little "lift". since the board is housed within a plastic sheath.  This would make them lighter after handling and picking up any heat from the equipment, but the timing and storage of the cards was not mentioned and the first weighing could have been after they were sitting in the sun for an hour, and the second weighing could have been made after sundown, or when the temperature of the room had dropped.  Also, the weight of the information would, if there is a difference between 1s and zeros be exactly correlated to the code the information was coded in.  That is an FF would be heavier (or lighter) than a 00.  It would not matter how "heavy" the information was, like a picture of a tank or a bicycle would weigh according to the weight of the paper and ink and not according to the amount of steel in the vehicles pictured. 

Edited by tar
Posted
45 minutes ago, John Cuthber said:

 

Or just look at the other vids they produced.

 

That footage combined with that horror scene type music is exactly what's wrong with today's kids chasing youtube hits. 

Posted (edited)

doesn't information itself have a slight mass that upon whirling about at relativistic speeds, gives an increase to mass/energy that allows measurability, such as with the casimir experiment for virtual particles and some other fundamentals such as the photon? It does seem unlikely that information in an SD card or other small storage device could be measured by weight, but then, isn't a black hole an example of how information can be accrued into a weighty substance? Any experiment with weight of such small devices would have to figure in the background noise such as air pressure  variations, if not weighed in a vaccuum and also variations in gravity on the earth, and even if done in space, with the impinging effects of  variations in microgravity and even of gravity waves noise coming from all directions...

Edited by hoola
Posted (edited)
13 hours ago, John Cuthber said:

Would you like to calculate roughly how sensitive the balance would need to be.
:)

To do that, we'd have to know how many electrons there are in a bit of information and that will be difficult...but lets try to make some informed assumptions. Lets assume we are dealing with silicon atoms which have 14 electrons. Considering that IBM says that about 1 milion atoms are needed to store 1 bit of information we arrive at 14 milion electrons per 1 bit of information. Assuming that this is accurate (which it isn't because we are dealing with SD cards not magnetic drives) it should be easy from now on:

They are using 12 SD cards of 512GB each, this comes down to 6144GB of data. This bit calculator tells me that 1 gigabyte is 8589934592 bits. 
8589934592 bits x 6144 = 52776558133248 bits in those 12 SD cards.
52776558133248 bits x 12000000 electrons in a bit = 6,33318697598976e+20
The electron mass is 
9.10938356 × 10-31 kg.
So now if somebody could multiply 
6,33318697598976e+20 x 9.10938356 × 10-31 we should end up with the actual mass in kilograms in 6144 Gigs of data. Frankly, I'm not able to make that calculation :/ 

Edited by koti
Posted

It's not the mass of the electron that matters. As John Cuthber has said, it's the mass from the energy difference of the states. 

(without a calculator it looks like the calc is 5 x 10^-10 but those electrons were already there, so it's irrelevant)

Posted (edited)
1 hour ago, swansont said:

It's not the mass of the electron that matters. As John Cuthber has said, it's the mass from the energy difference of the states. 

(without a calculator it looks like the calc is 5 x 10^-10 but those electrons were already there, so it's irrelevant)

Hmm...Im not sure I get this. Where and how is the energy difference being stored in an SD card? If we deal say with a spring snd we compress it, it will store some potencial energy and the mass of the spring will increase. This would be an example of energy/mass difference between states right? How does that correspond to SD cards or am I missing something? I always thought that flash memory like SD cards actually store electrons.

Edited by koti
Posted
7 hours ago, koti said:

Hmm...Im not sure I get this. Where and how is the energy difference being stored in an SD card? If we deal say with a spring snd we compress it, it will store some potencial energy and the mass of the spring will increase. This would be an example of energy/mass difference between states right? How does that correspond to SD cards or am I missing something? I always thought that flash memory like SD cards actually store electrons.

You trap some electrons in a transistor that makes up the bit. The electrons come from somewhere else in the circuit.

Posted
10 hours ago, swansont said:

It's not the mass of the electron that matters.

 

2 hours ago, swansont said:

You trap some electrons in a transistor that makes up the bit. The electrons come from somewhere else in the circuit.

Im confused, please help me to understand. As far as I know, electrons are being physically trapped within a flash memory chip to store 0's and 1's on it so it would seem that the electron mass has to contribute to the mass of the chip?

Posted
15 minutes ago, koti said:

 

Im confused, please help me to understand. As far as I know, electrons are being physically trapped within a flash memory chip to store 0's and 1's on it so it would seem that the electron mass has to contribute to the mass of the chip?

We're not talking about the mass on the chip, we're talking about the change in the mass of the chip. If the electrons are simply moved around on the chip, the mass of electrons does not change.

Posted
4 minutes ago, swansont said:

We're not talking about the mass on the chip, we're talking about the change in the mass of the chip. If the electrons are simply moved around on the chip, the mass of electrons does not change.

The electrons don't move around the chip. they move in and out of the chip.

Posted
38 minutes ago, swansont said:

I'm reading through the link you posted and this is more complicated than I thought. I still don't get it, either an electron is trapped inside the chip and leaves when data is being erased or not. Or maybe I'm just too dense...I don't know, I will need to read up on this later on in the evening.

Posted
17 minutes ago, koti said:

I'm reading through the link you posted and this is more complicated than I thought. I still don't get it, either an electron is trapped inside the chip and leaves when data is being erased or not. Or maybe I'm just too dense...I don't know, I will need to read up on this later on in the evening.

The charge is trapped within the transistor, and leaves when the bit is erased. 

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