Quantum Physics - Mass of Data

Jaybird180

Jaybird180

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Let's say you buy a new Hard Drive, something in the multiple terabyte range...multiple Petabyte range, in-fact. You unwrap the package on put it on the world's most accurate scale. It measures accurately down to the yoctogram (10^-24 grams).

You format the new disk and begin filling it with your data. After the drive is full, you weigh it again.

Does the drive's mass have a delta? Yes or No?

Does your answer change if the drive is a solid-state vs mechanical drive? Which drive has the larger delta?


----Edit------
Please explain your answers
 
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No change. It is not like writing on a piece of paper with a pen or pencil that leaves ink or graphite behind. It merely rearranges the electrical charges that tell the computer whether the bit is on or off. So theoretically, you could claim that the data is intangible and therefore not subject to certain specific laws regarding seizure.
Hypothetically, that is.
 
Assuming the hard drive is allowed to come to thermal equilibrium with its surroundings before being weighed, and it isn't in an external magnetic field, I don't see why there would be any change in energy or mass. The energy in the different orientations of the magnetic domains should not cause any net change in energy. I suspect if you impose an external magnetic field and store all "1" bits and compare the weight to the same drive that has all the bits "0" then I think you should find a difference in weight.

There is a definite change in entropy, though, regardless of technology used.

EDIT: I meant information entropy.
 
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In fact, here's a demo that will help both of you see why it has no impact on entropy or weight:

10110101111010101101010
01111000111111110110100

Which one of those would weigh more? Ok, is it possible to put it back to the original point (aka, negating entropy?)
10110101111010101101010

Yep.
 
SkyHog said:
In fact, here's a demo that will help both of you see why it has no impact on entropy or weight:

10110101111010101101010
01111000111111110110100

Which one of those would weigh more? Ok, is it possible to put it back to the original point (aka, negating entropy?)
10110101111010101101010

Yep.
Click to expand...

Well if you use different font weights, and a "1" weighs less than a "0" ..... :D
 
0100111001101111001000000110001101101000011000010110111001100111011001010010000001101001011011100010000001101101011000010111001101110011
 
Okay - to get topic back on track:

The electrical charge applied to the sectors, platters of the drive are electrons, which turn an off state to an on state (0 to 1). Electrons have mass. Therefore the mass of the drive has increased.
 
Jaybird180 said:
Okay - to get topic back on track:

The electrical charge applied to the sectors, platters of the drive are electrons, which turn an off state to an on state (0 to 1). Electrons have mass. Therefore the mass of the drive has increased.
Click to expand...

All the hard drives I'm familiar with store information by changing orientation of magnetic domains. There is no change in the number of electrons - if there were the drive would not stay electrically neutral.
 
Jim Logajan said:
All the hard drives I'm familiar with store information by changing orientation of magnetic domains. There is no change in the number of electrons - if there were the drive would not stay electrically neutral.
Click to expand...
Sounds like a fancy way of saying electrical charge???
 
Correct. Electrons are not deposited. Electrical current carries a magnetic field. The field causes the bit flip from 0 to 1. It analogous to 2 refrigerator magnets in a box (2 bits). You wave a third magnet around outside and can flip the two in the box. The magnets don't change mass when they flip.
 
Neither ssd nor platter based drive lose their data when power is removed (thank goodness!). Ram does. But, the result is still the same, it is flow of electrons not a quantified change. In= out, if you wish.
 
masloki said:
Correct. Electrons are not deposited. Electrical current carries a magnetic field. The field causes the bit flip from 0 to 1. It analogous to 2 refrigerator magnets in a box (2 bits). You wave a third magnet around outside and can flip the two in the box. The magnets don't change mass when they flip.
Click to expand...


So you're saying there was current flowing in the brand new drive from the factory when it had all zero's on it. And now the same drive has one's on it, the poles have been shifted 90*. Is that about the sum of it???
 
Jaybird180 said:
Okay - to get topic back on track:

The electrical charge applied to the sectors, platters of the drive are electrons, which turn an off state to an on state (0 to 1). Electrons have mass. Therefore the mass of the drive has increased.
Click to expand...

No.

You have a static weight, because the same effort turning a 1 to a 0 is also turning a 0 to a 1. There's no net gain or loss of any electrons, neutrons, protons, weight, or anything else.

Think of it in laymans terms: You have a switch on a wall - does it weigh more to have the switch be up, or down?
 
Jaybird180 said:
So you're saying there was current flowing in the brand new drive from the factory when it had all zero's on it. And now the same drive has one's on it, the poles have been shifted 90*. Is that about the sum of it???
Click to expand...

When it came from the factory, it was a collection of magnetic dust glued on a wheel, likely never powered. Your formatting, waved an electromagnet over very precise locations. The computer tells the electromagnet 0 or 1, causing a magnetic field (rapidly!) which when passed by the dust sets the magnetic orientation. The same electro-magnet can be a reader or writer.

This, smaller by about 1000x
http://upload.wikimedia.org/wikipedia/commons/9/92/Homemade_Electromagnet.jpg
 
Do not wave that by a hard drive as you will seriously munge the data. And doing that particular experiment makes batteries very hot! :yikes:
 
SkyHog said:
No.

You have a static weight, because the same effort turning a 1 to a 0 is also turning a 0 to a 1. There's no net gain or loss of any electrons, neutrons, protons, weight, or anything else.
Click to expand...

It takes energy to turn those domains, so the platter heats up. That heat has mass. However, that mass change is a consequence of the writing process, not the information content.

There is a allegedly a lower limit on the amount of energy that has to be expended in switching bits. See http://en.wikipedia.org/wiki/Landauer's_principle

Think of it in laymans terms: You have a switch on a wall - does it weigh more to have the switch be up, or down?
Click to expand...

Ahem. The switch in the up position has slightly more potential energy than when it is in the down position....

Better make that a switch that toggles left and right.
 
In my house it weighs more. Nothing to do with electrons, heat, or protons, just the dust it collects from sitting in my house!
 
Jim Logajan said:
Ahem. The switch in the up position has slightly more potential energy than when it is in the down position....

Better make that a switch that toggles left and right.
Click to expand...

Weight = Mass * Gravity. What does potential energy have to do with it?
 
PilotAlan said:
????????????????

I freely admit my knowledge of physics is limited to Science Channel and reading science magazines since I was a kid.
Please educate me.
Click to expand...

You might find this more educational and possibly more authoritative than from "some guy on the internet":
http://plato.stanford.edu/entries/equivME/#1.2.1

dmspilot said:
Weight = Mass * Gravity. What does potential energy have to do with it?
Click to expand...

If E=mc2, then m=E/c2. Shouldn't matter what form the energy E takes. However, you do have a point because the potential energy isn't in the switch itself but is probably in the gravitational field between the earth and the switch. At least I think that is the case.
 
Jim Logajan said:
You might find this more educational and possibly more authoritative than from "some guy on the internet":
http://plato.stanford.edu/entries/equivME/#1.2.1



If E=mc2, then m=E/c2. Shouldn't matter what form the energy E takes. However, you do have a point because the potential energy isn't in the switch itself but is probably in the gravitational field between the earth and the switch. At least I think that is the case.
Click to expand...
I never would have thought about that! Thanks. But let's keep in mind that this above is a mathematical theory. We should be able to demonstrate that heat has mass if this is true.
 
Jaybird180 said:
I never would have thought about that! Thanks. But let's keep in mind that this above is a mathematical theory. We should be able to demonstrate that heat has mass if this is true.
Click to expand...

Does a rolling ball have more mass than a stationary one? All that heat is is movement.

Remember that energy and mass can be converted from one to the other, but are not the same thing.
 
SkyHog said:
No.

You have a static weight, because the same effort turning a 1 to a 0 is also turning a 0 to a 1. There's no net gain or loss of any electrons, neutrons, protons, weight, or anything else.

Think of it in laymans terms: You have a switch on a wall - does it weigh more to have the switch be up, or down?
Click to expand...

I'm a DeVry drop out so I could be wrong:rolleyes:

...but that is my understanding also. In other words the data was already on the drive, so you're not really adding anything. You're just rearranging the magnetic field, to change logic states. 01-10
 
Does an abacus weigh more if you slide the counters to one side or the other?
 
Skylane81E said:
Does a rolling ball have more mass than a stationary one?
Click to expand...

Absolutely it does.

This is actually the reason that Special Relativity has the magic c speed limit for massive bodies. As objects go faster, they have more momentum, a form of energy. As such, thanks to E=mc^2, they have more mass. As the speed approaches c, the increase in momentum increases exponentially. The mass of such an object travelling at c would be infinite. As such, it would take an infinite amount of energy to accelerate said object to the speed of light.
 
EdFred said:
Does an abacus weigh more if you slide the counters to one side or the other?
Click to expand...

Depends on if the abacus is on a flat surface or not. And this specifically deals with weight, not mass.

If it is at all inclined, then those beads that are higher will have a lower weight than those that are lower, as they are farther from the centre of the Earth when in the higher position. As such, they experience a lower gravitational force, and weigh less.
 
JeffDG said:
Depends on if the abacus is on a flat surface or not. And this specifically deals with weight, not mass.

If it is at all inclined, then those beads that are higher will have a lower weight than those that are lower, as they are farther from the centre of the Earth when in the higher position. As such, they experience a lower gravitational force, and weigh less.
Click to expand...

So you're saying that at 20 or 30 thousand feet, in one G (no steep turns), my 190lb body weighs less?:dunno:
 
redtail said:
So you're saying that at 20 or 30 thousand feet, in one G (no steep turns), my 190lb body weighs less?:dunno:
Click to expand...

It most certainly does.

Fg=(G*m*me)/r^2

Force of Gravity = Gravitational Constant * mass of the object * mass of the earth / radius (distance between the CG of the Earth and the CG of the object) squared.

Increase the r, even by the most minuscule amount, and Fg goes down.

And this is simple Newtonian gravitation, we're not even looking at relativistic effects.
 
Of course heat has mass:
1. Heat is energy.
2. Mass and energy are interchangeable.
Ergo.

As far as proving it, it is as simple as powering a rocket towards light speed. The more energy you put into the rocket the greater it's mass becomes.
Read a popularized version of the explanation of the effects of E = MC²
 
JeffDG said:
It most certainly does.

Fg=(G*m*me)/r^2

Force of Gravity = Gravitational Constant * mass of the object * mass of the earth / radius (distance between the CG of the Earth and the CG of the object) squared.

Increase the r, even by the most minuscule amount, and Fg goes down.

And this is simple Newtonian gravitation, we're not even looking at relativistic effects.
Click to expand...

Of course. What was I thinking:dunno:.
Astronauts weigh less in orbit and they're in a constant free fall.

It's early, let me go get another cup of coffee:rolleyes:
 
redtail said:
Of course. What was I thinking:dunno:.
Astronauts weigh less in orbit and they're in a constant free fall.

It's early, let me go get another cup of coffee:rolleyes:
Click to expand...

LOL

Yeah, the weightlessness in orbit is not due to there being no gravity there (else they wouldn't be in orbit), but the fact that they're in free-fall.

Wait until someone makes the point that if you weigh an old-fashioned watch (that you have to wind), it will have more mass when wound than when it's not.
 
Interesting point about the conversion of matter and energy - I was reading a research text recently about magnetars (hyper magnetized neutron stars), and the author was discussing the strength of the magnetic field at the surface. The field is incredibly strong, and represents energy pure unit volume - in fact the energy per unit volume converts to approximately 10,000 times the density of lead per equivalent volume via our friend E=MC2 - all in the magnetic field. And yes, gravity has an effect on that field, and that field adds to the local gravity.
 
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JeffDG said:
Absolutely it does.

This is actually the reason that Special Relativity has the magic c speed limit for massive bodies. As objects go faster, they have more momentum, a form of energy. As such, thanks to E=mc^2, they have more mass. As the speed approaches c, the increase in momentum increases exponentially. The mass of such an object travelling at c would be infinite. As such, it would take an infinite amount of energy to accelerate said object to the speed of light.
Click to expand...

This brings back memories of calculus class on limits....getting closer and closer (but never getting there).
 
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