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Einstein-Landauer culinary units (www.smbc-comics.com)

submitted 2 weeks ago by green_copper@kbin.earth to c/science_memes@mander.xyz

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SMBC Comic

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[-] HawlSera@lemm.ee 29 points 2 weeks ago

Information is physical? I'm gonna need a source on that one.

[-] cholesterol@lemmy.world 20 points 2 weeks ago

The idea is that information must have a physical representation. But I don't know how that would lead to a standardized mass of a byte.

[-] vithigar@lemmy.ca 22 points 2 weeks ago* (last edited 2 weeks ago)

No, you missed the point. See @milicent_bystandr@lemm.ee's comment and link to Landauer's Principle, the namesake of which is literally named in the title of the post.

TL;DR: Storing information requires a change in entropy. A change in entropy requires a change in energy. There must be a minimum non-zero amount of energy required for a given quantity of information. Energy is mass due to mass-energy equivalence. ∴ information has mass independent of its physical representation.

[-] cholesterol@lemmy.world 2 points 2 weeks ago

There must be a minimum non-zero amount of energy required for a given quantity of information.

Okay, but I still don't get how that leads to a standardized measure of energy/mass for a given amount of bytes. That seems to be the premise of the comic.

information has mass independent of its physical representation.

So what is the mass of a byte of 'pure' information? And how do you derive it?

[-] vithigar@lemmy.ca 17 points 2 weeks ago

So what is the mass of a byte of ‘pure’ information? And how do you derive it?

That's all in the linked wikipedia article, but since you asked:

At room temperature, the Landauer limit represents an energy of approximately 0.018 eV (2.9×10^−21^ J).

That's 1 bit, so 1 byte is eight times that, which you can plug into E=mc^2^ to get its absurdly small equivalent mass.

It's important(?) to note that Landauer's Principle is not settled science and has yet to be rigorously proven, unless there's some recent development which the comic is referencing. I haven't checked.

[-] cholesterol@lemmy.world 2 points 2 weeks ago

That’s all in the linked wikipedia article

I appreciate you spelling some of it out, because I'm just curious and don't have the background knowledge to really navigate this.

[-] kevin2107@lemmy.world 1 points 2 weeks ago

Then appreciate it for what it is. A meme.

[-] kevin2107@lemmy.world 1 points 2 weeks ago

Go back to school

[-] lennivelkant@discuss.tchncs.de 2 points 2 weeks ago

When referencing another person's comment, it can be helpful to link to that comment or the article you mentioned.

I'd also like to point out that many Wikipedia articles, particularly those written by experts on a given scientific subject, tend to be daunting rather than helpful for people not yet familiar with that subject.

Explanations like the one you offered in this comment and the next reply can help make topics more approachable, so I very much appreciate that.

To illustrate my point:

In this case, the article first describes the principle as "pertaining to a lower theoretical limit of energy consumption of computation", which doesn't directly highlight the connection to information storage. The next sentence then mentions "irreversible change in information" and "merging two computational paths", both of which are non-trivial.

From a brief glance at the article on reversible computing linked further on, I gather that "irreversible" here doesn't mean "you can't flip the bit again" but rather something like "you can't deterministically figure out the previous calculation from its result", so the phrase boils down to "storing a piece of information" for our context. The example of "merging computational paths" probably has no particular bearing on the energy value of information either and can be ignored as well.

Figuring out the resulting logic that you so kindly laid out – again, thank you for that! – requires a degree of subject-specific understanding to know what parts of the explanation can be safely ignored.

Of course, experts want to be accurate and tend to think in terms they're familiar with, so I don't fault them for that. The unfortunate result is that their writings are often rather intransparent to laypeople and linking to Wikipedia articles isn't always the best way to convey an understanding.