Exa-Exabyte
Exa-Exabyte
[Miss Lenhart is holding a pointer, and is pointing it towards a blackboard behind her, while she addresses her student Cueball who is sitting on a chair at a desk to the left of her, holding his hands on his knees.] Miss Lenhart: Biology is hard because there's so much of it. Earth hosts about 10 exa-exabytes worth of DNA.
[In a frame-less panel, the panel has panned to the left and is now showing Miss Lenhart holding the pointer to her side, but without the blackboard. In front of her is now both Cueball and Megan sitting at their desks. Cueball has taken one hand on to the table. Megan has both hands folded on the table in front of her.] Cueball: What's an exa-exabyte? Miss Lenhart: It's 10 36 bytes. Cueball: How do I picture that? Miss Lenhart: Imagine you had an exabyte of data, but each byte contained an exabyte of data.
[Zoom in on Cueball's head. A starburst to the right indicates Miss Lenhart's voice from off-panel.] Cueball: I can't even picture what an exabyte is. Miss Lenhart (off-panel): It's 10 18 bytes. Cueball: But how do I picture 10 18 ?
[Zoomed out to showing Megan, Cueball, and Miss Lenhart along with the blackboard. Megan has raised a hand palm up. Cueball is looking back at her over his shoulders.  Miss Lenhart is forming a closed first with her empty hand, the one without the pointer.] Megan: Imagine you had 10 apples. Megan: Now imagine 18 smaller apples, floating next to them and a little above. Cueball: Cool, got it. Miss Lenhart: No!
In 1519: Venus , release date May 1, 2015, Miss Lenhart indicated that she was retiring as a primary or secondary school teacher in a month. Here we see Megan and Cueball, both adults, sitting in a classroom setting with Miss Lenhart providing instruction.  A reasonable assumption is that Miss Lenhart has taken some form of adult education job during her retirement.  For example, in the United States it is common for community colleges to use low paid adjunct professors who either have a day job or another source of income such as a teacher's pension.
There is also a hint of irony in her having to now put up with the same type of blatantly incorrect explanations that she herself was freely giving out just prior to her retirement.
This comic is arguably the ninth comic in a series of comics related to the COVID-19 pandemic . This comic does not mention the disease but it does mention biology.
This is a comic about the difficulty of picturing or understanding large numbers. As mentioned in the comic, an exabyte is 10 18 bytes, while an "exa-exabyte"—not a common word, but one that abuses the principles of metric prefixes —would be 10 36 bytes. 10 36 is properly given the name undecillion (in short scale, and sextillion in long scale). 
According to a 2015 article by The New York Times , researchers estimate that there are about 5 * 10 37 DNA base pairs on Earth (50 trillion trillion trillion). So Miss Lenhart 's claim of 10 exa-exabytes—1 * 10 37 bytes is a reasonable approximation ( Fermi estimation ).  (The estimate was 5 plus or minus 4 * 10 37 .  There are 4 possible base pairs, or 2 bits per pair, a byte is 8 bits.)
These numbers are larger than most people can imagine. Even much smaller numbers such as a billion (10 9 ) or a trillion (10 12 ) are hard to imagine. For instance:
Wikipedia has an article on the exabyte and one on large numbers which describes various things close to 10 18 .
Cueball expresses his difficulty in visualizing a number even as large as one exabyte (10 18 bytes).
Megan trivializes the problem away by describing an exabyte as 10 apples, with "18 smaller apples, floating next to them and a little above", representing the notation 10 18 using apples for digits. This is entirely unhelpful, as using apples in a base-1 enumeration offers no obvious advantages over base-10 in understanding exponents; Megan's bad advice & Cueball's seemingly ready acceptance of it causes Miss Lenhart to yell out "No!" in frustration.
The title text further trivializes the problem of visualizing large numbers by suggesting that you can visualize 10 18 as a number by simply visualizing the similar-looking number of 10 13 with some extra lines drawn to turn the 3 into an 8. Changes in exponents can cause huge changes in the value shown, and this is no exception: Changing that 3 into an 8 changes the value by a factor of 100,000.
Randall has previously discussed the difficulty of large numbers in 2091: Million, Billion, Trillion , 1894: Real Estate , and 558: 1000 Times .
1605: DNA also discusses how "hard" biology is.
[Miss Lenhart is holding a pointer, and is pointing it towards a blackboard behind her, while she addresses her student Cueball who is sitting on a chair at a desk to the left of her, holding his hands on his knees.] Miss Lenhart: Biology is hard because there's so much of it. Earth hosts about 10 exa-exabytes worth of DNA.
[In a frame-less panel, the panel has panned to the left and is now showing Miss Lenhart holding the pointer to her side, but without the blackboard. In front of her is now both Cueball and Megan sitting at their desks. Cueball has taken one hand on to the table. Megan has both hands folded on the table in front of her.] Cueball: What's an exa-exabyte? Miss Lenhart: It's 10 36 bytes. Cueball: How do I picture that? Miss Lenhart: Imagine you had an exabyte of data, but each byte contained an exabyte of data.
[Zoom in on Cueball's head. A starburst to the right indicates Miss Lenhart's voice from off-panel.] Cueball: I can't even picture what an exabyte is. Miss Lenhart (off-panel): It's 10 18 bytes. Cueball: But how do I picture 10 18 ?
[Zoomed out to showing Megan, Cueball, and Miss Lenhart along with the blackboard. Megan has raised a hand palm up. Cueball is looking back at her over his shoulders.  Miss Lenhart is forming a closed first with her empty hand, the one without the pointer.] Megan: Imagine you had 10 apples. Megan: Now imagine 18 smaller apples, floating next to them and a little above. Cueball: Cool, got it. Miss Lenhart: No!
In 1519: Venus , release date May 1, 2015, Miss Lenhart indicated that she was retiring as a primary or secondary school teacher in a month. Here we see Megan and Cueball, both adults, sitting in a classroom setting with Miss Lenhart providing instruction.  A reasonable assumption is that Miss Lenhart has taken some form of adult education job during her retirement.  For example, in the United States it is common for community colleges to use low paid adjunct professors who either have a day job or another source of income such as a teacher's pension.
There is also a hint of irony in her having to now put up with the same type of blatantly incorrect explanations that she herself was freely giving out just prior to her retirement.