## 1161: "Hand Sanitizer"

This forum is for the individual discussion thread that goes with each new comic.

Moderators: Moderators General, Prelates, Magistrates

collinstocks
Posts: 11
Joined: Wed Apr 02, 2008 7:52 pm UTC

### 1161: "Hand Sanitizer"

Title text: "Hipster CDC Reports Flu Epidemic Peaked Years Ago"

200 000 000 * 0.01% = 20 000
I agree with the last panel
Also, why does he need a calculator in the third panel?
Edit: I'm not sure I understand the title text...

rhomboidal
Posts: 797
Joined: Wed Jun 15, 2011 5:25 pm UTC
Contact:

### Re: 1161 Hand Sanitizer

I've heard that the top .01% owns half of all head colds.

Annirak
Posts: 54
Joined: Tue Jun 26, 2007 6:55 pm UTC

### Re: 1161 Hand Sanitizer

Hand sanitizer merchants have been telling us all a dirty lie.
[X]Wife
[X]Car
[X]Rain
Now all I need is a movie to set off that pet peeve.

Quicksilver
Posts: 437
Joined: Wed Apr 29, 2009 6:21 am UTC

### Re: 1161 Hand Sanitizer

Web Designers always told us that 99.9% of uptime on servers wasn't impressive for this reason. That 0.01% always adds up.
Last edited by Quicksilver on Wed Jan 16, 2013 10:07 am UTC, edited 1 time in total.

Brandesianisme
Posts: 6
Joined: Wed Jan 16, 2013 8:31 am UTC

### Re: 1161 Hand Sanitizer

I'm pretty sure you aren't supposed to multiply by 0.01%

poit
Posts: 2
Joined: Wed Jan 16, 2013 8:36 am UTC

### Re: 1161 Hand Sanitizer

Killing 99.99% wouldn't mean you multiply by 0.01, it would mean you multiply by 0.0001.

And they claim these things can kill 99.99% because that's all they can prove they kill. They probably kill 100% given enough concentration and time, but since they can't prove it, they can't claim it.

ijuin
Posts: 1104
Joined: Fri Jan 09, 2009 6:02 pm UTC

### Re: 1161 Hand Sanitizer

This would be more impressive if it weren't for the fact that the human body already contains several TRILLION bacteria, about 90% of which are in our intestine and colon and without which we would have trouble digesting our food.

Also, plain old epidermis vulgaris, the most common skin bacterium on clean, healthy human skin, may cause the occasional pimple, but they are also our "guard dogs" against the more dangerous invaders--they do NOT like to share their habitat with outsiders and will try to kick them out before they can get under our skin. It's the invaders that get past these guard bacteria that our actual immune system has to deal with. Without these guards, we would have to fight all invading microbes ourselves, which is part of why kids raised in overly-sterile environments have immune problems.

It's also kind of amazing that despite being inundated with bacteria like this, most people even before the discovery of antibiotics and antiseptics only experienced a few hundred noticeable infections in a lifetime. It's a testament to how efficient our immune systems really are--it's only those germs that our immune systems can't figure out that are an actual threat.

jiquera
Posts: 2
Joined: Wed Jan 16, 2013 8:49 am UTC

### Re: 1161 Hand Sanitizer

is it me or is there a mathematical error in this comic?

Say it would kill 0% then 200M * 1.00 = 200M germs will survive
Say it would kill 50% then 200M * 0.50 = 100M germs will survive
Say it would kill 99% then 200M * 0.01 = 2M germs will survive
Say it would kill 99.99% then 200M * 0.0001 = 20K germs will survive

the comic says 99.99% but then multiplies with 0.01% ?!?!?!
this shouldnt happen in XKCD comics

cheers

jiq

jiquera
Posts: 2
Joined: Wed Jan 16, 2013 8:49 am UTC

### Re: 1161 Hand Sanitizer

ah wait... I missed the '%' sign well my faith has been restored

sardia
Posts: 6797
Joined: Sat Apr 03, 2010 3:39 am UTC

### Re: 1161 Hand Sanitizer

Don't forget the other side of the equation, evolution. What's do you call a germ that kills everyone it infects? Extinct. Diseases usually moderate themselves so that the vectors(humans) live long enough to spread themselves. It's why Ebola has such a hard time spreading, it kills too fast.

Annirak
Posts: 54
Joined: Tue Jun 26, 2007 6:55 pm UTC

### Re: 1161 Hand Sanitizer

sardia wrote:What's do you call a germ that kills everyone it infects? Extinct. ... Ebola has such a hard time spreading, it kills too fast.

And yet, it persists...
[X]Wife
[X]Car
[X]Rain
Now all I need is a movie to set off that pet peeve.

Istaro
Posts: 101
Joined: Mon Jan 05, 2009 6:00 pm UTC

### Re: 1161 Hand Sanitizer

Quicksilver wrote:Web Designers always told us that 99% of uptime on servers wasn't impressive for this reason. That 0.01% always adds up.

Or 1%, even?

J L
Posts: 242
Joined: Mon Jan 25, 2010 11:03 am UTC
Location: Germany
Contact:

### Re: 1161 Hand Sanitizer

Annirak wrote:
sardia wrote:What's do you call a germ that kills everyone it infects? Extinct. ... Ebola has such a hard time spreading, it kills too fast.

And yet, it persists...

Correct me if I'm wrong, but Plague bacteria kill rats, fleas, everything, and were quite a "success" before the rise of antibiotics and vaccines. It seems the germs can survive without a host, and need them only for spreading.

Edit: I don't get the title text, either.

verano
Posts: 3
Joined: Mon Jan 11, 2010 7:57 am UTC

### Re: 1161 Hand Sanitizer

I always assumed (← there might be the mistake) that the 99.99% refers to types of bacteria, while the sneeze droplet's millions of germs would mainly be of the same type?

TomRobbins
Posts: 21
Joined: Fri Mar 19, 2010 4:37 am UTC

### Re: 1161 Hand Sanitizer

verano wrote:I always assumed (← there might be the mistake) that the 99.99% refers to types of bacteria, while the sneeze droplet's millions of germs would mainly be of the same type?

I believe you are correct. So this is either an oversight by Randall. Or the stick man character (I have a hard time telling the characters apart unless they're wearing a style of hat) in this particular comic isn't really bright.

Quicksilver
Posts: 437
Joined: Wed Apr 29, 2009 6:21 am UTC

### Re: 1161 Hand Sanitizer

Istaro wrote:
Quicksilver wrote:Web Designers always told us that 99% of uptime on servers wasn't impressive for this reason. That 0.01% always adds up.

Or 1%, even?
sorry, I was meant to write 99.99%.
Last edited by Quicksilver on Wed Jan 16, 2013 10:21 am UTC, edited 1 time in total.

Angelastic
Posts: 700
Joined: Thu Nov 03, 2011 8:36 am UTC
Location: .at (let's see what's through here!)
Contact:

### Re: 1161 Hand Sanitizer

Quicksilver wrote:
Istaro wrote:
Quicksilver wrote:Web Designers always told us that 99% of uptime on servers wasn't impressive for this reason. That 0.01% always adds up.

Or 1%, even?
sorry, I was meant to write 99.9%.
Or 99.99%, even?
Knight Temporal, and Archdeacon of buttermongery and ham and cheese sandwiches. Nobody sells butter except through me.
Smiley by yappobiscuits. Avatar by GLR, buffygirl, BlitzGirl & mscha, with cari.j.elliot's idea.
Haiku Detector
starts a trend to make way for
my robot army.

Quicksilver
Posts: 437
Joined: Wed Apr 29, 2009 6:21 am UTC

### Re: 1161 Hand Sanitizer

Angelastic wrote:
Quicksilver wrote:
Istaro wrote:
Quicksilver wrote:Web Designers always told us that 99% of uptime on servers wasn't impressive for this reason. That 0.01% always adds up.

Or 1%, even?
sorry, I was meant to write 99.9%.
Or 99.99%, even?
I'M TIRED AND DRUNK, OK? D:<

Zards
Posts: 1
Joined: Wed Jan 16, 2013 10:22 am UTC

### Re: 1161 Hand Sanitizer

Is it just me, or is he calculating how many germs would be left after 99% were killed, as opposed to 99.99%? Shouldn't 99.99% of germs killed result in 0.0001 left alive? Is that what the joke is? Am I not dumb enough for this one?

TeddyB
Posts: 5
Joined: Wed Jan 02, 2013 5:51 pm UTC

### Re: 1161 Hand Sanitizer

Can someone explain the alt-text? Google doesn't help me understand what Hipster CDC is...
Aside from that, I agree with the sentiment of this comic, and it's also worth spreading the word that those alcohol gels don't get rid of Norovirus. Although it's obviously futile to try to scrub away all microbes from your skin, far better to eat healthily and keep your immune system in good order.

Technical Ben
Posts: 2986
Joined: Tue May 27, 2008 10:42 pm UTC

### Re: 1161 Hand Sanitizer

Reapply, reapply, reapply, reapply!

(Yes, that is meant to be 4x )
It's all physics and stamp collecting.
It's not a particle or a wave. It's just an exchange.

rmsgrey
Posts: 3630
Joined: Wed Nov 16, 2011 6:35 pm UTC

### Re: 1161 Hand Sanitizer

Technical Ben wrote:Reapply, reapply, reapply, reapply!

(Yes, that is meant to be 4x )

To leave just 1 in 1020?

Annirak
Posts: 54
Joined: Tue Jun 26, 2007 6:55 pm UTC

### Re: 1161 Hand Sanitizer

TomRobbins wrote:
verano wrote:I always assumed (← there might be the mistake) that the 99.99% refers to types of bacteria, while the sneeze droplet's millions of germs would mainly be of the same type?

I believe you are correct. So this is either an oversight by Randall. Or the stick man character (I have a hard time telling the characters apart unless they're wearing a style of hat) in this particular comic isn't really bright.

Actually, that is a mistake. Randall has it right (as usual).

The standard test is run on 60 slides inoculated with a specific bug, and 59 of them treated with the product must exhibit the claimed rate of germ death. The 60th can fail to allow for a mistake on the part of testers, according to Jean Schoeni, director of research at TRAC Microbiology, which conducts EPA testing.

http://online.wsj.com/article/SB126092257189692937.html
[X]Wife
[X]Car
[X]Rain
Now all I need is a movie to set off that pet peeve.

Annirak
Posts: 54
Joined: Tue Jun 26, 2007 6:55 pm UTC

### Re: 1161 Hand Sanitizer

What's always bothered me about antibacterials and other sanitizers is natural selection. Widespread use of these products seems to encourage microbes which are immune to them.

I like the plasma sanitizer.
[X]Wife
[X]Car
[X]Rain
Now all I need is a movie to set off that pet peeve.

You, sir, name?
Posts: 6983
Joined: Sun Apr 22, 2007 10:07 am UTC
Location: Chako Paul City
Contact:

### Re: 1161 Hand Sanitizer

Wtf. Just wash your hands with soap and water. If you're not doing surgery, that's enough.
I edit my posts a lot and sometimes the words wrong order words appear in sentences get messed up.

peewee_RotA
Posts: 504
Joined: Mon Dec 12, 2011 1:19 pm UTC

### Re: 1161 Hand Sanitizer

The hipster CDC loved viruses before they were colds.
"Vowels have trouble getting married in Canada. They can’t pronounce their O’s."

dbmag9
Posts: 29
Joined: Wed Sep 19, 2007 5:13 pm UTC

### Re: 1161 Hand Sanitizer

collinstocks wrote:Edit: I'm not sure I understand the title text...

J L wrote:Edit: I don't get the title text, either.

TeddyB wrote:Can someone explain the alt-text? Google doesn't help me understand what Hipster CDC is...

The CDC is the centre for disease control, who I assume declare when an outbreak constitutes an epidemic, and when it peaks and so on. Hipsters stereotypically abhor anything mainstream, leading to the phrase "I liked [obscure band X] before it was cool". Cf. the last panel of http://xkcd.com/460/, come to think of it. So the Hipster CDC is saying that the flu epidemic was at its best years ago, before everyone started getting it.
-dbmag9

Carlington
Posts: 1588
Joined: Sun Mar 22, 2009 8:46 am UTC
Location: Sydney, Australia.

### Re: 1161 Hand Sanitizer

That 0.01% is a pretty rare strain. I wouldn't expect that you've heard of it, so don't worry.
Kewangji: Posdy zwei tosdy osdy oady. Bork bork bork, hoppity syphilis bork.

Eebster the Great: What specifically is moving faster than light in these examples?
doogly: Hands waving furiously.

Please use he/him/his pronouns when referring to me.

Condor70
Posts: 18
Joined: Wed Jan 11, 2012 8:11 am UTC

### Re: 1161 Hand Sanitizer

collinstocks wrote:Title text: "Hipster CDC Reports Flu Epidemic Peaked Years Ago"

Edit: I'm not sure I understand the title text...

If we ignore the Hipster association it's still a valid statement. The current flu epidemic is tiny in comparison to the influenza pandemics of the last century.

Annirak
Posts: 54
Joined: Tue Jun 26, 2007 6:55 pm UTC

### Re: 1161 Hand Sanitizer

Carlington wrote:That 0.01% is a pretty rare strain. I wouldn't expect that you've heard of it, so don't worry.

Again, it's not kinds of bacteria, it's the number bacteria out of a representative (or non-representative) sample of kinds. I posted a link to a WSJ article explaining this, with a reference from an EPA tester above. Those claims must be validated by the EPA, so the tester's explanation is valid.
[X]Wife
[X]Car
[X]Rain
Now all I need is a movie to set off that pet peeve.

Carlington
Posts: 1588
Joined: Sun Mar 22, 2009 8:46 am UTC
Location: Sydney, Australia.

### Re: 1161 Hand Sanitizer

I know. I was sacrificing scientific accuracy for the sake of humour.
Kewangji: Posdy zwei tosdy osdy oady. Bork bork bork, hoppity syphilis bork.

Eebster the Great: What specifically is moving faster than light in these examples?
doogly: Hands waving furiously.

Please use he/him/his pronouns when referring to me.

jowee26
Posts: 2
Joined: Wed Jan 16, 2013 1:04 pm UTC

### Re: 1161 Hand Sanitizer

Wouldn't it be 200,000,000 x 0.0001 ?

Again, it's probably just the stick figure not understanding things, or my math is wronng.

mikrit
Posts: 402
Joined: Sat Apr 14, 2012 8:13 pm UTC
Location: Sweden

### Re: 1161 Hand Sanitizer

ijuin wrote:This would be more impressive if it weren't for the fact that the human body already contains several TRILLION bacteria...
Oh dear. I hope that's the tiny American trillion (1012), not the European trillion (1018).
Hatted and wimpled by ergman.
Dubbed "First and Eldest of Ottificators" by svenman.
Febrion wrote: "etc" is latin for "this would look better with more examples, but I can't think of any".

Angelastic
Posts: 700
Joined: Thu Nov 03, 2011 8:36 am UTC
Location: .at (let's see what's through here!)
Contact:

### Re: 1161 Hand Sanitizer

ijuin wrote:This would be more impressive if it weren't for the fact that the human body already contains several TRILLION bacteria

Indeed, it contains more bacteria than human cells. They're smaller though, so I think the human cells still account for most of the mass.
Knight Temporal, and Archdeacon of buttermongery and ham and cheese sandwiches. Nobody sells butter except through me.
Smiley by yappobiscuits. Avatar by GLR, buffygirl, BlitzGirl & mscha, with cari.j.elliot's idea.
Haiku Detector
starts a trend to make way for
my robot army.

FrobozzWizard
Posts: 61
Joined: Wed Feb 02, 2011 2:01 pm UTC

### Re: 1161 Hand Sanitizer

Weird Al had a pretty good take on this problem years ago:

Sometimes I really wanna be alone...
But that's one state I'm never in...
Because I know that I've got millions upon millions
Of tiny, one-celled organisms living on my skin

Weird Al - Germs

cellocgw
Posts: 2053
Joined: Sat Jun 21, 2008 7:40 pm UTC

### Re: 1161 Hand Sanitizer

Annirak wrote:
sardia wrote:What's do you call a germ that kills everyone it infects? Extinct. ... Ebola has such a hard time spreading, it kills too fast.

And yet, it persists...

IIRC it persists in non-human hosts, where it's far less deadly.
https://app.box.com/witthoftresume
Former OTTer
Vote cellocgw for President 2020. #ScienceintheWhiteHouse http://cellocgw.wordpress.com
"The Planck length is 3.81779e-33 picas." -- keithl
" Earth weighs almost exactly π milliJupiters" -- what-if #146, note 7

orthogon
Posts: 3075
Joined: Thu May 17, 2012 7:52 am UTC
Location: The Airy 1830 ellipsoid

### Re: 1161 Hand Sanitizer

Annirak wrote:
TomRobbins wrote:
verano wrote:I always assumed (← there might be the mistake) that the 99.99% refers to types of bacteria, while the sneeze droplet's millions of germs would mainly be of the same type?

I believe you are correct. So this is either an oversight by Randall. Or the stick man character (I have a hard time telling the characters apart unless they're wearing a style of hat) in this particular comic isn't really bright.

Actually, that is a mistake. Randall has it right (as usual).

I also thought the same as verano. For decades, bleach bottles used to say "kills all known germs", which does appear to refer to types (unless "known" means that they have tagged individual bacteria and given them names.). Then suddenly they started saying "kills 99.99% of germs", which gave me the impression that some germ(s) had been discovered that it didn't kill, meaning they could no longer make the former claim. But assuming Annirak is right, they've actually started making a different claim that sounds similar.
xtifr wrote:... and orthogon merely sounds undecided.

jc
Posts: 353
Joined: Fri May 04, 2007 5:48 pm UTC
Location: Waltham, Massachusetts, USA, Earth, Solar System, Milky Way Galaxy
Contact:

### Re: 1161 Hand Sanitizer

verano wrote:I always assumed (← there might be the mistake) that the 99.99% refers to types of bacteria, while the sneeze droplet's millions of germs would mainly be of the same type?

Funny; I'd always interpreted such claims as saying that the 0.01% left are those with some resistance to the antibiotics used, which would then expand their numbers due to the elimination of their competition.

With a "kill rate" that low, hand sanitizers are primarily tools for forcing the evolution of resistance to our current antibiotics.

willpellmn
Posts: 93
Joined: Wed Apr 21, 2010 11:05 am UTC

### Re: 1161 Hand Sanitizer

The alt-text is pure fridge brilliance.

You, sir, name?
Posts: 6983
Joined: Sun Apr 22, 2007 10:07 am UTC
Location: Chako Paul City
Contact:

### Re: 1161 Hand Sanitizer

jowee26 wrote:Wouldn't it be 200,000,000 x 0.0001 ?

Again, it's probably just the stick figure not understanding things, or my math is wronng.

I think you'll find 0.01% = 0.0001
I edit my posts a lot and sometimes the words wrong order words appear in sentences get messed up.