1231: "Habitable Zone"

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

Moderators: Moderators General, Prelates, Magistrates

User avatar
Linux0s
Posts: 247
Joined: Sat Dec 29, 2007 7:34 pm UTC

1231: "Habitable Zone"

Postby Linux0s » Fri Jun 28, 2013 6:06 am UTC

Image

Title text: They have a telescope pointed RIGHT AT US!

"Hey... that guy has the same phone as me!"
If the male mind truly were a machine it would consist of a shaft and a bushing.

User avatar
rhomboidal
Posts: 759
Joined: Wed Jun 15, 2011 5:25 pm UTC
Contact:

Re: 1231: "Habitable Zone"

Postby rhomboidal » Fri Jun 28, 2013 6:08 am UTC

This is a major part of NASA's funding problems: so much of its budget goes to its outlandishly exorbitant practical jokes.

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

Re: 1231: "Habitable Zone"

Postby Quicksilver » Fri Jun 28, 2013 6:12 am UTC

How would you line up the mirror?

User avatar
rivulatus
Posts: 44
Joined: Tue Jun 11, 2013 1:14 am UTC

Re: 1231: "Habitable Zone"

Postby rivulatus » Fri Jun 28, 2013 6:49 am UTC

It would be worth it, and probably the most expensive practical joke ever.

ijuin
Posts: 799
Joined: Fri Jan 09, 2009 6:02 pm UTC

Re: 1231: "Habitable Zone"

Postby ijuin » Fri Jun 28, 2013 7:11 am UTC

Maybe, but once the astronomer takes a good look at the planet's spectrograph, he's going to notice that it looks suspiciously identical to Earth.

User avatar
da Doctah
Posts: 803
Joined: Fri Feb 03, 2012 6:27 am UTC

Re: 1231: "Habitable Zone"

Postby da Doctah » Fri Jun 28, 2013 7:23 am UTC

Did anyone besides me think the announcement should have started with "Good news, everyone!"?

User avatar
mrob27
Posts: 1237
Joined: Tue Jun 28, 2011 2:19 am UTC
Location: 〗  
Contact:

Re: 1231: "Habitable Zone"

Postby mrob27 » Fri Jun 28, 2013 9:17 am UTC

Didn't Bugs Bunny play this trick on Marvin the Martian?
Robert Munafohttp://mrob.com@mrob_27
Image
I ᴍᴀᴅᴇ sᴏɍᴛᴡᴀʀᴇ ᴛʜᴀᴛ Rᴀɴᴅᴀʟʟ ɍᴏᴜɴᴅ ᴜsᴇɍᴜʟ ɪɴ ᴛʜɪs хᴋᴄᴅ

User avatar
Klear
Posts: 1965
Joined: Sun Jun 13, 2010 8:43 am UTC
Location: Prague

Re: 1231: "Habitable Zone"

Postby Klear » Fri Jun 28, 2013 11:30 am UTC

da Doctah wrote:Did anyone besides me think the announcement should have started with "Good news, everyone!"?


It does look kinda like the smelloscope...

User avatar
Whizbang
The Best Reporter
Posts: 2238
Joined: Fri Apr 06, 2012 7:50 pm UTC
Location: New Hampshire, USA

Re: 1231: "Habitable Zone"

Postby Whizbang » Fri Jun 28, 2013 12:15 pm UTC

Easier still, just cover the observation area in a translucent dome and project a ultra-HD image onto/through it.

brenok
Needs Directions
Posts: 507
Joined: Mon Oct 17, 2011 5:35 pm UTC
Location: Brazil

Re: 1231: "Habitable Zone"

Postby brenok » Fri Jun 28, 2013 12:24 pm UTC

Quicksilver wrote:How would you line up the mirror?


Huge swarm of geosynchronous satellites.

And this

User avatar
orthogon
Posts: 2690
Joined: Thu May 17, 2012 7:52 am UTC
Location: The Airy 1830 ellipsoid

Re: 1231: "Habitable Zone"

Postby orthogon » Fri Jun 28, 2013 12:37 pm UTC

Whizbang wrote:Easier still, just cover the observation area in a translucent dome and project a ultra-HD image onto/through it.

This reminds me of the Channel 4 programme Space Cadets. I seem to be the only person who saw it. For me it raised a whole load of questions related to psychology, ethics and the public understanding of Science.
xtifr wrote:... and orthogon merely sounds undecided.

User avatar
Jackpot777
Posts: 328
Joined: Wed Sep 14, 2011 1:19 pm UTC

Re: 1231: "Habitable Zone"

Postby Jackpot777 » Fri Jun 28, 2013 12:48 pm UTC

Quicksilver wrote:How would you line up the mirror?


Seeing as the angle of incidence is equal to the angle of reflection at right angles to the plane of the mirror, I'd say: pointing right back at us, thanks for asking.

Technically correct (best kind, etc.).

User avatar
CocoaNutCakery
Posts: 66
Joined: Fri May 24, 2013 6:26 am UTC
Contact:

Re: 1231: "Habitable Zone"

Postby CocoaNutCakery » Fri Jun 28, 2013 2:07 pm UTC

I was talking about the discovery of these planets with my sister and my mom the other day and mentioning the fact that it used to be people saying, "I think it's arrogant to think that we're the only life out there," were crazy whereas the ones that insisted on no alien life were sane. These days, those that insist that there's no alien life are kind of regarded as idiots.

Not to say that aliens have visited us, just that they most likely exist in one form or another.

And, at each point in time, we think that we've gotten to the point where we're knowledgeable enough to know what's a crazy claim and what isn't.

So what will it be in 20 years? Which crazy people will actually turn out to be ahead of their time?

User avatar
cellocgw
Posts: 1760
Joined: Sat Jun 21, 2008 7:40 pm UTC

Re: 1231: "Habitable Zone"

Postby cellocgw » Fri Jun 28, 2013 2:10 pm UTC

Quicksilver wrote:How would you line up the mirror?


No problem: just use a giant corner cube.
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

User avatar
peewee_RotA
Posts: 500
Joined: Mon Dec 12, 2011 1:19 pm UTC

Re: 1231: "Habitable Zone"

Postby peewee_RotA » Fri Jun 28, 2013 2:18 pm UTC

No Tauday references?

I question Randall's dedication to trendy math topics.
http://tauday.com/
"Vowels have trouble getting married in Canada. They can’t pronounce their O’s."

http://timelesstherpg.wordpress.com/about/

User avatar
Klear
Posts: 1965
Joined: Sun Jun 13, 2010 8:43 am UTC
Location: Prague

Re: 1231: "Habitable Zone"

Postby Klear » Fri Jun 28, 2013 2:19 pm UTC

CocoaNutCakery wrote:I was talking about the discovery of these planets with my sister and my mom the other day and mentioning the fact that it used to be people saying, "I think it's arrogant to think that we're the only life out there," were crazy whereas the ones that insisted on no alien life were sane. These days, those that insist that there's no alien life are kind of regarded as idiots.

Not to say that aliens have visited us, just that they most likely exist in one form or another.


I'm pretty sure people who said we are not alone in the universe were considered crazy because people assumed they meant "and they visited us" or "and I have proof". And they assume(d) it correctly in majority of cases.

User avatar
Whizbang
The Best Reporter
Posts: 2238
Joined: Fri Apr 06, 2012 7:50 pm UTC
Location: New Hampshire, USA

Re: 1231: "Habitable Zone"

Postby Whizbang » Fri Jun 28, 2013 2:26 pm UTC

Image

User avatar
Adam H
Posts: 1267
Joined: Thu Jun 16, 2011 6:36 pm UTC

Re: 1231: "Habitable Zone"

Postby Adam H » Fri Jun 28, 2013 3:20 pm UTC

Wouldn't you have to put the mirror halfway between the telescope and where the astronomer expects to see the planet?
-Adam

rmsgrey
Posts: 3074
Joined: Wed Nov 16, 2011 6:35 pm UTC

Re: 1231: "Habitable Zone"

Postby rmsgrey » Fri Jun 28, 2013 3:31 pm UTC

cellocgw wrote:
Quicksilver wrote:How would you line up the mirror?


No problem: just use a giant corner cube.


Only problem with a cube-corner is that it has those three seams...

Besides, you'd want some sort of demagnification effect to get the apparent distance up far enough...

I'd be tempted by a large spherical mirror.

PiZZaMartijn
Posts: 1
Joined: Fri Jun 28, 2013 3:37 pm UTC

Re: 1231: "Habitable Zone"

Postby PiZZaMartijn » Fri Jun 28, 2013 3:38 pm UTC

Sounds like you need a edgeless safety cube

Carteeg_Struve
Posts: 111
Joined: Mon Jun 08, 2009 12:56 pm UTC

Re: 1231: "Habitable Zone"

Postby Carteeg_Struve » Fri Jun 28, 2013 3:40 pm UTC

Adam H wrote:Wouldn't you have to put the mirror halfway between the telescope and where the astronomer expects to see the planet?


Yeah, but unlike most government funded projects this would actually be worth it. :D

User avatar
Whizbang
The Best Reporter
Posts: 2238
Joined: Fri Apr 06, 2012 7:50 pm UTC
Location: New Hampshire, USA

Re: 1231: "Habitable Zone"

Postby Whizbang » Fri Jun 28, 2013 3:47 pm UTC

Carteeg_Struve wrote:
Adam H wrote:Wouldn't you have to put the mirror halfway between the telescope and where the astronomer expects to see the planet?


Yeah, but unlike most government funded projects this would actually be worth it. :D



Maybe it really would be, too. Think about it. How are we to really know what a planet with life looks like from lightyears away? Send out a vast1 mirror a lightyear away, aim a telescope at it (maybe leave a large enough marker on it so you know you are viewing the mirror instead of just space), and look at earth.

1 Like, really, really vast. Like bigger than your mom vast.

Vertices
Posts: 11
Joined: Tue Sep 06, 2011 8:35 pm UTC

Re: 1231: "Habitable Zone"

Postby Vertices » Fri Jun 28, 2013 4:04 pm UTC

Whizbang wrote:Maybe it really would be, too. Think about it. How are we to really know what a planet with life looks like from lightyears away? Send out a vast1 mirror a lightyear away, aim a telescope at it (maybe leave a large enough marker on it so you know you are viewing the mirror instead of just space), and look at earth.

1 Like, really, really vast. Like bigger than your mom vast.


Then, as Murphy would have it, an actual other planet with intelligent life would just happen to be behind the mirror, and we'd never know about it.

User avatar
Whizbang
The Best Reporter
Posts: 2238
Joined: Fri Apr 06, 2012 7:50 pm UTC
Location: New Hampshire, USA

Re: 1231: "Habitable Zone"

Postby Whizbang » Fri Jun 28, 2013 4:09 pm UTC

Vertices wrote:Then, as Murphy would have it, an actual other planet with intelligent life would just happen to be behind the mirror, and we'd never know about it.


Maybe that has already happened. Maybe we are the ones behind a mirror, or even many mirrors. Maybe the universe is just full of intelligent species, all too busy looking at themselves in the mirror to go out and explore.

Image

User avatar
tibfulv
Posts: 48
Joined: Tue Nov 27, 2012 11:31 am UTC

Re: 1231: "Habitable Zone"

Postby tibfulv » Fri Jun 28, 2013 4:13 pm UTC

It's a little known fact that this is precisely what Voyager 1 was sent out to do.

Proof: Carl Sagan worked on Voyager. He also proposed the mechanism for searching for exo-planets. A coincidence? I think not.

User avatar
serutan
Posts: 88
Joined: Mon May 17, 2010 2:18 pm UTC
Location: Baja Arizona

Re: 1231: "Habitable Zone"

Postby serutan » Fri Jun 28, 2013 5:55 pm UTC

mrob27 wrote:Didn't Bugs Bunny play this trick on Marvin the Martian?


No, he replaced the eyepiece with the Illudium Q-36 Space Modulator
For a sentient herbivore, discretion is the only part of valor. - Larry Niven

RogueCynic
Posts: 359
Joined: Sun Nov 22, 2009 10:23 pm UTC

Re: 1231: "Habitable Zone"

Postby RogueCynic » Fri Jun 28, 2013 6:00 pm UTC

Wouldn't it be easier to put a picture of the earth on the telescope lens? BTW It was a plutonium pu238 space modulator.
I am Lord Titanius Englesmith, Fancyman of Cornwood.
See 1 Kings 7:23 for pi.
If you put a prune in a juicer, what would you get?

O10infinity
Posts: 3
Joined: Fri Jun 28, 2013 6:14 pm UTC

Re: 1231: "Habitable Zone"

Postby O10infinity » Fri Jun 28, 2013 6:25 pm UTC

What kind of bounds can we place on giant space mirrors? Presumably, we've actively searched for them at cosmological scales.

User avatar
Klear
Posts: 1965
Joined: Sun Jun 13, 2010 8:43 am UTC
Location: Prague

Re: 1231: "Habitable Zone"

Postby Klear » Fri Jun 28, 2013 6:49 pm UTC

RogueCynic wrote:Wouldn't it be easier to put a picture of the earth on the telescope lens? BTW It was a plutonium pu238 space modulator.


It worked against the superior bicycle-makers.

Farabor
Posts: 147
Joined: Wed Apr 06, 2011 9:46 am UTC

Re: 1231: "Habitable Zone"

Postby Farabor » Fri Jun 28, 2013 7:04 pm UTC

PiZZaMartijn wrote:Sounds like you need a edgeless safety cube


The earth actually has 4 24 hour days per day.....

User avatar
Whizbang
The Best Reporter
Posts: 2238
Joined: Fri Apr 06, 2012 7:50 pm UTC
Location: New Hampshire, USA

Re: 1231: "Habitable Zone"

Postby Whizbang » Fri Jun 28, 2013 7:05 pm UTC

I did a google search for "Mavin Martian Telescope" to see if there were any funny or especially relevant images to be found. Sadly, this is the best I could find: Image

However, I would like to know why there is a picture of a woman breastfeeding mixed in with the results (scroll down a few pages). I would click the link, but I am at work. The image name is "breast-milk-discovery.jpg" and the description on mouseover says "what we think martians look like".

Also, I found this by searching for "space mirror":
Image

aymblym
Posts: 2
Joined: Fri Jun 28, 2013 10:09 pm UTC

Re: 1231: "Habitable Zone"

Postby aymblym » Fri Jun 28, 2013 10:29 pm UTC

I'm surprised no one mentioned that the mirror would have to be half the diameter of Earth, otherwise the edges of the reflection would be cut off... Even a 1 nm-thick aluminum foil would weigh 340000 tons. This would require 100 years to produce, at current production capacity. Assuming very optimistic launch costs of $2,000 per kg, the launch alone would amount to $680 billion dollars.

I don't even want to think how hard it would be to keep the foil perfectly flat or how hard it would be to protect it during launch.

CocoaNutCakery wrote:These days, those that insist that there's no alien life are kind of regarded as idiots.

Oh yeah? Care to explain why?

rmsgrey
Posts: 3074
Joined: Wed Nov 16, 2011 6:35 pm UTC

Re: 1231: "Habitable Zone"

Postby rmsgrey » Sat Jun 29, 2013 1:51 am UTC

aymblym wrote:I'm surprised no one mentioned that the mirror would have to be half the diameter of Earth, otherwise the edges of the reflection would be cut off... Even a 1 nm-thick aluminum foil would weigh 340000 tons. This would require 100 years to produce, at current production capacity. Assuming very optimistic launch costs of $2,000 per kg, the launch alone would amount to $680 billion dollars.

I don't even want to think how hard it would be to keep the foil perfectly flat or how hard it would be to protect it during launch.


Another advantage of the spherical mirror.

aymblym wrote:
CocoaNutCakery wrote:These days, those that insist that there's no alien life are kind of regarded as idiots.

Oh yeah? Care to explain why?


One reason would be that when you start plugging numbers into the Drake Equation, you realise that, for extraterrestrial life not to exist, you need the probability of life arising on a habitable planet to be incredibly small.

Experimentally, mixing the gases and liquids abundant on pre-biotic Earth and exposing them to any of several energy sources for a week or two produces amino acids and DNA/RNA bases. Not exactly the same as creating life in the laboratory, but certainly suggestive - it definitely points away from life being unique to Earth.

Observationally, once life gets established on a planet, it finds ways to survive in incredibly harsh environments, so wiping out all life on a planet would take something pretty drastic...

More fundamental when it comes to general perception is that aliens are not just scientific speculation - they're part of the popular culture, and have been for decades, so the idea of aliens is widely accepted as plausible even if the details are scientifically unlikely...

aymblym
Posts: 2
Joined: Fri Jun 28, 2013 10:09 pm UTC

Re: 1231: "Habitable Zone"

Postby aymblym » Sat Jun 29, 2013 2:55 am UTC

rmsgrey wrote:Another advantage of the spherical mirror.

Yes, I didn't see your post; it would definitely be the way to go.

rmsgrey wrote:One reason would be that when you start plugging numbers into the Drake Equation, you realise that, for extraterrestrial life not to exist, you need the probability of life arising on a habitable planet to be incredibly small.

And there's no reason why it couldn't be incredibly small indeed. The probability of billions of billions of typewriter monkeys writing even 10% of The Raven is mindblowingly small.

rmsgrey wrote:Experimentally, mixing the gases and liquids abundant on pre-biotic Earth and exposing them to any of several energy sources for a week or two produces amino acids and DNA/RNA bases. Not exactly the same as creating life in the laboratory, but certainly suggestive - it definitely points away from life being unique to Earth.

It's a very far cry from creating life capable of evolving. There is a bigger gap between unorganized amino acids and life than between silicon and a microprocessor. These are well known and interesting experiments, but to extrapolate from that and call anyone who isn't a believer in alien life an idiot is just ridiculous!

rmsgrey wrote:Observationally, once life gets established on a planet, it finds ways to survive in incredibly harsh environments, so wiping out all life on a planet would take something pretty drastic...

More fundamental when it comes to general perception is that aliens are not just scientific speculation - they're part of the popular culture, and have been for decades, so the idea of aliens is widely accepted as plausible even if the details are scientifically unlikely...

I agree with you on both points.

algorerhythms
Posts: 42
Joined: Fri Nov 02, 2007 4:23 pm UTC

Re: 1231: "Habitable Zone"

Postby algorerhythms » Sat Jun 29, 2013 3:32 am UTC

The more I look at this the more I'm convinced a spherical mirror wouldn't work. So the goal would be to get a virtual image that appears to be very far away with a reasonable magnification factor (i.e. so it actually looks like the Earth). So, to get a far-away image, you might try a concave mirror, but to get a far-away virtual image, you'd end up with a big magnification factor. If you assume the mirror is in low-earth orbit (~500 km, let's say) and you're trying to present an image that appears 50 light years (~ 5x10^14 km) away, you'd have a magnification factor of 10^12, causing the far-away Earth to appear enormous. So let's go the other way, and try to make a very small virtual image that's close, using a convex mirror. If you're going for a magnification factor of 10^-12, which would make the earth appear the size it would if it were about 50 light years away, you'd need a mirror (still assuming it's in low-earth orbit) that has a focal length of about 50 microns. Problem is it would be very difficult to make a mirror that has a radius of 50 microns large enough for the task. Plus, there would be the issue of the mirror moving relative to the stars if it's near the earth, though I suppose there are ways around that.

Of course I could be looking at this in entirely the wrong way. I am a bit sleep-deprived today. Prove me wrong! :D
The nerdy webcomic that I update on Saturdays: Cesium Comics

User avatar
CocoaNutCakery
Posts: 66
Joined: Fri May 24, 2013 6:26 am UTC
Contact:

Re: 1231: "Habitable Zone"

Postby CocoaNutCakery » Sat Jun 29, 2013 4:11 am UTC

rmsgrey wrote:
aymblym wrote:
CocoaNutCakery wrote:These days, those that insist that there's no alien life are kind of regarded as idiots.

Oh yeah? Care to explain why?


One reason would be that when you start plugging numbers into the Drake Equation, you realise that, for extraterrestrial life not to exist, you need the probability of life arising on a habitable planet to be incredibly small.

Experimentally, mixing the gases and liquids abundant on pre-biotic Earth and exposing them to any of several energy sources for a week or two produces amino acids and DNA/RNA bases. Not exactly the same as creating life in the laboratory, but certainly suggestive - it definitely points away from life being unique to Earth.

Observationally, once life gets established on a planet, it finds ways to survive in incredibly harsh environments, so wiping out all life on a planet would take something pretty drastic...

More fundamental when it comes to general perception is that aliens are not just scientific speculation - they're part of the popular culture, and have been for decades, so the idea of aliens is widely accepted as plausible even if the details are scientifically unlikely...


And none of this was really "common knowledge" with pseudoskeptics a decade or so ago. Skeptics, the real kind, actually went and found that information that makes the probably of Earth containing all the life in the universe very low. And pseudoskeptics continued to doubt anyway. I've thrown piles of clinical trials from well-established journals such as Psychotherapy and Psychosomatics and Advances in Nutrition, and they're all just tossed aside. In other words, I'm considered completely bonkers because I actually read the clinical data and form my view based on that, rather than what some guy over which the pseudoskeptic community is losing their collective shit is saying.

And then, ten years from now, those same pseudoskeptics will be calling me crazy as I point out the newest clinical data, all the while talking about the same things I'd been trying to tell them for the past ten years and insisting that it's because the circumstances are different. That there's evidence for it, whereas there wasn't before (nevermind absence of evidence vs. evidence of absence or the fact that there's plenty of evidence for it), or something like that.

Of course, to be fair, I recently came across a situation that underscored the fact that I'm a bit of a pseudoskeptic myself. At least I know enough to actually seek out the evidence for or against before I actually publicly denounce a claim, though.

ijuin
Posts: 799
Joined: Fri Jan 09, 2009 6:02 pm UTC

Re: 1231: "Habitable Zone"

Postby ijuin » Sat Jun 29, 2013 7:18 am UTC

Personally, I expect that life in general will be found to be relatively common, but that we will find only a handful of actual starfaring civilizations in our galaxy.

Consider that, out of Earth's 4.5 billion years of history, there have been (as far as we know) no sapient species prior to the rise of hominids in the past five million years. Even then, we didn't make the "breakthrough" into modern-style intelligence with language and deliberately designed tools until maybe 200 thousand years ago. This implies that the amount of time that any planet spends having life but no "people" greatly dwarfs the amount of time that civilization would exist on it (unless you want to speculate about hyper-advanced billion-year-lifespan civilizations that are probably above our level of comprehension). Thus, very few of the planets that we see would be within the "window" between where it first develops a civilization that can be detected from light-years away, and when they have advanced beyond our hope to comprehend.

User avatar
StClair
Posts: 398
Joined: Fri Feb 29, 2008 8:07 am UTC

Re: 1231: "Habitable Zone"

Postby StClair » Sat Jun 29, 2013 8:14 am UTC

Any astronomer dumb enough to fall for this one deserves to.

User avatar
Copper Bezel
Posts: 2416
Joined: Wed Oct 12, 2011 6:35 am UTC
Location: Web exclusive!

Re: 1231: "Habitable Zone"

Postby Copper Bezel » Sat Jun 29, 2013 8:27 am UTC

ijuin wrote:Personally, I expect that life in general will be found to be relatively common, but that we will find only a handful of actual starfaring civilizations in our galaxy.


Pedantic correction re: deliberate toolmaking. But yes, sapience seems to have been a lucky break, and separately, we'd be quite lucky to run into anyone at all in our age group. I can't imagine that the even one Ma from now, we would really have much to say to folks like us.

And it still seems worth pointing out that complex life took much longer to develop on Earth than the first life did, which lends some credence to the idea of many planets of microbial life toting along just fine without ever happening to experiment with multicellular forms. I know that part of the problem on Earth was that the environment wasn't really hospitable to multicellular life of the kind we ended up with until we accidentally the atmosphere, but I'd still think that small differences in the environment could easily inhibit that next step.
So much depends upon a red wheel barrow (>= XXII) but it is not going to be installed.

she / her / her

User avatar
peewee_RotA
Posts: 500
Joined: Mon Dec 12, 2011 1:19 pm UTC

Re: 1231: "Habitable Zone"

Postby peewee_RotA » Sat Jun 29, 2013 11:01 pm UTC

Depending on which part of the path you put the mirror..

"OH MY GOD! A GIANT EYE!"
"Vowels have trouble getting married in Canada. They can’t pronounce their O’s."

http://timelesstherpg.wordpress.com/about/


Return to “Individual XKCD Comic Threads”

Who is online

Users browsing this forum: mscha and 36 guests