1276: "Angular Size"

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1276: "Angular Size"

Postby rhomboidal » Fri Oct 11, 2013 4:04 am UTC

Image

Title Text: If the celestial sphere were mapped to the Earth's surface, astronomy would get a LOT easier; you'd just need a magnifying glass.

I need to see this in secondary-school textbooks. Tomorrow.

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Re: 1276: "Angular Size"

Postby Caffeine » Fri Oct 11, 2013 4:19 am UTC

Well, I'm impressed :) and a nice nod to 1253

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Re: 1276: "Angular Size"

Postby poxic » Fri Oct 11, 2013 4:25 am UTC

Caffeine wrote:and a nice nod to 1253

Thanks for that. I was wondering what the jelly-filled planet business was about.
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Re: 1276: "Angular Size"

Postby dividingbyzero » Fri Oct 11, 2013 4:30 am UTC

MIght as well make the joke now:

Uranus is about the size of a soccer field.

(Just to be clear, I know it's supposed to be -angular- size, but trying to incorporate that into the joke would make it seem like something BHG would say (like in comic #89).)

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Re: 1276: "Angular Size"

Postby xjr » Fri Oct 11, 2013 4:32 am UTC

OK, help here– where is the football field? Is it meant to be the size of that whole box? because it's not that much bigger than a soccer field... CONFUSED

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Re: 1276: "Angular Size"

Postby delefrati » Fri Oct 11, 2013 4:32 am UTC

So did it means that an E. Colli could "see" a solar eclipse if one of the voyagers were passing in front of the Sun?

Spoiler:
If one of the voyagers were between the Sun and the Earth, and if they casted a strong shadow, and if the E. Colli could actually "see" something...?

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Re: 1276: "Angular Size"

Postby texttheater » Fri Oct 11, 2013 4:48 am UTC

I don't get panel #2: why does it say "football field" there?

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Re: 1276: "Angular Size"

Postby edenist » Fri Oct 11, 2013 4:49 am UTC

delefrati wrote:So did it means that an E. Colli could "see" a solar eclipse if one of the voyagers were passing in front of the Sun?

Spoiler:
If one of the voyagers were between the Sun and the Earth, and if they casted a strong shadow, and if the E. Colli could actually "see" something...?


1) If voyager was between the sun and the earth, it's angular size would be much larger than e-coli
2) http://en.wikipedia.org/wiki/Umbra

So, no. We still would not see an "eclipse".
Last edited by edenist on Fri Oct 11, 2013 4:51 am UTC, edited 1 time in total.

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Re: 1276: "Angular Size"

Postby phlip » Fri Oct 11, 2013 4:50 am UTC

delefrati wrote:So did it means that an E. Colli could "see" a solar eclipse if one of the voyagers were passing in front of the Sun?

No, it's more like... to an observer at the centre of the Earth, the voyagers could be nearly eclipsed by a single E. Coli on the surface.

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enum ಠ_ಠ {°□°╰=1, °Д°╰, ಠ益ಠ╰};
void ┻━┻︵​╰(ಠ_ಠ ⚠) {exit((int)⚠);}
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Re: 1276: "Angular Size"

Postby joecentric » Fri Oct 11, 2013 4:54 am UTC

Forgive me, but what is the phrase "football field" doing in the third subpanel?

I'd think that the soccer field would be enough (and pretty much the same size).

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Re: 1276: "Angular Size"

Postby quolnok » Fri Oct 11, 2013 4:56 am UTC

I'm clearly focused on the wrong thing, but is it common to find E. Coli infested laptops on ping pong tables in English soccer fields?

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Re: 1276: "Angular Size"

Postby BlitzGirl » Fri Oct 11, 2013 5:02 am UTC

joecentric wrote:Forgive me, but what is the phrase "football field" doing in the third subpanel?

I was wondering that, too. Mustard, perhaps? I'm not sure what that label is indicating.
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Re: 1276: "Angular Size"

Postby Eternal Density » Fri Oct 11, 2013 5:10 am UTC

Baobabs, the angular size of the sun and moon is more riverish than I expected!
BlitzGirl wrote:
joecentric wrote:Forgive me, but what is the phrase "football field" doing in the third subpanel?

I was wondering that, too. Mustard, perhaps? I'm not sure what that label is indicating.

I second the vote of mustard.
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Re: 1276: "Angular Size"

Postby joecentric » Fri Oct 11, 2013 5:12 am UTC

BlitzGirl wrote:Mustard, perhaps?


Holy cow, I had to look that up, and whaddya know, it was what I thought it was. Awesome!

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Re: 1276: "Angular Size"

Postby phlip » Fri Oct 11, 2013 5:13 am UTC

My guess is that the "football field" words are some leftovers from editing, and aren't meant to be there...

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Re: 1276: "Angular Size"

Postby keithl » Fri Oct 11, 2013 5:21 am UTC

delefrati wrote:So did it means that an E. Colli could "see" a solar eclipse if one of the voyagers were passing in front of the Sun?

Spoiler:
If one of the voyagers were between the Sun and the Earth, and if they casted a strong shadow, and if the E. Colli could actually "see" something...?


No full eclipse if the spacecraft was more than 400 meters above the E. Coli. The 3.7 meter high gain antenna casts the biggest shadow, and farther than 400 meters is smaller than the angular size of the sun. So what you would see, if it was orbiting 400km up, is a tiny spot obscuring 1ppm of the sun's disk, transiting in less than half a second. You could not see that; hypothetical eyes on an E. Coli would have much smaller "lenses" than yours, much worse angular acuity ( they would, at best, be like radio antennas for light) so they wouldn't be able to locate the sun in the sky, much less observe a tiny dot moving across it.

If the spacecraft was at planetary distances, say halfway to the sun, fuggedaboudit. I doubt if any conceivable full-disk imager could detect the tiny change in solar light output (3E-17) during the longer (but much rarer) transits.
Last edited by keithl on Fri Oct 11, 2013 5:35 am UTC, edited 1 time in total.

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Re: 1276: "Angular Size"

Postby texttheater » Fri Oct 11, 2013 5:22 am UTC

joecentric wrote:
BlitzGirl wrote:Mustard, perhaps?


Holy cow, I had to look that up, and whaddya know, it was what I thought it was. Awesome!


Could you... elaborate on that?

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Re: 1276: "Angular Size"

Postby keithl » Fri Oct 11, 2013 5:33 am UTC

quolnok wrote:I'm clearly focused on the wrong thing, but is it common to find E. Coli infested laptops on ping pong tables in English soccer fields?
I'm guessing a picture of that will appear on this forum within 24 hours. Given that E. Coli normally inhabits feces, the picture may also disparage the operating system the laptop runs.

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Re: 1276: "Angular Size"

Postby TaviRider » Fri Oct 11, 2013 5:34 am UTC

I think there's a glaring omission: The ISS. Very small object, yet very close...

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Re: 1276: "Angular Size"

Postby patzer » Fri Oct 11, 2013 5:35 am UTC

texttheater wrote:
joecentric wrote:
BlitzGirl wrote:Mustard, perhaps?


Holy cow, I had to look that up, and whaddya know, it was what I thought it was. Awesome!


Could you... elaborate on that?

OTTish word for an accidental error in an image.

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Re: 1276: "Angular Size"

Postby Iranon » Fri Oct 11, 2013 5:45 am UTC

Ohh, product placement!
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Re: 1276: "Angular Size"

Postby BlitzGirl » Fri Oct 11, 2013 6:06 am UTC

keithl wrote:
quolnok wrote:I'm clearly focused on the wrong thing, but is it common to find E. Coli infested laptops on ping pong tables in English soccer fields?
I'm guessing a picture of that will appear on this forum within 24 hours. Given that E. Coli normally inhabits feces, the picture may also disparage the operating system the laptop runs.

That took less than 24 minutes to make:

Image
Redundant:
Spoiler:
EnglishSoccerField.png

No redundakitty. They prefer OTT spoilers, I think.

(Nothing is to scale. And hahaha Mountain Lion poop, or something.)
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Re: 1276: "Angular Size"

Postby atimholt » Fri Oct 11, 2013 6:27 am UTC

It’s worth noting that Isaac Asimov came up with this concept first. Let me just see if I can find it real quick…

…found it in a book of mine (Fact and Fancy), but not on the internet. It’s in an essay called “Heaven on Earth”.

This is a useful page: http://www.isfdb.org/cgi-bin/title.cgi?123801
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Re: 1276: "Angular Size"

Postby deadlywonky » Fri Oct 11, 2013 6:50 am UTC

I hate to be a pedant, and I know that Americans use the term "Freeway" but its "Motorway" in the UK. Also if anyone called the M25 a Freeway, they would laughed out of the room, it's known locally as the world's largest car park.

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Re: 1276: "Angular Size"

Postby CharlieP » Fri Oct 11, 2013 7:20 am UTC

deadlywonky wrote:I hate to be a pedant, and I know that Americans use the term "Freeway" but its "Motorway" in the UK. Also if anyone called the M25 a Freeway, they would laughed out of the room, it's known locally as the world's largest car park.


I don't mind being a pedant at all, and want to point out that the M25 doesn't go all the way round - there's a gap where it crosses the Thames to the east of London. 8-)
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Re: 1276: "Angular Size"

Postby Djehutynakht » Fri Oct 11, 2013 8:10 am UTC

This was done totally so he could include 4942 Munroe in there.

Which he should. It's an awesome development and I look forward to him including it in stuff for a while.

Anyways, besides the reference, pretty cool. Not entirely sure how to conceptualize it, But I think I must be tired.

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Re: 1276: "Angular Size"

Postby J L » Fri Oct 11, 2013 8:19 am UTC

I'm afraid of my tilde key now.

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Re: 1276: "Angular Size"

Postby Sampy » Fri Oct 11, 2013 9:57 am UTC

CharlieP wrote:
deadlywonky wrote:I hate to be a pedant, and I know that Americans use the term "Freeway" but its "Motorway" in the UK. Also if anyone called the M25 a Freeway, they would laughed out of the room, it's known locally as the world's largest car park.


I don't mind being a pedant at all, and want to point out that the M25 doesn't go all the way round - there's a gap where it crosses the Thames to the east of London. 8-)


I'm interested to know what the grey area to the South West of London represents. It's the same colour as the Thames which implies it is water, but it doesn't actually correspond to anything that's really there!

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Re: 1276: "Angular Size"

Postby gothick » Fri Oct 11, 2013 10:17 am UTC

deadlywonky wrote:I hate to be a pedant, and I know that Americans use the term "Freeway" but its "Motorway" in the UK. Also if anyone called the M25 a Freeway, they would laughed out of the room, it's known locally as the world's largest car park.


I did think that "orbital freeway" was a rather grand title compared to "ring road", which is how I normally hear the M25 described... "Orbital", yes, "freeway": no.

The football field confused me, too, of course, not just because I wasn't sure why it was there, but also because "football field" and "soccer field" mean the same thing in the UK...

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Re: 1276: "Angular Size"

Postby Xenomortis » Fri Oct 11, 2013 10:44 am UTC

"Orbital freeway" is indeed, a rather grandiose term for what is actually a circular car park.
Image

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Re: 1276: "Angular Size"

Postby jalopezp » Fri Oct 11, 2013 11:12 am UTC

I guess this is the only place to say this. Some of these threw me off. If you look up the angular diameters of the planets, you see that they vary considerably - not least because at times they are much closer to us than others. If we take the diameter of the earth to be 40075 kilometres, 1" is equivalent to about 30.92 metres. Now Mars ranges in size between 3.5" and 25.1", which would make it vary between 776m (about its size in the picture) and 108m. Venus varies even more, between 296 and 2041 metres. While we're at it, the sun is between 58.6 and 60.7Km in diameter, while the moon goes from 54.3 to 63.3Km, all these very close to the area encompassed the M25.

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Re: 1276: "Angular Size"

Postby eran_rathan » Fri Oct 11, 2013 11:23 am UTC

so much win on so many levels.
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Re: 1276: "Angular Size"

Postby cellocgw » Fri Oct 11, 2013 11:44 am UTC

BlitzGirl wrote:
keithl wrote:
quolnok wrote:I'm clearly focused on the wrong thing, but is it common to find E. Coli infested laptops on ping pong tables in English soccer fields?
I'm guessing a picture of that will appear on this forum within 24 hours. Given that E. Coli normally inhabits feces, the picture may also disparage the operating system the laptop runs.

That took less than 24 minutes to make:

Image
Redundant:
Spoiler:
EnglishSoccerField.png

No redundakitty. They prefer OTT spoilers, I think.

(Nothing is to scale. And hahaha Mountain Lion poop, or something.)


Hey -- what's the difference between a British Soccer Field, a USA Soccer Field, and for that matter a Brazilian Soccer Field? :twisted:
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Re: 1276: "Angular Size"

Postby cellocgw » Fri Oct 11, 2013 11:47 am UTC

He left out a Very Important Celestial Object

Also not quite sure how the Chrono-Synclastic Infandibulum fits into this scale.
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Re: 1276: "Angular Size"

Postby orthogon » Fri Oct 11, 2013 11:59 am UTC

Sampy wrote:
CharlieP wrote:
deadlywonky wrote:I hate to be a pedant, and I know that Americans use the term "Freeway" but its "Motorway" in the UK. Also if anyone called the M25 a Freeway, they would laughed out of the room, it's known locally as the world's largest car park.


I don't mind being a pedant at all, and want to point out that the M25 doesn't go all the way round - there's a gap where it crosses the Thames to the east of London. 8-)


I'm interested to know what the grey area to the South West of London represents. It's the same colour as the Thames which implies it is water, but it doesn't actually correspond to anything that's really there!

It looks like it's the South Downs National Park, and I am one of today's lucky 10,000 because I didn't know we had a new National Park (since 2011).

The name "orbital motorway" comes from the fact that the M25 represents the 3s orbital; the 2s is the North/South circular and the 1s is the "Inner Ring Road". Plans to build the three 2p orbital motorways proved impractical owing to the enormous amount of civil engineering required, in particular for the vertically-oriented 2pz.
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Re: 1276: "Angular Size"

Postby Quicksilver » Fri Oct 11, 2013 12:11 pm UTC

Disappointed in the lack of a "Your Mom" joke.

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Re: 1276: "Angular Size"

Postby project2051 » Fri Oct 11, 2013 12:58 pm UTC

cellocgw wrote:
Hey -- what's the difference between a British Soccer Field, a USA Soccer Field, and for that matter a Brazilian Soccer Field? :twisted:


The way the grass is cut.

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Re: 1276: "Angular Size"

Postby CocoaNutCakery » Fri Oct 11, 2013 1:04 pm UTC

gothick wrote:The football field confused me, too, of course, not just because I wasn't sure why it was there, but also because "football field" and "soccer field" mean the same thing in the UK...


Which is weird, considering the fact that the UK is the one of the few nations that practices both association football (soccer) and another major type of football (in this case, rugby).

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Re: 1276: "Angular Size"

Postby willdude » Fri Oct 11, 2013 1:05 pm UTC

My one quibble: wouldn't the "shadow" of the other celestial bodies in our solar system vary greatly based on their and Earth's relative orbital points around the sun, and thus the distance between the two?

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Re: 1276: "Angular Size"

Postby jgh » Fri Oct 11, 2013 1:06 pm UTC

cellocgw wrote:Hey -- what's the difference between a British Soccer Field, a USA Soccer Field, and for that matter a Brazilian Soccer Field? :twisted:
You mean: what's the difference between a standard international football field, and a USA handegg field?

A handegg field is 360 feet x 160 feet (109.72 m x 48.76 m).
A international standard football field is 105m x 68m (344.48 feet x 223.10 feet).


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