Search found 272 matches

by KarenRei
Sat Jan 20, 2018 2:38 am UTC
Forum: Individual XKCD Comic Threads
Topic: 0325: "A-Minus-Minus"
Replies: 128
Views: 39178

Re: 0325: "A-Minus-Minus"

In the spirit of this comic, when I received an email to the wrong address (someone with the same name as me who lives in California; I live in Iceland), instead of deleting it, I replied. The person was a flooring installer in California, sending me a draft of an upcoming project. =================...
by KarenRei
Wed Dec 06, 2017 2:18 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1924: "Solar Panels"
Replies: 60
Views: 3902

Re: 1924: "Solar Panels"

install even cheaper solar panels next to the road; no need for foundations, as there would be no loads on the panels LOL. Sorry, engineering doesn't work like that. What you're describing is otherwise known as "debris flying into traffic at high speeds during a windstorm". On my land I h...
by KarenRei
Wed Dec 06, 2017 2:22 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1924: "Solar Panels"
Replies: 60
Views: 3902

Re: 1924: "Solar Panels"

60% is completely unrealistic. I was thinking something more like 30%, optimistically speaking. The dirt is a huge problem. Even on tilting panels raised above ground level, dust accumulation results in losses between 1% and 50%. http://ucsdnews.ucsd.edu/pressrelease/cleaning_solar_panels_often_not...
by KarenRei
Wed Dec 06, 2017 1:48 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1924: "Solar Panels"
Replies: 60
Views: 3902

Re: 1924: "Solar Panels"

To put a more precise point on it: here's the breakdown of the costs for a solar farm: https://www.nrel.gov/docs/fy16osti/67142.pdf Page 38: Panels are $0,64/W out of $1,42 on a large (>100MW) solar farm, or out of $1,82 on a small (<5MW) solar farm. That's 45% and 35%, respectively. The non-panel o...
by KarenRei
Wed Dec 06, 2017 1:03 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1924: "Solar Panels"
Replies: 60
Views: 3902

Re: 1924: "Solar Panels"

Karen, while your post is interesting and certainly a far cry from the "solar freaking roadways" lunacy, I have to say I am still thoroughly unconvinced by the concept. The major advantages relating to land use and ease of construction only really apply to areas where the land near the hi...
by KarenRei
Tue Dec 05, 2017 3:07 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1924: "Solar Panels"
Replies: 60
Views: 3902

Re: 1924: "Solar Panels"

Is there any particular reason why this solution should be exclusive to solar roads? No. Concrete and brick pavers are used for roads in some places , but generally for aesthetics; historically, they've usually been more expensive because they're generally laid by hand. That said, you can now get p...
by KarenRei
Tue Dec 05, 2017 1:53 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1924: "Solar Panels"
Replies: 60
Views: 3902

Re: 1924: "Solar Panels"

Big screwup in this comic by using the word "easier" rather than "better". It may be "easier" for someone to put solar panels in their yard than on their roof. Heck, it might even be easier for them to put them in a tree. That doesn't make it "better". Also, r...
by KarenRei
Wed Nov 15, 2017 1:17 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1916: "Temperature Preferences"
Replies: 82
Views: 6044

Re: 1916: "Temperature Preferences"

Reykjavík calling! And yes, while our winters aren't that cold (though very windy and wet!), our summers are wonderful. Average daily high in July is something like 15-16°C (or, for Americans: 15-16°C also; come on, learn metric you guys...)
by KarenRei
Fri Feb 03, 2017 2:15 am UTC
Forum: What If?
Topic: What-if 0153: "Hide the Atmosphere"
Replies: 46
Views: 12863

Re: What-if 0153: "Hide the Atmosphere"

As some side trivia, "freezing out the atmosphere" is a serious proposition for terraforming Venus. Big sunshade, freeze it out steadily, let it concentrate in the lowpoints (which deepen from the weight), manualy assist with concentrating the rest, then pave over it with insulation and co...
by KarenRei
Mon Jan 09, 2017 3:29 pm UTC
Forum: Science
Topic: Light in a fog
Replies: 14
Views: 2212

Re: Light in a fog

Bringing up a mirror just complicates it. Because sure, in the direct-collimated-sunlight case I could add a mirror beside the original solar panel that reflects light onto the back of the panel and causes its generation to double. But I could also add a mirror that would make its generation increas...
by KarenRei
Sun Jan 08, 2017 9:05 pm UTC
Forum: Science
Topic: Light in a fog
Replies: 14
Views: 2212

Re: Light in a fog

Indeed, that's what intuition says. The thing that makes me hesitate is that if you put the same double-sided solar cell in 1000W/m² direct sunlight, you only get 200W, not 400W. There's a naggling feeling that the two situations should be equivalent and I'm trying to figure out how to convince myse...
by KarenRei
Sun Jan 08, 2017 4:05 pm UTC
Forum: Science
Topic: Light in a fog
Replies: 14
Views: 2212

Re: Light in a fog

If you just had a layer of perfectly scattering fog in between the sun and the solar panel, then yes, 1/6 of the light will leave the layer in 1/6 of the solid angle available, because it's evenly distributed across all angles and we've decided that 1/6 of them are useful, while the other 5/6 of th...
by KarenRei
Sun Jan 08, 2017 1:14 pm UTC
Forum: What If?
Topic: What-If 0145: "Fire From Moonlight"
Replies: 157
Views: 37902

Re: What-If 0145: "Fire From Moonlight"

Topic related to this thread here:

viewtopic.php?f=18&t=121131&p=4129899#p4129899
by KarenRei
Sun Jan 08, 2017 12:29 am UTC
Forum: Science
Topic: Light in a fog
Replies: 14
Views: 2212

Re: Light in a fog

Probably neither. I don't think you can assume a constant 1000W/m² radiation from every direction everywhere inside the fog. Even if all the scattering inside the fog evens out, you have a huge portion of the light that'll get reflected back to the sun immediately after entering the fog. Summing up...
by KarenRei
Sat Jan 07, 2017 10:51 pm UTC
Forum: Science
Topic: Light in a fog
Replies: 14
Views: 2212

Light in a fog

I want to make sure my grasp on this is correct. Envision a fog with infinitely long extinction coefficient (perfectly reflective particles) lit up by the sun with a given solar constant (let's say 1000W/m^2). Inside the fog you place a 20% efficient 1m^2 solar panel that functions equally well from...
by KarenRei
Wed Dec 07, 2016 12:09 pm UTC
Forum: What If?
Topic: What-If 0153: "Peptides" [removed]
Replies: 22
Views: 9843

Re: What-If 0153: "Peptides"

With rare but extant Selenocysteine (O) and Pyrrolysine (U) and without the colonial spelling, "Deinsitutionali s ation" is a perfectly cromulant peptide chain... Well, geez, if you're going to do that then you can do "pneumonoultramicroscopicsilicovolcanoconiosis" (45 letters) ...
by KarenRei
Tue Dec 06, 2016 12:59 pm UTC
Forum: What If?
Topic: What-If 0153: "Peptides" [removed]
Replies: 22
Views: 9843

Re: What-If 0153: "Peptides"

This question is really weak. Is knowledge of grep and the mere existence of "/usr/share/words" really that rare of a skillset? egrep -i "^[ARNDCEQGHILKMFPSTWYV]*$" /usr/share/dict/words | awk '{print length, $0}' | sort -n | cut -d " " -f2- egrep -i "^(ALA|ARG|ASN...
by KarenRei
Sun Oct 30, 2016 8:58 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1749: "Mushrooms"
Replies: 47
Views: 7362

Re: 1749: "Mushrooms"

I've got mushrooms in the garden. I've got Armillaria mellea . It ate the hedge. It looks a lot like Galerina marginata so I'm not going to eat it right back. Mushrooms are the primary reason I wish that smartphones came with DNA sequencers. :Þ Re. A. virosa/Destroying Angel... it's famous for its ...
by KarenRei
Fri Oct 21, 2016 4:13 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1749: "Mushrooms"
Replies: 47
Views: 7362

Re: 1749: "Mushrooms"

A friend of mine calls fungi "the vampires of the plant world".

Not exactly phylogenically correct, but...
by KarenRei
Wed Oct 19, 2016 3:23 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1747: "Spider Paleontology"
Replies: 43
Views: 7038

Re: 1747: "Spider Paleontology"

I have to admit that I'd be totally chuffed to find evidence that Dinosaurs* built elaborate bowers surrounded by carefully segregated piles of colored materials, like the bowerbird . Unfortunately, that's probably about as unlikely as Randall's future folk learning about spiderwebs without using t...
by KarenRei
Tue Oct 18, 2016 4:10 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1747: "Spider Paleontology"
Replies: 43
Views: 7038

Re: 1747: "Spider Paleontology"

So, if I'm understanding you correctly, you're arguing that the majority of the diversity among dinosaurs can be found in birds, a lineage 65 million years old, even though dinosaurs had already been diversifying for 170 million years? To not put too fine of a point on it: the dinosaurs are defined ...
by KarenRei
Tue Oct 18, 2016 2:11 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1747: "Spider Paleontology"
Replies: 43
Views: 7038

Re: 1747: "Spider Paleontology"

Birds have had 65 million years to diversify. And dinosaurs had 170 million years to diversify before getting up to the point of further diversifying into the subset of dinosaurs known as birds - your point? As birds are a subset of dinosaurs, it's inherent that their diversity will be less than th...
by KarenRei
Mon Oct 17, 2016 11:10 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1747: "Spider Paleontology"
Replies: 43
Views: 7038

Re: 1747: "Spider Paleontology"

Probably best done with atomic-level physical crystal manipulation (multi-atom level of resolution, to deal with error correction after random radiation hits.... Store it at L4 or L5 (or both?) of Mercury (stable, relatively clean of crossing asteroids compared to other planets), with a planar whip...
by KarenRei
Mon Oct 17, 2016 1:38 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1747: "Spider Paleontology"
Replies: 43
Views: 7038

1747: "Spider Paleontology"

http://imgs.xkcd.com/comics/spider_paleontology.png Alt-text: "Whenever you see a video of birds doing something weird, remember: Birds are a small subset of dinosaurs, so the weirdness of birds is a small subset of the weirdness of dinosaurs." --- I think people who design CG dinosaurs w...
by KarenRei
Tue Sep 13, 2016 11:36 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1732: "Earth Temperature Timeline"
Replies: 523
Views: 66961

Re: 1732: "Earth Temperature Timeline"

SecondTalon wrote:
Stargazer71 wrote:meaniehead as a pejorative about a dozen times


Here's what's going to happen.... ... (snip)


Where's a "Like" button when you need one?
by KarenRei
Tue Sep 13, 2016 9:56 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1732: "Earth Temperature Timeline"
Replies: 523
Views: 66961

Re: 1732: "Earth Temperature Timeline"

So, apparently Elon Musk is an XKCD fan ;)

https://twitter.com/elonmusk/status/775632728548970500
by KarenRei
Mon Aug 22, 2016 2:21 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1723: "Meteorite Identification"
Replies: 30
Views: 7749

Re: 1723: "Meteorite Identification"

Despite knowing that the vast majority of things people suspect are meteorrites aren't, I once got tricked into thinking that an unusual shaped ("fingerprint"-looking), highly naturally polished piece of basalt might be when it easily deflected my studfinder. It was then that I learned tha...
by KarenRei
Sat Jul 09, 2016 12:50 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1702: "Home Itch Remedies"
Replies: 33
Views: 5330

Re: 1702: "Home Itch Remedies"

Hehe ;) As a side note, the Icelandic language is unusually easy for making duck jokes because the word for "duck" and all of its various declensions (önd, andar, endur, andir, anda, öndum...) closely resembles a number of differents words used in forming compounds.(words equivalent to the...
by KarenRei
Mon Jul 04, 2016 8:21 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1702: "Home Itch Remedies"
Replies: 33
Views: 5330

Re: Home Itch Remedies

So the best home remedy is to move to Iceland Not a good idea... The name of the lake (Icelandic mý ("midge") and vatn ("lake"); the lake of midges) comes from the huge numbers of midges to be found there in the summer. Except that they don't bite. They form big clouds, and look...
by KarenRei
Tue May 10, 2016 9:36 am UTC
Forum: Mathematics
Topic: Seemingly simple
Replies: 16
Views: 3036

Re: Seemingly simple

C/x = B/sqrt(B^2 -(A-x)^2) This should be C/x = B/sqrt(B^2 + (A-x)^2), since sqrt(B^2 + (A-x)^2) is the length of the hypotenuse of the large right triangle. Then, C sqrt(B^2 + (A-x)^2) = B x C^2 (B^2 + (A-x)^2) = B^2 x^2 B^2 C^2 + A^2 C^2 - 2 A C^2 x + C^2 x^2 = B^2 x^2 0 = (B^2 - C^2) x^2 + (2 A ...
by KarenRei
Tue May 10, 2016 7:49 am UTC
Forum: Mathematics
Topic: Seemingly simple
Replies: 16
Views: 3036

Re: Seemingly simple

C/x = B/sqrt(B^2 -(A-x)^2) C = x * B/sqrt(B^2 -(A-x)^2) x * B/sqrt(B^2 -(A-x)^2) - C = 0 This isn't in the form Ax^2 + Bx + C = 0... and I don't remember how to get it in that form ;) And Wolfram Alpha last night was just looping forever, while today it says "Standard computing time exceeded&qu...
by KarenRei
Tue May 10, 2016 12:49 am UTC
Forum: Mathematics
Topic: Seemingly simple
Replies: 16
Views: 3036

Seemingly simple

Either I'm tired, an idiot, or this problem isn't as easy as it looks (solve for X; all corners that look like right angles are right angles):

Image

Can anyone enlighten me as to which one it is?
by KarenRei
Thu Mar 17, 2016 2:51 am UTC
Forum: What If?
Topic: What-If 0148: "Eat the Sun"
Replies: 40
Views: 15750

Re: What-If 0148: "Eat the Sun"

Meh, Cadbury Creme Eggs are nothing. Here in Iceland we have "Páskaegg" (lit. "Easter Egg"), which are like this: Not purely a purely mid-Atlantic(-ridge) phenomenon, I assure you. I can't definitively speak for the US (I presume that it happens!) but the shops in the UK are ful...
by KarenRei
Wed Mar 16, 2016 7:06 pm UTC
Forum: What If?
Topic: What-If 0148: "Eat the Sun"
Replies: 40
Views: 15750

Re: What-If 0148: "Eat the Sun"

Now I just want to contribute to Randall's Creme Egg pile... Meh, Cadbury Creme Eggs are nothing. Here in Iceland we have "Páskaegg" (lit. "Easter Egg"), which are like this: https://c1.staticflickr.com/8/7615/17001375115_6e346a56d4.jpg http://www.visir.is/apps/pbcsi.dll/storyim...
by KarenRei
Sat Feb 20, 2016 9:33 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1645: "Toasts"
Replies: 81
Views: 13913

Re: 1645: "Toasts"

Image
by KarenRei
Fri Feb 19, 2016 5:42 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1645: "Toasts"
Replies: 81
Views: 13913

Re: 1645: "Toasts"

Okay, I guess my mind is in the gutter...

Fatheads for my real friends and real head for my fat friends.
Hotrods for my real friends and real rods for my hot friends.
Manholes for my real friends and a real holes for my man-friends.

... this is getting out of hand...
by KarenRei
Sat Feb 13, 2016 5:39 pm UTC
Forum: Science
Topic: Venus chemical engineering
Replies: 0
Views: 3065

Venus chemical engineering

Hi all. I've been idly thinking a lot about how to provision a floating colony on Venus in a simple, reliable manner. There are two issues I'm having a bit of trouble on: 1) Removal (to an exhaust stream) of SO2 from a stream also containing H2O and O2 2) Either: 2a) Separation of individual acids f...
by KarenRei
Wed Feb 10, 2016 11:00 pm UTC
Forum: What If?
Topic: What-If 0145: "Fire From Moonlight"
Replies: 157
Views: 37902

Re: What-If 0145: "Fire From Moonlight"

Simplest case: take a spherical black body at thermal equilibrium. Then put it next to a mirror. Not even a focusing mirror, just a simple plane. Doesn't the side of the black body facing the mirror end up warmer than the side facing away? This does assume the background is cooler than the black bo...
by KarenRei
Wed Feb 10, 2016 10:31 pm UTC
Forum: Science
Topic: Landing rockets upright is unnecessary?
Replies: 61
Views: 9666

Re: Landing rockets upright is unnecessary?

This would require an infinitely large nozzle, so one does as much as they can with the nozzle that they have. The more gas involved (even gas that doesn't take part in the reaction), the more fully they can approach ambient for a given-sized nozzle. No, and actually the space shuttle main engines ...
by KarenRei
Wed Feb 10, 2016 4:46 pm UTC
Forum: Science
Topic: Is the entire universe a black hole?
Replies: 13
Views: 3078

Re: Is the entire universe a black hole?

Some interesting reading on the subject: http://cds.cern.ch/record/348993/files/9803052.pdf They posit an inflation-driven effect at high densities (a dilation gravity) that would mean that there's no such thing as a singularity, and that both black holes and our universe would be versions of the sa...

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