## Search found 2312 matches

Thu Dec 15, 2016 5:28 am UTC
Forum: Science
Topic: What to Do With a Nearby Black Hole
Replies: 11
Views: 2931

### Re: What to Do With a Nearby Black Hole

9 cm is pretty small. If modern space telescopes have an angular resolution of 100 mas = 0.5 μrad, then using the approximation tan x = x, the black hole wouldn't be observable until it was a mere 200 km away. Of course, that ignores the problem of contrast; the black hole provides almost no contras...
Wed Dec 14, 2016 6:52 pm UTC
Forum: Science
Topic: What to Do With a Nearby Black Hole
Replies: 11
Views: 2931

### Re: What to Do With a Nearby Black Hole

If it is planet-sized, its apparent temperature will be lower than the CMBR, but maybe high enough to measure. The temperature of a Schwarzschild black hole of mass m at infinity is (in Planck units) 1/(8π m ). Planet Nine has a predicted mass of around 3 × 10 33 , yielding a temperature of 1 × 10 ...
Sat Dec 10, 2016 5:49 am UTC
Forum: Mathematics
Topic: Geometric Growth vs. Geometric Pattern
Replies: 3
Views: 1667

### Re: Geometric Growth vs. Geometric Pattern

The third type of sequence is superexponential, yielding the explicit formula T n = (T 0 ) pⁿ . You get this sequence for p = 2, T 0 = 2: 2, 4, 16, 256, 65536, 4294967296, ... A more interesting variant instead has T n = p Tₙ₋₁ . This yields the explicit formula T n = ( ⁿp ) T₀ , where n p is p tetr...
Thu Dec 08, 2016 5:01 am UTC
Forum: Language/Linguistics
Topic: Miscellaneous language questions
Replies: 485
Views: 45714

### Re: Miscellaneous language questions

The θ→f definitely isn't rare in AAVE, though I think stereotypes have made it seem somewhat more common than it actually is. But you will hear it at least in the Midwest reasonably often and I assume other regions, too. I can't say for sure where it's most common. Wikipedia says it is called Th-fro...
Wed Nov 30, 2016 7:00 am UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2853
Views: 561186

### Re: RELATIVITY QUESTIONS! (and other common queries)

How is the magnetic field not photons? What does photon mean to you? For me, a photon is a little shortcut for talking about the particle-ish behavior in QED, but not so important. Light and magnetism are both just shades of QED. If you want to split out the radiative term in a propogating field as...
Tue Nov 29, 2016 10:52 am UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2853
Views: 561186

### Re: RELATIVITY QUESTIONS! (and other common queries)

Xanthir wrote:Light is literally an EM wave. Magnetism is transmitted by photons. If photons are very slightly slowed down from c by virtual particles, then "magnetic force" is too, because it's literally photons.

The magnetic field is not "literally photons" which is his whole point.
Tue Nov 22, 2016 5:43 pm UTC
Forum: Mathematics
Topic: 'Math is Pseudoscience and Fake Astrology' (Strange, Fringe Views by Prominent Figures)
Replies: 10
Views: 4461

### Re: 'Math is Pseudoscience and Fake Astrology' (Strange, Fringe Views by Prominent Figures)

jewish_scientist wrote:This reminds me a lot of when works using imaginary numbers were first published and everyone was like 'How much opium is this guy on?'

You must be pretty old to remember that.
Fri Nov 18, 2016 7:11 pm UTC
Forum: Mathematics
Topic: Odd or Even?
Replies: 10
Views: 3381

### Re: Odd or Even?

You don't have to change the definition of "even," just use a different one. f(x) = 1 is an even function, so it makes sense to say "1 is even" in that respect.
Thu Nov 17, 2016 8:07 pm UTC
Forum: Mathematics
Topic: Trying to figure out a thing in a video game.
Replies: 5
Views: 1909

### Re: Trying to figure out a thing in a video game.

And one card being activated does not influence the probability for the others? Indeed, it does not. They're all their own instance of chance. Nothings stacks in any way, you just get more 'dice throws' per sword hit. This statement can be interpreted in two different ways: 1. Cards have completely...
Thu Nov 17, 2016 7:43 pm UTC
Forum: Science
Topic: Is entanglement that surprising?
Replies: 27
Views: 4955

### Re: Is entanglement that surprising?

Nevertheless, in the "classical limit," the two models are equivalent, and that classical limit coincides precisely with the world we are most familiar with. So it would be hard to argue this was a coincidence. You are right that this is true more generally. For instance, the fact that all...
Mon Nov 14, 2016 3:00 pm UTC
Forum: Science
Topic: Science fleeting thoughts
Replies: 76
Views: 10762

### Re: Science fleeting thoughts

stekp wrote:
gd1 wrote:There is a person named Naomi Watts. I wonder what Naomi Amperes would be like?

I think she would be potentially different.

You're thinking of Naomi Volts, who isn't as well known anymore because Naomi Amps is more current.
Fri Nov 11, 2016 10:50 am UTC
Forum: Language/Linguistics
Topic: Think Before Naming Your Child
Replies: 1622
Views: 279900

### Re: Think Before Naming Your Child

ThemePark wrote:Unless of course it stands for William The First or some such.

William The First would be a pretty poor choice for a name, I think.
Wed Nov 09, 2016 6:37 am UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2853
Views: 561186

### Re: RELATIVITY QUESTIONS! (and other common queries)

I think the meanings are pretty much the same. Something that is constant doesn't change from one day to the next. I don't think that most people who consider the word "constant" think about Lorentz boosts.
Mon Nov 07, 2016 8:47 pm UTC
Forum: Language/Linguistics
Topic: Regional Dialect and Idiolect Oddities (pronunciation)
Replies: 822
Views: 183870

### Re: Regional Dialect and Idiolect Oddities (pronunciation)

I'm still trying to figure out how "toh" is pronounced.
Sun Nov 06, 2016 2:34 am UTC
Forum: Language/Linguistics
Topic: Regional Dialect and Idiolect Oddities (pronunciation)
Replies: 822
Views: 183870

### Re: Regional Dialect and Idiolect Oddities (pronunciation)

And yet both pronunciations are used. Here is a brewer from Russian River talking about one of their beers called Pliny the Younger.
Sat Nov 05, 2016 3:57 am UTC
Forum: Language/Linguistics
Topic: Words you think English should have or bring back.
Replies: 643
Views: 114811

### Re: Words you think English should have or bring back.

Is there an official list of "actual phobias"? As I understand it, if a real person somewhere presented with all the symptoms of a specific phobia for small holes, then it would be "actual." And there are a lot of people with strange phobias; it isn't common of course, but even r...
Fri Nov 04, 2016 10:07 am UTC
Forum: Language/Linguistics
Topic: Regional Dialect and Idiolect Oddities (pronunciation)
Replies: 822
Views: 183870

### Re: Regional Dialect and Idiolect Oddities (pronunciation)

Definitely /ɛ/ in twenty for me (/ˈtwɛnt.i~ˈtwɛɾ̃.i/, possibly /ˈtwɛn.i/, but definitely no /ʌ/). Rhymes with "plenty". I'd probably pronounce Pliny /ˈplaɪn.i/ (rhymes with "whiny" but not "plenty"), but that may just be because I haven't heard that name pronounced eno...
Thu Nov 03, 2016 6:32 pm UTC
Forum: Language/Linguistics
Topic: Regional Dialect and Idiolect Oddities (pronunciation)
Replies: 822
Views: 183870

### Re: Regional Dialect and Idiolect Oddities (pronunciation)

Mega85 wrote:how do you pronounce "twenty"? i pronounce it as [tʰwʌn(tʰ)i]. it doesn't rhyme with "plenty" [plɪn(tʰ)i] for me.

Plenty is a homophone for Pliny (Gaius Plinius)?
Wed Nov 02, 2016 4:00 am UTC
Forum: Science
Topic: Quantum Fluctuations questions
Replies: 21
Views: 4663

### Re: Quantum Fluctuations questions

What is the difference between many worlds and "decoherent histories"? I thought the idea of MWI was that the "branching events" were physically just decoherence. In other words, there is no collapse (no particular history is ever selected), but decoherent histories are nonintera...
Wed Nov 02, 2016 3:56 am UTC
Forum: Language/Linguistics
Topic: Regional Dialect and Idiolect Oddities (pronunciation)
Replies: 822
Views: 183870

### Re: Regional Dialect and Idiolect Oddities (pronunciation)

do you distinguish the following pairs of words: fill/feel fell/fail full/fool for me, those three pairs are all distinct. Yes; for me the first of each pair has one syllable and the second has two. But do you distinguish the vowel sounds? For me, the latter are also usually two syllables (though I...
Fri Oct 28, 2016 4:42 pm UTC
Forum: Science
Topic: Weakening evidence for dark energy
Replies: 12
Views: 2827

### Re: Weakening evidence for dark energy

The evidence for accelerating expansion in this study being "only" three sigma rather than five doesn't sound to me like a compelling evidence to say "it doesn't exist". I'm not sure if you can really stack standard deviations in this manner, but wouldn't a 95% CI around a "...
Fri Oct 28, 2016 8:48 am UTC
Forum: Science
Topic: Weakening evidence for dark energy
Replies: 12
Views: 2827

### Weakening evidence for dark energy

A friend of mine linked me an article titled "Marginal evidence for cosmic acceleration from Type Ia supernovae" which claims that a recent survey of a large sample of Type Ia supernovae is consistent with a constant rate of expansion (p > 0.003). This is surprising, given a five sigma cer...
Tue Oct 25, 2016 6:15 pm UTC
Forum: Mathematics
Topic: Three externally tangent circles sharing a single point of tangency
Replies: 19
Views: 4050

### Re: Three externally tangent circles sharing a single point of tangency

To be clear, all three circles are coplanar? Because otherwise it definitely is not true.
Sun Oct 23, 2016 2:27 am UTC
Forum: Science
Topic: Is entanglement that surprising?
Replies: 27
Views: 4955

### Re: Is entanglement that surprising?

Classical physics is certainly a special case of quantum physics, if that's what you mean. It's the special case as the scale gets sufficiently large, called the "classical limit." And separability is due to decoherence and noise; technically there is still a ton of entanglement, but essen...
Tue Oct 18, 2016 5:10 pm UTC
Forum: Science
Topic: Science fleeting thoughts
Replies: 76
Views: 10762

### Re: Science fleeting thoughts

The abstract calls it a "comprehensive sample of mammals," so probably not. Anyway, that's not what the study was about; it was about predicting a murder rate for prehistoric humans based on phylogeny.
Mon Oct 17, 2016 3:58 am UTC
Forum: Mathematics
Topic: Trisecting an angle
Replies: 63
Views: 8920

### Re: Trisecting an angle

Here is a simple work of angle trisection. Wantzel's proof is right about 3rd grade equation but also spoke that if you find a second grade equation (specific kind) then is solvable using ruler and compass. -> https://www.scribd.com/doc/312754356/Angle-Trisection-Simple Second doc: I have found alg...
Sat Oct 15, 2016 9:21 pm UTC
Forum: Science
Topic: Science fleeting thoughts
Replies: 76
Views: 10762

### Re: Science fleeting thoughts

I wasn't basing any of those numbers on anything but a wild guess. I was trying to get across the more general idea that diluting even a lot of drugs in the ocean seems like an inefficient way to get fish high.
Sat Oct 15, 2016 1:14 am UTC
Forum: Science
Topic: Science fleeting thoughts
Replies: 76
Views: 10762

### Re: Science fleeting thoughts

I have no clue how much water saltwater fish drink. Obviously it depends on the fish. 50 mL/day seemed fair for a small fish. Is it not? I really don't know. For freshwater fish, I guess they don't really "drink" per se. In either case, I guess most exposure would be through skin or gills,...
Fri Oct 14, 2016 2:06 am UTC
Topic: 1745: "Record Scratch"
Replies: 45
Views: 7448

### Re: 1745: "Record Scratch"

The "78 RPM era" might be close to your Civil War, but not ours... Define "ours". If you are from Brazil, China, Colombia, Costa Rica, Greece, Italy, Korea, Laos, Malaysia, Mexico, Myanmar, Nicaragua, Palestine, Paraguay, Spain, Sudan or Vietnam, then "the civil war" (...
Wed Oct 12, 2016 8:15 pm UTC
Topic: 1745: "Record Scratch"
Replies: 45
Views: 7448

### Re: 1745: "Record Scratch"

Analog vinyl record scratches have indisputably superior audio quality to digital CD skips AND mp3 stutters. True, but it's a lot easier to keep your CD from skipping than your album from getting scratched (and mp3 files should never really stutter on modern hardware). pet peeve: when people say &q...
Wed Oct 12, 2016 7:38 pm UTC
Forum: Science
Topic: Science fleeting thoughts
Replies: 76
Views: 10762

### Re: Science fleeting thoughts

There's also the fact that a lot of sewage efluent flows into rivers instead of directly into ocean, so concentrations will be higher there. I found this article (pdf) about bio-accumulation of pharmaceuticals. (I don't know what their affiliations are though.) Right, but the quoted post was talkin...
Wed Oct 12, 2016 2:45 am UTC
Forum: Science
Topic: Science fleeting thoughts
Replies: 76
Views: 10762

### Re: Science fleeting thoughts

Some work has been done on the environmental impacts of common medications too, such as birth control pills which have shown measured impacts on marine life downstream from big cities. The idea that a pandemic situation would cause something like this in the short-term is interesting, but also obvi...
Sat Oct 08, 2016 3:31 pm UTC
Forum: Science
Topic: Expected oldest person in history
Replies: 32
Views: 6601

### Re: Expected oldest person in history

The fact that Calment lived so long suggests the distribution is not Gaussian, and if rare exceptions are all that matters for setting records, how can a model that does not predict them prove anything useful in this respect?
Sat Oct 08, 2016 1:12 am UTC
Forum: Mathematics
Topic: Why does x=y -> f(x)=f(y)?
Replies: 12
Views: 2483

### Re: Why does x=y -> f(x)=f(y)?

Equality is treated pretty loosely in most languages too, especially with 0 and -0, for instance. A function IsNegative(x) that returns true for -0 and false for 0 is easy to define, but 0==-0 returns true.
Fri Oct 07, 2016 10:31 pm UTC
Forum: Mathematics
Topic: Why does x=y -> f(x)=f(y)?
Replies: 12
Views: 2483

### Re: Why does x=y -> f(x)=f(y)?

1/2 and 2/4 are, by the usual definitions, either elements of the same rational number (where rational numbers are defined as equivalence classes of ordered pairs of integers, with the second integer nonzero, and a/b means (a,b)) or representations of the same rational number (using an axiomatic def...
Fri Oct 07, 2016 8:43 pm UTC
Forum: Language/Linguistics
Topic: Why are some linguistic patterns irritating?
Replies: 59
Views: 9180

### Re: Why are some linguistic patterns irritating?

"Leave things there" as in "stop arguing after this post."
Fri Oct 07, 2016 12:51 am UTC
Forum: Mathematics
Topic: 1 is Not Prime
Replies: 17
Views: 3883

### Re: 1 is Not Prime

The real question is what makes the "fundamental theorem of algebra" fundamental or a theorem of algebra.
Fri Oct 07, 2016 12:41 am UTC
Forum: Mathematics
Topic: Why does x=y -> f(x)=f(y)?
Replies: 12
Views: 2483

### Re: Why does x=y -> f(x)=f(y)?

It depends on what rules of inference or transformation you are using. There are many equivalent formal systems, some of which include an axiom (or axiom schema) of substitution. The axioms used in algebra class typically are special cases or simplifications of more general axioms used by mathematic...
Thu Oct 06, 2016 4:14 pm UTC
Forum: Language/Linguistics
Topic: Why are some linguistic patterns irritating?
Replies: 59
Views: 9180

### Re: Why are some linguistic patterns irritating?

If you think I'll sit around as the world goes by You're thinkin' like a fool 'cause it's a case of do or die Out there is a fortune waiting to be had If you think I'll let you go you're mad You've got another thing comin' You've got another thing comin' Makes sense to me. He's wrong about what's c...
Thu Oct 06, 2016 4:04 pm UTC