Good_Burning_Plastic

Karma: 1,103

Good_Burning_Plastic Jun 11, 2017, 2:53 PM
0 points
in reply to: MaryCh’s comment on: Stupid Questions June 2017

So, they don’t just form very small micelles within the body of the, well, liquid of which there’s more there?

I don’t think they would. After all, olive oil and sunflower oils are themselves mixtures of several different fatty acids.

if their amounts are comparable, they will just separate according to gravity

Not if they form a solution, which I think they do. After all it’s not like if you leave a bottle of vodka alone all the water will sink to the bottom and all the ethanol will float to the top.

Good_Burning_Plastic May 21, 2017, 8:01 AM
2 points
in reply to: lmn’s comment on: Thoughts on civilization collapse
No, I don’t. I was just pointing out that you picked a very disingenuous way of stating that. (You could have said instead, for example, “some people who said something mean about the migrants have gotten harsher sentences”)

true facts

Huh. I’ve been living for a year in a city where most of the population is foreign-born (myself included) and it doesn’t look like it’s going to hell. In particular I feel safer here than in certain other places with many fewer immigrants.

You may want to learn about how chilling effects on free speech work.

Judging by the number of people I hear saying ridiculous things about migrants every day, I wonder what would happen if such “chilling effects” were not in place—would my Facebook feed ever contain anything else at all?

Good_Burning_Plastic May 19, 2017, 9:23 AM
0 points
in reply to: cousin_it’s comment on: Open thread, May 15 - May 21, 2017

If you make 100 loaves and sell them for 99 cents each, you’ve provided 1 dollar of value to society, but made 100 dollars for yourself.

Total, $101. (Society also includes you.)

If you make 100 loaves and give them away to those who can’t afford it, you’ve provided 100 dollars of value to society, but made zero for yourself.

Total, $100.

Good_Burning_Plastic May 19, 2017, 9:21 AM
2 points
in reply to: lmn’s comment on: Thoughts on civilization collapse

So basically you’re conceding I’m right, but still want to call bullshit on it.

If by “some” you literally meant nothing but “more than zero”, fine. (But “some” people get harsh sentences for pretty much anything, so “some people get harsh sentences for X” is not very informative about how little X is tolerated.)

But usually “somebody who does X undergoes Y” is used to imply something like “if you do X you’ll most likely undergo Y”, which in this case is very far from being the case. (I just have to spend some time on Facebook to see dozens of western Europeans saying mean things about migrants and AFAIK hardly any of them have ever gotten any sentence.) So I’m getting the impression that you were using the literal meaning as the motte and the colloquial meaning as the bailey.

Good_Burning_Plastic May 16, 2017, 8:23 AM
2 points
in reply to: lmn’s comment on: Thoughts on civilization collapse

There is a significant qualitative difference

Did you mean to type “quantitative”? If you didn’t, what difference?

Good_Burning_Plastic Apr 29, 2017, 5:49 PM
0 points
in reply to: Lumifer’s comment on: Open thread, Apr. 24 - Apr. 30, 2017
Once per decade per planet (i.e. 2e-10/km²/yr) is “particularly often”?

Good_Burning_Plastic Apr 29, 2017, 1:29 PM
0 points
in reply to: gilch’s comment on: Open thread, Apr. 24 - Apr. 30, 2017

Fukushima

That was caused by the fourth strongest earthquake in the world in half a century, so it’s not something you’d expect to happen particularly often.

Good_Burning_Plastic Apr 20, 2017, 8:24 AM
0 points
in reply to: Kallandras’s comment on: Cheating Omega
Okay, make that “with probability greater than 99.95%”.

Good_Burning_Plastic Apr 20, 2017, 8:23 AM
1 point
on: Cheating Omega

Now, I’ve pre-committed that after Omega offers me The Deal, I’ll make two quantum coin flips. If I get two tails in a row, I’ll two-box. Otherwise, I’ll one-box.

Omega predicted that and put the large box in a quantum superposition entangled with those of the coins, such that it will end up containing $1M if you get at least a head and containing an equal mass of blank paper otherwise.

Good_Burning_Plastic Apr 15, 2017, 5:33 PM
0 points
in reply to: Thomas’s comment on: Open thread, Apr. 10 - Apr. 16, 2017

relativistic mass

That’s not a very useful concept, because it’s nothing but the total energy measured in different units. It only has a name of its own for hysterical raisins. A much more useful concept is the invariant mass, which is the square root of the total energy squared minus the total momentum squared (in suitable units), which (as the name suggests) is the same in all frames of references; in particular, it equals the total energy in the frame of reference where the total momentum is zero. Nowadays when people say “mass” they usually mean the invariant mass, because it makes more sense to call the relativistic mass “total energy” instead.

Good_Burning_Plastic Apr 15, 2017, 5:25 PM
0 points
in reply to: Thomas’s comment on: Open thread, Apr. 10 - Apr. 16, 2017

At one moment, nothing can be faster than light, the next moment there is a billion of faster than light galaxies.

The next moment, it’s okay, they are not faster than light, only the space is replicating itself between us an them.

Exactly. If you have two ants on a rubber band and you stretch the rubber band, the time derivative of the distance between the ants may be larger than twice the maximum speed at which an ant can walk, but that’s not due to the ants walking so there’s no paradox.

Good_Burning_Plastic Apr 15, 2017, 5:20 PM
0 points
in reply to: simon’s comment on: Open thread, Apr. 10 - Apr. 16, 2017

2) do the galaxies appear deformed when viewed in a telescope?

Even in flat Minkowski space-time and even with stereo vision, no they wouldn’t, because the fact that the light from the far side of an object left it earlier than the light from the near side compensates the length “contraction”. If anything, if the object is moving perpendicularly to the line of sight you would see it rotated.

(And I find “length contraction” a pretty misleading name. It’s a purely kinematic effect due to the geometry of spacetime, and no more of a “contraction” than the fact that the height of a pencil is less if it’s askew than if it’s upright.)

Good_Burning_Plastic Apr 14, 2017, 4:37 PM
0 points
in reply to: Thomas’s comment on: Open thread, Apr. 10 - Apr. 16, 2017

A photon is usually redshifted.

Yes. Thanks. Fixed.

Good_Burning_Plastic Apr 11, 2017, 10:39 PM
0 points
in reply to: Thomas’s comment on: Open thread, Apr. 10 - Apr. 16, 2017

I don’t like this solution.

But it’s the standard way the luminosity distance is defined.

There is nowhere the speed of light to be seen there.

Units with c = 1 are used in the formulas.

OTOH, the “curvature of space” they mention, is not very necessary in our flat space.

Space alone is flat (within measurement uncertainties), but space-time is curved, because space expands with time.

But the Lorentz factor would be needed here.

It’s not the easiest way to treat objects moving with the Hubble flow...

Not only for the time dilatation factor, by which the energy output is to be reduced—but also for the relativistic mass increase by the same factor.

Yes, there are two (1+z) factors, one because fewer photons are emitted per unit time because “time was slower back then” (I know, not a very clear way to put it) and one because each photon is redshifted. The luminosity distance is defined with one (1+z) factor so that when you divide by its square you get (1+z)^-2.

And for the length contraction as well!

No, because we’re talking about the total luminosity of the galaxy—if its length is contracted and its luminosity density is increased by the same factor, nothing changes.

That’s the real problem, I think.

What do you mean? It’s not like this is an open question in cosmology. The implications of the FLRW metric have been well known for decades.

Good_Burning_Plastic Apr 11, 2017, 11:08 AM
0 points
in reply to: Thomas’s comment on: Open thread, Apr. 10 - Apr. 16, 2017
Yes, they do. That’s where the extra (1 + z) factor in the definition of luminosity distance comes from.

Good_Burning_Plastic Apr 8, 2017, 1:19 PM
1 point
in reply to: bogus’s comment on: The Ancient God Who Rules High School

Simply starting school later would not have substantial effects in the long run, anymore than, say, changing to DST, or moving to a different timezone would.

Wait… DST makes sunrises and sunsets later by civil clocks, so I would expect its effects to be quite the opposite of starting school later (and pretty similar to those of starting schools earlier). Did you mean to say something like “abolishing DST” instead, or am I missing something?

Good_Burning_Plastic Apr 8, 2017, 7:53 AM
1 point
in reply to: bogus’s comment on: The Ancient God Who Rules High School

Anyone can adjust their circadian rhythm by just going to sleep earlier,

No, the circadian rhythm doesn’t work that way. Perhaps you don’t notice because your chronotype is earlier than your lifestyle required so you never had much trouble falling asleep even when going to bed relatively early, but people with later chronotypes if they go to bed earlier will just take more time to fall asleep.

Good_Burning_Plastic Apr 5, 2017, 11:07 PM
0 points
in reply to: dxu’s comment on: Open thread, Apr. 03 - Apr. 09, 2017
On the other hand, utilitarianism is a subset of consequentialism, so whereas a criticism of utilitarianism is not necessarily a criticism of consequentialism, the converse is true.

Good_Burning_Plastic Apr 5, 2017, 11:05 PM
0 points
in reply to: the gears to ascension’s comment on: Project Hufflepuff: Planting the Flag

I think people who say[1] that guess culture only exists some places are meaningfully confused.

Or maybe they just don’t fall prey to the fallacy of gray and realize it sometimes might make sense to call something black even though it doesn’t literally scatter exactly no light at all (otherwise there’d be no point in having a word if it didn’t apply to anything at all).

Good_Burning_Plastic Apr 2, 2017, 9:11 PM
1 point
in reply to: the gears to ascension’s comment on: Project Hufflepuff: Planting the Flag

I don’t think you can escape guess culture.

Sometimes you can escape it literally, e.g. move to a different city or find a different social circle.