At any moment there is atleast one pair of diametrically opposite points on Earth's surface which have same atmospheric temprature and pressure. And that's because Maths. It's quite fascinating to me
Ask HN: Teach me something new
191–200 of 782 posts
Re: Ask HN: Teach me something new
#192I watched a piano/music teaching video from the 60s yesterday that made it all "click" [1] Most modern music chords patterns are easy to find out on piano. Start on any of the white keys, and play 7 white keys left to right. That is called a mode: a series of notes separated by certain intervals to compose a song. Different modes have different vibes. Atmosphere of the song ( sad or happy) is directly correlated by h…
Great explanation given the text restrictions, - stepping away from the white notes, 7th chords are 135b7...as opposed to M7.
My favorite way to confound beginners -
1 3 5 - five (fifth) 1 3 - three (third) 3 5 - three (third) Therefore 3 + 3 = 5.
Once they get that, the rest is easy, especially explaining b13 notes etc.
Re: Ask HN: Teach me something new
#193You probably don't have free will, you have no more control of the thoughts that motivate you to take action as you do the thoughts that do not.
I agree that we have little control over our thoughts. But we are the "haver" of these thoughts. There is some system that the thoughts are originating from. I like to think (hehe) of it as the (real-time) operating system, with thoughts originating from different subprocesses and actions being in the user land. The primary function of this OS (not the thinking part "me") is to survive. We can't control the OS directly, but we can facilitate our actions and environment in accordance with our OS.
Re: Ask HN: Teach me something new
#194Almost everything around you has been designed by another person, or teams of people.
“Life can be much broader once you discover one simple fact, and that is, everything around you that you call life was made up by people that were no smarter than you … the minute that you understand that you can poke life … that you can change it, you can mould it … that’s maybe the most important thing.” – Steve Jobs
Re: Ask HN: Teach me something new
#195Adjoints, norms and fixed points underlie like 90% of all formal systems https://github.com/adamnemecek/adjoint/.
Re: Ask HN: Teach me something new
#196Earlier quoted context omitted.
You forgot the part where people suspect that we are Boltzmann brains.
If I’m a Boltzmann brain that can only survive for an instant, why do I experience existing for a whole lifetime?
You haven't experienced a whole lifetime. Every moment up until the current [whatever the smallest unit of time really physically possible is] is just a memory of an experience. Subjectively from your perspective there's absolutely no difference between having actually experienced all that and merely having memories of having experienced all of it. You could materialize into existence for exactly one moment and believe you've lived an entire lifetime, but in reality you're just a brain floating in space experiencing one brief moment of a lie told by the chance arrangement of the molecules that make up your being.
Re: Ask HN: Teach me something new
#197Colors don't exist outside of your brain.
Well, our brains are only wired up to detect a limited spectrum of colors. There are insects and birds that can detect a greater variety of color. So, how can it just exist in our brains?
One way to look at colors is to see them as qualia, which is basically a subjective experience. Electromagnetic waves come in a large range of frequencies, some of which excite the nerve endings in your retina, causing your brain to experience colors. But colors are a bit more complicated than that: for example, there is no such thing as just "yellow": yellow is the subjective term given by humans when there is a certain balance between the excitation of their there-color vision. You can experience the exact same sense of "yellow" from different types of light: there is true monochromatic yellow around 580nm, but you can also experience that same yellow when mixing the right amount of red and green light. There is no wave of 580nm in the second case, but still you see the same color.
Re: Ask HN: Teach me something new
#198Double-clicking on text selects the whole word. Double-clicking and dragging selects text word-by-word. Triple-clicking selects the whole paragraph. Middle-clicking a link opens it in a new tab. Middle-clicking a tab closes it. Middle-clicking in general often has useful functionality!
Double-clicking the title bar of a window toggles between sized-window and full-size-window mode
Re: Ask HN: Teach me something new
#199Colors don't exist outside of your brain.
Colours are, in the outside world, fuzzy ranges of electromagnetic frequencies: they do «exist outside of your brain».
(Similarly, "brain" and "mind" are not the same.)
Otherwise, the intended general idea is that found e.g. at the beginning of Arthur Schopenhauer's Welt als Wille und Vorstellung:
> "The world is my representation": this holds true for every living, cognitive being, although only a human being can bring it to abstract, reflective consciousness: and if he actually does so he has become philosophically sound
Re: Ask HN: Teach me something new
#200Most rape victims in the United States are men: https://www.hrw.org/reports/2001/prison/report.html Caution: that’s hard, explicit, distressing reading.
(2001)
I wonder what aspects have gotten worse over the years and how the dynamic has shifted, if at all. Or maybe it doesn't matter this was from 20 years ago? :<