ocfnash

13 ms·

91.
by ocfnash 8y ago
I quite enjoy mentally parsing these "offers" in logically equivalent ways. E.g., "buy one get one free" as "only sold in units of two" or even "each purchase of one requires compulsory purchase of a secon
92.
Gravitational Wave Detections Will Settle Hubble Constant Conundrum(simonsfoundation.org)
1 points by ocfnash 8y ago|0 comments
93.
by ocfnash 8y ago
This article includes the assertion: "Think, for instance, of the common idea that individual recycling can stave off climate change – this in spite of the fact that one hundred companies produce 71 percent of carbon emissions." R
94.
by ocfnash 8y ago
I plead guilty to commenting without reading. Thank you for the gentle reminder!
95.
by ocfnash 8y ago
This reminds me of pitch-drop experiments: https://en.wikipedia.org/wiki/Pitch_drop_experiment Pitch flows _slowly_. Apparently it is so viscous that at room temperature a suspended blob might release a drop about once
96.
by ocfnash 8y ago
I tend to agree, I was thinking this as I wrote the above.
97.
by ocfnash 8y ago
My rule of thumb is that if a subject area includes the word "science" in its title, it is less likely to follow the scientific method. Physicists don't assert that they study "physics science", nor do chemists desc
98.
by ocfnash 8y ago
In addition to formalising _theorems_, one can aim to formalise _definitions_. See here for some discussion: https://mathoverflow.net/questions/311071/which-mathematical... Of course the two are very much intertwi
99.
by ocfnash 8y ago
For a long time, I used to dismiss intuitionism but more recently I've come to find it an attractive standpoint. For one thing, you really only gain by trying to be constructive. If, in some logical system without LEM (law of excluded
100.
by ocfnash 8y ago
And thus obeys good old Mendelian inheritance rules perfectly!
101.
by ocfnash 8y ago
This was news to me and pretty striking: > The concept of orientability has important implications. Take enantiomers. These chemical compounds have the same chemical structures except for one key difference: they are mirror images of one
102.
by ocfnash 8y ago
It is a Mobius strip. To convince yourself it might be useful to imagine a point on the surface and imagine tracing it along the strip (avoiding the edges) and seeing if you get back to where your started.
103.
The Scientists Who Pee Plutonium(warisboring.com)
2 points by ocfnash 8y ago|0 comments
104.
by ocfnash 8y ago
Thanks. With regard to: > Can we have a version where one can go far away and come back time-reversed? Or is that excluded by CT=P symmetry breaking? I don't know. Having mulled these thoughts further after writing the above I'
105.
by ocfnash 8y ago
Great point, I agree! It seems to me that the statement that Wu's experiment holds globally is equivalent to the statement that the universe has an orientation so I now tend to think the universe does not admit one of these orientation
106.
by ocfnash 8y ago
Good question, but no. For example the Klein bottle or real projective plane are closed surfaces containing no boundary. Incidentally the Mobius strip need not have a edge; you can leave out the boundary circle at the cost of having a non-c
107.
by ocfnash 8y ago
I believe it is possible that our universe is not orientable, and so there may exist closed paths which, if followed, reverse orientation upon returning to the starting point. If you were right-handed and traversed such a loop, you would no
108.
by ocfnash 8y ago
The poor Maple developer who tried to fix the "bug" is active on MathOverflow and commented briefly on his experience of this in a comment below this answer: https://mathoverflow.net/a/11607
109.
by ocfnash 8y ago
The article finishes with the rather vague and somewhat terrifying assertion that: "It is estimated that the Airbus A380, comparable in complexity to the Dreamliner, has more than 100 million lines of code."
110.
by ocfnash 8y ago
This is only tangentially-relevant, but I recently read that the earth's mantle is mostly solid! (It does still flow, but as a solid.) The state of the rock beneath the crust is subject to two competing influences: * High temperature [
111.
QED – an interactive textbook(math.ucla.edu)
26 points by ocfnash 8y ago|1 comments
112.
Random Points on a Sphere (Part 2)(johncarlosbaez.wordpress.com)
2 points by ocfnash 8y ago|0 comments
113.
by ocfnash 8y ago
Cycling infrastructure in Ireland is woeful but there are great people working to improve it: https://twitter.com/ibikedublin They're eager for help ;-)
114.
by ocfnash 8y ago
In Ireland, we introduced a tax on plastic bags in 2002 and it had an enormous impact. (Actually we called it a levy: Irish governments never introduce new taxes, but love to introduce new levies!) One detail works in its favour surprisingl
115.
by ocfnash 8y ago
I note that each shipwreck record includes a date of loss. I'd be interested to see a histogram of frequency by year.
116.
by ocfnash 8y ago
Indeed, and the name was a deliberate play on the Irish word for play, "súgradh".
117.
by ocfnash 8y ago
I completely agree (though it is some years since I was at school). Still, as Lockhart points out: at least art and music are recognised as arts . Surely even the ropiest music and art educations at least admit that these arts are: 1.
118.
by ocfnash 8y ago
And I believe this is _the_ https://en.wikipedia.org/wiki/Clifford_Stoll !
119.
by ocfnash 8y ago
In this context I highly recommend Lockhart’s Lament: https://www.maa.org/external_archive/devlin/LockhartsLament....
120.
by ocfnash 8y ago
There seems to be some confusion in this thread between ferroelectric vs ferromagnetic. These are two distinct physical phenomena. FRAM is based on the former whereas magnetic core memory is based on the latter. With this in mind, I’m not s

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