A Christmas, String Lights, Story

I bought some LED string lights before Christmas and we had them in the office, for some random cheer. The lights were mixed colours, red green and blue. They were powered by two AA batteries, and we left them on continuously for more than a week. After a while I thought some of the lights were broken but later someone else pointed out to me that only one colour remained lit.

Only green LEDs for Christmas?

Only green LEDs for Christmas?

With only the green LEDs apparently lit, the voltage measurement on the battery was 1.153 V (1.156 V with no current flowing). A fresh battery capable of lighting all the colours of LED provides a voltage of 1.311 V with the current flowing (1.325 V with no current flowing).

LEDS lit R-G-B with full voltage.

LEDS lit R-G-B with full voltage.

Strangely green LED’s are the least efficient colour, so it’s strange they would be the last ones lit…

For change in voltage, red LEDs take the least to work, and as the colour moves up the colour spectrum toward blue, the voltage requirement increases (green is between red and blue).

Approximation of spectral colours on a display results in somewhat distorted chromaticity — Wikipedia

So does this mean these LED’s aren’t really naturally green ones, and rely on phosphor filtering? Or some other technology?

Is this a problem of perception of brightness of different colours?

80s tracks

These long forgotten 80’s track seem eerily familiar.

Royal Societies Inspiring Scientists

The Royal Society put together some student resources on Inspiring British scientists with minority ethnic heritage. My Supervisor Harry Bhadeshia is twice as inspiring as the rest, as you can see from the Royal Societies Tweet:

Royal Soc Inspiring Scientists

Royal Soc Inspiring Scientists

Link to resources

Superbainite on stage at Apollo theatre

img_20161015_211056

Among the Yamabushi (Narrow Road Part 4)

Victoria Vardley on Matsuo Bashō, with some beautiful sketches.

Tsundoku bookcase

Back on the road with Bashō and his straw sandals…

One of the high points of his journey, figuratively as well as literally, was his pilgrimage to the 出羽三山(でわさんざん) Dewa Sanzan, three mountains of Dewa Province, which is a very sacred place in Shintō and Buddhism and in the 修験道(しゅげんどう) Shugendō mountain ascetic sect. This is a syncretic religion combining elements of Shintō and Buddhism, Taoism and other beliefs. Practitioners are known as 修験者(しゅげんじゃ) Shugenja or 山伏(やまぶし) Yamabushi (someone who prostrates himself in the mountains – the ‘bushi’ here is not the same as the word ‘bushi’ 武士(ぶし) meaning ‘warrior’). They go on foot through the mountains practising austerities, for example meditating while standing under ice-cold waterfalls – perhaps familiar to anyone who has read Mishima’s Sea of Fertility tetralogy? (Here is an interview with a Shugendō practitioner explaining some of the practices and the philosophy behind them.)

The three…

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Compiling Fortran

Mixing of Fortran types occurs, and often results in problems when mixing free-form Fortran with older styles of Fortran, and when using different compilers.

As pointed out at Geek Tricks.

In Fortran 90/95, a “&” at the end of a line, or in the front of a line, is treated as line continuation sign. But in Fortran 77, it has to be a character at the sixth column. In the code I get, most “&”‘s comply to the Fortran 77 format, but some are not. So I move all “&”‘s to the sixth column, and now the code compile with gfortran.

If you want to replace lots ampersands from the ‘first column’ to the ‘sixth column’ on a lot of lines you could use ‘sed’ string editor to do that.

sed 's/^&/ &/g' input.f > output.f

You also need to check for lines which are too long in your input.

Many errors can be suppressed for now, with command such as gfortran -std=legacy output.f -o justwork

Python-Pen-Pineapple-apple-Pen

# -*- coding: utf-8 -*-
"""
Program to print pineapple pen apple pen, playing with strings and lists.
@author: mathew
"""

print("PPAP Program")

p = 'pen'
a = 'apple'

P = 'pineapple'

if 'pen' in p and 'apple' in a:
ap = [a, p]

if 'pen' in p and 'pineapple' in P:
pP = [p, P]

print(ap)
print(reversed(pP))

PPAP = (pP, ap,)

print(PPAP)

print(p)
print(a)
print(a,p)

print(p)
print(P)
print(P,p)

print(p,P,a,p)

print(a,p)
print(p,P)

print(p,P,a,p)

for string in reversed(ap):
print(string)

for string in Pp:
print(string)

for string in reversed(ap):
print(string, end='')

for string in Pp:
print(string, end='')

Thanks to Kelsey Ellison for introducing me to this earworm.

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