Ciro Santilli (@cirosantilli) - New articles

Isomers were quite confusing for early chemists, before atomic theory was widely accepted, and people where thinking mostly in terms of proportions of equations, related: Section "Isomers suggest that atoms exist".

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Law of physics Updated 2025-07-16

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Jakob Schwichtenberg Updated 2025-07-16

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Personal website: jakobschwichtenberg.com/

PhD at Karlsruhe Institute of Technology in 2019: www-kseta.ttp.kit.edu/fellows/Jakob.Schwichtenberg/ on the strong CP problem.

Books:

No-Nonsense Quantum Field Theory: A Student-Friendly Introduction by Jakob Schwichtenberg (2020)

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Japanese company Updated 2025-07-16

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Jasraj Updated 2025-07-16

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This dude is amazing. He apparently has many devotional songs.

Video 1.

Pandit Jasraj and Ustad Zakir Hussain - 1987 - Haveli Sangeet, Malkauns, and Bhairavi

. Source.

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Mechanics Updated 2025-07-16

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This section is more precisely about classical mechanics.

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Physics conference Updated 2025-07-16

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SQL tree traversal Updated 2025-07-16

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Example: nodejs/sequelize/raw/tree.js

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CIA 2010 covert communication websites / 2012 Internet Census hostprobes Updated 2025-07-16

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Hostprobes quick look on two ranges:

208.254.40:

... similar down

208.254.40.95	1334668500	down	no-response
208.254.40.95	1338270300	down	no-response
208.254.40.95	1338839100	down	no-response
208.254.40.95	1339361100	down	no-response
208.254.40.95	1346391900	down	no-response
208.254.40.96	1335806100	up	unknown
208.254.40.96	1336979700	up	unknown
208.254.40.96	1338840900	up	unknown
208.254.40.96	1339454700	up	unknown
208.254.40.96	1346778900	up	echo-reply (0.34s latency).
208.254.40.96	1346838300	up	echo-reply (0.30s latency).
208.254.40.97	1335840300	up	unknown
208.254.40.97	1338446700	up	unknown
208.254.40.97	1339334100	up	unknown
208.254.40.97	1346658300	up	echo-reply (0.26s latency).

... similar up

208.254.40.126	1335708900	up	unknown
208.254.40.126	1338446700	up	unknown
208.254.40.126	1339330500	up	unknown
208.254.40.126	1346494500	up	echo-reply (0.24s latency).
208.254.40.127	1335840300	up	unknown
208.254.40.127	1337793300	up	unknown
208.254.40.127	1338853500	up	unknown
208.254.40.127	1346454900	up	echo-reply (0.23s latency).

208.254.40.128	1335856500	up	unknown
208.254.40.128	1338200100	down	no-response
208.254.40.128	1338749100	down	no-response
208.254.40.128	1339334100	down	no-response
208.254.40.128	1346607900	down	net-unreach
208.254.40.129	1335699900	up	unknown

... similar down

Suggests exactly 127 - 96 + 1 = 31 IPs.

208.254.42:

... similar down

208.254.42.191	1334522700	down	no-response
208.254.42.191	1335276900	down	no-response
208.254.42.191	1335784500	down	no-response
208.254.42.191	1337845500	down	no-response
208.254.42.191	1338752700	down	no-response
208.254.42.191	1339332300	down	no-response
208.254.42.191	1346499900	down	net-unreach

208.254.42.192	1334668500	up	unknown
208.254.42.192	1336808700	up	unknown
208.254.42.192	1339334100	up	unknown
208.254.42.192	1346766300	up	echo-reply (0.40s latency).
208.254.42.193	1335770100	up	unknown
208.254.42.193	1338444900	up	unknown
208.254.42.193	1339334100	up	unknown

... similar up

208.254.42.221	1346517900	up	echo-reply (0.19s latency).
208.254.42.222	1335708900	up	unknown
208.254.42.222	1335708900	up	unknown
208.254.42.222	1338066900	up	unknown
208.254.42.222	1338747300	up	unknown
208.254.42.222	1346872500	up	echo-reply (0.27s latency).
208.254.42.223	1335773700	up	unknown
208.254.42.223	1336949100	up	unknown
208.254.42.223	1338750900	up	unknown
208.254.42.223	1339334100	up	unknown
208.254.42.223	1346854500	up	echo-reply (0.13s latency).

208.254.42.224	1335665700	down	no-response
208.254.42.224	1336567500	down	no-response
208.254.42.224	1338840900	down	no-response
208.254.42.224	1339425900	down	no-response
208.254.42.224	1346494500	down	time-exceeded

... similar down

Suggests exactly 223 - 192 + 1 = 31 IPs.

Let's have a look at the file 68: outcome: no clear hits like on 208. One wonders why.

It does appears that long sequences of ranges are a sort of fingerprint. The question is how unique it would be.

First:

n=208
time awk '$3=="up"{ print $1 }' $n | uniq -c | sed -r 's/^ +//;s/ /,/' | tee $n-up-uniq
t=$n-up-uniq.sqlite
rm -f $t
time sqlite3 $t 'create table tmp(cnt text, i text)'
time sqlite3 $t ".import --csv $n-up-uniq tmp"
time sqlite3 $t 'create table t (i integer)'
time sqlite3 $t '.load ./ip' 'insert into t select str2ipv4(i) from tmp'
time sqlite3 $t 'drop table tmp'
time sqlite3 $t 'create index ti on t(i)'

This reduces us to 2 million IP rows from the total possible 16 million IPs.

OK now just counting hits on fixed windows has way too many results:

sqlite3 208-up-uniq.sqlite "\
SELECT * FROM (
  SELECT min(i), COUNT(*) OVER (
    ORDER BY i RANGE BETWEEN 15 PRECEDING AND 15 FOLLOWING
  ) as c FROM t
) WHERE c > 20 and c < 30
"

Let's try instead consecutive ranges of length exactly 31 instead then:

sqlite3 208-up-uniq.sqlite <<EOF
SELECT f, t - f as c FROM (
  SELECT min(i) as f, max(i) as t
  FROM (SELECT i, ROW_NUMBER() OVER (ORDER BY i) - i as grp FROM t)
  GROUP BY grp
  ORDER BY i
) where c = 31
EOF

271. Hmm. A bit more than we'd like...

Another route is to also count the ups:

n=208
time awk '$3=="up"{ print $1 }' $n | uniq -c | sed -r 's/^ +//;s/ /,/' | tee $n-up-uniq-cnt
t=$n-up-uniq-cnt.sqlite
rm -f $t
time sqlite3 $t 'create table tmp(cnt text, i text)'
time sqlite3 $t ".import --csv $n-up-uniq-cnt tmp"
time sqlite3 $t 'create table t (cnt integer, i integer)'
time sqlite3 $t '.load ./ip' 'insert into t select cnt as integer, str2ipv4(i) from tmp'
time sqlite3 $t 'drop table tmp'
time sqlite3 $t 'create index ti on t(i)'

Let's see how many consecutives with counts:

sqlite3 208-up-uniq-cnt.sqlite <<EOF
SELECT f, t - f as c FROM (
  SELECT min(i) as f, max(i) as t
  FROM (SELECT i, ROW_NUMBER() OVER (ORDER BY i) - i as grp FROM t WHERE cnt >= 3)
  GROUP BY grp
  ORDER BY i
) where c > 28 and c < 32
EOF

Let's check on 66:

grep -e '66.45.179' -e '66.45.179' 66

not representative at all... e.g. several convfirmed hits are down:

66.45.179.215   1335305700      down    no-response
66.45.179.215   1337579100      down    no-response
66.45.179.215   1338765300      down    no-response
66.45.179.215   1340271900      down    no-response
66.45.179.215   1346813100      down    no-response

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Galactic algorithm Updated 2025-07-16

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Conjecture Updated 2025-07-16

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A conjecture is an open problem in mathematics for which some famous dude gave heuristic arguments which indicate if the theorem is true or false.

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Ciro Santilli @cirosantilli 37