Internet forum Updated 2025-07-16
Invariance of the speed of light Updated 2025-07-16
This single experimental observation/idea is the basis for all of special relativity.
Special relativity is the direct result of people bending their backs to accommodate for this really weird fact.
Isomer Updated 2025-07-16
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".
Law of physics Updated 2025-07-16
Jakob Schwichtenberg Updated 2025-07-16
Japanese company Updated 2025-07-16
Mechanics Updated 2025-07-16
This section is more precisely about classical mechanics.
Physics conference Updated 2025-07-16
CIA 2010 covert communication websites 2012 Internet Census hostprobes Updated 2025-07-16
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 downSuggests 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 downSuggests exactly 223 - 192 + 1 = 31 IPs.
It does appears that long sequences of ranges are a sort of fingerprint. The question is how unique it would be.
First:This reduces us to 2 million IP rows from the total possible 16 million IPs.
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)'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:271. Hmm. A bit more than we'd like...
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
EOFAnother 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
EOFLet's check on 66:not representative at all... e.g. several convfirmed hits are down:
grep -e '66.45.179' -e '66.45.179' 6666.45.179.215 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 Galactic algorithm Updated 2025-07-16
Hadron Updated 2025-07-16
Monophyly Updated 2025-07-16
Double bond Updated 2025-07-16
Inner source Updated 2025-07-16
If you are going to do closed source, at least do it like this.
Basically the opposite of need to know for software.
Jordan-Holder Theorem Updated 2025-07-16
MicroPython connection tool Updated 2025-07-16
E. Coli K-12 Updated 2025-07-16
Television show Updated 2025-07-16
Stack Overflow maximum 200 daily reputation limit Updated 2025-07-16
Why. Why. Why is there no limit to how much I can help, but there is a limit to how many thanks I can get?
At most, limit it to a single answer to avoid highly publicized events, e.g. an answer being shared on Reddit. But across answers? It makes no sense.
The two ways main ways to overcome this limit are the 15 point answer accept reputation and bounties.
Newspaper Updated 2025-09-09
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