Is Xyzzy a time traveller?
 

He/she published a list that already correctly includes [URL="http://www.mersenneforum.org/showpost.php?p=432769&postcount=1"]M50 at 2016-04-29, 17:49[/URL].

[QUOTE=jnml;476829]He/she published a list that already correctly includes [URL="http://www.mersenneforum.org/showpost.php?p=432769&postcount=1"]M50 at 2016-04-29, 17:49[/URL].[/QUOTE]
April 2016? Yes, that was the month that Mike took the forum's database server on a fast trip around Alpha Centauri...

[QUOTE=jnml;476829]He/she published a list that already correctly includes [URL="http://www.mersenneforum.org/showpost.php?p=432769&postcount=1"]M50 at 2016-04-29, 17:49[/URL].[/QUOTE]Oh bugger. Now horseshit will go back and change history. Again.

Look at his avatar.

He already knows M51 through M239.

I understand some people may enjoy the feeling of superiority, anyway a simple, technical
answer could probably be useful as well.

[QUOTE=jnml;476836]I understand some people may enjoy the feeling of superiority, anyway a simple, technical answer could probably be useful as well.[/QUOTE]The answer is simple, so simple that finding it is left as an exercise.

[QUOTE=jnml;476829]He/she published a list that already correctly includes [URL="http://www.mersenneforum.org/showpost.php?p=432769&postcount=1"]M50 at 2016-04-29, 17:49[/URL].[/QUOTE]
It is elementary, Watson. The forum is a database. One can set date for any message to any value, if one has access to it.

Who could possibly have access to the naked database? Hint: [SPOILER]perhaps user with uid=1? uid=2? uid=3?[/SPOILER]
[url]http://www.mersenneforum.org/member.php?u=3[/url]

[QUOTE=Batalov;476846]It is elementary, Watson. The forum is a database. One can set date for any message to any value, if one has access to it.

Who could possibly have access to the naked database? Hint: [SPOILER]perhaps user with uid=1? uid=2? uid=3?[/SPOILER]
[url]http://www.mersenneforum.org/member.php?u=3[/url][/QUOTE]

I wish I had u=77232917...

U=1 and u=2 have been erased. Also, many Mersenne exponents does not map to users.

[QUOTE=Batalov;476846]It is elementary, Watson. The forum is a database. One can set date for any message to any value, if one has access to it.

Who could possibly have access to the naked database? Hint: [SPOILER]perhaps user with uid=1? uid=2? uid=3?[/SPOILER]
[url]http://www.mersenneforum.org/member.php?u=3[/url][/QUOTE]

I'm a programmer, I can imagine that. I would just never expect anyone to do that to a
public forum database w/o losing trust of its users.

It happened recently on Reddit in a slightly different form, IIRC, and the outcome was not
very good.

I'm not complaining, I'm sad to learn the news.

[QUOTE=jnml;476849]I'm not complaining, I'm sad to learn the news.[/QUOTE]
What news?

[QUOTE=jnml;476849]I'm a programmer, I can imagine that. I would just never expect anyone to do that to a
public forum database w/o losing trust of its users.

It happened recently on Reddit in a slightly different form, IIRC, and the outcome was not
very good.

I'm not complaining, I'm sad to learn the news.[/QUOTE]Old posts can be edited/updated also. It isn't a big deal.