1) Message boards : Science : To Make Two Black Holes Collide, Try Three (Message 3811)
Posted 7 Oct 2019 by Gunnar Hjern
Post:
This was cited over at Einstein. It looks like it might be of interest here.

The spiraling dance of a pair of colliding black holes should last for billions of years. Yet we’ve caught about 10 black hole collisions since 2016 — far more than we would expect. Some process must be at work to accelerate the collision process, to make black holes come together more quickly than anticipated.
https://www.quantamagazine.org/to-make-two-black-holes-collide-try-three-20190815/

Yes, that might be a viable explanation, but I'm not sure it will hold all the way through. It seems a bit too far fetched to me.

Why not investigate in dark matter (DM) instead?

As we perceive DM it is a form of rather thin gas of weakly interactive massive particles (WIMPs), that would accumulate around galaxies and other massive objects -- especially black holes (BHs). When two BHs -- that are expected to gather each a very dense cloud of DM -- start to dance, then the DM will likely over time carry away a substantial amount of energy, without telling us so -- it will still be dark. The DM gas heat will have to be carried away by other mechanisms instead.

At the very end, when the final inspiraling happens (that produces the GWs that we can see with LIGO/Virgo), the temperature of the DM gas must be absolutely crazy in the vicinity of the BHs, and thus it is expected to by utterly thin and not able to apply much breaking force. It will then instead be the GWs that carries away the final energy and the BHs can collide.

This is of course pure speculation, and I'm a computer scientist, not a physicist, but I hope someone (real astro-physicist or particle physicist) could do some initial calculations and write a paper about it.

//Gunnar
2) Message boards : Number crunching : More wu to process (Message 3590)
Posted 24 Jul 2019 by Gunnar Hjern
Post:
Hi!
Are there any package in the Ubuntu and/or Debian repositories that contain just that libmvec.1.so file?
If so, the fix might be as simple as apt-get installing that package, but then I guess it must be exactly THAT file:
On the Ubuntu 18.04 machine that I'm sitting at just now, I can find both libmvec-2.27.so , libmvec.so.1 , and libmvec.so , along with some static .a libraries.
If you can recompile the app with libmvec statically linked, that might be a better solution.
//Gunnar
3) Message boards : Number crunching : More wu to process (Message 3588)
Posted 24 Jul 2019 by Gunnar Hjern
Post:
Hi Krzysztof!

It is only the hostid=54252 machine that producing compute-error so far, but I haven't forced the other empty machines yet, so there will likely be more of my hosts showing this error.
It seems that none of the machines still running Ubuntu 14.x have got that file, but I could find it on one of the Ubuntu 18.x computer that I have here. I will check on the other machines when I get home in an hour or so.

//Gunnar
4) Message boards : Number crunching : More wu to process (Message 3586)
Posted 24 Jul 2019 by Gunnar Hjern
Post:
Hi!
I've just made one more observation:
It seems like the file libmvec yet again is dynamically linked, because I get the error
error while loading shared libraries: libmvec.so.1: cannot open shared object file: No such file or directory

from some of my computers.
//Gunnar
5) Message boards : Number crunching : More wu to process (Message 3583)
Posted 24 Jul 2019 by Gunnar Hjern
Post:
Hi!
I've tried the update-button several times, and I have also tried the "Reset project".
At the end I completely removed the project from the computer, and then added it again,
but not even that helped.
//Gunnar
6) Message boards : Number crunching : More wu to process (Message 3581)
Posted 24 Jul 2019 by Gunnar Hjern
Post:
Hi Krzysztof!

I can see there are over 3 million WU:s ready to send but nevertheless my computers get
"Project has no tasks available" answers when asking for WU:s??
Some of them have run completely dry now, having no work at all.

Kindest regards,
Gunnar
7) Message boards : Number crunching : Server issue when editing prefs (Message 3162)
Posted 20 Dec 2018 by Gunnar Hjern
Post:
Hi Shadak!

Although I'm not an expert on CSS, I at least have some basic knowledge in PHP-programming.
I do not think that this is a CSS problem, as the message clearly tells about a big problem in the PHP-script
"edit_forum_preferences_form.php".
Unfortunately I don't have this script, so I cannot tell why it complains about the call to the bbcode_info().

Kindest regards,
Gunnar
8) Message boards : Number crunching : Server issue when editing prefs (Message 3160)
Posted 19 Dec 2018 by Gunnar Hjern
Post:
Hi!

I was just trying to edit some preferences
( "community preferences" on
https://universeathome.pl/universe/edit_forum_preferences_form.php )
when I encountered this:
Fatal error: Call to undefined function bbcode_info() in /home/boincadm/projects/universe/html/user/edit_forum_preferences_form.php on line 87.

The page was cut in half and most of the forms where lacking. The dropdown menus on "community" and "server" didn't work either.

Kindest regards,
Gunnar
9) Message boards : News : BHDB application (Message 2863)
Posted 5 May 2018 by Gunnar Hjern
Post:
I have done over 200 tasks since yesterday evening, an I only have 5 errors. That doesn't seem too alarming to me, but it could of course be a little bit better. ;-)

The faulty tasks are all from batch #17. All my machines run Linux, and most of them Xubuntu 14.04 or 16.04.
Just 5 errors are too few to make any good statistics from, so I cannot tell if the version of OS or Boinc client could make any difference.

I'm crunching on, and hoping not to get more errors! :-)

Have a good weekend all of you!!

//Gunnar
10) Message boards : News : BHDB application (Message 2807)
Posted 15 Apr 2018 by Gunnar Hjern
Post:
Hi Krzysztof!

Something seems weird with the validator or transitioner!
No WUs are being validated, and my "Validation pending" numbers are growing.
When I looked on the server status page, I could see that there where only 3 WUs in the "waiting for validation" field, but the "Transitioner backlog" is steadily growing and is over 8 hours now.
All "Server status" are green, but something seems stuck in the server work-chain.

Hope you can fix it before your travel.

Have a nice week!!!

//Gunnar
11) Message boards : News : BHDB application (Message 2780)
Posted 8 Apr 2018 by Gunnar Hjern
Post:
That sounds promising! :-)

These two batches (12 and 14) have really went remarkably well.
I've done over 700 already, and not one single error or invalid! - Wow!

Congratulation to a really good work!!!

//Gunnar
12) Message boards : News : BHDB application (Message 2771)
Posted 6 Apr 2018 by Gunnar Hjern
Post:
Well, not on the new batch I think!

I've already done 20 (10 valid and 10 pend.) so I guess the error rate is well below 5% now.
That's sure good enough for me, so I'll keep them running through the night.

Have a nice weekend!!

//Gunnar
13) Message boards : News : BHDB application (Message 2751)
Posted 24 Mar 2018 by Gunnar Hjern
Post:
Why are batch 3 and 5s being sent out again. Pls stop sending us those!


I just found this in the log on one of my dozen computers:

Aborting task universe_bhdb_180109_5_25449975_20000_1-999999_450200_5: exceeded disk limit: 890.09MB > 858.31MB
Aborting task universe_bhdb_180109_5_25734975_20000_1-999999_735200_6: exceeded disk limit: 896.42MB > 858.31MB
Aborting task universe_bhdb_180109_5_25429975_20000_1-999999_430200_4: exceeded disk limit: 900.92MB > 858.31MB
Aborting task universe_bhdb_180109_5_55024945_20000_1-999999_25200_2: exceeded disk limit: 899.32MB > 858.31MB
Aborting task universe_bhdb_180109_5_55364945_20000_1-999999_365200_3: exceeded disk limit: 936.15MB > 858.31MB

In all I have around 60 erroneous tasks since yesterday. :-(

It seems like the disk limits still are too low. Please increase them a bit before sending out next batch!

Have a nice weekend!!

//Gunnar
14) Message boards : Number crunching : Batch #10 OK? - When comes #11? (Message 2736)
Posted 20 Mar 2018 by Gunnar Hjern
Post:
THANX!!!

Changing all my machines to crunch BHDB tasks now! :-)

Have a nice evening!

//Gunnar
15) Message boards : Number crunching : Batch #10 OK? - When comes #11? (Message 2731)
Posted 17 Mar 2018 by Gunnar Hjern
Post:
Hi Krzysztof!

Batch #10 worked out quite good for me - only a few comp.err.! :-)
Did it give you the results you expected?
When are you going to send out a new batch of WU's?

Have a nice weekend!!!

//Gunnar
16) Message boards : News : BHDB application (Message 2729)
Posted 16 Mar 2018 by Gunnar Hjern
Post:
It seem like we're getting _10 WU:s now! So far I've done a few dozen and no errors but none verified yet either. Great to see we're back in business again!


Yes, I do agree!
I've done 134 so far, of which 65 are valid, none invalid, and only one single Comp.Err.

Keep on sending out more WU's - we're happy to crunch 'em all weekend! :-)))

//Gunnar
17) Message boards : News : BHDB application (Message 2672)
Posted 11 Mar 2018 by Gunnar Hjern
Post:
Hi Pututu!

The wuid's that you list doesn't tell me much. It's rather the wu-names,
those that you find on the topmost row on those liked pages,
that I found out tells more of which version they have:

The wuid=14675480
has the name:
"universe_bhdb_180109_5_70479930_20000_1-999999_480200"
and due to my experience tasks with lower number than
...180109_5_89xxxxxx_...
are not likely to complete! :-(

Tasks with that number on the other side, and higher, has been 100% successful for me this evening! :-)
As the tasks names are clearly visible in the rightmost column in the client, it's easy to find and ditch all the lower numbered wu's.
Since aprox. 18:00 this evening I've completed no less than 73 wu's, of which 43 are validated and 30 pending!

It's obvious that this project now is working again! :-) :-) :-)

Nice weekend!!!

//Gunnar
18) Message boards : News : BHDB application (Message 2669)
Posted 10 Mar 2018 by Gunnar Hjern
Post:
Well, at least it seems that things have started to go better now.
I have 8 valids and 13 pending, so I'll keep on crunching at least until tomorrow.

I've noticed that no task with a number less that
180109_5_89xxxxxx_xxx...
completes, but I havn't had any errors with tasks above that number, so now I've ditched all of them below.

Some "lemons" are still coming in, but now most new tasks have numbers above
180109_5_100xxxxxx_xxx...

Let's see what's gonna happen next.

Nice weekend to all of U!

//Gunnar
19) Message boards : Number crunching : Those ever-restarting UV-reionization tasks... (Message 2289)
Posted 6 Jul 2017 by Gunnar Hjern
Post:
Hi Aaron!

Thanks for your advice on unselecting different task-types!
I've done so now, and allowed new tasks on the computer that is currently running U@H.

About those 211 tasks that's out there, I hope that the admins can revoke them, so they won't become eternal show-stoppers for hundreds of cpu-cores.

If the admins put out a notice when they fixed the issue with the endless restaring, I'll gladly try it again. That'll have to be sometime when I can supervise the computers and stop the tasks if they misbehave.

//Gunnar
20) Message boards : Number crunching : Those ever-restarting UV-reionization tasks... (Message 2287)
Posted 6 Jul 2017 by Gunnar Hjern
Post:
Today I saw a UV-task in the task list of one of my computers, and although it had a deadline of several month ahead I was far too curious not to run it at once! :-)

Unfortunately though, it behaved the same way as they did a couple of month before: That is they run for about 14 minutes (although they are listed to run in about one minute) and then the same task starts all over again, and again, and again, and again.....

I have taken ten screen dumps of the properties for that one task as it restarted all over again (see below) and the task had already restarted a several times before that.

What makes these tasks restart instead of reporting themselves to the server???

Could anything be done to the very erratic runtime prognosis, that says they should only take on minute although they in reality take more than 14 minutes to complete?

It would be very interesting to run them, but now I don't even dare to run the normal BH-spin, because I might catch one or two UV-reion.-tasks and then be standing there forever without doing any good at all. :-(

//Gunnar


























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