mersenneforum.org  

Go Back   mersenneforum.org > Extra Stuff > Science & Technology

Reply
Thread Tools
Old 2019-12-12, 17:36   #2631
kriesel
 
kriesel's Avatar
 
"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest

5,437 Posts
Default

The Aging Spacecraft of Deep Space

https://www.theatlantic.com/science/...tellar/596152/
kriesel is online now   Reply With Quote
Old 2019-12-14, 16:00   #2632
henryzz
Just call me Henry
 
henryzz's Avatar
 
"David"
Sep 2007
Cambridge (GMT/BST)

2×33×109 Posts
Default

https://www.newscientist.com/article...umber-factors/
This is quite an improvement over anything I have seen before. It is a shame that this is a number easily factorable by Fermat's method. Maybe they relied on that.
henryzz is offline   Reply With Quote
Old 2019-12-14, 16:23   #2633
Till
 
Till's Avatar
 
"Tilman Neumann"
Jan 2016
Germany

1CE16 Posts
Default

Quote:
Originally Posted by henryzz View Post
It is a shame that this is a number easily factorable by Fermat's method. Maybe they relied on that.

1048589 = 2^20 + 13 and 1048601 = 2^20+25. They may have exploited as well that the difference of both factors from 2^20 is representable in 5 bit.
Till is offline   Reply With Quote
Old 2019-12-14, 19:59   #2634
Dr Sardonicus
 
Dr Sardonicus's Avatar
 
Feb 2017
Nowhere

2×3×19×41 Posts
Default

US finally giving boot to official foot measurement
Quote:
In 1893, the U.S. government defined a foot as 1,200 meters divided by 3,937. Plug those numbers into a calculator and you get 0.3048006 meters. Those last three digits (and it goes on even longer if you want to be technical) are important. Don’t forget them.

In 1933, the international foot was invented. It was simpler: 0.3048 meters, exactly. Those last three digits just get eliminated.

But those digits kept bedeviling engineers. So in 1959, the U.S. government started the international switch and it will finish the job in 2022.
Dr Sardonicus is offline   Reply With Quote
Old 2019-12-15, 12:22   #2635
mart_r
 
mart_r's Avatar
 
Dec 2008
you know...around...

11·61 Posts
Default

Quote:
Originally Posted by henryzz View Post
https://www.newscientist.com/article...umber-factors/
This is quite an improvement over anything I have seen before. It is a shame that this is a number easily factorable by Fermat's method. Maybe they relied on that.
Is there any chance of an explanation as to why they used 15 instead of 19 in that picture??
mart_r is offline   Reply With Quote
Old 2019-12-15, 12:56   #2636
xilman
Bamboozled!
 
xilman's Avatar
 
"𒉺𒌌𒇷𒆷𒀭"
May 2003
Down not across

1078510 Posts
Default

Quote:
Originally Posted by mart_r View Post
Is there any chance of an explanation as to why they used 15 instead of 19 in that picture??
It may be that it´s the smallest "non-trivial" composite. It has at least two distinct prime factors and it is not an even number.

That was the reasoning I remember being made when the factorization of 15 held the record for a quantum computation.
xilman is offline   Reply With Quote
Old 2019-12-15, 15:48   #2637
mart_r
 
mart_r's Avatar
 
Dec 2008
you know...around...

10100111112 Posts
Default

Quote:
Originally Posted by xilman View Post
It may be that it´s the smallest "non-trivial" composite. It has at least two distinct prime factors and it is not an even number.

That was the reasoning I remember being made when the factorization of 15 held the record for a quantum computation.
I was thinking along these lines, but that still doesn't explain the lack of 19.
mart_r is offline   Reply With Quote
Old 2019-12-16, 05:46   #2638
CRGreathouse
 
CRGreathouse's Avatar
 
Aug 2006

3×1,993 Posts
Default

Quote:
Originally Posted by henryzz View Post
https://www.newscientist.com/article...umber-factors/
This is quite an improvement over anything I have seen before. It is a shame that this is a number easily factorable by Fermat's method. Maybe they relied on that.
Does anyone know details on the algorithm in question, VQF?
CRGreathouse is offline   Reply With Quote
Old 2019-12-16, 05:49   #2639
CRGreathouse
 
CRGreathouse's Avatar
 
Aug 2006

3·1,993 Posts
Default

Quote:
Originally Posted by mart_r View Post
Is there any chance of an explanation as to why they used 15 instead of 19 in that picture??
It could be a mistake, or it could be that (as A061346(1)) it's the single most-factored number by quantum computers.
CRGreathouse is offline   Reply With Quote
Old 2019-12-16, 06:03   #2640
axn
 
axn's Avatar
 
Jun 2003

5,087 Posts
Default

Quote:
Originally Posted by CRGreathouse View Post
It could be a mistake, or it could be that (as A061346(1)) it's the single most-factored number by quantum computers.
Or it could be a stock photo taken by a professional photographer instead of a mathematician. Much ado about nothing!
axn is online now   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Official "Faits erronés dans de belles-lettres" thread ewmayer Lounge 39 2015-05-19 01:08
Official "all-Greek-to-me Fiction Literature and Cinema" Thread ewmayer Science & Technology 41 2014-04-16 11:54
Official "Lasciate ogne speranza" whinge-thread cheesehead Soap Box 56 2013-06-29 01:42
Official "Ernst is a deceiving bully and George is a meanie" thread cheesehead Soap Box 61 2013-06-11 04:30
Official "String copy Statement Considered Harmful" thread Dubslow Programming 19 2012-05-31 17:49

All times are UTC. The time now is 13:35.


Fri Aug 6 13:35:36 UTC 2021 up 14 days, 8:04, 1 user, load averages: 2.28, 2.33, 2.40

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.