作者存档: nick - 第15页

2012 Mayan apocalypse rumors have dark side, NASA warns


NASA scientists took time on Wednesday, Nov. 28, to soothe 2012 doomsday fears, warning against the dark side of Mayan apocalypse rumors — frightened children and suicidal teens who truly fear the world may come to an end Dec. 21.
These fears are based on misinterpretations of the Mayan calendar. On the 21st, the date of the winter solstice, a calendar cycle called the 13th b’ak’tun comes to an end. Although Maya scholars agree that the ancient Maya would not have seen this day as apocalyptic, rumors have spread that a cosmic event may end life on Earth on that day.
Thus NASA’s involvement. The space agency maintains a 2012 information page debunking popular Mayan apocalypse rumors, such as the idea that a rogue planet will hit Earth on Dec. 21, killing everyone. (In fact, astronomers are quite good at detecting near-Earth objects, and any wandering planet scheduled to collide with Earth in three weeks would be the brightest object in the sky behind the sun and moon by now.)
“There is no true issue here,” David Morrison, an astrobiologist at NASA Ames Research Center, said during a NASA Google+ Hangout event. “This is just a manufactured fantasy.”
Real-world consequences
‘While this is a joke to some people and a mystery to others, there is a core of people who are truly concerned.’
– David Morrison, an astrobiologist at NASA Ames Research Center
Unfortunately, Morrison said, the fantasy has real-life consequences. As one of NASA’s prominent speakers on 2012 doomsday myths, Morrison said, he receives many emails and letters from worried citizens, particularly young people. Some say they can’t eat, or are too worried to sleep, Morrison said. Others say they’re suicidal.
“While this is a joke to some people and a mystery to others, there is a core of people who are truly concerned,” he said.
Not every 2012 apocalypse believer thinks the world will end on Dec. 21. Some, inspired by New Age philosophies, expect a day of universal peace and spiritual transformation. But it’s impressionable kids who have NASA officials worried.
“I think it’s evil for people to propagate rumors on the Internet to frighten children,” Morrison said.
Myths and misconceptions
NASA scientists took questions via social media in the hour-long video chat, debunking doomsday myths from the rogue planet Nibiru to the danger of killer solar flares.
In fact, said NASA heliophysicist Lika Guhathakurta, it’s true that the sun is currently in an active phase of its cycle, meaning electromagnetic energy has picked up. Large solar flares can impact electronics and navigation systems on Earth, but satellites monitoring the sun give plenty of warning and allow officials to compensate for the extra electromagnetic activity when it hits our atmosphere. What’s more, Guhathakurta said, this particular solar maximum is the “wimpiest” in some time — scientists have no reason to expect solar storms beyond what our planet has weathered in the past.
Nor are any near-Earth objects, planetary or otherwise, threatening to slam into our planet on Dec. 21, said Don Yeomans, a planetary scientist who tracks near-Earth objects at NASA’s Jet Propulsion Laboratory. The only close asteroid approach on the horizon is forecast to occur on Feb. 13, 2013, when an asteroid will pass within 4.5 Earth radii to our planet (for perspective, Earth’s radius is 3,963 miles, or 6,378 kilometers). The asteroid is not going to hit Earth, Yeomans said.
Other rumors — that the Earth’s magnetic field will suddenly reverse or that the planet will travel almost 30,000 light-years and fall into the black hole at the center of the Milky Way galaxy — were also dismissed. (A light-year is the distance light travels in one year, or about 6 trillion miles, or 10 trillion km.)
One popular rumor that the planet will undergo a complete blackout from Dec. 23 to 25 earned a “What?” and blank looks from the panel of scientists.
Ultimately, concerns about Earth’s fate would be better focused on slow-acting problems such as climate change rather than some sort of cosmic catastrophe, said Andrew Fraknoi, an astronomer at Foothill College in California.
Mitzi Adams, a heliophysicist at NASA’s Marshall Space Flight Center, agreed.
“The greatest threat to Earth in 2012, at the end of this year and in the future, is just from the human race itself,” Adams said.

From: http://www.foxnews.com

Ubuntu 12.04 中自定义DNS服务器设置

[转]
随着Ubuntu 12.04 LTS版的发布,我自然要体验下最新的Ubuntu 12.04 Server版了。习惯性的安装配置好了之后,开始配置静态IP设置。别的配置都没有什么问题,但是在配置DNS服务器的时候出了问题。

大家都知道,要修改Linux系统的DNS服务器,只需要编辑/etc/resolv.conf文件即可。然而在Ubuntu 12.04里面,打开这个文件后,虽然可以看到配置信息,但是同时也看到了文件头里醒目的两行注释:

#Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
# DO NOT EDIT THIS FILE BY HAND — YOUR CHANGES WILL BE OVERWRITTEN
大意是这个文件是由resolvconf程序进行动态生成的,请不要手动修改,修改的信息将会被覆盖。这究竟是怎么回事呢?

首先当然是不死心了,往里面添加了自己的DNS服务器地址后保存退出,发现能生效。看上去似乎没有什么问题了。

然而,在重启后,我添加的信息果然没有了!被系统自动覆盖了。

但是我真的很需要自己配置DNS服务器,Ubuntu Desktop版中可以借助图形界面的工具,进行手动配置,这个没有什么问题。但是对于Ubuntu Server版来说,没有图形工具了,必须要自己修改文件进行配置才行,这下这个文件每次启动后都会被覆盖了,要怎么样才能让我自己的DNS服务器信息能保存到系统里呢?

网上搜索了一下,发现了解决办法,原来只需要往resolvconf这个程序的目录里写入一个新配置文件就可以解决。让我们一起看看怎么样在Ubuntu 12.04 LTS Server版中配置自己的DNS服务器吧!

首先我们需要创建一个文件/etc/resolvconf/resolv.conf.d/tail:

#vim /etc/resolvconf/resolv.conf.d/tail
然后我们在这个文件里写入自己要添加的DNS服务器,格式与以前的/etc/resolv.conf文件一致:

nameserver 8.8.8.8
nameserver 8.8.4.4
然后输入wq保存退出。接下来我们重启下resolvconf程序,让配置生效:

#/etc/init.d/resolvconf restart
再去看看/etc/resolv.conf文件,自己添加的DNS服务器果然乖乖的写进去了!至此问题完美解决!

— 最简单的还是直接sudo apt-get remove resolvconf,然后直接改/etc/resolv.conf – -! 这么一堆,何必呢

自动线程编译器复活摩尔定律

程序的速度应该每过一两年就会增加一倍,因为摩尔定律预言处理器性能会每隔18个月翻一番。但在多核时代,单核的性能趋于平稳,而计算机软件还无法充分利用多个核心的全部功能,原因与程序的多线程代码有关。现在,微软研究院Jared Parsons等人的论文(PDF)已被OOPSLA接受出版,论文描述了一种方法可以让编译器自动线程单线程程序, 让摩尔定律的改进能重走上正轨。

微软团队的方法是让编译器跟踪易变性(mutability),判断哪些代码可以并行化哪些不能。研究团队声称他们已经编 写了数百万行代码,开发了一个web server,MPEG解码器等各种应用程序,表示他们的语言可用于实际产品。不过微软目前尚未公开代码。

诅咒下移动的破网

慢不说,上传文件都失败

宣州谢朓楼饯别校书叔云


弃我去者,昨日之日不可留;

乱我心者,今日之日多烦忧。

长风万里送秋雁,对此可以酣高楼。

蓬莱文章建安骨,中间小谢又清发。

俱怀逸兴壮思飞,欲上青天揽明月。

抽刀断水水更流,举杯消愁愁更愁。

人生在世不称意,明朝散发弄扁舟。

We’re Back


经历了短暂的连接问题后,Wonderland恢复运行 11/11/2012
负载均衡组件更新完毕 11/14/2012

HD4000 vs. 9600MGT


3年前买的独立显卡9600MGT,想想跑游戏不错。现在看看最新的Air,低频版的i5,HD4000 跑分已经和当时中端独立显卡不相上下了。科技进步真是快。

大明山行

Link

Ubuntu下配置samba实现文件夹共享

一. samba的安装:
sudo apt-get insall samba
sudo apt-get install smbfs

二. 创建共享目录:
mkdir /home/share
sodu chmod 777 /home/share

三. 创建Samba配置文件:
1. 保存现有的配置文件
sudo cp /etc/samba/smb.conf /etc/samba/smb.conf.bak

2. 修改现配置文件
sudo gedit /etc/samba/smb.conf

在smb.conf最后添加
[share]
path = /home/share
available = yes
browsealbe = yes
public = yes
writable = yes

四. 创建samba帐户
sudo touch /etc/samba/smbpasswd
sudo smbpasswd -a username

然后会要求你输入samba帐户的密码

[如果没有第四步,当你登录时会提示 session setup failed: NT_STATUS_LOGON_FAILURE]

五. 重启samba服务器
sudo /etc/init.d/samba restart

六. 测试
smbclient -L //localhost/share

七,使用
可以到windows下输入ip使用了,在文件夹处输入 “\\” + “Ubuntu机器的ip或主机名” + “\\” + “share”

例行密码修改

@21:00 Nov. 1st