注册 登录  
 加关注
   显示下一条  |  关闭
温馨提示!由于新浪微博认证机制调整,您的新浪微博帐号绑定已过期,请重新绑定!立即重新绑定新浪微博》  |  关闭

郭晔菲的原创博客

凭皓华、敲击桥边倦客;任所爱、惊动千古心髓。

 
 
 

日志

 
 
关于我

今夜色暗无月光,独座窗前绣诗行。 字字推敲细细琢,咏不成歌睡不香。 手举青衫骨格骄,双唇自画野蛮腰。 心红胆大莺啼梦,脚拿虬髯我是猫。 湖头随晚笑,柳向客船行。故事春梅树,枝条陌上鲸。快眼思家国,飞鸿晓雾名。千秋风雅颂,直视好男生。 (原创文章皆为本人作品,具有无可置疑的版权,仅供交流,请勿侵权,多谢合作!本博客不参与任何圈子的期刊、杂志有奖竞赛、有奖评比。这个博客是我的官方博客,官方就是我,我就是官方。任何人不得抄袭!)

网易考拉推荐

Are We About To Send 'Spacechips' To The Stars?  

2016-06-27 09:11:53|  分类: 英语学习 |  标签: |举报 |字号 订阅

  下载LOFTER 我的照片书  |
Are We About To Send Spacechips To The Stars? - 山人 - 郭晔菲的原创博客
 Lubin is a respected scientist who has done most of his studies in cosmology. "Most of my work is very traditional," Lubin says. "I am a very conservative scientist. I don't usually go out on the edge."
So if Lubin is a guy who stays away from the edges, what about his road map? "This," Lubin says freely, "is definitely on the edge."
To set things in context, remember that we first escaped Earth orbit about 60 years ago. Since then we have accomplished some pretty impressive feats. But nothing we've done so far even gets us anywhere close to the stars. It took 10 years for the New Horizons probe to cross the solar system and reach Pluto. But even with its remarkable velocity of 58,000 km/hr it would still require around 100 millennia for New Horizons to cross typical interstellar distances. That means the challenges involved in getting an interstellar probe to its target in anything close to a human lifetime are immense.
That is where Lubin comes in. Along with his studies of the early universe, Lubin and his team have also been working on technologies associated with "directed energy." When you hear that term you could think "laser" — but there's more to it than that. Lubin has been using advances in the science of photonics to explore arrays of laser systems that work together creating extremely powerful, large-scale beams of directed energy.
Lubin calls his idea Directed Energy System for Targeting of Asteroids and exploRation or DE-STAR. As the name implies, the genesis of the research program was using the lasers to defend Earth from asteroids.
"Since we started our program, we've probably gone through about 100 undergraduate researchers because they just love the idea of destroying something," Lubin told me.
And destroy things they did.
"We had all kinds of objects in the lab that [the students] blew holes through," says Lubin. "One student brought in a bullet-proof vest and we blew a hole through that."
But Lubin's team quickly saw the possibilities for interstellar travel. Light particles (called photons) carry momentum and can push on the things they interact with. This is the principle behind proposals to use sunlight to push giant solar sails around interplanetary space. People also have imagined using Earth-bound lasers fired at a sails for propulsion before.
But it's the low-cost "phased array" lasers Lubin studies that represent a new direction. Adding them to the equation means high-powered spacecraft drivers might be possible in near term (decades not centuries).
Reaching the stars, however, requires reaching velocities close to light speed. The nearest star is 4.3 light-years away. That means it would take 4.3 years traveling at light speed to get to there. But the more mass you want to send to the stars, the more energy you need to accelerate that mass close to light speed. While Lubin's directed energy system can push a sail (and a tethered spaceship) outward, a reasonable version of the machine can only get the craft close to the light-speed limit if you think really, really small. That's why rather than spaceships, Lubin wants to send "spacechips."
As his road map paper puts it, "...we consider functional spacecraft on a wafer, including integrated optical communications, imaging systems, photon thrusters, power and sensors combined with directed energy propulsion."
So, basically, we're talking about sending smartphones to the stars. That, my friends, is edgy.
So how did the edgy ideas in Lubin's road map become part of Yuri Milner's $100 million Starshot program? After giving a talk at the SETI Institute, Lubin's paper found its way to members of Breakthrough Initiatives, including Milner. Then, in January, Lubin and Milner met to discuss the road map.
"He's a truly fascinating individual," Lubin says of Milner. "He's both someone of means and quite a deep thinker. He had been dreaming of doing something in the realm of interstellar but nothing he had looked at was credible."
According to Lubin, Milner and his institute had been exploring "real ideas" in the sense of thinking about, for instance, using anti-matter as a propellant. But while anti-matter is real and its physics is understood (as opposed to a warp drive), doing anything meaningful with it was just too hard (and, hence, too expensive) to imagine.
"Our stuff is really hard, but anti-matter is even harder," says Lubin.
So what Milner saw in Lubin's approach was something that, with time and development, might be technologically feasible and economically possible. Lubin says Milner told him that this idea was the first thing he had seen that was really credible.
So the question Milner, Lubin and others, including Harvard astrophysicist Avi Loeb, tried to answer in their meeting was whether the road map lead to something real. The answer Milner eventually found was "yes." And that, in part, was how the Starshot program was born.
Lubin takes pains to explain that what must happen now is a long, multi-decade road of development. In particular, what is needed is not just new technology but the new technologies that can make the next generation of new and cheaper technologies possible.
"If someone asked in 1961 how much would it cost to get the moon in 1962 you would say that question doesn't even make sense," Lubin says. That's because multiple layers of breakthroughs that fed on each other were all required to make the moon landing possible.
So if the question is "Are we ready to send a starchip to the nearest stars soon?" — the answer is most definitely no. But something new, something radical and something truly fascinating has most definitely begun. Lubin, Milner and Breakthrough Initiatives are indeed dreaming a most audacious dream. Perhaps Lubin himself put it best in his road map paper:
  评论这张
 
阅读(11)| 评论(0)
推荐

历史上的今天

在LOFTER的更多文章

评论

<#--最新日志,群博日志--> <#--推荐日志--> <#--引用记录--> <#--博主推荐--> <#--随机阅读--> <#--首页推荐--> <#--历史上的今天--> <#--被推荐日志--> <#--上一篇,下一篇--> <#-- 热度 --> <#-- 网易新闻广告 --> <#--右边模块结构--> <#--评论模块结构--> <#--引用模块结构--> <#--博主发起的投票-->
 
 
 
 
 
 
 
 
 
 
 
 
 
 

页脚

网易公司版权所有 ©1997-2017