文明等级是什么意思

文明等级，也叫卡尔达舍夫等级，是由苏联科学家尼古拉·卡尔达舍夫于1963年提出的一种用于衡量一个文明的技术以及先进等级的一种方法，被用于很多科幻作品。

.bilibili-video-container {
border: 1px solid rgba(170,170,170,0.37);
max-width: 100%;
}
.bilibili-video-container.exec {
display: table;
}
.bilibili-iframe-container,
.bilibili-video-container {
display: none;
}
.bilibili-video-container,
.bilibili-video-container .bilibili-widescreen,
.bilibili-video-container iframe {
max-width: 100%;
background-color: #fff!important;
}
.bilibili-title {
padding: .2em 6.5em .2em 1em;
position: relative;
}
.bilibili-title a {
word-break: break-word;
}
.bilibili-widescreen {
position: absolute;
display: none;
width: 1em;
right: calc(-2rem - 1px);
border: 1px solid rgba(170,170,170,0.37);
padding: .25rem .5rem;
line-height: 1.5em;
top: -2px;
user-select: none;
cursor: pointer;
}
.onshow .bilibili-widescreen{
display: block;
}
.bilibili-toggle {
position: absolute;
top: calc(50% - .5em);
right: .7em;
line-height: 1em;
cursor: pointer;
padding-left: 1em;
background-image: url(/skins/Vector/images/search-ltr.png?39f97);
background-image: linear-gradient(transparent,transparent), url(data:image/svg+xml,%3C%3Fxml%20version%3D%221.0%22%20encoding%3D%22UTF-8%22%3F%3E%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20width%3D%2212%22%20height%3D%2213%22%3E%3Cg%20stroke-width%3D%222%22%20stroke%3D%22%236c6c6c%22%20fill%3D%22none%22%3E%3Cpath%20d%3D%22M11.29%2011.71l-4-4%22%2F%3E%3Ccircle%20cx%3D%225%22%20cy%3D%225%22%20r%3D%224%22%2F%3E%3C%2Fg%3E%3C%2Fsvg%3E);
background-image: linear-gradient(transparent,transparent), url(/skins/Vector/images/search-ltr.svg?07752)!ie;
background-image: -o-linear-gradient(transparent,transparent), url(/skins/Vector/images/search-ltr.png?39f97);
background-position: left center;
background-repeat: no-repeat;
}
.bilibili-toggle:hover {
color: #36b;
}
.bilibili-video-button,
.bilibili-video-button:visited {
display: inline-block;
margin: 4px 5px;
padding: 10px 25px;
font-size: 14px;
text-align: center;
color: #fff;
background: #de698c;
border-radius: 4px;
}
.bilibili-iframe-container {
padding: 6px;
position: relative;
border: 0 solid rgba(170,170,170,0.37);
border-top-width: 1px;
}
.bilibili-video-container:not([data-max-width]) .bilibili-iframe-container {
max-width: calc(100% - 12px)!important;
}
.bilibili-video-container:not([data-max-width]).onshow .bilibili-iframe-container {
max-height: calc(100% - 27px)!important;
}
.bilibili-video-container textarea {
background: white;
color: black;
width: 80%;
margin: auto;
}
.bilibili-iframe-overlay {
width: 0;
height: 0;
padding-top: 30%;
text-align: center;
box-sizing: border-box;
background: rgb(167, 215, 249);
position: absolute;
top: 3px;
left: 6px;
z-index: 2;
}
.bilibili-iframe-retry-link {
position: absolute;
top: 10px;
right: 10px;
display: none;
background: white;
padding: 0px 0.5em;
}