The Golden Record Cover

In the upper left-hand corner is an easily recognized drawing of the phonograph record and the stylus carried with it. The stylus is in the correct position to play the record from the beginning. Written around it in binary arithmetic is the correct time of one rotation of the record, 3.6 seconds, expressed in time units of 0.70 billionths of a second, the time period associated with a fundamental transition of the hydrogen atom. The drawing indicates that the record should be played from the outside in. Below this drawing is a side view of the record and stylus, with a binary number giving the time to play one side of the record — about an hour.

左上角是一幅一眼就能认出的图：唱片，以及随唱片一起携带的唱针。唱针停在正确的位置上，可以从头开始播放。图的四周用二进制写着唱片转一圈的准确时间——3.6 秒；所用的时间单位是十亿分之 0.70 秒，也就是氢原子一种基本跃迁所对应的时间周期。这幅图还表明，唱片应当从外圈往里播放。它下面是唱片和唱针的侧视图，旁边的二进制数给出了播完一面所需的时间——大约一小时。

The information in the upper right-hand portion of the cover is designed to show how pictures are to be constructed from the recorded signals. The top drawing shows the typical signal that occurs at the start of a picture. The picture is made from this signal, which traces the picture as a series of vertical lines, similar to ordinary television (in which the picture is a series of horizontal lines). Picture lines 1, 2 and 3 are noted in binary numbers, and the duration of one of the "picture lines," about 8 milliseconds, is noted. The drawing immediately below shows how these lines are to be drawn vertically, with staggered "interlace" to give the correct picture rendition. Immediately below this is a drawing of an entire picture raster, showing that there are 512 vertical lines in a complete picture. Immediately below this is a replica of the first picture on the record to permit the recipients to verify that they are decoding the signals correctly. A circle was used in this picture to ensure that the recipients use the correct ratio of horizontal to vertical height in picture reconstruction.

封套右上部分的信息，是为了说明怎样从录下的信号里重建图像。最上面的图画的是每幅图像开头处的典型信号。图像就由这段信号构成：信号把画面描成一列列竖线，和普通电视相似（电视的画面是一行行横线）。图中用二进制数标出了第 1、2、3 条画面线，还标出了一条“画面线”的时长，约 8 毫秒。紧接着下面的图说明这些线要竖着画，并以错开的“隔行”方式排列，才能还原出正确的画面。再下面是一整幅图像的光栅图，表明一幅完整的图像由 512 条竖线组成。再往下，是唱片上第一幅图像的复制品，好让接收者核对自己的解码是否正确。这幅图里用了一个圆，是为了确保接收者在重建图像时采用正确的横竖比例。

Electroplated onto the record's cover is an ultra-pure source of uranium-238 with a radioactivity of about 0.00026 microcuries. The steady decay of the uranium source into its daughter isotopes makes it a kind of radioactive clock. Half of the uranium-238 will decay in 4.51 billion years. Thus, by examining this two-centimeter diameter area on the record plate and measuring the amount of daughter elements to the remaining uranium-238, an extraterrestrial recipient of the Voyager spacecraft could calculate the time elapsed since a spot of uranium was placed aboard the spacecraft. This should be a check on the epoch of launch, which is also described by the pulsar map on the record cover.

唱片封套上电镀了一小块超纯的铀-238 源，放射性约为 0.00026 微居里。铀源稳定地衰变成它的子体同位素，这使它成了一种放射性时钟。铀-238 的一半要经过 45.1 亿年才会衰变掉。因此，旅行者号飞船的地外接收者只要检查唱片上这块直径两厘米的区域，测出子体元素与剩余铀-238 的比例，就能算出自从这一小点铀被放上飞船以来过去了多长时间。这可以用来核对发射的年代——封套上的脉冲星地图也描述了这个年代。