This is Scientific American — 60-Second Science. I'm Cynthia Graber.
Many people remember the colors of the rainbow by the acronym ROY G. BIV. For red, orange, yellow, green, blue, indigo and violet. Well, the color indigo just made news.
Indigo gets its name from the plant Indigofera tinctoria and its relatives, which supply the dye that makes fabric the rich, beautiful color between blue and violet.
Indigo dye was used around the ancient world in fabrics created from Egypt to China to Meso and South America. And it's in South America that researchers recently found the oldest known example of fabrics dyed with indigo.
The artifacts were discovered at Huaca Prieta, a ceremonial mound on the coast in northern Peru. But their color was initially hidden by the grey tones that had leached into them from the materials used in the mound itself. But when a conservator carefully washed the fabric, the true colors reappeared.
"And it was at that point that I realized we probably had indigo and it was probably the world's oldest indigo."
Jeffrey Splitstoser, an anthropologist at George Washington University.
"Which was really exciting. I hadn't thought I'd be discovering, or we would be discovering, the world's oldest indigo, when I took on this project."
The research is in the journal Science Advances.
The dyed fabric is about 6,000 years old.
"In the Middle East there are inscriptions that discuss blue fabrics that date to about 3100 B.C. These are just texts though. And so we think they're referring probably to the earliest Old World indigo-blue dyed textiles. So that would date to about 5,000 years ago, 3100 B.C. And so these are at least 1,000 years older than that. And the earliest known indigo blue textiles were from Egypt and they date to around 4400 B.P., before present. So these are almost 2,000 years older than those."
Splitstoser says that the discovery means it's likely that the techniques to dye fabric blue were developed in the Americas before they were developed in Egypt.
"It really means that we have to look at the ancient Andes as one of the earliest sources of textile innovations in the world."
Thanks for listening for Scientific American — 60-Second Science Science. I'm Cynthia Graber.
许多人记得彩虹的颜色按照首字母排列为ROYGBIV 。这些首字母分别代表红、橙、黄、绿、蓝、靛、紫 。而靛色最近有了新的消息 。
靛蓝染料在古代用于对布料进行染色，而这些布料一般产自埃及、中国、中美洲以及南美洲等地方 。最近，研究人员就在南美洲发现了目前已知最古老的靛蓝染色布料 。
人们在普雷塔遗址发现了这些手工艺品，普雷塔遗址位于秘鲁北部海岸，是一个曾用于举行仪式的土丘 。但是这些手工艺品的颜色最初被灰色基调所掩盖，而灰色来自于土堆本身材料的渗透 。但是，当一位文物修复员仔细清理这些布料后，其真正的颜色重新显现出来 。
“这太让人兴奋了 。我在做这个项目的时候，从来没想过我或者说我们会发现世界上最古老的靛蓝色 。”
约公元前3100年，在中东有讨论蓝色布料的铭文 。虽然这些只是文字材料 。不过，我们认为它们指的可能是最古老的靛蓝色纺织品 。因此，靛蓝色染料的历史可追溯到5000年前，即大约公元前3100年 。而这些新发现的染色布料至少要早1000年 。此前已知最古老的靛蓝色纺织品来自于古埃及，距今大约4400年 。所以，新发现的染色布料比那些要早约2000年 。
谢谢大家收听科学美国人——60秒科学 。我是辛西娅·格雷伯 。
1. take on 承担，接受(尤指艰巨工作或重大责任)；
例句：He is ready to take on heavy responsibilities.
2. refer to 提到，指的是；
例句：It can refer to an academic subject or a practical skill.
3. at least （数量）至少，不少于；
例句：Cacao has been cultivated for at least three millennia in Mexico, Central and South America.