什么是化學痕跡?它們危險嗎?

什么是化學痕跡?它們危險嗎?

The persistent high-altitude contrails are more than stripes in the stratosphere. They are the stuff of conspiracy theories on par with Area 51, the Roswell UFO crash and who shot JFK.

持續(xù)的高空尾跡不僅僅是平流層的條紋。這些都是陰謀論的內容，與51區(qū)、羅斯韋爾UFO墜毀事件和刺殺肯尼迪事件一樣。

The trails coming out of planes are harmless and normal, say scientists. (Photo: Vaclav Volrab/Shutterstock)

The chemtrail conspiracy theory claims that some contrails are chemical, biological or otherwise toxic elements sprayed at high altitudes by government agencies — of some sort — for the purpose of — well, something not good.

“化學痕跡陰謀論”聲稱，一些飛機尾跡是政府機構在高空噴灑的化學、生物或其他有毒物質，其目的是——嗯，是不好的。

Normal jet airliner exhaust contrails quickly dissipate, the conspiracy theory holds. Chemtrails — which are loaded with toxic heavy metals and heaven knows what else — linger in the sky for hours.

陰謀論認為，普通噴氣式飛機的尾氣尾跡會很快消散。含有有毒重金屬和天知道還有什么其他物質的化學物質會在空中停留數(shù)小時。

The theory has no scientific basis, writes Grant Petty, a professor of atmospheric science and the University of Wisconsin-Madison.

威斯康辛大學麥迪遜分校的大氣科學教授格蘭特•佩蒂寫道，這一理論沒有科學依據(jù)。

“The lifetime and behavior of contrails depend on the environmental conditions in which they form,” Petty writes. “Growing contrails result when the humidity at high altitudes is at or above the saturation point with respect to ice. So when condensation is injected in the atmosphere at those altitudes, the microscopic particles of ice don’t simply evaporate, they persist and even grow, and they are spread by the winds into broader patches of cirrus cloud.”

佩蒂寫道:“尾跡的壽命和行為取決于它們形成的環(huán)境條件。”“當高海拔地區(qū)的濕度達到或超過冰的飽和點時，就會產生越來越多的尾跡。因此，當這些高度的大氣中注入冷凝物時，微小的冰粒不僅會蒸發(fā)，還會持續(xù)存在，甚至會增長，它們會被風吹散成更大范圍的卷云。”

If persistent contrails are more common, Petty suggests, it is because there is more high-altitude airliner traffic and the stratospheric humidity is higher because of the moisture left by the contrails of all that traffic.

佩蒂認為，如果持續(xù)的飛機尾跡更常見，那是因為高空航班的流量更多，而平流層的濕度也更高，因為飛機尾跡所留下的水分。

The researchers were also shown four images that are often identified as chemtrails. All of them said they were just ordinary contrails, and they gave peer-reviewed citations to support their claims.

研究人員還看到了四幅通常被認為是化學痕跡的圖像。他們都說這些只是普通的軌跡，并給出了經(jīng)過同行評審的引文來支持他們的說法。

“We wanted to establish a scientific record on the topic of secret atmospheric spraying programs for the benefit of those in the public who haven't made up their minds," said study co-author Steven Davis of University of California Irvine, in a statement. "The experts we surveyed resoundingly rejected contrail photographs and test results as evidence of a large-scale atmospheric conspiracy."

加州大學歐文分校的史蒂文·戴維斯是這項研究的共同作者，他在一份聲明中說:“我們想建立一個關于秘密大氣噴灑計劃的科學記錄，以造福那些還沒有下定決心的公眾。”“我們調查的專家成功地駁斥了航跡照片和測試結果，認為它們是大規(guī)模大氣陰謀的證據(jù)。”

The researchers say the goal of their study isn't to try to change the minds of those convinced chemtrails exist "these individuals usually only reject counter-evidence as further proof of their theories." Instead, they say they just wanted to offer objective science for a basis of discussion.

研究人員表示，他們的研究目的并不是試圖改變那些堅信化學實驗存在的人的想法，“這些人通常只是拒絕將反證據(jù)作為他們理論的進一步證據(jù)。”相反，他們說他們只是想提供客觀科學作為討論的基礎。