揭秘太陽的“雀斑”——黑子
古人認(rèn)為它們是太陽神臉上生的麻子，抑或太陽內(nèi)的星辰，現(xiàn)代人猜想它們和UFO以及各種超自然現(xiàn)象密不可分——這種神秘物質(zhì)就是太陽黑子，它們能量巨大，也會時不時給人類的生活帶來麻煩，讓我們隨本文一起揭開太陽黑子的面紗吧。
The Aztecs[1] thought that their sun god had pockmarks on his face. The ancient Chinese referred to them as stars inside the solar orb. One Renaissance astronomer argued that they were actually undiscovered planets. Today, some believe their appearance is linked to UFO sightings and paranormal activity. Others offer them as an alternative explanation for human-caused climate change. The rest of us wonder if they’re the reason for dropped cell phone calls or static-plagued radio stations.
We’re talking about sunspots, those peculiar dark areas that pop up regularly on the surface of the sun. They usually appear in pairs or in groups on either side of the sun’s equator. Sunspots vary tremendously in size, ranging from less than 200 miles across to many times the size of the Earth. Some small sunspots may last for less than an hour, but larger ones can last up to six months. Some sunspots—such as one in 2004 that measured 20 times the size of our planet—are big enough to be seen by the naked eye.
Astronomers in ancient China noticed sunspots several thousand years ago. The I-Ching or Book of Changes, which dates back to the 12th century B.C., mentions the phenomenon. The first written record of a sunspot sighting dates to 28 B.C., when it was noted that “the sun was yellow at its rising and a black vapor as large as a coin was observed at its center.” On the other side of the world, the Aztecs, who ruled Mexico before the Spanish arrived in the 1500s, also paid a lot of attention to the sun. As we discussed, their creation myth featured a sun god with a pockmarked face.
In Europe, people had a harder time accepting the existence of sunspots. That was because everyone—including the Catholic Church—accepted Greek philosopher Aristotle’s idea that the heavens were perfect and unchanging. Instead, when a large sunspot appeared for eight days in A.D. 807, they dismissed the phenomenon as the passage of the planet Mercury across the sun.
However, after the telescope was developed in the early 1600s, the Italian astronomer Galileo and others clearly saw that the sun had dark spots. Astronomer and Catholic priest Christoph Scheiner tried to come up with an explanation that didn’t contradict Church teachings; he argued that the spots actually were undiscovered planets that orbited very close to the sun and were visible only when the planets were in front of the sun. Despite Scheiner’s attempts, Galileo correctly figured out that sunspots were part of the sun itself by closely studying the movement of sunspots over time. By the mid-1700s, European astronomers were recording and compiling their observations of sunspots on a daily basis.
As scientists accumulated more and more data, they began to notice that sunspot activity developed a pattern. In 1843, astronomer S.H. Schwabe was the first to describe the 11-year sunspot cycle.
Since then, scientists used have used an array of tools—including giant solar telescopes that were specially cooled to observe the sun’s light without being distorted by its heat—to learn more about the physics of sunspots.
Sunspots occur because the sun isn’t a hunk of rock like the Earth and the inner planets, but a ball of continually circulating hot gases that doesn’t move in one piece. The interior and the exterior of the sun rotate separately; the outside rotates more quickly at the equator than at the solar north and south poles. Over time, all that messy and uneven movement twists and distorts the sun’s main magnetic field in the same way that your bed sheets get wrinkled and bunched up when you toss and turn in your sleep. The bunched up spots—actually twists in the magnetic field lines—have so much magnetic power that they push back the hot gases beneath them and prevent the heat from rising directly to the surface. In other words, they become sunspots.
Because sunspots are cooler than the rest of the sun’s surface, they look darker. At the same time, the hot gases blocked by these sunspots flow into the areas around them, making those areas even hotter and brighter than normal. This contrast makes sunspots stand out even more.
Sunspots’ Effect on Earth
Sunspots are connected with other solar events like flares and coronal mass ejections (CMEs). A solar flare is a sudden release of energy from the sun, while a CME actually shoots hot plasma from the sun into space. The precise mechanisms that trigger flares and CMEs are not yet known, but the bigger the group of sunspots, the more intense such solar weather tends to be.
Flares and CMEs can send enormous amounts of energy and charged particles hurtling into collision with the Earth’s atmosphere, where they can cause magnetic storms that disrupt or alter radio and cell phone communication and can wreak havoc with electrical grids. In 1989, for example, a power surge triggered by solar energy damaged transformers that were part of the Hydro-Quebec power system. That surge left 6 million people in Canada and the northeastern U.S. without electricity for more than nine hours.
The increase in radiation that accompanies a solar flare is a theoretical health hazard to spacewalking astronauts, crew and passengers in high-flying aircraft, but there isn’t any evidence that people have actually gotten sick from such exposure.
It’s unclear if there’s a link between solar weather and changes in the Earth’s climate, because our planet’s climate is influenced by so many other factors—from volcanic eruptions to man-made emissions of greenhouse gases. In the 1600s and 1700s, when there was almost no sunspot activity, coincided with a period of cold temperatures and severe winters in Europe and North America. However, scientists haven’t been able to determine if the two phenomena were actually related, though they think that a decrease in the sun’s ultraviolet emissions may have triggered the change in climate.
UFO watchers and paranormal enthusiasts also see links between the unknown and increased sunspot activity, but there may be more of a correlation with the intensity of a person’s belief in mystical phenomena.
阿茲特克人覺得那是他們的太陽神臉上生的麻子;古代中國人把它們叫做太陽內(nèi)部的星辰;還有一位文藝復(fù)興時期的天文學(xué)家提出：它們其實是尚待發(fā)現(xiàn)的行星。如今，一些人認(rèn)為它們的出現(xiàn)與UFO和超自然活動有關(guān);還有人把它們認(rèn)作是人為引起的氣候變化的另一種表現(xiàn);我們剩下的人則懷疑它們是手機信號中斷和無線電臺靜電干擾的罪魁禍?zhǔn)住?/p>
我們所說的就是太陽黑子，那些定期突然出現(xiàn)在太陽表面的奇特黑色區(qū)域。通常它們會在太陽赤道的一側(cè)成對或成群出現(xiàn)。黑子的大小差別巨大，小的直徑不到二百英里，大的比地球還大很多倍。一些小的太陽黑子可能只存在不到一小時(就消失了)，而大的黑子可以持續(xù)存在六個月之久。一些黑子，比如2004年出現(xiàn)的大小為地球20倍的那個，大到我們可以用肉眼就能觀察到。
早在幾千年前，中國古代的天文學(xué)家們就注意到了太陽黑子現(xiàn)象。公元前12世紀(jì)的《易經(jīng)》提到了這一現(xiàn)象。首次觀測太陽黑子的書面記載是在公元前28年，當(dāng)時的記載是“太陽初升時呈黃色，中間可見硬幣大小的一團黑色霧氣。”在地球的另一端，16世紀(jì)西班牙入侵前一直統(tǒng)治著墨西哥的阿茲特克人也很注重察太陽。正如我們上文提到的，他們的創(chuàng)世紀(jì)神話中就有生了麻子臉的太陽神的形象。
在歐洲，人們接受太陽黑子卻經(jīng)歷了艱難的過程。那是因為當(dāng)時的每個人，包括天主教派，都接受了希臘哲學(xué)家亞里士多德的觀點，即認(rèn)為上天是完美無缺并恒定不變的。于是，當(dāng)公元807年一個巨大的太陽黑子出現(xiàn)并持續(xù)了八天時，他們并未放在心上，只是覺得那是因為水星路過太陽所致。
然而，17世紀(jì)早期望遠(yuǎn)鏡發(fā)明之后，意大利天文學(xué)家伽利略和其他天文學(xué)家都清楚地觀測到了太陽上的黑色陰影。天文學(xué)家、天主教牧師克里斯托夫?沙因爾努力想給出一種不違背教會教義的解釋，他堅稱這些黑點實際上是尚待發(fā)現(xiàn)的行星，它們緊緊地圍繞著太陽運轉(zhuǎn)，并且只有擋在太陽前面時才可以被觀測到。盡管沙因爾努力辯解，伽利略在連續(xù)觀察并仔細(xì)研究太陽活動之后，還是正確地指出：太陽黑子是太陽自身的組成部分。到了18世紀(jì)中葉，歐洲的天文學(xué)家們開始逐天記錄并編纂他們對太陽黑子的觀測情況。
隨著科學(xué)家們積累了越來越多的數(shù)據(jù)，他們開始注意到太陽黑子的活動是遵循著一定規(guī)律的。1843年，天文學(xué)家S.H. 施瓦貝第一個描述了太陽黑子11年一次的周期。
自那時起，科學(xué)家們便運用了一系列工具——包括巨型太陽望遠(yuǎn)鏡——來認(rèn)識太陽黑子的更多物理特性，巨型太陽望遠(yuǎn)鏡經(jīng)過特殊處理，能濾過并冷卻太陽的熱量，這樣觀察太陽光的時候就不會被其熱量所干擾。
太陽黑子的產(chǎn)生是因為太陽與地球和內(nèi)行星那樣由大塊巖石組成的構(gòu)造不同，太陽是一團由不停環(huán)繞運動的熱氣構(gòu)成的球體，并且并不整體運動。太陽的內(nèi)部和外部各自旋轉(zhuǎn);其外部的赤道部位比南北極轉(zhuǎn)速要快。久而久之，這種混亂、不平衡的運動逐漸改變、扭曲了太陽的主要磁場，就好像你在床上睡覺時，翻來覆去使床單變皺和鼓起來一樣。這些鼓起的區(qū)域(實際上是磁力線上的扭曲)的磁力特別大，于是它們將底下的熱氣推回來，并阻止熱量直接升到太陽表面。換句話說，它們就成了太陽黑子。
因為太陽黑子比太陽表面的其他區(qū)域溫度要低，所以它們看起來顏色更黑。同時，被這些太陽黑子阻擋的熱氣涌入它們周邊的區(qū)域，使得這些區(qū)域變得比平時溫度更高，顏色更明亮。這種對比便襯托得太陽黑子更為突出。
太陽黑子對地球的影響
太陽黑子與其他太陽現(xiàn)象，如耀斑和日冕物質(zhì)拋射也有著一定關(guān)聯(lián)。太陽耀斑是太陽能量的突然釋放;而日冕物質(zhì)拋射實際上是太陽上灼熱的等離子體向宇宙空間的散射。引發(fā)耀斑和日冕物質(zhì)拋射的確切機理尚不可知，但是黑子群的規(guī)模越大，此類太陽活動就越為劇烈。
耀斑和日冕物質(zhì)拋射能夠釋放巨大的能量和無數(shù)帶電的粒子，并與地球的大氣層猛烈碰撞，從而引發(fā)磁暴，干擾或更改無線電或手機通信信號，并可對電力系統(tǒng)造成嚴(yán)重破壞。例如在1989年，太陽能量釋放引發(fā)的能量激增就造成了魁北克水電系統(tǒng)變壓器的損壞，從而導(dǎo)致加拿大和美國東北部地區(qū)的600萬人口遭遇長達(dá)九個多小時的電力中斷。
理論上而言，伴隨太陽耀斑產(chǎn)生的輻射能增加對太空漫步的宇航員、高空飛行的飛機上的機務(wù)人員和乘客也會造成一種健康危害，但目前還沒有證據(jù)表明這種輻射能可以致病。
太陽活動與地球氣候變化的關(guān)系目前還有待論證，因為地球氣候同時受到許多其他因素的影響——從火山爆發(fā)到人為溫室氣體的排放。在17和18世紀(jì)，太陽活動幾乎為零，歐洲和北美地區(qū)恰恰就出現(xiàn)了低溫和嚴(yán)寒天氣。然而，盡管科學(xué)家們認(rèn)為太陽散發(fā)紫外線的減少可能會引發(fā)氣候變化，他們尚不能確定這兩種現(xiàn)象存在確定的因果關(guān)系。
UFO的觀測者和超自然現(xiàn)象愛好者們也認(rèn)為太陽黑子活動的增加與這類未知現(xiàn)象有關(guān)，但也許這與人們對神秘現(xiàn)象的相信程度更為相關(guān)吧。
古人認(rèn)為它們是太陽神臉上生的麻子，抑或太陽內(nèi)的星辰，現(xiàn)代人猜想它們和UFO以及各種超自然現(xiàn)象密不可分——這種神秘物質(zhì)就是太陽黑子，它們能量巨大，也會時不時給人類的生活帶來麻煩，讓我們隨本文一起揭開太陽黑子的面紗吧。
The Aztecs[1] thought that their sun god had pockmarks on his face. The ancient Chinese referred to them as stars inside the solar orb. One Renaissance astronomer argued that they were actually undiscovered planets. Today, some believe their appearance is linked to UFO sightings and paranormal activity. Others offer them as an alternative explanation for human-caused climate change. The rest of us wonder if they’re the reason for dropped cell phone calls or static-plagued radio stations.
We’re talking about sunspots, those peculiar dark areas that pop up regularly on the surface of the sun. They usually appear in pairs or in groups on either side of the sun’s equator. Sunspots vary tremendously in size, ranging from less than 200 miles across to many times the size of the Earth. Some small sunspots may last for less than an hour, but larger ones can last up to six months. Some sunspots—such as one in 2004 that measured 20 times the size of our planet—are big enough to be seen by the naked eye.
Astronomers in ancient China noticed sunspots several thousand years ago. The I-Ching or Book of Changes, which dates back to the 12th century B.C., mentions the phenomenon. The first written record of a sunspot sighting dates to 28 B.C., when it was noted that “the sun was yellow at its rising and a black vapor as large as a coin was observed at its center.” On the other side of the world, the Aztecs, who ruled Mexico before the Spanish arrived in the 1500s, also paid a lot of attention to the sun. As we discussed, their creation myth featured a sun god with a pockmarked face.
In Europe, people had a harder time accepting the existence of sunspots. That was because everyone—including the Catholic Church—accepted Greek philosopher Aristotle’s idea that the heavens were perfect and unchanging. Instead, when a large sunspot appeared for eight days in A.D. 807, they dismissed the phenomenon as the passage of the planet Mercury across the sun.
However, after the telescope was developed in the early 1600s, the Italian astronomer Galileo and others clearly saw that the sun had dark spots. Astronomer and Catholic priest Christoph Scheiner tried to come up with an explanation that didn’t contradict Church teachings; he argued that the spots actually were undiscovered planets that orbited very close to the sun and were visible only when the planets were in front of the sun. Despite Scheiner’s attempts, Galileo correctly figured out that sunspots were part of the sun itself by closely studying the movement of sunspots over time. By the mid-1700s, European astronomers were recording and compiling their observations of sunspots on a daily basis.
As scientists accumulated more and more data, they began to notice that sunspot activity developed a pattern. In 1843, astronomer S.H. Schwabe was the first to describe the 11-year sunspot cycle.
Since then, scientists used have used an array of tools—including giant solar telescopes that were specially cooled to observe the sun’s light without being distorted by its heat—to learn more about the physics of sunspots.
Sunspots occur because the sun isn’t a hunk of rock like the Earth and the inner planets, but a ball of continually circulating hot gases that doesn’t move in one piece. The interior and the exterior of the sun rotate separately; the outside rotates more quickly at the equator than at the solar north and south poles. Over time, all that messy and uneven movement twists and distorts the sun’s main magnetic field in the same way that your bed sheets get wrinkled and bunched up when you toss and turn in your sleep. The bunched up spots—actually twists in the magnetic field lines—have so much magnetic power that they push back the hot gases beneath them and prevent the heat from rising directly to the surface. In other words, they become sunspots.
Because sunspots are cooler than the rest of the sun’s surface, they look darker. At the same time, the hot gases blocked by these sunspots flow into the areas around them, making those areas even hotter and brighter than normal. This contrast makes sunspots stand out even more.
Sunspots’ Effect on Earth
Sunspots are connected with other solar events like flares and coronal mass ejections (CMEs). A solar flare is a sudden release of energy from the sun, while a CME actually shoots hot plasma from the sun into space. The precise mechanisms that trigger flares and CMEs are not yet known, but the bigger the group of sunspots, the more intense such solar weather tends to be.
Flares and CMEs can send enormous amounts of energy and charged particles hurtling into collision with the Earth’s atmosphere, where they can cause magnetic storms that disrupt or alter radio and cell phone communication and can wreak havoc with electrical grids. In 1989, for example, a power surge triggered by solar energy damaged transformers that were part of the Hydro-Quebec power system. That surge left 6 million people in Canada and the northeastern U.S. without electricity for more than nine hours.
The increase in radiation that accompanies a solar flare is a theoretical health hazard to spacewalking astronauts, crew and passengers in high-flying aircraft, but there isn’t any evidence that people have actually gotten sick from such exposure.
It’s unclear if there’s a link between solar weather and changes in the Earth’s climate, because our planet’s climate is influenced by so many other factors—from volcanic eruptions to man-made emissions of greenhouse gases. In the 1600s and 1700s, when there was almost no sunspot activity, coincided with a period of cold temperatures and severe winters in Europe and North America. However, scientists haven’t been able to determine if the two phenomena were actually related, though they think that a decrease in the sun’s ultraviolet emissions may have triggered the change in climate.
UFO watchers and paranormal enthusiasts also see links between the unknown and increased sunspot activity, but there may be more of a correlation with the intensity of a person’s belief in mystical phenomena.
阿茲特克人覺得那是他們的太陽神臉上生的麻子;古代中國人把它們叫做太陽內(nèi)部的星辰;還有一位文藝復(fù)興時期的天文學(xué)家提出：它們其實是尚待發(fā)現(xiàn)的行星。如今，一些人認(rèn)為它們的出現(xiàn)與UFO和超自然活動有關(guān);還有人把它們認(rèn)作是人為引起的氣候變化的另一種表現(xiàn);我們剩下的人則懷疑它們是手機信號中斷和無線電臺靜電干擾的罪魁禍?zhǔn)住?/p>
我們所說的就是太陽黑子，那些定期突然出現(xiàn)在太陽表面的奇特黑色區(qū)域。通常它們會在太陽赤道的一側(cè)成對或成群出現(xiàn)。黑子的大小差別巨大，小的直徑不到二百英里，大的比地球還大很多倍。一些小的太陽黑子可能只存在不到一小時(就消失了)，而大的黑子可以持續(xù)存在六個月之久。一些黑子，比如2004年出現(xiàn)的大小為地球20倍的那個，大到我們可以用肉眼就能觀察到。
早在幾千年前，中國古代的天文學(xué)家們就注意到了太陽黑子現(xiàn)象。公元前12世紀(jì)的《易經(jīng)》提到了這一現(xiàn)象。首次觀測太陽黑子的書面記載是在公元前28年，當(dāng)時的記載是“太陽初升時呈黃色，中間可見硬幣大小的一團黑色霧氣。”在地球的另一端，16世紀(jì)西班牙入侵前一直統(tǒng)治著墨西哥的阿茲特克人也很注重察太陽。正如我們上文提到的，他們的創(chuàng)世紀(jì)神話中就有生了麻子臉的太陽神的形象。
在歐洲，人們接受太陽黑子卻經(jīng)歷了艱難的過程。那是因為當(dāng)時的每個人，包括天主教派，都接受了希臘哲學(xué)家亞里士多德的觀點，即認(rèn)為上天是完美無缺并恒定不變的。于是，當(dāng)公元807年一個巨大的太陽黑子出現(xiàn)并持續(xù)了八天時，他們并未放在心上，只是覺得那是因為水星路過太陽所致。
然而，17世紀(jì)早期望遠(yuǎn)鏡發(fā)明之后，意大利天文學(xué)家伽利略和其他天文學(xué)家都清楚地觀測到了太陽上的黑色陰影。天文學(xué)家、天主教牧師克里斯托夫?沙因爾努力想給出一種不違背教會教義的解釋，他堅稱這些黑點實際上是尚待發(fā)現(xiàn)的行星，它們緊緊地圍繞著太陽運轉(zhuǎn)，并且只有擋在太陽前面時才可以被觀測到。盡管沙因爾努力辯解，伽利略在連續(xù)觀察并仔細(xì)研究太陽活動之后，還是正確地指出：太陽黑子是太陽自身的組成部分。到了18世紀(jì)中葉，歐洲的天文學(xué)家們開始逐天記錄并編纂他們對太陽黑子的觀測情況。
隨著科學(xué)家們積累了越來越多的數(shù)據(jù)，他們開始注意到太陽黑子的活動是遵循著一定規(guī)律的。1843年，天文學(xué)家S.H. 施瓦貝第一個描述了太陽黑子11年一次的周期。
自那時起，科學(xué)家們便運用了一系列工具——包括巨型太陽望遠(yuǎn)鏡——來認(rèn)識太陽黑子的更多物理特性，巨型太陽望遠(yuǎn)鏡經(jīng)過特殊處理，能濾過并冷卻太陽的熱量，這樣觀察太陽光的時候就不會被其熱量所干擾。
太陽黑子的產(chǎn)生是因為太陽與地球和內(nèi)行星那樣由大塊巖石組成的構(gòu)造不同，太陽是一團由不停環(huán)繞運動的熱氣構(gòu)成的球體，并且并不整體運動。太陽的內(nèi)部和外部各自旋轉(zhuǎn);其外部的赤道部位比南北極轉(zhuǎn)速要快。久而久之，這種混亂、不平衡的運動逐漸改變、扭曲了太陽的主要磁場，就好像你在床上睡覺時，翻來覆去使床單變皺和鼓起來一樣。這些鼓起的區(qū)域(實際上是磁力線上的扭曲)的磁力特別大，于是它們將底下的熱氣推回來，并阻止熱量直接升到太陽表面。換句話說，它們就成了太陽黑子。
因為太陽黑子比太陽表面的其他區(qū)域溫度要低，所以它們看起來顏色更黑。同時，被這些太陽黑子阻擋的熱氣涌入它們周邊的區(qū)域，使得這些區(qū)域變得比平時溫度更高，顏色更明亮。這種對比便襯托得太陽黑子更為突出。
太陽黑子對地球的影響
太陽黑子與其他太陽現(xiàn)象，如耀斑和日冕物質(zhì)拋射也有著一定關(guān)聯(lián)。太陽耀斑是太陽能量的突然釋放;而日冕物質(zhì)拋射實際上是太陽上灼熱的等離子體向宇宙空間的散射。引發(fā)耀斑和日冕物質(zhì)拋射的確切機理尚不可知，但是黑子群的規(guī)模越大，此類太陽活動就越為劇烈。
耀斑和日冕物質(zhì)拋射能夠釋放巨大的能量和無數(shù)帶電的粒子，并與地球的大氣層猛烈碰撞，從而引發(fā)磁暴，干擾或更改無線電或手機通信信號，并可對電力系統(tǒng)造成嚴(yán)重破壞。例如在1989年，太陽能量釋放引發(fā)的能量激增就造成了魁北克水電系統(tǒng)變壓器的損壞，從而導(dǎo)致加拿大和美國東北部地區(qū)的600萬人口遭遇長達(dá)九個多小時的電力中斷。
理論上而言，伴隨太陽耀斑產(chǎn)生的輻射能增加對太空漫步的宇航員、高空飛行的飛機上的機務(wù)人員和乘客也會造成一種健康危害，但目前還沒有證據(jù)表明這種輻射能可以致病。
太陽活動與地球氣候變化的關(guān)系目前還有待論證，因為地球氣候同時受到許多其他因素的影響——從火山爆發(fā)到人為溫室氣體的排放。在17和18世紀(jì)，太陽活動幾乎為零，歐洲和北美地區(qū)恰恰就出現(xiàn)了低溫和嚴(yán)寒天氣。然而，盡管科學(xué)家們認(rèn)為太陽散發(fā)紫外線的減少可能會引發(fā)氣候變化，他們尚不能確定這兩種現(xiàn)象存在確定的因果關(guān)系。
UFO的觀測者和超自然現(xiàn)象愛好者們也認(rèn)為太陽黑子活動的增加與這類未知現(xiàn)象有關(guān)，但也許這與人們對神秘現(xiàn)象的相信程度更為相關(guān)吧。
