真    理    诞    生    于    一    百    个    问    号    之    后   

 有    人    说    过    这    样    一    句    话   : 真    理    诞    生    于    一    百    个    问    号    之    后   。 其    实   , 这     句    话    本    身    就    是    一    个    真    理   
 纵    观    千    百    年    来    的    科    学    技    术    发    展    史   , 那    些    在    科    学    领    域    有    所    建    树    的    人   , 都    善    于    从    细    微    的   、 司    空    见    惯    的    现    象    中    发    现    问    题   , 不    断    发    问   , 不    断    发    问   , 不    断    探    疑    问   , 追    根    求    源   , 最    后    把   ? 拉    直    变    成   !, 找    到    真    理   
 波    义    耳    是    世    纪    英    国    著    名    的    化    学    家   。 一    天   , 他    急    匆    匆    地    向    自    己    的    实    验    室    走    去   , 路    过    花    圃    时   , 阵    阵    醉    人    的    香    气    扑    鼻    而    来   , 他    这    才    发    现    花    圃    里    的    花    已    经    开    了   。 他    摘    下    几    朵    紫    罗    兰    插    入    一    个    盛    水    的    烧    瓶    中   , 然    后    开    始    和    助    手    们    做    实    验   。 不    巧    的    是   , 一    个    助    手    不    慎    把    一    滴    盐    酸    溅    到    了    紫    罗    兰    上   , 爱    花    的    波    义    耳    急    忙    把    冒    烟    的    紫    罗    兰    冲    洗    了    一    下   , 重    新    插    入    花    瓶    中   。 谁    知    过    了    一    会    儿   , 溅    上    盐    酸    的    花    瓣    竟    奇    迹    般    地    变    红    了   。 波    义    耳    立    即    敏    感    地    意    识    到   , 紫    罗    兰    中    有    一    种    物    质    遇    到    盐    酸    会    变    红   。 那    么   , 这    种    物    质    到    底    是    什    么   ? 别    的    植    物    中    会    不    会    有    同    样    的    物    质   ? 别    的    酸    对    这    种    物    质    会    有    什    么    样    的    反    应   ? 这    一    奇    怪    的    现    象    以    及    一    连    串    的    问    题   , 促    使    波    义    耳    进    行    了    许    多    实    验   。 由    此    他    发    现   , 大    部   
 分    花    草    受    酸    或    碱    的    作    用    都    会    改    变    颜    色   , 其    中    以    石    蕊    地    衣    中    提    取    的    紫    色    浸    液    最    明    显   : 它    遇    酸    变    成    红    色   , 遇    碱    变    成    蓝    色   。 利    用    这    一    特    点   , 波    义    耳    制    成    了    实    验    中    常    用    的    酸    碱    试    纸   —— 石    蕊    试    纸   。 从    那    以    后   , 这    种    试    纸   — 直    被    广    泛    应    用    于    化    学    实    验    中   
 这    样    的    事    情    不    止    一    例   。 世    纪    初    的    一    天   , 因    病    住    院    的    德    国    气    象    学    家    魏    格    纳    正    无    聊    地    看    着    墙    上    的    世    界    地    图   , 突    然    发    现    南    美    洲    东    海    岸    的    凸    出    部    分    与    非    洲    西    海    岸    的    凹    陷    部    分   , 竟    然    不    可    思    议    地    互    相    吻    合   ! 魏    格    纳    被    自    己    偶    然    的    发    现    惊    呆    了   。 这    不    会    是    一    种    巧    合    吧   ? 他    将    地    图    上    的    一    块    块    陆    地    作    了    比    较   , 结    果    发    现   , 从    海    岸    线    的    情    形    看   , 地    球    上    所    有    的    大    陆    都    能    较    好    地    吻    合    在    一    起   。 病    愈    之    后   , 魏    格    纳    开    始    认    真    地    研    究    这    个    有    趣    的    现    象   。 他    阅    读    了    大    量    的    相    关    文    献   , 同    时    搜    集    古    生    物    学    方    面    的    证    据   。 他    注    意    到   , 一    位    名    叫    米    歇    尔    逊    的    生    物    学    家    发    现   , 在    美    国    东    海    岸    有    一    种    蚯    蚓   , 欧    洲    西    海    岸    的    同    纬    度    地    区    也    有    这    种    蚯    蚓   , 而    在    美    国    西    海    岸    却    没    有    这    种    蚯    蚓   。 魏    格    纳    认    为   , 这    种    蚯    蚓    的    分    布    情    况    正    说    明   , 欧    洲    大    陆    与    美    洲    大    陆    本    来    是    连    在    一    起    的   , 否    则   , 蚯    蚓    即    使    是    插    上    翅    膀    也    难    以    飞    渡    重    洋   。 年   , 魏    格    纳    系    统    整    理    了    他    的    大    陆    漂    移    学    说   , 出    版    了   《 海    陆    的    起    源   》 一    书   , 在    地    质    学    界    产    生    了    重    大    影    响   
 更    有    趣    的    是    一    位    名    叫    阿    瑟    林    斯    基    的    俄    裔    美    国    睡    眠    研    究    专    家   。 一    次   , 他    发    现    儿    子    在    睡    觉    的    时    候   , 眼    珠    忽    然    转    动    起    来   。 他    感    到    很    奇    怪   : 为    什    么    睡    觉    时    眼    珠    会    转    动   ? 这    会    不    会    与    做    梦    有    关   ? 会    是    什    么    关    系    呢   ? 阿    瑟    林    斯    基    带    着    一    连    串    的    疑    问   , 对    自    己    八    岁    的    儿    子    进    行    了    实    验   , 结    果    表    明   : 脑    电    波    的    变    化    与    做    梦    有    关   。 接    着   , 他    又    对    二    十    名    成    年    人    进    行    了    反    复    的    观    察    实    验   , 最    后    得    出    结    论   : 睡    眠    中    眼    珠    快    速    转    动   
 的    时    候   , 人    的    脑    电    波    也    会    发    生    较    大    的    变    化   , 这    是    人    最    容    易    做    梦    的    阶    段   。 阿    瑟    林    斯    基    的    研    究    成    果   , 成    为    心    理    学    家    研    究    做    梦    的    重    要    依    据   
 在    科    学    史    上   , 这    样    的    事    例    还    有    很    多   , 这    说    明    科    学    并    不    神    秘   , 真    理    并    不    遥    远   。 只    要    你    见    微    知    著   , 善    于    发    问    并    不    断    探    索   , 那    么   , 当    你    解    决    了    若    干    个    问    号    之    后   , 就    有    可    能    发    现    真    理   
 仿    照    课    文    的    写    法   , 用    具    体    事    例    说    明    一    个    观    点   , 如    有    志    者    事    竟    成    玩    也    能    玩    出    名    堂   
 詹    天    佑    是    我    国    杰    出    的    爱    国    工    程    师   。 从    北    京    到    张    家    口    这    一    段    铁    路   , 最    早    是    在    他    的    主    持    下    修    筑    成    功    的   。 这    是    第    一    条    完    全    由    我    国    的    工    程    技    术    人    员    设    计    施    工    的    铁    路    干    线   
 从    北    京    到    张    家    口    的    铁    路    长    两    百    千    米   , 是    联    结    华    北    和    西    北    的    交    通    要    道   。 当    时   , 清    政    府    刚    提    出    修    筑    的    计    划   , 一    些    帝    国    主    义    国    家    就    出    来    阻    挠   , 他    们    都    要    争    夺    这    条    铁    路    的    修    筑    权   , 想    进    一    步    控    制    我    国    的    北    部   。 帝    国    主    义    者    谁    也    不    肯    让    谁   , 事    情    争    持    了    好    久    得    不    到    解    决   。 他    们    最    后    提    出    一    个    条    件   : 清    政    府    如    果    用    本    国    的    工    程    师    来    修    筑    铁    路   , 他    们    就    不    再    过    问   。 他    们    以    为    这    样    一    要    挟   , 铁    路    就    无    法    动    工   , 最    后    还    得    求    助    于    他    们   。 帝    国    主    义    者    完    全    想    错    了   , 中    国    那    时    候    已    经    有    了    自    己    的    工    程    师   , 詹    天    佑    就    是    其    中    一    位   
 年   , 清    政    府    任    命    詹    天    佑    为    总    工    程    师   , 修    筑    从    北    京    到    张    家    口    的    铁    路   。 消    息    一    传    出    来   , 全    国    轰    动   , 大    家    说    这    一    回    咱    们    可    争    了    一    口    气   。 帝    国    主    义    者    却    认    为    这    是    个    笑    话   。 有    一    家    外    国    报    纸    轻    蔑    地    说   : 能    在    南    口    以    北    修    筑    铁    路    的    中    国    工    程    师    还    没    有    出    世    呢   。 原    来   , 从    南    口    往    北    过    居    庸    关    到    八    达    岭   , 一    路    都    是    高    山    深    涧   、 悬    崖    峭    壁   。 他    们    认    为   , 这    样    艰    巨    的    工    程   , 外    国    著    名    的    工    程    师    也    不    敢    轻    易    尝    试   , 至    于    中    国    人   , 是    无    论    如    何    也    完    成    不    了    的   
 詹    天    佑    不    怕    困    难   , 也    不    怕    嘲    笑   , 毅    然    接    受    了    任    务   , 马    上    开    始    勘    测    线    路   。 哪    里    要    开    山   , 哪    里    要    架    桥   , 哪    里    要    把    陡    坡    铲    平   , 哪    里    要    把    弯    度    改    小   , 都    要    经    过    勘    测   , 进    行    周    密    计    算   。 詹    天    佑    经    常    对    工    作    人    员    说   : 我    们    的    工    作    首    先    要    精    密   , 不    能    有    一    点    儿    马    虎   。 大    概    差    不    多    这    类    说    法    不    应    该    出    自    工    程    人    员    之    口   。 他    亲    自    带    着    学    生    和    工    人   , 扛    着    标    杆   , 背    着    经    纬    仪   , 在    峭    壁    上    定    点    制    图   。 塞    外    常    常    狂    风    怒    号   , 黄    沙    满    天   , 一    不    小    心    还    有    坠    入    深    谷    的    危    险   。 不    管    条    件    怎    样    恶    劣   , 詹    天    佑    始    终    坚    持    在    野    外    工    作   。 白    天   , 他    攀    山    越    岭   , 勘    测    线    路   ; 晚    上   , 他    就    在    油    灯    下    绘    图   , 计    算   。 为    了    寻    找    一    条    合    适    的    线    路   , 他    常    常    请    教    当    地    的    农    民   。 遇    到    困    难   , 他    总    是    想   : 这   
 是    中    国    人    自    己    修    筑    的    第    一    条    铁    路   , 一    定    要    把    它    修    好   , 否    则   , 不    但    惹    外    国    人    讥    笑   , 还   
 会    使    中    国    的    工    程    师    失    掉    信    心   
 铁    路    要    经    过    很    多    高    山   , 不    得    不    开    凿    隧    道   , 其    中    数    居    庸    关    和    八    达    岭    两    条    隧    道    的    工    程    最    艰    巨   。 居    庸    关    山    势    高   , 岩    层    厚   , 詹    天    佑    决    定    采    用    从    两    端    同    时    向    中    间    凿    进    的    办    法   。 山    顶    的    泉    水    往    下    渗   , 隧    道    里    满    是    泥    浆   , 工    地    上    没    有    抽    水    机   , 詹    天    佑    就    带    头    挑    着    水    桶    去    排    水   。 八    达    岭    隧    道    有    居    庸    关    隧    道    的    三    倍    长   。 他    跟    老    工    人    一    起    商    量   , 决    定    采    用    中    部    凿    井    法   , 先    从    山    顶    往    下    打    一    口    大    的    竖    井    和    一    口    小    的    竖    井   , 再    分    别    向    两    头    开    凿   , 外    面    两    端    也    同    时    施    工   , 把    工    期    缩    短    了    一    半   
 铁    路    经    过    青    龙    桥    附    近   , 坡    度    特    别    大   。 火    车    怎    样    才    能    爬    上    这    样    的    陡    坡    呢   ?  詹    天    佑    顺    着    山    势   , 设    计    了    一    种    人    字    形    线    路   。 北    上    的    列    车    到    了    南    口    就    用    两    个    火    车    头   , 一    个    在    前    边    拉   , 一    个    在    后    边    推   。 过    青    龙    桥    之    后   , 列    车    向    东    北    前    进   , 过    了    人    字    形    线    路    的    岔    道    口    就    倒    过    来   , 原    先    推    的    火    车    头    拉   , 原    先    拉    的    火    车    头    推   , 使    列    车    折    向    西    北    前    进   。 这    样    一    来   , 火    车    上    山    就    容    易    多    了   
 京    张    铁    路    不    满    四    年    就    全    线    竣    工    了   , 比    计    划    提    早    了    两    年   。 这    件    事    给    了     藐    视    中    国    的    帝    国    主    义    者    一    个    有    力    的    回    击   。 今    天   , 我    们    乘    火    车    去    八    达    岭   ,  过    青    龙    桥    车    站   , 可    以    看    到    一    座    铜    像   , 那    就    是    詹    天    佑    的    塑    像   
 本    文    选    自   《 十    年    制    学    校    小    学    课    本    试    用    本    语    文    第    十    册   》, 有    改    动   

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