1/288 <font color=red>bg</font> 09-07 18:43:01-09-07 18:43:06 Hello everyone,<br>2/288 <font color=red></font> 09-07 18:43:02-09-07 18:43:11 I am Li Yongde.<br>3/288 <font color=red>aaa</font> 09-07 18:43:02-09-07 18:43:06 Today, I will continue to guide you through Einstein's littl...<br>4/288 <font color=red>hp</font> 09-07 18:43:03-09-07 18:43:06 A Simple Explanation of Righteousness and General Relativity...<br>5/288 <font color=red></font> 09-07 18:43:04-09-07 18:43:13 In the previous episode,<br>6/288 <font color=red>n</font> 09-07 18:43:04-09-07 18:43:09 We introduced Einstein's life.<br>7/288 <font color=red>bg</font> 09-07 18:43:07-09-07 18:43:14 This time, we're going to talk about how Einstein thought th...<br>8/288 <font color=red></font> 09-07 18:43:08-09-07 18:43:13 In the introduction of this pamphlet,<br>9/288 <font color=red>aaa</font> 09-07 18:43:08-09-07 18:43:13 Einstein mentioned Euclid, the ancient Greek mathematician w...<br>10/288 <font color=red>hp</font> 09-07 18:43:09-09-07 18:43:14 Euclid wrote a book of geometry.<br>11/288 <font color=red>xss</font> 09-07 18:43:10-09-07 18:43:25 In this book,<br>12/288 <font color=red>n</font> 09-07 18:43:14-09-07 18:43:19 Euclid abstracted the concepts of points, lines, and surface...<br>13/288 <font color=red></font> 09-07 18:43:14-09-07 18:43:19 And five postulates were proposed.<br>14/288 <font color=red></font> 09-07 18:43:15-09-07 18:43:19 What are axioms?<br>15/288 <font color=red>aaa</font> 09-07 18:43:16-09-07 18:43:19 These are the five axioms that Euclid used as a starting poi...<br>16/288 <font color=red>de</font> 09-07 18:43:17-09-07 18:43:25 Determine a straight line.<br>17/288 <font color=red></font> 09-07 18:43:17-09-07 18:43:25 II.<br>18/288 <font color=red>bg</font> 09-07 18:43:18-09-07 18:43:25 Any line segment can be extended into a straight line.<br>19/288 <font color=red>hp</font> 09-07 18:43:19-09-07 18:43:25 Third,<br>20/288 <font color=red></font> 09-07 18:43:20-09-07 18:43:25 With a point as the center,<br>21/288 <font color=red></font> 09-07 18:43:22-09-07 18:43:30 A line segment can form a circle with a radius.<br>22/288 <font color=red>n</font> 09-07 18:43:24-09-07 18:43:25 Fourth,<br>23/288 <font color=red>aaa</font> 09-07 18:43:25-09-07 18:43:30 All right angles are equal.<br>24/288 <font color=red>bg</font> 09-07 18:43:25-09-07 18:43:30 A little bit outside the straight line,<br>25/288 <font color=red></font> 09-07 18:43:26-09-07 18:43:35 And there is only one line that is parallel to the known str...<br>26/288 <font color=red>hp</font> 09-07 18:43:27-09-07 18:43:30 Based on these five assumptions,<br>27/288 <font color=red>n</font> 09-07 18:43:28-09-07 18:43:30 Through rigorous logical reasoning,<br>28/288 <font color=red>de</font> 09-07 18:43:28-09-07 18:43:35 Euripides has reached many conclusions,<br>29/288 <font color=red></font> 09-07 18:43:29-09-07 18:43:35 These conclusions are called theorems.<br>30/288 <font color=red>xss</font> 09-07 18:43:30-09-07 18:43:45 Based on the collective,<br>31/288 <font color=red>bg</font> 09-07 18:43:31-09-07 18:43:35 Based on the theorem,<br>32/288 <font color=red>aaa</font> 09-07 18:43:32-09-07 18:43:35 Eurydice,<br>33/288 <font color=red></font> 09-07 18:43:32-09-07 18:43:35 Built a geometric structure.<br>34/288 <font color=red>hp</font> 09-07 18:43:33-09-07 18:43:35 This is Euclidean geometry.<br>35/288 <font color=red>n</font> 09-07 18:43:35-09-07 18:43:45 Are Euclidean geometry really true?<br>36/288 <font color=red>bg</font> 09-07 18:43:36-09-07 18:43:45 Einstein said,<br>37/288 <font color=red></font> 09-07 18:43:38-09-07 18:43:45 This question is meaningless.<br>38/288 <font color=red></font> 09-07 18:43:39-09-07 18:43:45 Because these five communes cannot be proven.<br>39/288 <font color=red>aaa</font> 09-07 18:43:40-09-07 18:43:45 Cannot be refuted.<br>40/288 <font color=red>hp</font> 09-07 18:43:42-09-07 18:43:45 Based on these five assumptions,<br>41/288 <font color=red></font> 09-07 18:43:44-09-07 18:43:54 You can only reach the conclusion after that.<br>42/288 <font color=red>de</font> 09-07 18:43:45-09-07 18:43:54 However, you cannot discard these assumptions.<br>43/288 <font color=red>bg</font> 09-07 18:43:45-09-07 18:43:54 Otherwise, geometry will become meaningless.<br>44/288 <font color=red>n</font> 09-07 18:43:48-09-07 18:43:54 At different times,<br>45/288 <font color=red></font> 09-07 18:43:48-09-07 18:43:54 We definitely need to use different sets.<br>46/288 <font color=red>aaa</font> 09-07 18:43:49-09-07 18:43:54 For example, Euclidean geometry tells us that the sum of the...<br>47/288 <font color=red></font> 09-07 18:43:51-09-07 18:43:54 That's the case on paper.<br>48/288 <font color=red>hp</font> 09-07 18:43:53-09-07 18:43:54 However, if we draw a triangle on a hyperbolic surface,<br>49/288 <font color=red>xss</font> 09-07 18:43:54-09-07 18:44:15 Its interior angles will be less than 180 degrees.<br>50/288 <font color=red>bg</font> 09-07 18:43:55-09-07 18:44:03 If you draw a triangle on a sphere,<br>51/288 <font color=red></font> 09-07 18:43:56-09-07 18:44:03 The angles are also greater than 180 degrees.<br>52/288 <font color=red>n</font> 09-07 18:43:56-09-07 18:44:03 At this point, we must abandon the assumptions of Euclidean ...<br>53/288 <font color=red></font> 09-07 18:43:58-09-07 18:44:03 And adopt the geometry of Roche or Riemannian geometry.<br>54/288 <font color=red>aaa</font> 09-07 18:43:59-09-07 18:44:03 Whether it's Euclidean geometry or Riemannian geometry,<br>55/288 <font color=red></font> 09-07 18:44:01-09-07 18:44:09 When the triangle we draw is very small,<br>56/288 <font color=red>de</font> 09-07 18:44:02-09-07 18:44:09 It will eventually degenerate into Euclidean geometry.<br>57/288 <font color=red>hp</font> 09-07 18:44:03-09-07 18:44:09 Einstein's opening like this,<br>58/288 <font color=red>bg</font> 09-07 18:44:04-09-07 18:44:15 Because his proposed theories of special and general relativ...<br>59/288 <font color=red></font> 09-07 18:44:04-09-07 18:44:09 All are based on assumptions.<br>60/288 <font color=red>aaa</font> 09-07 18:44:05-09-07 18:44:09 Just, his thinking was more profound and universal than Newt...<br>61/288 <font color=red></font> 09-07 18:44:07-09-07 18:44:09 And when the speed is far less than the speed of light,<br>62/288 <font color=red>n</font> 09-07 18:44:08-09-07 18:44:15 Or when the object is not very heavy?<br>63/288 <font color=red>hp</font> 09-07 18:44:10-09-07 18:44:15 The pattern will revert to Newton's laws.<br>64/288 <font color=red></font> 09-07 18:44:11-09-07 18:44:21 Okay, let's start with the Euclidean geometry of spacetime f...<br>65/288 <font color=red>aaa</font> 09-07 18:44:12-09-07 18:44:15 In 1687,<br>66/288 <font color=red></font> 09-07 18:44:12-09-07 18:44:16 Newton wrote the book "Principia Mathematica," which is cons...<br>67/288 <font color=red>de</font> 09-07 18:44:13-09-07 18:44:21 He said, "absolute space."<br>68/288 <font color=red></font> 09-07 18:44:15-09-07 18:44:21 In essence,<br>69/288 <font color=red>bg</font> 09-07 18:44:16-09-07 18:44:21 is independent of any external factor,<br>70/288 <font color=red>n</font> 09-07 18:44:17-09-07 18:44:21 He never exercises.<br>71/288 <font color=red>hp</font> 09-07 18:44:18-09-07 18:44:21 And it will never change,<br>72/288 <font color=red>aaa</font> 09-07 18:44:18-09-07 18:44:21 Absolute real time mathematics.<br>73/288 <font color=red>xss</font> 09-07 18:44:19-09-07 18:44:29 In essence,<br>74/288 <font color=red></font> 09-07 18:44:21-09-07 18:44:29 It is uniformly flowing.<br>75/288 <font color=red>bg</font> 09-07 18:44:22-09-07 18:44:29 Independent of any external factors.<br>76/288 <font color=red></font> 09-07 18:44:24-09-07 18:44:29 When Newton wrote this sentence,<br>77/288 <font color=red>aaa</font> 09-07 18:44:25-09-07 18:44:29 Maybe you don't feel like you have discovered anything new.<br>78/288 <font color=red>n</font> 09-07 18:44:26-09-07 18:44:29 Because this is what has been happening for thousands of yea...<br>79/288 <font color=red>de</font> 09-07 18:44:26-09-07 18:44:36 The world in people's minds is absolutely empty.<br>80/288 <font color=red></font> 09-07 18:44:28-09-07 18:44:45 Newton, on the other hand, simply expressed this idea in mor...<br>81/288 <font color=red>hp</font> 09-07 18:44:29-09-07 18:44:36 In the hundred years after Newton,<br>82/288 <font color=red>bg</font> 09-07 18:44:30-09-07 18:44:36 Most people think this is obvious.<br>83/288 <font color=red></font> 09-07 18:44:31-09-07 18:44:36 In other words,<br>84/288 <font color=red>aaa</font> 09-07 18:44:31-09-07 18:44:36 Absolute spacetime is a hypothetical concept.<br>85/288 <font color=red></font> 09-07 18:44:34-09-07 18:44:37 Can we find absolute space and time?<br>86/288 <font color=red>n</font> 09-07 18:44:34-09-07 18:44:36 Imagine a scenario where...<br>87/288 <font color=red>xss</font> 09-07 18:44:35-09-07 18:44:53 In the vast expanse of space,<br>88/288 <font color=red>bg</font> 09-07 18:44:37-09-07 18:44:45 We are piloting a spaceship, drifting through the cosmos.<br>89/288 <font color=red></font> 09-07 18:44:39-09-07 18:44:45 Can we determine how fast the spaceship is moving at this mo...<br>90/288 <font color=red>hp</font> 09-07 18:44:40-09-07 18:44:45 Unfortunately,<br>91/288 <font color=red></font> 09-07 18:44:41-09-07 18:44:45 If there are no reference objects around,<br>92/288 <font color=red>n</font> 09-07 18:44:43-09-07 18:44:45 We can't do that.<br>93/288 <font color=red>aaa</font> 09-07 18:44:44-09-07 18:44:45 Suppose there is a very stable ship,<br>94/288 <font color=red>de</font> 09-07 18:44:45-09-07 18:44:53 In the cabin,<br>95/288 <font color=red>bg</font> 09-07 18:44:45-09-07 18:44:53 If you don't look outside,<br>96/288 <font color=red></font> 09-07 18:44:47-09-07 18:44:53 Through any mechanical experiment in the cabin,<br>97/288 <font color=red>hp</font> 09-07 18:44:48-09-07 18:44:53 We couldn't measure the speed of the boat relative to the sh...<br>98/288 <font color=red></font> 09-07 18:44:49-09-07 18:44:53 This is because Newton's laws are variational.<br>99/288 <font color=red>aaa</font> 09-07 18:44:51-09-07 18:44:53 That is to say,<br>100/288 <font color=red>n</font> 09-07 18:44:52-09-07 18:44:53 In any inertial reference frame,<br>101/288 <font color=red></font> 09-07 18:44:53-09-07 18:45:03 The forms of Newton's laws are all the same.<br>102/288 <font color=red>bg</font> 09-07 18:44:53-09-07 18:45:03 This is called Galileo's principle of relativity.<br>103/288 <font color=red>hp</font> 09-07 18:44:54-09-07 18:45:03 The earliest mention of this can be found in Galileo's Dialo...<br>104/288 <font color=red></font> 09-07 18:44:55-09-07 18:45:03 Newton's laws tell us that,<br>105/288 <font color=red></font> 09-07 18:44:57-09-07 18:45:03 Objects at rest tend to stay at rest, and objects in motion ...<br>106/288 <font color=red>aaa</font> 09-07 18:44:58-09-07 18:45:03 But he couldn't tell us,<br>107/288 <font color=red>n</font> 09-07 18:44:59-09-07 18:45:03 How fast is the movement? It's not that important.<br>108/288 <font color=red>de</font> 09-07 18:44:59-09-07 18:45:03 Whether or not we can find Newton,<br>109/288 <font color=red>xss</font> 09-07 18:45:01-09-07 18:45:22 Assuming that absolute spacetime exists.<br>110/288 <font color=red>bg</font> 09-07 18:45:04-09-07 18:45:15 And if a spaceship has a relative velocity of v with respect...<br>111/288 <font color=red>hp</font> 09-07 18:45:04-09-07 18:45:10 Then, the simple relationship of speed addition and subtract...<br>112/288 <font color=red>n</font> 09-07 18:45:05-09-07 18:45:10 In the eyes of Newton and Galileo,<br>113/288 <font color=red></font> 09-07 18:45:06-09-07 18:45:10 This is obvious.<br>114/288 <font color=red>aaa</font> 09-07 18:45:07-09-07 18:45:10 They were convinced of the existence of absolute space.<br>115/288 <font color=red></font> 09-07 18:45:07-09-07 18:45:15 But you don't necessarily have to find him.<br>116/288 <font color=red>de</font> 09-07 18:45:10-09-07 18:45:15 Absolute space is like a mythical creator,<br>117/288 <font color=red></font> 09-07 18:45:10-09-07 18:45:22 Maxwell discovered the equations of electromagnetism.<br>118/288 <font color=red>aaa</font> 09-07 18:45:11-09-07 18:45:15 And after it was proposed that light is just an electromagne...<br>119/288 <font color=red></font> 09-07 18:45:12-09-07 18:45:15 The problem of finding absolute space has become very urgent...<br>120/288 <font color=red>hp</font> 09-07 18:45:13-09-07 18:45:15 Maxwell proposed a set of equations,<br>121/288 <font color=red>n</font> 09-07 18:45:15-09-07 18:45:22 He told us,<br>122/288 <font color=red>bg</font> 09-07 18:45:15-09-07 18:45:22 A changing electric field can produce a magnetic field,<br>123/288 <font color=red></font> 09-07 18:45:16-09-07 18:45:22 Changing magnetic fields can generate electric fields,<br>124/288 <font color=red></font> 09-07 18:45:17-09-07 18:45:22 If electric and magnetic fields are mutually excited,<br>125/288 <font color=red>hp</font> 09-07 18:45:19-09-07 18:45:22 This will create a fluctuation.<br>126/288 <font color=red>aaa</font> 09-07 18:45:20-09-07 18:45:22 This is an electromagnetic wave.<br>127/288 <font color=red>de</font> 09-07 18:45:21-09-07 18:45:29 And, according to the set of electromagnetic equations,<br>128/288 <font color=red>bg</font> 09-07 18:45:23-09-07 18:45:29 The ability to accurately calculate the speed of electromagn...<br>129/288 <font color=red></font> 09-07 18:45:24-09-07 18:45:29 This is the speed of light.<br>130/288 <font color=red>n</font> 09-07 18:45:26-09-07 18:45:29 Therefore, Maxwell said that...<br>131/288 <font color=red></font> 09-07 18:45:26-09-07 18:45:29 Light is a type of electromagnetic wave.<br>132/288 <font color=red></font> 09-07 18:45:27-09-07 18:45:36 Mechanical waves are transmitted in a medium,<br>133/288 <font color=red>aaa</font> 09-07 18:45:28-09-07 18:45:29 For example, sound waves are transmitted in the air.<br>134/288 <font color=red>hp</font> 09-07 18:45:29-09-07 18:45:29 The rate of ascent is actually relative to the speed of air.<br>135/288 <font color=red>xss</font> 09-07 18:45:29-09-07 18:45:42 As the saying goes,<br>136/288 <font color=red>bg</font> 09-07 18:45:30-09-07 18:45:36 Following the wind,<br>137/288 <font color=red>n</font> 09-07 18:45:31-09-07 18:45:36 It is not a good day.<br>138/288 <font color=red>aaa</font> 09-07 18:45:32-09-07 18:45:36 And the person who heard it was Zhang Wen, because he called...<br>139/288 <font color=red></font> 09-07 18:45:32-09-07 18:45:36 Fast speed,<br>140/288 <font color=red>hp</font> 09-07 18:45:33-09-07 18:45:36 However, light can also propagate in a vacuum.<br>141/288 <font color=red></font> 09-07 18:45:35-09-07 18:45:47 It doesn't rely on a medium like air or water, unlike mechan...<br>142/288 <font color=red>de</font> 09-07 18:45:36-09-07 18:45:46 So, who is the speed of light relative to?<br>143/288 <font color=red>bg</font> 09-07 18:45:37-09-07 18:45:42 We know that,<br>144/288 <font color=red>n</font> 09-07 18:45:38-09-07 18:45:42 If the Galilean transformation is correct,<br>145/288 <font color=red></font> 09-07 18:45:38-09-07 18:45:42 Relative to different reference frames,<br>146/288 <font color=red></font> 09-07 18:45:41-09-07 18:45:47 The speed of light should not be the same.<br>147/288 <font color=red>aaa</font> 09-07 18:45:41-09-07 18:45:46 This contradicts Maxwell's equations, which calculate a cons...<br>148/288 <font color=red>hp</font> 09-07 18:45:42-09-07 18:45:46 Everyone, please pay attention.<br>149/288 <font color=red>bg</font> 09-07 18:45:43-09-07 18:45:53 This is a very important question that cannot be ignored.<br>150/288 <font color=red></font> 09-07 18:45:44-09-07 18:45:52 If there were a lighthouse on Earth,<br>151/288 <font color=red>n</font> 09-07 18:45:46-09-07 18:45:52 Sent light into the universe,<br>152/288 <font color=red>xss</font> 09-07 18:45:47-09-07 18:46:07 The Earth rotates around the Sun at a certain speed.<br>153/288 <font color=red>aaa</font> 09-07 18:45:47-09-07 18:45:53 Is it relative to the Earth or relative to the Sun?<br>154/288 <font color=red>hp</font> 09-07 18:45:49-09-07 18:45:53 No matter what answer you give,<br>155/288 <font color=red>de</font> 09-07 18:45:52-09-07 18:45:58 We can all question,<br>156/288 <font color=red></font> 09-07 18:45:52-09-07 18:45:58 Why isn't it another situation?<br>157/288 <font color=red></font> 09-07 18:45:53-09-07 18:45:58 A reasonable guess is that,<br>158/288 <font color=red>n</font> 09-07 18:45:54-09-07 18:45:58 Perhaps the speed of light is relative to the source.<br>159/288 <font color=red></font> 09-07 18:45:55-09-07 18:45:58 If a lighthouse on Earth emits light,<br>160/288 <font color=red>bg</font> 09-07 18:45:57-09-07 18:46:03 Therefore, the speed of light is relative to Earth.<br>161/288 <font color=red>aaa</font> 09-07 18:45:57-09-07 18:45:58 If the sun emits light,<br>162/288 <font color=red>hp</font> 09-07 18:45:58-09-07 18:46:03 Therefore, the speed of light is relative to the sun.<br>163/288 <font color=red>n</font> 09-07 18:45:59-09-07 18:46:03 However, this idea was quickly dismissed by people.<br>164/288 <font color=red></font> 09-07 18:46:00-09-07 18:46:07 Because there are many binary stars in the universe,<br>165/288 <font color=red>aaa</font> 09-07 18:46:01-09-07 18:46:03 Two stars or one star and a dark star.<br>166/288 <font color=red></font> 09-07 18:46:01-09-07 18:46:07 For example, white dwarfs.<br>167/288 <font color=red>de</font> 09-07 18:46:02-09-07 18:46:07 Rotating around each other.<br>168/288 <font color=red></font> 09-07 18:46:03-09-07 18:46:13 Like the Sirius we know, it is a binary star.<br>169/288 <font color=red>bg</font> 09-07 18:46:04-09-07 18:46:13 Normally, when we see Sirius A, there is a...<br>170/288 <font color=red>aaa</font> 09-07 18:46:04-09-07 18:46:07 There is also a white dwarf star.<br>171/288 <font color=red>hp</font> 09-07 18:46:06-09-07 18:46:07 It is Paradise.<br>172/288 <font color=red>n</font> 09-07 18:46:07-09-07 18:46:13 They revolve around each other.<br>173/288 <font color=red></font> 09-07 18:46:08-09-07 18:46:13 For binary star systems,<br>174/288 <font color=red></font> 09-07 18:46:09-09-07 18:46:13 In different locations,<br>175/288 <font color=red>aaa</font> 09-07 18:46:11-09-07 18:46:13 The speed of a star relative to Earth can vary.<br>176/288 <font color=red>hp</font> 09-07 18:46:12-09-07 18:46:13 Okay, let's say a and b are two stars that orbit each other.<br>177/288 <font color=red>de</font> 09-07 18:46:12-09-07 18:46:21 The Earth is below the left side of the binary star,<br>178/288 <font color=red>xss</font> 09-07 18:46:13-09-07 18:46:36 So, when b moves to the top left corner?<br>179/288 <font color=red>bg</font> 09-07 18:46:14-09-07 18:46:21 Approaching Earth,<br>180/288 <font color=red></font> 09-07 18:46:16-09-07 18:46:21 When it's in the lower right corner, it will move away from ...<br>181/288 <font color=red>aaa</font> 09-07 18:46:17-09-07 18:46:21 If the speed of light is relative to the source,<br>182/288 <font color=red></font> 09-07 18:46:18-09-07 18:46:21 Then the light emitted by b is faster.<br>183/288 <font color=red>n</font> 09-07 18:46:18-09-07 18:46:21 The light emitted from the tip of a brush is slower.<br>184/288 <font color=red></font> 09-07 18:46:20-09-07 18:46:29 The arrival time will also vary.<br>185/288 <font color=red>hp</font> 09-07 18:46:21-09-07 18:46:29 In other words,<br>186/288 <font color=red>bg</font> 09-07 18:46:22-09-07 18:46:36 The light that arrives at Earth from the binary star system ...<br>187/288 <font color=red>aaa</font> 09-07 18:46:24-09-07 18:46:29 When we observe a binary star,<br>188/288 <font color=red></font> 09-07 18:46:25-09-07 18:46:29 Each star should have a light arc.<br>189/288 <font color=red></font> 09-07 18:46:26-09-07 18:46:29 It's like lighting a cigarette when you were young,<br>190/288 <font color=red>n</font> 09-07 18:46:26-09-07 18:46:29 Spinning in the night,<br>191/288 <font color=red>de</font> 09-07 18:46:29-09-07 18:46:36 Due to visual persistence,<br>192/288 <font color=red></font> 09-07 18:46:29-09-07 18:46:36 We will feel that the fireworks are drawing a bright line in...<br>193/288 <font color=red>hp</font> 09-07 18:46:30-09-07 18:46:36 However, astronomical observations show that both binary sta...<br>194/288 <font color=red></font> 09-07 18:46:31-09-07 18:46:36 No lake,<br>195/288 <font color=red>n</font> 09-07 18:46:33-09-07 18:46:36 This can only mean that the speed of light is independent of...<br>196/288 <font color=red>aaa</font> 09-07 18:46:34-09-07 18:46:36 It seems like we have to find a medium for light.<br>197/288 <font color=red></font> 09-07 18:46:34-09-07 18:46:45 Scientists have come up with the idea of ancient Greeks,<br>198/288 <font color=red>bg</font> 09-07 18:46:37-09-07 18:46:45 Aristotle,<br>199/288 <font color=red>hp</font> 09-07 18:46:38-09-07 18:46:45 He once proposed that there was a substance permeating the u...<br>200/288 <font color=red></font> 09-07 18:46:38-09-07 18:46:45 Ethereum is very transparent.<br>201/288 <font color=red>n</font> 09-07 18:46:39-09-07 18:46:45 Even the light from distant stars can still reach Earth.<br>202/288 <font color=red></font> 09-07 18:46:41-09-07 18:46:45 With this magical substance, ether,<br>203/288 <font color=red>aaa</font> 09-07 18:46:42-09-07 18:46:45 I finally understand the logic.<br>204/288 <font color=red>de</font> 09-07 18:46:43-09-07 18:46:50 The speed of light is 300,000 kilometers per second.<br>205/288 <font color=red>xss</font> 09-07 18:46:43-09-07 18:47:00 And the Earth is traveling through space.<br>206/288 <font color=red>bg</font> 09-07 18:46:46-09-07 18:46:50 Ether has a speed relative to Earth.<br>207/288 <font color=red>hp</font> 09-07 18:46:46-09-07 18:46:50 This is called ether wind.<br>208/288 <font color=red>n</font> 09-07 18:46:47-09-07 18:46:50 If we were to launch a beam of light in the direction of the...<br>209/288 <font color=red></font> 09-07 18:46:48-09-07 18:46:55 Then this light will be quite fast.<br>210/288 <font color=red></font> 09-07 18:46:49-09-07 18:46:55 More than 30,000 kilometers per second.<br>211/288 <font color=red>aaa</font> 09-07 18:46:49-09-07 18:46:50 What if we sent a beam of light in the opposite direction to...<br>212/288 <font color=red></font> 09-07 18:46:50-09-07 18:47:00 So, the speed of light will be relatively slow.<br>213/288 <font color=red>bg</font> 09-07 18:46:51-09-07 18:47:00 Less than 30,000 kilometers per second.<br>214/288 <font color=red>hp</font> 09-07 18:46:53-09-07 18:46:55 At this point,<br>215/288 <font color=red>n</font> 09-07 18:46:54-09-07 18:46:55 Scientists are once again amazed by their own unparalleled i...<br>216/288 <font color=red>aaa</font> 09-07 18:46:54-09-07 18:46:55 Conquered,<br>217/288 <font color=red>de</font> 09-07 18:46:55-09-07 18:47:05 The remaining work is to conduct an experiment.<br>218/288 <font color=red></font> 09-07 18:46:56-09-07 18:47:05 Find the Earth's speed relative to its own axis.<br>219/288 <font color=red>aaa</font> 09-07 18:46:57-09-07 18:47:00 The inertial frame of reference is the absolute space that N...<br>220/288 <font color=red></font> 09-07 18:46:57-09-07 18:47:06 I conducted an experiment with Edward More on the topic of "...<br>221/288 <font color=red>n</font> 09-07 18:47:00-09-07 18:47:00 This is the famous Michelson-Morley experiment.<br>222/288 <font color=red>hp</font> 09-07 18:47:00-09-07 18:47:05 They first shone a beam of light onto a piece of glass,<br>223/288 <font color=red>bg</font> 09-07 18:47:01-09-07 18:47:06 The back is also coated with a thin layer of silver.<br>224/288 <font color=red>aaa</font> 09-07 18:47:02-09-07 18:47:06 That's right, the glass can transmit some light.<br>225/288 <font color=red>n</font> 09-07 18:47:04-09-07 18:47:06 Light,<br>226/288 <font color=red></font> 09-07 18:47:05-09-07 18:47:14 Can also reflect some light.<br>227/288 <font color=red>xss</font> 09-07 18:47:06-09-07 18:47:43 This is called a semi-reflective, semi-transmissive lens whe...<br>228/288 <font color=red></font> 09-07 18:47:06-09-07 18:47:14 There was interference on the screen.<br>229/288 <font color=red>hp</font> 09-07 18:47:07-09-07 18:47:14 According to Michaelis and More's idea,<br>230/288 <font color=red>de</font> 09-07 18:47:08-09-07 18:47:14 Due to the existence of Ether,<br>231/288 <font color=red>bg</font> 09-07 18:47:10-09-07 18:47:18 The speed of light in different directions may vary slightly...<br>232/288 <font color=red>aaa</font> 09-07 18:47:11-09-07 18:47:14 Because of the movement of light in the ether,<br>233/288 <font color=red></font> 09-07 18:47:11-09-07 18:47:15 It's like a small boat moving downstream at a constant speed...<br>234/288 <font color=red>n</font> 09-07 18:47:12-09-07 18:47:18 The ship sailing against the current,<br>235/288 <font color=red></font> 09-07 18:47:14-09-07 18:47:24 The time it takes to cross the river by boat is different fr...<br>236/288 <font color=red>hp</font> 09-07 18:47:15-09-07 18:47:20 When two beams of light overlap on the observation screen, i...<br>237/288 <font color=red>aaa</font> 09-07 18:47:16-09-07 18:47:20 You can see the interference patterns by simply looking thro...<br>238/288 <font color=red>de</font> 09-07 18:47:17-09-07 18:47:24 However, if a light path's propagation time is slightly long...<br>239/288 <font color=red></font> 09-07 18:47:17-09-07 18:47:28 Then the stripes will appear to move left or right.<br>240/288 <font color=red></font> 09-07 18:47:18-09-07 18:47:24 This experiment has a very high accuracy.<br>241/288 <font color=red>bg</font> 09-07 18:47:20-09-07 18:47:28 Even if the two light beams have a very small difference in ...<br>242/288 <font color=red>n</font> 09-07 18:47:21-09-07 18:47:24 You can all see the movement of the stripes.<br>243/288 <font color=red>hp</font> 09-07 18:47:22-09-07 18:47:24 Due to the Earth's rotation around the sun,<br>244/288 <font color=red>aaa</font> 09-07 18:47:23-09-07 18:47:28 Sometimes to the east,<br>245/288 <font color=red></font> 09-07 18:47:25-09-07 18:47:30 Sometimes to the west,<br>246/288 <font color=red></font> 09-07 18:47:26-09-07 18:47:32 The Earth cannot always be at rest relative to a fixed ether...<br>247/288 <font color=red>hp</font> 09-07 18:47:26-09-07 18:47:28 No matter which direction the wind blows,<br>248/288 <font color=red>n</font> 09-07 18:47:27-09-07 18:47:28 When we rotate the workbench ninety degrees,<br>249/288 <font color=red>de</font> 09-07 18:47:28-09-07 18:47:37 Light traveling horizontally and vertically will exchange,<br>250/288 <font color=red>bg</font> 09-07 18:47:29-09-07 18:47:37 The time it takes for the two light paths to travel has chan...<br>251/288 <font color=red>aaa</font> 09-07 18:47:32-09-07 18:47:37 Then, we will inevitably observe the movement of stripes.<br>252/288 <font color=red>hp</font> 09-07 18:47:33-09-07 18:47:37 According to Michael's vision and estimation,<br>253/288 <font color=red></font> 09-07 18:47:34-09-07 18:47:46 They should be able to observe a movement equivalent to 0.03...<br>254/288 <font color=red>n</font> 09-07 18:47:34-09-07 18:47:37 But the result was disappointing to them.<br>255/288 <font color=red></font> 09-07 18:47:35-09-07 18:47:43 After rotating the experimental table, the interference patt...<br>256/288 <font color=red></font> 09-07 18:47:37-09-07 18:47:42 Still,<br>257/288 <font color=red>aaa</font> 09-07 18:47:38-09-07 18:47:43 Are the clauses moving too little?<br>258/288 <font color=red>bg</font> 09-07 18:47:39-09-07 18:47:47 Later, they used a reflective method to expand the light bar...<br>259/288 <font color=red>hp</font> 09-07 18:47:40-09-07 18:47:43 Theoretically, the stripes should move by zero point four.<br>260/288 <font color=red>n</font> 09-07 18:47:42-09-07 18:47:43 And the accuracy of the instrument is 0.1 millimeters.<br>261/288 <font color=red>de</font> 09-07 18:47:43-09-07 18:47:51 But the result is still no movement of stripes.<br>262/288 <font color=red></font> 09-07 18:47:43-09-07 18:47:47 Finally, Michael and More reluctantly announced that...<br>263/288 <font color=red>aaa</font> 09-07 18:47:44-09-07 18:47:47 No matter how, the interference stripes are completely invis...<br>264/288 <font color=red></font> 09-07 18:47:45-09-07 18:47:55 The Michelson-Morley experiment, which was designed to detec...<br>265/288 <font color=red>hp</font> 09-07 18:47:46-09-07 18:47:48 Newton assumed the existence of absolute time and space.<br>266/288 <font color=red>xss</font> 09-07 18:47:46-09-07 18:48:11 According to the calculation of light speed based on electro...<br>267/288 <font color=red>n</font> 09-07 18:47:47-09-07 18:47:50 People assume that the speed of light is the speed of light ...<br>268/288 <font color=red></font> 09-07 18:47:48-09-07 18:48:01 Therefore, absolute space and time or the ether can be found...<br>269/288 <font color=red>bg</font> 09-07 18:47:49-09-07 18:47:57 However, all experiments to find the state of affairs have f...<br>270/288 <font color=red></font> 09-07 18:47:49-09-07 18:47:55 The speed of light always seems to be constant.<br>271/288 <font color=red>aaa</font> 09-07 18:47:50-09-07 18:47:53 This is where the constancy of light speed and Galilean tran...<br>272/288 <font color=red>hp</font> 09-07 18:47:51-09-07 18:47:55 That is, Newton's assumptions led to results that were incon...<br>273/288 <font color=red>n</font> 09-07 18:47:52-09-07 18:47:58 Just like according to Euclid's theory,<br>274/288 <font color=red>de</font> 09-07 18:47:54-09-07 18:48:05 The sum of the angles in a triangle is 180 degrees.<br>275/288 <font color=red>aaa</font> 09-07 18:47:56-09-07 18:48:03 But we drew a triangle in space.<br>276/288 <font color=red></font> 09-07 18:47:58-09-07 18:48:05 The angles inside are not 180 degrees.<br>277/288 <font color=red>hp</font> 09-07 18:47:59-09-07 18:48:05 Maybe it's time to propose a new hypothesis.<br>278/288 <font color=red></font> 09-07 18:48:01-09-07 18:48:06 These theories were the most cutting-edge physics theories o...<br>279/288 <font color=red>bg</font> 09-07 18:48:02-09-07 18:48:11 During his teenage years, when Einstein was still in high sc...<br>280/288 <font color=red>n</font> 09-07 18:48:05-09-07 18:48:11 Read a lot of books,<br>281/288 <font color=red></font> 09-07 18:48:06-09-07 18:48:17 I understand all the above questions.<br>282/288 <font color=red>aaa</font> 09-07 18:48:07-09-07 18:48:11 After Einstein graduated,<br>283/288 <font color=red>de</font> 09-07 18:48:08-09-07 18:48:17 While discussing issues in the Academy of Olympia,<br>284/288 <font color=red></font> 09-07 18:48:08-09-07 18:48:11 Einstein finally overturned Newton's assumptions.<br>285/288 <font color=red>hp</font> 09-07 18:48:09-09-07 18:48:11 Proposed his own theory of space and time.<br>286/288 <font color=red></font> 09-07 18:48:11-09-07 18:48:17 How did Einstein say it?<br>287/288 <font color=red>bg</font> 09-07 18:48:12-09-07 18:48:17 Follow me,<br>288/288 <font color=red>aaa</font> 09-07 18:48:13-09-07 18:48:17 We will continue our discussion on relativity in the next is...<br>