"Mountain Chief, in this way, am I considered to have succeeded~? Then what you promised me at the beginning will count! ”

Hearing Li Zexuan's affirmation, Mo Lingwei suddenly became excited and hurriedly said.

Li Zexuan chuckled and said, "Hehe, this is still far from success!" At the beginning, I said that I would let you build an astronomical telescope, Miss Mo, don't you think that with this little thing, you can see the moon in the sky~? ”

Mo Lingwei blinked curiously and said, "Why can't it work?" My clairvoyance can already see far away, can't I use it to see the moon~? ”

"Of course not!"

Seeing that Yan Shaoning next to him was also puzzled, Li Zexuan had to patiently explain to him: "I told you before that the magnification of this clairvoyance is related to the focal length of the objective lens and eyepiece, and the clairvoyance you are doing now has a magnification of about seven to eight times at most, that is to say, with this person who looks a hundred zhang away, that is, he is observing at a distance similar to about ten to twelve zhang, and the moon is about 880,000 miles away from us, do you say that with this thing, can we see what the moon looks like?" ”

(Usually the moon is about 400,000 kilometers away from the earth, in the Tang Dynasty, it was Li Shimin's double step (one step on the left and right feet) as the size standard, called "step", and stipulated that 300 steps are one mile, one-fifth of a "step" - one foot, Tang Dynasty - the ruler is now 0.303 meters, one mile is 454 meters, which is equivalent to the distance between the earth and the moon is almost equivalent to 880,000 li in the Tang Dynasty)

"Eight hundred and eighty thousand miles? How far is that~? ”

After hearing this, the two were speechless, Yan Shaoning thought for a while and asked, "Xiao Xuan, according to your meaning, do we only need to increase the magnification of clairvoyance next~?" ”

Li Zexuan pondered his chin and replied: "Well, but it's not just a matter of increasing the magnification, when the magnification is too high, the image of the clairvoyant will eventually be distorted, you must find a way to reduce the problem of imaging distortion, otherwise the magnification is useless~!" ”

Mo Lingwei frowned and said puzzledly: "Mountain Chief, what is imaging distortion?" ”

It's no wonder that she is unfamiliar, mainly because this knowledge has not been mentioned in the physics textbook of the first volume.

Li Zexuan organized a language and explained: "I told you the imaging principle of the convex lens before, in fact, those are the cases when the rays are close to the central optical axis, but in fact, there are always some rays that are not close to the central optical axis, they are at the edge of the lens, and the final image of this part of the light is a certain deformation compared with the actual object, which I call distortion!"

For clairvoyance, if you want to get a higher magnification, the length of its overall optical path will become longer, and at this time, a small distortion will be even greater after such a long optical system! So don't neglect the image quality while increasing the clairvoyant magnification in the future! According to my experience, as long as you can ensure a magnification of more than 30 times, you can basically meet the requirements of astronomical observations! ”

Li Zexuan is very, very familiar with the telescope, when he was in high school, his dormitory buddy brought a telescope, which was called to see the scenery opposite the dormitory, but there was only a girls' dormitory opposite. In the end, Skynet was restored, negligent but not leaky, and the kid's telescope was confiscated by the head teacher who suddenly checked the bed.

When he was in college, thanks to the geographical location of the school, on an open day of a planetarium in the capital, he spent thirty-five yuan to go in and walk around, which can be regarded as having personally gotten his hands on astronomical telescopes, and his undergraduate and graduate studies involved a considerable part of the optical knowledge, and even polished the lens by himself in the internship, in the era of the Tang Dynasty, he can be called an expert in optics! This is also why he can explain to Mo Lingwei and Yan Shaoning is the Tao.

"That Xiaoxuan, how do we solve the imaging distortion~?"

To be honest, Yan Shaoning was not shocked at all that Li Zexuan could always have an endless stream of novel knowledge popping up in his brain, because he had already been numbed by shock, and the more important thing than shock was that he needed to try his best to absorb the new knowledge that Li Zexuan had revealed.

"It's hard!"

Li Zexuan shook his head with a complicated face, for the imaging distortion and chromatic aberration of the lens, the method of glued lenses is often used in modern times, by fixing more than two lenses with photosensitive glue, and then baking with ultraviolet light, after two curing processes, a group of glued lenses can be obtained.

In modern precision optical components, such as the objective lens of a microscope, the eyepiece of a telescope, etc., the lens group that has been glued together by photosensitive glue is used. If you only use a simple convex or concave lens, it is difficult to get good imaging results.

However, in this era of extremely backward basic science, it is tantamount to a fool's dream to control imaging distortion like a modern optical lens company.

"It's hard, but you can find a way to replace a simple single lens with a lens set of many small lenses that are closely spaced, while keeping the overall imaging light path the same! The result may be different~! ”

After thinking about it for a long time, Li Zexuan could only use a dead horse as a live horse doctor in the end, and said.

Yan Shaoning and Mo Lingwei were both in deep thought.

.............................

"Bell bell ~!"

With a burst of "crisp" gongs and drums, today's training in Yanhuang Academy finally ended, and Qin Qiong (who was late in the morning because of the heavy rain and bad roads) as the chief instructor of military training of the academy, decisively blew the horn of the order at this time.

"After school~!"

Today's students' enthusiasm for training is very high, and there is no need to deliberately embarrass people on this, so Qin Qiong's impression of the instructors is quite good. When it's time to get out of school, let the students go to school decisively, and don't drag the mud and water at all!

"Oh~! It's a holiday~! ”

"I can finally go home and sleep in~!"

"Haha~! I won't be out for the next two days! In the academy, it's really not easy to take a day or two off~! ”

The students erupted in cheers, and then Yanhuang Academy became a sea of joy, and cheers could be heard everywhere. The students ran back to the dormitory like a gust of wind, and then rushed out of the dormitory, out of the gate of the academy, and went directly to Chang'an City under the mountain.

......................................... ()

Please remember that the first domain name of this book is:. Mobile version reading URL: