光和无线电波
Energy is one of the primary constituents of the universe. It is conserved throughout the physical universe, never created or never destroyed but transforming from one form to another. Human technology, primarily, is based on the knowledge of methods to manipulate these forms to produce a desired outcome. In physics, energy is one of the core concepts of investigation, along with matter. Electromagnetic radiation was comprehensively explained by physicist James Clarke Maxwell in 1860`s.
电磁辐射可以视为横向波,其中电场和磁场彼此垂直于垂直,并沿繁殖方向振荡。波的能量在电场和磁场中,因此,电磁波不需要传播介质。在真空中,电磁波以光速传播,这是一个常数(2.9979 x 108ms-1). The intensity/strength of the electric field and the magnetic field has a constant ratio, and they oscillate in phase. (i.e. the peaks and the troughs are occurring at the same time during propagation)
电磁波具有不同的波长和频率。基于频率,这些波显示的属性不同。因此,我们命名了具有不同名称的不同频率范围。光和无线电波是具有不同频率的电磁辐射的两个范围。当所有波列在上升或降序顺序中,我们称其为电磁频谱。
光波
光是波长380 nm至740 nm之间的电磁辐射。这是我们眼睛敏感的光谱范围。因此,人类使用可见光看到事物。人眼的颜色感知基于光的频率/波长。
With the increase in frequency (decrease in the wavelength), the colors vary from red to violet as shown in the diagram.
EM频谱中紫罗兰色之外的区域被称为Ultra Violet(UV)。红色区域下方的区域称为红外线,热辐射发生在该区域。
The sun emits most of its energy as UV and visible light. Therefore, life developed on earth has a very close relationship to the visible light as an energy source, media for visual perception, and many other things.
无线电波
The region is the EM spectrum below the infrared region is known as the Radio region. This region has wavelengths from 1mm to 100km (the corresponding frequencies are from 300 GHz to 3 kHz). This region is further divided into several regions as given in the table below. Radio waves are basically used for communication, scanning, and imaging processes.
乐队名称 |
缩写 |
ITU band |
Frequency and wavelength in the air |
用法 |
Tremendously low frequency |
TLF |
< 3 Hz > 100,000公里 |
天然和人造电磁噪声 |
|
Extremely low frequency |
精灵 |
3 |
3–30 Hz 100,,,,000km – 10,000 km |
与潜艇的沟通 |
超低频率 |
SLF |
30–300 Hz 10,000公里 - 1000公里 |
与潜艇的沟通 |
|
超低频率 |
ULF |
300–3000 Hz 1000公里 - 100公里 |
潜艇通信,矿山内的通信 |
|
频率非常低 |
VLF |
4 |
3–30 kHz 100公里 - 10公里 |
Navigation, time signals, submarine communication, wireless heart rate monitors, geophysics |
低频 |
如果 |
5 |
30–300 kHz 10km – 1 km |
导航,时间信号,AM长浪广播(欧洲和亚洲部分),RFID,业余广播 |
Medium frequency |
MF |
6 |
300–3000 kHz 1公里 - 100 m |
AM (medium-wave) broadcasts, amateur radio, avalanche beacons |
High frequency |
HF |
7 |
3–30 MHz 100m – 10 m |
Shortwave broadcasts, citizens’ band radio, amateur radio and over-the-horizon aviation communications, RFID, Over-the-horizon radar, Automatic link establishment (ALE) / Near Vertical Incidence Skywave (NVIS) radio communications, Marine and mobile radio telephony |
非常高的频率 |
VHF |
8 |
30–300 MHz 10m – 1 m |
FM, television broadcasts and line-of-sight ground-to-aircraft and aircraft-to-aircraft communications. Land Mobile and Maritime Mobile communications, amateur radio, weather radio |
超高频 |
UHF |
9 |
300–3000 MHz 1 m – 100 mm |
Television broadcasts, microwave ovens, microwave devices/communications, radio astronomy, mobile phones, wireless LAN, Bluetooth, ZigBee, GPS and two-way radios such as Land Mobile, FRS and GMRS radios, amateur radio |
超高频 |
SHF |
10 |
3–30 GHz 100毫米 - 10毫米 |
射电天文学,微波设备/通信,无线LAN,大多数现代雷达,通信卫星,卫星电视广播,DBS,业余无线电 |
Extremely high frequency |
EHF |
11 |
30–300 GHz 10mm – 1 mm |
Radio astronomy, high-frequency microwave radio relay, microwave remote sensing, amateur radio, directed-energy weapon, millimeter wave scanner |
Terahertz or Tremendously high frequency |
thz或thf |
12 |
300–3,000 GHz1 mm - 100μm |
Terahertz Imaging - 在某些医学应用,超快分子动力学,凝结物理学,Terahertz时域光谱,Terahertz Computing/Compucations,Sub-MM遥感,业余无线电无线电上的潜在替换X射线 |
[Source: http://en.wikipedia.org/wiki/Radio_spectrum]
光波和无线电波有什么区别?
• The radio waves and light are both electromagnetic radiations.
•与无线电波相比,从相对较高的能量源/过渡发出光。
• Light has higher frequencies than radio waves and has shorter wavelengths.
• Both light and radio waves display usual properties of waves, such as reflection, refraction, and so forth. However, the behavior of each property is dependent on the wavelength/ frequency of the wave.
• Light is a narrow band of frequency in the EM spectrum while radio occupies a large portion of the EM spectrum, which is further divided into different regions based on the frequencies.
实际上,科学家都被证明是错误的。
测试表明,声波确实在真空中出现。
每隔几秒钟发出声音的小型设备被放置在塑料管内。末端用相同的有机玻璃覆盖。将一个小的塑料软管放入一个钻入大管中的孔中。软管连接到真空上。它吸收了所有的空气,达到了太空中真空的标准(我相信它在仪表上注册了28个。无论标准是什么,它都达到了)。
Then the noise maker was turned on. From standing outside, everyone could clearly hear the sound. That was a myth. I can’t believe that the scientific community has lied to us about such a fundamental science property. Looking at it, it makes sense why this has been misinformed to the public. Now, a lot of different theories have also been obliterated because of this FACT.
实际上这不是一个真空,因为管being in there. The tube picked up the resonance and conveyed it to any items it was attached to (assuming it was not floating). Science is not a rabbit hole, stop believing that it is.
If you mean, in a vacuum is the absence of pressure, you are incorrect that sound propagates in a vacuum. Sound is the constant change in pressure, you have to have a dual state to generate sound.
管子内的噪音制造者是如何支撑的?噪音制造机与管子的任何接触,无论多么抑制,都将使管子的外部成为噪音制造商的“响起板”,因此将声音通过管子外的空气传输到听众。
不错的信息过渡,我感谢它!