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LogicalAcid
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If our temperature is already above the necessary temperature to emit radio waves? At our temperature we emit mainly infrared right?
cjl said:We do emit radio. It's just much, much fainter than the infrared we emit. Similarly, the sun emits much more infrared per square meter than we do, even though it peaks in the visible.
Lemme rephrase that, why do antennas have the ability to send out radio waves, if we emit radio waves as well?LogicalAcid said:Then we are basically antennas? Why can't we be used as antennas then?
pallidin said:To suggest that biological systems, emitting IR, must ALSO emit lower frequencies is false.
There is no natural requirement for a biological system emitting a specific wavelength to be required to emit all the other sub-wavelengths down to zero.
LogicalAcid said:If our temperature is already above the necessary temperature to emit radio waves? At our temperature we emit mainly infrared right?
cjl said:That's reasonably accurate.
The reason we see each other in visible light is because we see the light reflected off of each other, not because we see the light emitted. The reason this is in the visible range is because that's where the sun's emission peaks.
Andy Resnick said:How do you know we don't?
Humans can be clearly imaged using the 8-12 um (LWIR) band, which corresponds closely to the peak in thermal emission.
I know that humans are opaque to millimeter waves (new airport full body scanners), and o we emit in the millimeter wave as well. But at some point we become transparent, and so by Kirchoff's law we won't emit in that waveband.
LogicalAcid said:Took it right outta my mouth, why is this?
LogicalAcid said:Kirchoff's law BRB
Andy Resnick said:I don't understand?
pallidin said:To suggest that biological systems, emitting IR, must ALSO emit lower frequencies is false.
There is no natural requirement for a biological system emitting a specific wavelength to be required to emit all the other sub-wavelengths down to zero.
LogicalAcid said:Lemme rephrase that, why do antennas have the ability to send out radio waves, if we emit radio waves as well?
LogicalAcid said:Then we are basically antennas? Why can't we be used as antennas then?
Humans do actually emit radio waves, but at very low levels. Our bodies contain charged particles that move in a magnetic field, which creates a weak electromagnetic field. However, these radio waves are much lower in frequency and power compared to the radio waves we use for communication.
Our eyes are only sensitive to a small range of electromagnetic radiation known as visible light. Radio waves have a much lower frequency and longer wavelength, making them invisible to the human eye. We need specialized equipment, such as antennas and receivers, to detect and interpret radio waves.
Yes, some animals can emit radio waves. For example, dolphins use echolocation, which involves emitting and receiving high-frequency sound waves, including radio waves. Certain species of birds also emit and receive radio waves as part of their communication and navigation systems.
Radio waves are used for communication because they can travel long distances and penetrate through obstacles like buildings and trees. They are also easy to produce and manipulate, making them ideal for transmitting information over long distances without the need for physical wires or cables.
Radio waves are non-ionizing radiation, meaning they do not have enough energy to break apart atoms and damage DNA. As a result, they are generally considered safe for humans in the low levels we are exposed to in everyday life. However, excessive exposure to high-powered radio waves, such as those from radar or microwave ovens, can cause tissue damage and potential health risks.