Why we don't use visible light to cook food?

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Discussion Overview

The discussion centers around the reasons why microwaves are used for cooking food instead of visible light. Participants explore the efficiency of energy transfer, penetration depth of radiation, and the intensity of light sources in relation to cooking applications.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants suggest that microwaves transfer energy to water molecules more efficiently than visible light due to the specific frequencies of the photons.
  • Others argue that the ability to generate sufficient power at a convenient frequency and the penetration depth of the radiation into food are critical factors in the effectiveness of microwaves for cooking.
  • It is noted that normal sources of visible light lack the necessary intensity for cooking, unless lasers are used, and that visible light does not penetrate materials well, limiting cooking to the surface of food.
  • Some participants mention that x-rays, which have even more energy per photon than microwaves, are not used for cooking, raising questions about the reasons behind this choice.
  • A participant recalls an advertisement for a pizza oven that claimed to use light sources for cooking, although details about its effectiveness remain unclear.
  • Another participant highlights the efficiency of converting electricity to microwaves compared to LEDs, suggesting this as a factor in the preference for microwaves.
  • It is mentioned that infrared radiation is used in conjunction with convection for grilling, indicating a different application of thermal radiation in cooking.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the effectiveness of different types of radiation for cooking, and the discussion remains unresolved with no consensus reached.

Contextual Notes

Limitations include varying assumptions about the efficiency of different light sources, the definitions of cooking effectiveness, and the specific conditions under which different types of radiation operate.

Anindya Mondal
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As we know that microwaves have less energy than visible light , then do we use microwave oven in cooking food instead of visible light?
 
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I'm pretty sure its because microwaves transfer energy to water molecules very efficiently. If you shine a micro-wave emitting flashlight on some water, it will heat up a lot more than if you shine a visible light emitting flashlight at some water.

Its about the specific frequency of the photons and that matching what water molecules will absorb.

Edit - I did some post-posting Googling (barn door after horse) and I am wrong. Its more about being able to generate enough power at a convenient frequency and how far into the food the radiation can penetrate as its dissipating its energy - not about making water molecules vibrate at some specific frequency.
 
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Normal sources of visible light are not high enough intensity unless you use a laser. You can use sunlight to cook although about half is infra red. .Another issue is that visible light does not penetrate material so cooking would only be on the surface you would have to rely on conduction to cook the inside.
 
x-rays have even more energy per photon. Why do you think they are not used for cooking? I can think of more than one reason.
 
Some years ago I saw an advert for a Pizza oven that used light sources for cooking. The ad claimed that they were faster blah blah. I did a quick search but as you can imagine "White light pizza oven" did not return anything useful.

Cheers
 
cosmik debris said:
Some years ago I saw an advert for a Pizza oven that used light sources for cooking. The ad claimed that they were faster blah blah. I did a quick search but as you can imagine "White light pizza oven" did not return anything useful.
Try a different search term... https://en.wikipedia.org/wiki/Easy-Bake_Oven
 
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nasu said:
x-rays have even more energy per photon. Why do you think they are not used for cooking? I can think of more than one reason.
What is the reason?
nasu said:
x-rays have even more energy per photon. Why do you think they are not used for cooking? I can think of more than one reason.
 
Grinkle said:
I'm pretty sure its because microwaves transfer energy to water molecules very efficiently. If you shine a micro-wave emitting flashlight on some water, it will heat up a lot more than if you shine a visible light emitting flashlight at some water.

Its about the specific frequency of the photons and that matching what water molecules will absorb.

Edit - I did some post-posting Googling (barn door after horse) and I am wrong. Its more about being able to generate enough power at a convenient frequency and how far into the food the radiation can penetrate as its dissipating its energy - not about making water molecules vibrate at some specific frequency.
Why microwaves transfer energy to molecules more efficiently?
 
  • #10
In addition to the above, microwave ovens work by creating a microwave cavity inside.
 
  • #11
Note that infrared radiation is used at least in conjunction with convection for grilles.
 

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