電子レンジが食べ物を温める仕組み

スライド 1 / 10

1. Ovens run at 2.45 GHz (2,450 MHz); the waves bounce off the metal walls; the food absorbs thembritannica.com
2. Ovens run at 2.45 GHz (2,450 MHz); the waves bounce off the metal walls; the food absorbs themfda.gov
3. Ovens run at 2.45 GHz (2,450 MHz); the waves bounce off the metal walls; the food absorbs themitu.int

スライド 2 / 10

1. A magnetron makes the waves: high voltage drives electrons from the centre outwards, a magnet swirls them past resonant cavities, an antenna and a metal channel (waveguide) carry the waves to the cavityhyperphysics.gsu.edu
2. A magnetron makes the waves: high voltage drives electrons from the centre outwards, a magnet swirls them past resonant cavities, an antenna and a metal channel (waveguide) carry the waves to the cavitybritannica.com
3. A magnetron makes the waves: high voltage drives electrons from the centre outwards, a magnet swirls them past resonant cavities, an antenna and a metal channel (waveguide) carry the waves to the cavityrpaulsingh.com
4. Home ovens put out about 700 to 1,250 W (rated cooking power)consumerreports.org

スライド 3 / 10

1. Water molecules are polar; the oscillating field twists them and they lag behind; their collisions turn this into heat; fats, sugars and dissolved salts absorb toowater.lsbu.ac.uk
2. Water molecules are polar; the oscillating field twists them and they lag behind; their collisions turn this into heat; fats, sugars and dissolved salts absorb toowtamu.edu
3. Water molecules are polar; the oscillating field twists them and they lag behind; their collisions turn this into heat; fats, sugars and dissolved salts absorb toobritannica.com
4. Water molecules are polar; the oscillating field twists them and they lag behind; their collisions turn this into heat; fats, sugars and dissolved salts absorb toocfs.gov.hk
5. The animation shows 4 field cycles in 6.4 s against 2.45 billion a second: slowed down billions of timesCalculation from the cited figures

スライド 4 / 10

1. Not a special water frequency: water's dielectric loss peaks near 20 GHz (a broad relaxation), where waves are absorbed in the first layer; 2.45 GHz sits in the 2,400 to 2,500 MHz ISM bandarxiv.org
2. Not a special water frequency: water's dielectric loss peaks near 20 GHz (a broad relaxation), where waves are absorbed in the first layer; 2.45 GHz sits in the 2,400 to 2,500 MHz ISM bandwater.lsbu.ac.uk
3. Not a special water frequency: water's dielectric loss peaks near 20 GHz (a broad relaxation), where waves are absorbed in the first layer; 2.45 GHz sits in the 2,400 to 2,500 MHz ISM banditu.int
4. Not a special water frequency: water's dielectric loss peaks near 20 GHz (a broad relaxation), where waves are absorbed in the first layer; 2.45 GHz sits in the 2,400 to 2,500 MHz ISM bandecfr.gov

スライド 5 / 10

1. Not from the inside out: outer layers are heated by the microwaves, the inside mainly by conductionfda.gov

スライド 6 / 10

1. Reflected waves form hot spots about half a wavelength (about 6 cm) apart; the wavelength is about 12.2 cm; the turntable moves food through them; cold spots remain, so stir and let food standphysics.umd.edu
2. Reflected waves form hot spots about half a wavelength (about 6 cm) apart; the wavelength is about 12.2 cm; the turntable moves food through them; cold spots remain, so stir and let food standitu.int
3. Reflected waves form hot spots about half a wavelength (about 6 cm) apart; the wavelength is about 12.2 cm; the turntable moves food through them; cold spots remain, so stir and let food standconsumerreports.org
4. Reflected waves form hot spots about half a wavelength (about 6 cm) apart; the wavelength is about 12.2 cm; the turntable moves food through them; cold spots remain, so stir and let food standgovinfo.gov

スライド 7 / 10

1. Ice is almost transparent to microwaves; thawed parts heat faster ("runaway heating") and can start cooking; defrost settings often cycle full power on and off (about 30%) so heat can spreadwater.lsbu.ac.uk
2. Ice is almost transparent to microwaves; thawed parts heat faster ("runaway heating") and can start cooking; defrost settings often cycle full power on and off (about 30%) so heat can spreadintechopen.com
3. Ice is almost transparent to microwaves; thawed parts heat faster ("runaway heating") and can start cooking; defrost settings often cycle full power on and off (about 30%) so heat can spreadpatents.google.com
4. Ice is almost transparent to microwaves; thawed parts heat faster ("runaway heating") and can start cooking; defrost settings often cycle full power on and off (about 30%) so heat can spreadpatents.google.com
5. Ice is almost transparent to microwaves; thawed parts heat faster ("runaway heating") and can start cooking; defrost settings often cycle full power on and off (about 30%) so heat can spreadfood.unl.edu

スライド 8 / 10

1. On thin, sharp metal (fork tines, crumpled foil) charge piles up and the air breaks down into a spark; thick, blunt racks built for the oven reflect the waves safelyscienceupdate.com
2. On thin, sharp metal (fork tines, crumpled foil) charge piles up and the air breaks down into a spark; thick, blunt racks built for the oven reflect the waves safelylivescience.com

スライド 9 / 10

1. The door mesh has holes of about 1 mm (some screens use about 1.6 mm); the waves are about 120 times bigger, light passes; ovens must have two interlocks that stop the waves when the door openshyperphysics.gsu.edu
2. The door mesh has holes of about 1 mm (some screens use about 1.6 mm); the waves are about 120 times bigger, light passes; ovens must have two interlocks that stop the waves when the door openspatents.google.com
3. The door mesh has holes of about 1 mm (some screens use about 1.6 mm); the waves are about 120 times bigger, light passes; ovens must have two interlocks that stop the waves when the door opensvan.physics.illinois.edu
4. The door mesh has holes of about 1 mm (some screens use about 1.6 mm); the waves are about 120 times bigger, light passes; ovens must have two interlocks that stop the waves when the door opensecfr.gov
5. US leakage limit: 5 mW/cm² at 5 cm over the oven's lifetime (1 mW/cm² before sale)ecfr.gov
6. US leakage limit: 5 mW/cm² at 5 cm over the oven's lifetime (1 mW/cm² before sale)fda.gov

1. In water at room temperature, most of the power is absorbed in the first 2 cm (penetration depth about 1.4 cm with Chaplin's values, about 1.7 to 1.9 cm with current loss data; either way more than half is absorbed by 2 cm)water.lsbu.ac.uk
2. In water at room temperature, most of the power is absorbed in the first 2 cm (penetration depth about 1.4 cm with Chaplin's values, about 1.7 to 1.9 cm with current loss data; either way more than half is absorbed by 2 cm)chimia.ch
3. In water at room temperature, most of the power is absorbed in the first 2 cm (penetration depth about 1.4 cm with Chaplin's values, about 1.7 to 1.9 cm with current loss data; either way more than half is absorbed by 2 cm)hyperphysics.gsu.edu