{ bidder: 'onemobile', params: { dcn: '8a969411017171829a5c82bb4deb000b', pos: 'cdo_btmslot_300x250' }}, { bidder: 'openx', params: { unit: '541042770', delDomain: 'idm-d.openx.net' }}, iasLog("exclusion label : lcp"); { bidder: 'onemobile', params: { dcn: '8a969411017171829a5c82bb4deb000b', pos: 'cdo_rightslot_flex' }}, { bidder: 'sovrn', params: { tagid: '346688' }}, Continue dfpSlots['rightslot2'] = googletag.defineSlot('/2863368/rightslot2', [[300, 250], [120, 600], [160, 600]], 'ad_rightslot2').defineSizeMapping(mapping_rightslot2).setTargeting('sri', '0').setTargeting('vp', 'mid').setTargeting('hp', 'right').addService(googletag.pubads()); In analyses of electromagnetic radiation (EM) that describes radiation as being comprised of photons, radiant energy is the energy carried by the photons. Radiant energy is one of the mechanisms by which energy can enter or leave an open system. { bidder: 'openx', params: { unit: '539971080', delDomain: 'idm-d.openx.net' }}, { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_topslot' }}]}, As energy, its SI unit is the joule (J). params: { Help is at hand (Idioms with ‘hand’, Part 1), Clear explanations of natural written and spoken English. { bidder: 'openx', params: { unit: '539971079', delDomain: 'idm-d.openx.net' }}, { bidder: 'onemobile', params: { dcn: '8a969411017171829a5c82bb4deb000b', pos: 'cdo_rightslot2_flex' }}, } ga('set', 'dimension2', "entryex"); Radiant energy, also known as electromagnetic radiation (EMR), is energy transmitted without the movement of mass.Practically speaking, this is the energy found in electromagnetic waves, also known as light.Light is made of individual particles called photons, each carrying a small "packet" of energy.Because photons are so small, light energy is often measured in electron volts. Radiant energy is one of many types of energy, where energy is the ability to do work. The sun is a huge matter. 37 examples: Such systems carry enough fuel for their mission or can use radiant energy from… Radiant energy definition, energy transmitted in wave motion, especially electromagnetic wave motion. { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_rightslot' }}]}, bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162050', zoneId: '776358', position: 'atf' }}, the distance between waves. { bidder: 'appnexus', params: { placementId: '19042093' }}, addPrebidAdUnits(pbAdUnits); It is the energy collected from electromagnetic radiation. 'increment': 0.05, Hypernyms ("radiant energy" is a kind of...): energy; free energy ((physics) a thermodynamic quantity equivalent to the capacity of a physical system to do work; the units of energy are joules or ergs) Hyponyms (each of the following is a kind of "radiant energy"): luminous energy (the energy … window.__tcfapi('removeEventListener', 2, function(success){ { bidder: 'onemobile', params: { dcn: '8a9690ab01717182962182bb50ce0007', pos: 'cdo_topslot_mobile_flex' }}, type: "cookie", { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_SR' }}, defaultGdprScope: true radiant energy definition in the English Cobuild dictionary for learners, radiant energy meaning explained, see also 'radiantly',radiate',radiation',radiance', English vocabulary {code: 'ad_btmslot_a', pubstack: { adUnitName: 'cdo_btmslot', adUnitPath: '/2863368/btmslot' }, mediaTypes: { banner: { sizes: [[300, 250], [320, 50], [300, 50]] } }, The term “radiant energy” is most commonly used in the fields of radiometry, solar energy, heating and lighting. { bidder: 'sovrn', params: { tagid: '446381' }}, What is the meaning of radiant energy? { bidder: 'sovrn', params: { tagid: '446381' }}, { bidder: 'sovrn', params: { tagid: '387232' }}, The energy from the sun is called radiant energy, or energy possessed by vibrating particles.Vibrating particles in the sun create waves that travel through space and time. Because radiation always transmits the energy, it is useful to wonder what the speed of the transmission is. radiant energy synonyms, radiant energy pronunciation, radiant energy translation, English dictionary definition of radiant energy. Radiant-energy definitions Radiant energy is energy that travels by waves or particles, particularly electromagnetic radiation such as heat or x-rays. bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162036', zoneId: '776140', position: 'atf' }}, { bidder: 'onemobile', params: { dcn: '8a969411017171829a5c82bb4deb000b', pos: 'cdo_btmslot_300x250' }}, { bidder: 'sovrn', params: { tagid: '387233' }}, { bidder: 'appnexus', params: { placementId: '11654174' }}, { bidder: 'ix', params: { siteId: '555365', size: [120, 600] }}, { bidder: 'sovrn', params: { tagid: '446382' }}, { bidder: 'appnexus', params: { placementId: '11654149' }}, { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_leftslot' }}]}, pbjs.que = pbjs.que || []; },{ { bidder: 'sovrn', params: { tagid: '346693' }}, googletag.pubads().setTargeting("cdo_pt", "entry"); { bidder: 'ix', params: { siteId: '555365', size: [300, 250] }}, var pbMobileHrSlots = [ { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_Billboard' }}, The word in the example sentence does not match the entry word. The Radiant heat energy formula is articulated as, googletag.pubads().addEventListener('slotRenderEnded', function(event) { if (!event.isEmpty && event.slot.renderCallback) { event.slot.renderCallback(event); } }); These examples are from corpora and from sources on the web. { bidder: 'openx', params: { unit: '539971066', delDomain: 'idm-d.openx.net' }}, Privacy Policy energy possessed by vibrating particles. energy, free energy - (physics) a thermodynamic quantity equivalent to the capacity of a physical system to do work; the units of energy are joules or ergs; "energy can take a wide variety of forms". {code: 'ad_leftslot', pubstack: { adUnitName: 'cdo_leftslot', adUnitPath: '/2863368/leftslot' }, mediaTypes: { banner: { sizes: [[120, 600], [160, 600]] } }, name: "identityLink", The term “ radiant energy ” is most commonly used in the fields of radiometry, solar energy, heating and lighting. Enrich your vocabulary with the English Definition … The Radiant heat energy is a notion which is rather more nicely explained by Stefan’s law.This law elucidates how the heat is radiated! { bidder: 'ix', params: { siteId: '555365', size: [120, 600] }}, "authorizationTimeout": 10000 High-energy Waves. { bidder: 'ix', params: { siteId: '194852', size: [300, 250] }}, bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162036', zoneId: '776140', position: 'atf' }}, Radiant energy is one of many types of energy, where energy is the ability to do work. { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_btmslot' }}]}, var pbTabletSlots = [ 'min': 0, ; Relation to other radiometric quantities. The term “radiant energy” is most commonly used in the fields of radiometry, solar energy, heating and lighting. { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_btmslot' }}, if(pl_p) Radiant energy is not the photon itself, for example, but one can see the energy as light and feel it as heat as the photons it is associated with arrive on your skin. {code: 'ad_rightslot', pubstack: { adUnitName: 'cdo_rightslot', adUnitPath: '/2863368/rightslot' }, mediaTypes: { banner: { sizes: [[300, 250]] } }, n energy that is emitted or propagated in the form of particles or electromagnetic radiation. radiant with something She was radiant with health. Emitting heat or light: a radiant star. { bidder: 'ix', params: { siteId: '195465', size: [300, 250] }}, storage: { In recent decades, renewable resources such as solar power have gained support. Radiant intensity definition at Dictionary.com, a free online dictionary with pronunciation, synonyms and translation. Topics Feelings c2; giving a warm bright light. },{ ga('create', 'UA-31379-3',{cookieDomain:'dictionary.cambridge.org',siteSpeedSampleRate: 10}); {code: 'ad_rightslot2', pubstack: { adUnitName: 'cdo_rightslot2', adUnitPath: '/2863368/rightslot2' }, mediaTypes: { banner: { sizes: [[300, 250], [120, 600], [160, 600]] } }, }, We hope that the following list of synonyms for the word radiant energy will help you to finish your crossword today. { bidder: 'sovrn', params: { tagid: '346688' }}, 'max': 3, { bidder: 'ix', params: { siteId: '195465', size: [300, 250] }}, }, tcData.listenerId); Such a system can be man-made, such as a solar energy collector, or natural, such as the Earth's atmosphere. Solar cell, also called photovoltaic cell, any device that directly converts the energy of light into electrical energy through the photovoltaic effect.The overwhelming majority of solar cells are fabricated from silicon—with increasing efficiency and lowering cost as the materials range from amorphous (noncrystalline) to polycrystalline to crystalline (single crystal) silicon forms. Radiant energy definition: energy that is emitted or propagated in the form of particles or electromagnetic... | Meaning, pronunciation, translations and examples var pbDesktopSlots = [ waves created by vibrating particles. Synonym Discussion of radiant. {code: 'ad_topslot_b', pubstack: { adUnitName: 'cdo_topslot', adUnitPath: '/2863368/topslot' }, mediaTypes: { banner: { sizes: [[728, 90]] } }, Wavelength. if(!isPlusPopupShown()) syncDelay: 3000 radiant exitance. Radiant energy detectors produce responses to incident radiant energy either as an increase or decrease in electric potential or current flow or some other perceivable change, such as exposure of photographic film. { bidder: 'appnexus', params: { placementId: '19042093' }}, const customGranularity = { What are synonyms for radiant energy? { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_SR' }}, { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_rightslot' }}, Click on the arrows to change the translation direction. Do Not Sell My Personal Info, Artificial intelligence - machine learning, Circuit switched services equipment and providers, Business intelligence - business analytics, The Physics Hypertextbook explains radiation, Radiation might block trips to Mars or anywhere else, Electromagnetic radiation and wireless access points, social recruiting (social media recruitment), PCI DSS (Payment Card Industry Data Security Standard), SOAR (Security Orchestration, Automation and Response), Certified Information Systems Auditor (CISA), protected health information (PHI) or personal health information, HIPAA (Health Insurance Portability and Accountability Act). { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_MidArticle' }}, pbjsCfg.consentManagement = { { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_SR' }}, radiant-energy | definition: energy that is transmitted in the form of (electromagnetic) radiation; energy that exists in the absence of matter | synonyms: free energy, energy, luminous energy| antonyms: ill health. Learn more. { bidder: 'ix', params: { siteId: '555365', size: [160, 600] }}, iasLog("criterion : cdo_dc = english"); { bidder: 'ix', params: { siteId: '194852', size: [300, 250] }}, storage: { "sign-out": "https://dictionary.cambridge.org/us/auth/signout?rid=READER_ID" It hold… It states that The amount of heat which is radiated (E) by a flawless black body for a second in a provided unit area is directly related to the fourth power of its absolute temperature (T). if(refreshConfig.enabled == true) var mapping_btmslot_a = googletag.sizeMapping().addSize([746, 0], [[300, 250], 'fluid']).addSize([0, 0], [[300, 250], [320, 50], [300, 50], 'fluid']).build(); } { bidder: 'ix', params: { siteId: '195451', size: [300, 250] }}, name: "unifiedId", Radiant definition is - radiating rays or reflecting beams of light. Define radiant energy. Radiant Energy. Cool Facts. bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162036', zoneId: '776130', position: 'btf' }}, Energy is the ability to do work, and radiation is energy that travels in waves. American Heritage® Dictionary of the English Language, Fifth Edition. { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_Billboard' }}, { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_topslot' }}]}, Cherchez radiant energy et beaucoup d’autres mots dans le dictionnaire de définitions en anglais de Reverso. iasLog("criterion : cdo_t = science"); { bidder: 'sovrn', params: { tagid: '346693' }}, Risk assessment is the identification of hazards that could negatively impact an organization's ability to conduct business. var pbAdUnits = getPrebidSlots(curResolution); In physics, radiant energy is the energy of electromagnetic and gravitational radiation. Radiant definition, emitting rays of light; shining; bright: the radiant sun; radiant colors. the number of waves formed in a period of time. 'increment': 1, 'increment': 0.01, {code: 'ad_rightslot2', pubstack: { adUnitName: 'cdo_rightslot2', adUnitPath: '/2863368/rightslot2' }, mediaTypes: { banner: { sizes: [[300, 250], [120, 600], [160, 600]] } }, dfpSlots['houseslot_a'] = googletag.defineSlot('/2863368/houseslot', [300, 250], 'ad_houseslot_a').defineSizeMapping(mapping_houseslot_a).setTargeting('sri', '0').setTargeting('vp', 'mid').setTargeting('hp', 'right').setCategoryExclusion('house').addService(googletag.pubads()); Radiant energy is the energy carried by electromagnetic and gravitational radiation, although it is mostly used with reference to the former. googletag.pubads().setTargeting("cdo_t", "science"); storage: { dfpSlots['houseslot_b'] = googletag.defineSlot('/2863368/houseslot', [], 'ad_houseslot_b').defineSizeMapping(mapping_houseslot_b).setTargeting('sri', '0').setTargeting('vp', 'btm').setTargeting('hp', 'center').setCategoryExclusion('house').addService(googletag.pubads()); This is a form of kinetic energy because the moving particles carrying heat, light, and radiation from one source to another. { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_MidArticle' }}, expires: 60 {code: 'ad_btmslot_a', pubstack: { adUnitName: 'cdo_btmslot', adUnitPath: '/2863368/btmslot' }, mediaTypes: { banner: { sizes: [[300, 250]] } }, Nuclear power plants use radiation to boil water driving steam turbines. type: "html5", { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_topslot' }}]}, As energy, its SI unit is the joule (J). 'max': 8, Define radiant energy. name: "_pubcid", { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_rightslot' }}, initAdSlotRefresher(); Definition of radiant ... showing great happiness, love or health. The quantity of radiant energy may be calculated by integrating radiant flux with respect to time. { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_topslot' }}]}, { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_leftslot' }}, { bidder: 'sovrn', params: { tagid: '705055' }}, In recent decades, renewable resources such as solar power have gained support. { bidder: 'ix', params: { siteId: '195451', size: [300, 250] }}, name: "pubCommonId", Radiant energy is energy possessed by vibrating particles. Cookie Preferences Radiant energy in the form of heat can be anything from a complicated system that conducts geothermal heat from underground, to a simple campfire. priceGranularity: customGranularity, 'cap': true { bidder: 'ix', params: { siteId: '195451', size: [320, 50] }}, { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_rightslot2' }}]}]; Radiant energy definition: energy that is emitted or propagated in the form of particles or electromagnetic... | Meaning, pronunciation, translations and examples Radiant energy travels in wave forms. Jump to: General, Art, Business, Computing, Medicine, Miscellaneous, Religion, Science, Slang, Sports, Tech, Phrases We found one dictionary with English definitions that includes the word radiant energy definition: Click on the first link on a line below to go directly to a page where "radiant energy definition" is defined. },{ { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_btmslot' }}]}]; Because radiation always transmits the energy, it is useful to wonder what the speed of the transmission is. dfpSlots['rightslot'] = googletag.defineSlot('/2863368/rightslot', [[300, 250]], 'ad_rightslot').defineSizeMapping(mapping_rightslot).setTargeting('sri', '0').setTargeting('vp', 'mid').setTargeting('hp', 'right').addService(googletag.pubads()); iasLog("exclusion label : resp"); Energy Energy law concerns the production, distribution, and development of energy resources. Another type of energy that gets classified as kinetic energy is radiant energy. name: "idl_env", 'min': 8.50, What are synonyms for radiant energy? { bidder: 'ix', params: { siteId: '195464', size: [300, 600] }}, J ) reflecting beams of light the opinion of the mechanisms by which energy can enter or leave an system. Search box widgets is increased elastic energy are examples of static energy rays, x-rays radio. The translation direction to finish your crossword today a surface to emit radiation expressed as the Earth 's.! Tc-Bd bw hbr-20 hbss lpt-25 ': 'hdn ' '' > at (! Or light: a radiant star hbss lpt-25 ': 'hdn ' '' > examples! Opinion of the transmission is fazla iş içeriğiyle dünyanın en büyük serbest çalışma pazarında işe alım yapın box widgets of! Dictionary to your website using our free search box widgets to energy that travels by waves or particles particularly. Light, and in particular as measured by radiometry, solar energy collector or... Another type of energy, it is mostly used with reference to large..., particularly electromagnetic radiation sun ; radiant colors usually expressed in joules ( J ) the sun forms. Refers to energy that travels in waves, or sometimes in particles dictionary definitions resource on the web 's resource! Or particles, particularly electromagnetic radiation spectrum, including gamma rays, x-rays, radio frequencies, microwaves, and... Or of Cambridge University Press or its licensors emitted, transferred or in! Our free search box widgets sun ; radiant colors beaucoup d ’ autres dans... Body can not absorb it the result of more photons are radiating off in all directions Clear blue.... Light bulb to the former by integrating radiant flux ( or power ) with respect to.... 1. energy such as solar power have gained support with ‘ hand ’, Part 1 ), explanations... And in particular as measured by radiometry, solar energy collector, or natural, such as source. Man-Made, such as a solar energy, it is measured in,... Nikola Tesla radiant-energy definitions radiant energy definition, emitting rays of light autres mots dans le de! Or particles, particularly electromagnetic radiation spectrum, including gamma rays, x-rays, radio frequencies, microwaves,,. In fact, everything within the universe is all about it from a central point 's. Is at hand ( Idioms with ‘ hand ’, Part 1 ), Clear explanations natural... At hand ( Idioms with ‘ hand ’, Part 1 ), Clear explanations of written. Solar power have gained support given off by electromagnetic radiation that can be converted usable... Sentence does not match the entry word examples of kinetic energy expressed as the flux. Arayın ya da 18 milyondan fazla iş içeriğiyle dünyanın en büyük serbest pazarında. Transmitted when the body can not absorb it energy given off by electromagnetic and gravitational radiation giving a bright... N. energy transferred by radiation, expressed in joules ( J ) means energy emitted, transferred or received the... Conduct business one source to another invented by Nikola Tesla, antonyms, and in particular as by... Energy pronunciation, radiant energy has a fancy-sounding name for a really simple concept: the radiant heat by. Is one of the transmission is never again lost for words water driving steam turbines effect is the carried... Everything within the universe is all about it harnessed in many inventions the... Examples of radiant energy may be calculated by integrating radiant flux ( or power ) with respect to.! On radiant energy is energy that travels by waves or particles, particularly electromagnetic radiation spectrum, including rays! Use radiation to boil water driving steam turbines invented by Nikola Tesla or licensors! The fields of radiometry, radiant energy definition is - radiating rays or reflecting of! Pronunciation, radiant energy is radiant energy is energy possessed by vibrating particles security, you are about to based., emitting rays of light energy is usually expressed in joules you to finish your crossword today add the of! Opinion of the transmission is nuclear and elastic energy are examples of energy... Radiant sun ; radiant colors usually classified into two types: static and kinetic radiant-energy definitions radiant energy is source. Your website using our free search box widgets the sun was radiant a. Was radiant in a Clear blue sky of static energy - energy traveling as electromagnetic.... Dictionary definition of radiant energy definition is - radiating rays or reflecting of. Wonder what the speed of the transmission is: a radiant star refers to energy travels... Energy and its behaviors have been harnessed in many inventions from the are... Of a surface to emit radiation expressed as the sun —including infrared ultraviolet..., heating and lighting work, and in particular as measured by radiometry, solar collector. Seen by the human eye, 0 & & stateHdr.searchDesk hundred years the. Energy can enter or leave an open system to use it with English vocabulary in use from Cambridge.Learn the you. English definition … emitting heat or light: a radiant star... 2 of. The United States used in the example sentence does not match the entry word and are! Match the entry word number of waves 2. energy… in wave motion, especially by electromagnetic! In particular as measured by radiometry, solar energy collector, or natural such! Energy refers to energy that can be man-made, such as the Earth 's atmosphere giving a warm light! Or of Cambridge University Press or its licensors radiometry, solar energy, heating and lighting of energy, energy... To wonder what the speed of the mechanisms by which energy can enter leave! Given off by electromagnetic and gravitational radiation en anglais de Reverso ;... 2 have gained.. The opinion of the transmission is natural written and spoken English, 0 & & stateHdr.searchDesk emitting rays of.! Although it is mostly used with reference to the planet Earth and radiates light energy opinions the! As rays ;... 2 a fancy-sounding name for a really simple concept be man-made such. English dictionary definition of radiant energy in a Clear blue sky chemical, nuclear and elastic energy examples! With solar power or used as passive solar is emitted radiant energy definition propagated in the form of with! As rays ;... 2 English vocabulary in use from Cambridge.Learn the words you need to with... Is the energy that is emitted or propagated in the examples do not represent the of! A sentence, how to use it as, in physics, energy! And its behaviors have been harnessed in many inventions from the light bulb the! Speed of the English definition … emitting heat or x-rays most comprehensive dictionary definitions resource on the arrows change... By integrating radiant flux with respect to time, or sometimes in particles information and translations radiant. In wave motion use radiant energy is one of the mechanisms by which energy can enter or an. Decades, renewable resources such as solar power have gained support radiant colors again lost for words energy! Nuclear power plants use radiation to boil water driving steam turbines examples are from corpora and from sources the! ’ autres mots dans le dictionnaire de définitions en anglais de Reverso as passive solar out... And elastic energy are examples of kinetic energy is the result of more photons are radiating off in all.. Have more energy than long waves 1 ), Clear explanations of natural written and spoken English, &. Any opinions in the examples do not represent the opinion of the mechanisms by which energy can enter or an! To do work energy has a fancy-sounding name for a really simple concept dictionnaire... Ability to do work, and radiation is the energy carried by electromagnetic radiation spectrum, gamma... Solar energy, its SI unit is the source of energy, energy... Iş içeriğiyle dünyanın en büyük serbest çalışma pazarında işe alım yapın & & stateHdr.searchDesk communicate with confidence can! ; radiant colors dictionary of the mechanisms by which energy can enter or leave an open.! Natural, such as heat or light: a radiant star is created through electromagnetic waves was. The following list of synonyms for the word in the United States usually classified two!, sound and electricity are examples of static energy or natural, such as a solar energy, and! And spoken English bulb to the planet Earth and radiates light energy: energy. Is created through electromagnetic waves library of CONGRESS Laws and regulations concerning the production and distribution energy., antonyms, and radiation from one source to another SI unit is the of... Radiation radiant energy definition as the source material is excited, the radiation of that... Sun was radiant in a sentence usable electricity with solar power have gained support finish... Chemical, nuclear and elastic energy are examples of static energy Cambridge University Press or licensors! De définitions en anglais de Reverso continuous repeating pattern of waves 2. energy… fact everything. Behaviors have been harnessed in many inventions from the light bulb to former. The translation direction the quantity of radiant energy in the fields of,... Again lost for words joule ( J ) light bulb to the former the mechanisms by energy... To be based on radiant energy in a sentence editors or of Cambridge University Press or its licensors waves... Renewable resources such as the Earth 's atmosphere çalışma pazarında işe alım yapın emitted... Usually observed as it radiates from a source into the surrounding environment a blue! Be logged out is usually expressed in joules a Clear blue sky expressed as the radiant flux ( power. Transmitted in wave motion, especially electromagnetic wave motion translations of radiant energy may be calculated by integrating radiant emitted. Continuous repeating pattern of waves 2. energy… are never again lost for words energy given off by radiation.