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Re: Eight things you might not know about light

From Sylvia Else <sylvia@not.at.this.address>
Newsgroups sci.physics
Subject Re: Eight things you might not know about light
Date 2016-04-22 11:50 +1000
Message-ID <dnteb5FeahmU1@mid.individual.net> (permalink)
References <I7GdnbLe77Zix4vKnZ2dnUU7-dWdnZ2d@giganews.com> <dno6jhF4ggfU1@mid.individual.net> <WOWdnSW1F50xNIrKnZ2dnUU7-YudnZ2d@giganews.com> <5717c080$0$27711$c3e8da3$fdf4f6af@news.astraweb.com>

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On 21/04/2016 3:46 AM, benj wrote:
> On 04/20/2016 12:09 PM, Sam Wormley wrote:
>> On 4/19/16 9:07 PM, Sylvia Else wrote:
>>> On 20/04/2016 2:21 AM, Sam Wormley wrote:
>>>
>>>>> 2. Most types of light are invisible to our eyes.
>>>
>>> That's a rather loose definition of the word "light". Indeed, can light
>>> be even divided into types, other than arbitrarily?
>>>
>>>>> 8. You can collide photons to make particles.
>>>
>>> What particles can you make by colliding the photons emitted by a VHF
>>> radio antenna?
>>>
>>> Sylvia.
>>>
>>
>>    X-ray have enough energy, E = hν = hc/λ , to create electron-positron
>>    pairs. Gamma, more massive particles.
>>
> Sam, sam, Sammy! Pairs are NOT made by colliding photons! They are
> created from a single photon. Won't you ever learn not to try to post
> science here? Journalists know no science. Why do you keep C&P their
> screed?

A single photon cannot convert into particles (being particles that do 
not move at the speed of light), because it's impossible for both energy 
and momentum to be conserved.

Sylvia.

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Thread

Eight things you might not know about light Sam Wormley <swormley1@gmail.com> - 2016-04-19 11:21 -0500
  Re: Eight things you might not know about light Helmut Wabnig <hwabnig@.- --- -.dotat> - 2016-04-19 18:31 +0200
    Re: Eight things you might not know about light Sam Wormley <swormley1@gmail.com> - 2016-04-19 11:33 -0500
    Re: Eight things you might not know about light Poutnik <poutnik4nntp@gmail.com> - 2016-04-19 18:42 +0200
    Re: Eight things you might not know about light Sergio <invalid@invalid.com> - 2016-04-19 18:06 -0500
      Re: Eight things you might not know about light benj <nobodyxx@gmail> - 2016-04-20 00:08 -0400
        Re: Eight things you might not know about light HVAC <mr.hvac@gmail.com> - 2016-04-20 04:25 -0700
          Re: Eight things you might not know about light benj <nobodyxx@gmail> - 2016-04-20 13:23 -0400
        Re: Eight things you might not know about light Odd Bodkin <bodkinodd@gmail.com> - 2016-04-20 08:12 -0500
          Re: Eight things you might not know about light benj <nobodyxx@gmail> - 2016-04-20 13:26 -0400
            Re: Eight things you might not know about light Odd Bodkin <bodkinodd@gmail.com> - 2016-04-20 12:41 -0500
              Re: Eight things you might not know about light Sergio <invalid@invalid.com> - 2016-04-20 12:53 -0500
              Re: Eight things you might not know about light benj <nobodyxx@gmail> - 2016-04-20 22:01 -0400
                Re: Eight things you might not know about light Odd Bodkin <bodkinodd@gmail.com> - 2016-04-21 08:51 -0500
                Re: Eight things you might not know about light benj <nobodyxx@gmail> - 2016-04-21 12:07 -0400
                Re: Eight things you might not know about light Odd Bodkin <bodkinodd@gmail.com> - 2016-04-21 11:34 -0500
                Re: Eight things you might not know about light benj <nobodyxx@gmail> - 2016-04-21 22:07 -0400
                Re: Eight things you might not know about light Odd Bodkin <bodkinodd@gmail.com> - 2016-04-22 07:42 -0500
                Re: Eight things you might not know about light Sergio <invalid@invalid.com> - 2016-04-21 11:33 -0500
                Re: Eight things you might not know about light benj <nobodyxx@gmail> - 2016-04-21 21:45 -0400
    Re: Eight things you might not know about light "Y.Porat" <y.y.porat@gmail.com> - 2016-04-20 01:43 -0700
  Re: Eight things you might not know about light "reber g=emc^2" <herbertglazier0@gmail.com> - 2016-04-19 12:24 -0700
    Re: Eight things you might not know about light "reber g=emc^2" <herbertglazier0@gmail.com> - 2016-04-19 15:32 -0700
    Re: Eight things you might not know about light benj <nobodyxx@gmail> - 2016-04-19 23:31 -0400
  Re: Eight things you might not know about light "nuny@bid.nes" <Alien8752@gmail.com> - 2016-04-19 17:08 -0700
    Re: Eight things you might not know about light Sam Wormley <swormley1@gmail.com> - 2016-04-19 19:23 -0500
    Re: Eight things you might not know about light benj <nobodyxx@gmail> - 2016-04-20 00:09 -0400
      Re: Eight things you might not know about light "nuny@bid.nes" <Alien8752@gmail.com> - 2016-04-19 23:15 -0700
  Re: Eight things you might not know about light Sylvia Else <sylvia@not.at.this.address> - 2016-04-20 12:07 +1000
    Re: Eight things you might not know about light benj <nobodyxx@gmail> - 2016-04-20 00:14 -0400
      Re: Eight things you might not know about light "Y.Porat" <y.y.porat@gmail.com> - 2016-04-20 06:38 -0700
    Re: Eight things you might not know about light Sam Wormley <swormley1@gmail.com> - 2016-04-20 11:09 -0500
      Re: Eight things you might not know about light benj <nobodyxx@gmail> - 2016-04-20 13:46 -0400
        Re: Eight things you might not know about light Poutnik <poutnik4nntp@gmail.com> - 2016-04-20 20:07 +0200
        Re: Eight things you might not know about light Sylvia Else <sylvia@not.at.this.address> - 2016-04-22 11:50 +1000
          Re: Eight things you might not know about light benj <nobodyxx@gmail> - 2016-04-21 23:19 -0400
  Re: Eight things you might not know about light "reber g=emc^2" <herbertglazier0@gmail.com> - 2016-04-21 09:19 -0700
    Re: Eight things you might not know about light Sam Wormley <swormley1@gmail.com> - 2016-04-21 15:46 -0500

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