CCT : A rough example to understand ...
You are in a room ...
In the center of the room is a
big square block of steel,sitting on an
Infra-red heater.
(no visible light can be emitted by this heater ,hypothetically ) .
Lights go off .
You are not able to see sh..
..Ok ?
Now ...
Heater starts to heat steel ....
( Ambient is i.e. 25 ° C-it does not matter ,that much ... )
Still you do not see anything ...Complete darkness ...
Steel now has reached 500°C .....
600° C ....
700° C ...
800° C ...
Oopppssss ..Something starts to be visible ....
A dark red -barely visible- light is starting to be seen coming from the steel block ...
At ~ 1730 °C ( 2000 K ) ,you are pretty sure by now ,that steel is emitting a really warm deep orange-red light ....
(Actually it happens in much lower temps for steel... )
As temperature of steel rises ,light becomes
brighter to you ( cause of "power " ? Or because of another reason ? )...
Light starts to become more and more white ....
At ~5225 ° C (steel has melted by now ..Inside a ceramic bowl -I forgot to mention .... ) -5500° K ,
steel now emits a bright neutral ( " Daylight" ) light ......
Whole room is lit brightly,now ... ( ...and the A/C working at max ..Ha-ha...).......
There ...I've told you the reason why it becomes brighter .....
Anyway .....
While you are spending the
same amount of energy to continuously heat the steel (rise it's temperature ) ...
( Watts of heater x time ) ...
So :
- How the heck light becomes more "powerful " ,while energy source supplies steel with same energy .... ?
Lumens of melted steel keep rising ,while power of heater is not !
Radiometrically ,if measured (light6 from steel ) is going to be the same amount like the source's energy .
You gave x amount of energy ,you got same back as light ...
( here we have to mention that the steel block is considered as ideal "black body radiator " .)
So what happens with your eyes ?
How on Earth light starts to become(appear ) more and more bright to you ,without extra energy spend ?
huh ?
....
Tip : From barely visible
deep red to bright
white .....
Some colors where added ....
Does anybody know more or less how that is happening ?
Electron Excitation ..
They start "jumping" "back 'n forth " from lower to higher states of energy (from heat )..
Releasing photons at every "jump back'n'forth..
As material keeps receiving energy ,overall "base energy state " is keep rising ....
So at a point ,photons being made ,have/contain more and more energy in them ....
Red =>amber=>yellow=>green=> blue=>violet=> uv ....
From lower to higher energy photons .....
So ,while metal block heats up ,more photons of higher energy state are being emitted ...
(power stays the same .....2000 Watts you gave steel in form of heat ?
2000 Watts of photons you'll get back ....
Number of photons change and not the overall amount of light's power ...
More simple ? Spectrum is " shifting " ....)
So for humans becomes brighter light ...Mainly cause of green photons ....
Further heating .....
At plasma state ...
Steel now emits UV ,microwaves ,x-rays ,gamma-rays .....
Actually the sun is a big block of Iron ( the core ) , in such plasma state (fussion ) ....
You know the rest ..More or less ......