Reduce minimum temperature to 3K to support CMB goals

[arouinfar]

A user wrote into phethelp requesting the ability to reduce the temperature to 3K, as they are unable to use the HTML5 version to fulfill their learning goals.

Good afternoon, I am a Physics teacher in British Columbia. I am contacting you regarding a change that was made in the new HTML simulation for the Blackbody Spectrum. In earlier versions students were able to manually enter a specific temperature in addition to using the sliding temperature scale. I created an activity for my Science 10 course which used your Blackbody simulation to determine the peak wavelength of the cosmic microwave background (CMB) which has a temperature of approximately 3 K. Since the new simulation does not offer the ability to enter temperatures less than 200 K, I am no longer able to complete the activity I created for my students.

I am just looking to offer some feedback for the next version of the simulation. If possible I would love to have that feature back in the simulation.

A similar request was made in #120 and the user there also had goals related to the cosmic microwave background (CMB). Let's revisit when this sim gets worked on again.