Black Body?  [ENDORSED]

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Daniel Rivas 3L
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Joined: Fri Sep 29, 2017 7:07 am

Black Body?

Postby Daniel Rivas 3L » Thu Oct 12, 2017 5:11 pm

I was just wondering if someone can explain what a black body is to me? Like is it just a thing that is extremely hot? And why is it called a black body if it is usually a glowing white object?

Alex Kashou
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Joined: Fri Sep 29, 2017 7:07 am

Re: Black Body?

Postby Alex Kashou » Thu Oct 12, 2017 5:38 pm

A black body is any object that can absorb any incoming light. It is emits thermal heat due to its high absorption rate. However, if it gets too hot it starts to emit light (glow) from increased amounts of thermal radiation. Thus, all you really need to know is that it is a black body that can absorb any incoming light unlike other objects (typically tested with metals).

Ramya Lakkaraju 1B
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Joined: Fri Sep 29, 2017 7:03 am

Re: Black Body?  [ENDORSED]

Postby Ramya Lakkaraju 1B » Thu Oct 12, 2017 11:19 pm

The term black body came about since these objects appear black in color at room temperature. They absorb all light and do not reflect any light.

Madeleine Farrington 1B
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Re: Black Body?

Postby Madeleine Farrington 1B » Fri Apr 13, 2018 7:13 pm

When you say that black bodies absorb all light, do you mean all light in the visible spectrum, or the entire electromagnetic spectrum?

Liliana Rosales 1E
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Joined: Wed Nov 15, 2017 3:03 am

Re: Black Body?

Postby Liliana Rosales 1E » Fri Apr 13, 2018 11:10 pm

I believe black bodies absorb the entire electromagnetic spectrum not just the visible spectrum.

Mei Blundell_1J
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Re: Black Body?

Postby Mei Blundell_1J » Sat Apr 14, 2018 9:33 am

Fun fact related to this topic: the Sun is a really efficient black body.

Sarai Viveros 1K
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Re: Black Body?

Postby Sarai Viveros 1K » Sat Apr 14, 2018 7:29 pm

Could you explain how the sun is a black body?

Shimran Kumar 1C
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Joined: Fri Apr 06, 2018 11:03 am

Re: Black Body?

Postby Shimran Kumar 1C » Sat Apr 14, 2018 7:36 pm

So as the second post under this topic explains, black bodies absorb all light in the electromagnetic spectrum and emit thermal radiation. However, when they get too hot, they emit light.

The sun follows this definition. The sun is very hot, so it emits light. As large stars cool down and die, they can become black holes. Black holes are known for absorbing everything. Thus, suns/stars are black bodies.

Gabi Landes 1-H
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Joined: Thu Feb 22, 2018 3:00 am

Re: Black Body?

Postby Gabi Landes 1-H » Sun Apr 22, 2018 4:43 pm

Liliana Rosales 1E wrote:I believe black bodies absorb the entire electromagnetic spectrum not just the visible spectrum.


They do! A black body is an object that absorbs all radiation falling on it, at all wavelengths.

Vienna Cimetta 1L
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Joined: Thu Feb 01, 2018 3:01 am

Re: Black Body?

Postby Vienna Cimetta 1L » Sun Apr 22, 2018 8:37 pm

Do you guys think we would be asked any questions on this topic? Or is it just another concept to know for future reference

Mohamad Farhat 1L
Posts: 40
Joined: Fri Apr 06, 2018 11:02 am

Re: Black Body?

Postby Mohamad Farhat 1L » Sun Apr 22, 2018 8:41 pm

I had a similar question to this one. I was curious how when wearing a black shirt on a hot day absorbs more heat.

Chem_Mod
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Re: Black Body?

Postby Chem_Mod » Sun Apr 22, 2018 8:44 pm

Please see Dr. Lavelle's class website for more information regarding test 2. He pointed this out during Friday's lecture to the class.
https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=18&t=30872

vivianndo_1L
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Joined: Fri Apr 06, 2018 11:02 am

Re: Black Body?

Postby vivianndo_1L » Mon Apr 23, 2018 12:43 am

Could someone please explain the relationship between the ultraviolet catastrophe and black bodies then?

Jamie Reniva 1J
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Joined: Wed Nov 15, 2017 3:00 am

Re: Black Body?

Postby Jamie Reniva 1J » Mon Apr 23, 2018 9:03 am

Why is it called black body?


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