## What is Black Body?

(Wien's law: $T\lambda _{max}=\frac{1}{5}C_{2}$ )

Kellylin_4D
Posts: 66
Joined: Sat Aug 24, 2019 12:17 am

### What is Black Body?

Can someone explain exactly what Black Body Radiation is and what is it for?

thanh24mai
Posts: 50
Joined: Thu Jul 25, 2019 12:17 am

### Re: What is Black Body?

So I'm not super sure, but I remember in lecture he was saying that a black body is something that absorbs radiation at all wavelengths.

AKhanna_3H
Posts: 104
Joined: Wed Sep 18, 2019 12:19 am

### Re: What is Black Body?

I also believe Dr. Lavelle said that it absorbs all radiation.

Minh Ngo 4G
Posts: 137
Joined: Thu Jul 25, 2019 12:17 am

### Re: What is Black Body?

An object that absorbs all EM radiation regardless of frequency

Ashley Osorio
Posts: 54
Joined: Thu Jul 11, 2019 12:17 am

### Re: What is Black Body?

From my understanding, black bodies is a misleading name because they're actually glowing white from how hot they are. Basically, they do absorb all wavelengths, but they don't reflect light, they radiate it. The amount of light emitted then depends on the temperature of the object being heated.

Mai V 4L
Posts: 111
Joined: Fri Sep 28, 2018 12:23 am

### Re: What is Black Body?

Does anyone know if this is going to be on the final?

Anokhi Patel 2B
Posts: 76
Joined: Fri Aug 09, 2019 12:17 am

### Re: What is Black Body?

What would it mean if we solved the black body dilemma, does that mean time travel.

Darren1j
Posts: 98
Joined: Wed Sep 30, 2020 9:37 pm

### Re: What is Black Body?

If it absorbs all light, and you need light to be reflected off an object to see it, would a black body be ... invisible? How would that work? In fact, how would a black hole look through a telescope if we could get near one?

Bella Bursulaya 3G
Posts: 133
Joined: Wed Sep 30, 2020 9:54 pm

### Re: What is Black Body?

A black body is a theoretical concept; it is an object that will absorb and/or emit all wavelengths of light. We don't know of any such objects to exist. I suppose if it's emitting light it should be detectable, but if it was just absorbing all light you wouldn't be able to see it. We may be able to detect it another way, I'm not sure. Perhaps through seeing how it manipulates gravity if it is big enough or if particles affect it. I am not quite sure, but it is a very interesting concept! Perhaps we can learn more about it in the book!

Joey_Okumura_1E
Posts: 111
Joined: Wed Sep 30, 2020 9:58 pm

### Re: What is Black Body?

A black body is a hypothetical object that absorbs all frequencies of light.
Last edited by Joey_Okumura_1E on Wed Oct 14, 2020 9:09 pm, edited 1 time in total.

Joey_Okumura_1E
Posts: 111
Joined: Wed Sep 30, 2020 9:58 pm

### Re: What is Black Body?

Mai V 4L wrote:Does anyone know if this is going to be on the final?
I do not think we will be tested on this since Dr. Lavelle told us we do not need to worry about it.

Nayra Gharpetian 3F
Posts: 86
Joined: Wed Sep 30, 2020 9:40 pm
Been upvoted: 1 time

### Re: What is Black Body?

a black body is an object that emits/absorbs all frequencies of light. however, this is a theoretical concept because no such object exists.

Eileen Quach Dis 2A
Posts: 168
Joined: Wed Sep 30, 2020 9:49 pm

### Re: What is Black Body?

A black body is a theoretical object that absorbs all frequencies of light. It doesn't exist in real life, and Professor didn't go in depth about it because we don't need to study it further.

Sam_Marasigan_3D
Posts: 92
Joined: Wed Sep 30, 2020 9:52 pm

### Re: What is Black Body?

A black body absorbs all energy/radiation (light) that falls on it.

Dominic Benna 2E
Posts: 93
Joined: Wed Sep 30, 2020 10:09 pm

### Re: What is Black Body?

Didn't Lavelle also say that we didn't necessarily need to know about Black Bodies for the course?

Alexandra Salata 2L
Posts: 86
Joined: Wed Sep 30, 2020 9:39 pm

### Re: What is Black Body?

Dr Lavelle specifically said that black body radiation is more of a physics subject and that we won't need to know what it is or any detail about it for Chem14A.

Andre Fabian 1F
Posts: 100
Joined: Wed Sep 30, 2020 10:03 pm
Been upvoted: 2 times

### Re: What is Black Body?

Hi there!

A black body is a substance that absorbs and emits all wavelengths. As such, because no light is reflected, black bodies are invisible to the eye. There are substances that exist that are very close property-wise to black bodies, yet there aren't any discoveries of actual substances meeting the full requirements of a "black body."

Hope this helps!
Andre

Taylor K 2D
Posts: 89
Joined: Wed Sep 30, 2020 9:35 pm
Been upvoted: 1 time

### Re: What is Black Body?

A black body is something that absorbs all light, but Lavelle said we didn't need to know that.

Kelly Yun 2I
Posts: 103
Joined: Wed Sep 30, 2020 10:03 pm

### Re: What is Black Body?

So theoretically, would it be black...?

Shruti Kulkarni 2I
Posts: 95
Joined: Thu Oct 08, 2020 12:16 am

### Re: What is Black Body?

Hi!!
Black body radiation is basically radiation that emits and can absorb all frequencies possible! It's a theorized concept but nothing in real life has this property.

SophiaJenny3I
Posts: 133
Joined: Wed Sep 30, 2020 9:56 pm
Been upvoted: 2 times

### Re: What is Black Body?

Hi! So a black body is a theoretical concept, there is nothing that we know of that has the associated characteristics of a black body. A black body, theoretically, absorbs all frequencies, and thus doesn't reflect anything. Also, Dr. Lavelle said we didn't have to worry about this concept, it's just interesting to know for now.

Yichen Fan 3A
Posts: 87
Joined: Wed Sep 30, 2020 9:59 pm

### Re: What is Black Body?

A black body is not really black, in fact you can never see it because it absorbs the lights of all frequencies and nothing will be reflected into your eyes. We call it a "black" body simply because black is the color that absorbs all the visible lights in our daily life which best resembles the theoretical model we created here.

Karina Grover 1A
Posts: 86
Joined: Wed Sep 30, 2020 9:34 pm
Been upvoted: 1 time

### Re: What is Black Body?

A black body is an object that absorbs all EM radiation (any and all frequencies) and, in consequence, produces black-body radiation/black light.

Shalyn Kelly 3H
Posts: 83
Joined: Wed Sep 30, 2020 9:55 pm

### Re: What is Black Body?

Hi! Bouncing off everyone above, black body radiation absorbs all light frequencies making it completely invisible. Currently, it is only a theoretical concept, because there're things close, but not quite invisible - also more of a physics one. Dr. Lavelle mentioned it a few times, but he also made sure to say that we won't have to worry about it (for tests and such).

Posts: 55
Joined: Wed Sep 30, 2020 9:55 pm

### Re: What is Black Body?

I believe this concept will not be fully addressed until a more advanced chem lesson, however, I do recall him mentioning it being all consuming. I expect it to be in Chem 14B or further.

Charlie Russell 2L
Posts: 103
Joined: Wed Sep 30, 2020 10:01 pm
Been upvoted: 1 time

### Re: What is Black Body?

Hey, so I just researched this question and thought I would come on Chem Comm and help some peers out.

"An example of a black body is a cavity with a small hole in it. Any light incident upon the hole goes into the cavity and is essentially never reflected out since it would have to undergo a very large number of reflections off walls of the cavity. If we make the walls absorptive (perhaps by painting them black), the cavity makes a perfect black body."

Hope this example might make the definitions stated make a little more sense!

Posts: 102
Joined: Wed Sep 30, 2020 10:03 pm
Been upvoted: 1 time

### Re: What is Black Body?

Dr.Lavelle defined a "black body" as an object that absorbs all wavelengths of light. (Easy way to remember it is that on the visible light spectrum, white light is the presence of all colors of light, whereas black is the absence of all light). However, this is only a theoretical notion as such an object doesn't exist.

Charlie Russell 2L
Posts: 103
Joined: Wed Sep 30, 2020 10:01 pm
Been upvoted: 1 time

### Re: What is Black Body?

Charlie Russell 3F wrote:Hey, so I just researched this question and thought I would come on Chem Comm and help some peers out.

"An example of a black body is a cavity with a small hole in it. Any light incident upon the hole goes into the cavity and is essentially never reflected out since it would have to undergo a very large number of reflections off walls of the cavity. If we make the walls absorptive (perhaps by painting them black), the cavity makes a perfect black body."

Hope this example might make the definitions stated make a little more sense!

I just also find out that they are pretty impossible and I think the closest to a perfect black body is a black hole!

Gustavo_Chavez_1K
Posts: 87
Joined: Wed Sep 30, 2020 9:46 pm

### Re: What is Black Body?

Black body is essentially a surface that absorbs all incident radiation that hits it and, in turn, emits black body radiation. This concept is idealized though since there isn't any surface that is completely black.

Susan Chamling 1F
Posts: 86
Joined: Wed Sep 30, 2020 9:42 pm

### Re: What is Black Body?

Black Body refers to a material that could, in theory, absorb all wavelengths of light, which renders it invisible due to no light reflecting off of its surface, which is required for us to see an object.

Jeremy Wei 2C
Posts: 62
Joined: Wed Sep 30, 2020 9:59 pm

### Re: What is Black Body?

Hi, Lavelle went over this briefly during lecture, but essentially black body is a theoretical concept where a material would absorb all forms of wavelengths/frequencies of EM radiation, making it appear "black" (it would be invisible to our eyes).

Sheryl Ocampo 1D
Posts: 85
Joined: Wed Sep 30, 2020 10:09 pm

### Re: What is Black Body?

I think it's the theoretical concept of a substance that absorbs or reflects all wavelengths of light

Melanie Krahn 1C
Posts: 55
Joined: Wed Sep 30, 2020 9:34 pm

### Re: What is Black Body?

Hello all,
If I'm not mistaken, Dr. Lavelle specifically mentioned that we do not need to know what black body radiation is and we will not be tested on it.

Eve Gross-Sable 1B
Posts: 87
Joined: Wed Sep 30, 2020 10:02 pm
Been upvoted: 1 time

### Re: What is Black Body?

He said in the lecture that we do not need to know about black body radiation for this class, but if it's just a curiosity thing I found this link pretty explanatory
http://galileo.phys.virginia.edu/classe ... ation.html

AHUNT_1A
Posts: 110
Joined: Wed Sep 30, 2020 9:41 pm

### Re: What is Black Body?

Brandon McClelland3L
Posts: 84
Joined: Wed Sep 30, 2020 9:31 pm

### Re: What is Black Body?

A black body is an object absorbs or emits all wavelengths of light.