Light travels in water and not through opaque objects?

  • Context: High School 
  • Thread starter Thread starter Christian Grey
  • Start date Start date
  • Tags Tags
    Light Water
Click For Summary

Discussion Overview

The discussion centers on the behavior of light as it interacts with different materials, specifically why light can travel through transparent substances like water and glass, while it cannot pass through opaque objects such as walls and floors. The scope includes theoretical explanations and conceptual clarifications regarding light absorption and material properties.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants propose that opaque materials absorb incoming photons, which causes them to warm slightly, while transparent materials allow some photons to pass through without absorption.
  • There is a suggestion that no material is perfectly transparent, and that if a transparent material is thick enough, an appreciable amount of photons will still be absorbed.
  • One participant questions why glass does not absorb photons in the same way that opaque materials do.
  • Another participant notes that while glass is transparent to visible light, it is opaque to UV light, indicating that transparency can depend on the wavelength of light.
  • It is mentioned that the atomic composition of materials affects the likelihood of photons being absorbed, with transparent materials having a lower probability of photons being energetic enough to excite electrons to higher energy states.
  • A later reply critiques a video explanation for oversimplifying the concept, arguing that it should refer to energy bands in solids rather than discrete energy levels, as the latter only occur in isolated atoms.

Areas of Agreement / Disagreement

Participants express differing views on the mechanisms behind light absorption and transmission in materials, with no consensus reached on the explanations provided.

Contextual Notes

Some claims rely on specific definitions of transparency and absorption, and the discussion does not resolve the complexities of energy states versus energy bands in materials.

Christian Grey
Messages
23
Reaction score
0
I want to know, why does light travel through water, glass etc and does not travel through opaque objects like wall, floor etc?
 
Science news on Phys.org
Opaque materials are absorbing the incoming photons, (and in doing so the material becomes slightly warmer).
Transparent materials allow some photons to pass through without being absorbed, but no material is perfectly transparent, if it is made thick enough an appreciable amount of photons still are absorbed.
 
rootone said:
Opaque materials are absorbing the incoming photons, (and in doing so the material becomes slightly warmer).
Transparent materials allow some photons to pass through without being absorbed, but no material is perfectly transparent, if it is made thick enough an appreciable amount of photons still are absorbed.
Why does glass doesn't absorb photons whereas opaque materials do?
 
While glass has transparency for visible light, it is opaque for UV light.
The reason why glass and some other materials permit some photons to pass through is because due the atomic composition of the material, the incoming photon has less liklyhood of being energetic enough to kick an electron into a higher energy state, (ie it is less likely to be absorbed).
 
Christian Grey said:
Why does glass doesn't absorb photons whereas opaque materials do?
have a look at this video ...
 
davenn said:
have a look at this video ...
The explanation is a bit too simple in the clip. He is talking in terms of discrete Energy Levels when they don't actually exist in condensed matter. There are Energy Bands in solids and not states. It would have been better to have said that, in a transparent substance, the next highest band is too high in energy for the electron to become excited into it.
Discrete energy states only occur in isolated atoms (in low pressure gases, aamof)
 

Similar threads

Undergrad What travels faster: visible light in water or X-rays in liquid mercury?
  • · Replies 6 ·
Replies
6
Views
3K
Undergrad Discover the Fascinating Fresnel and Arago Spot Experiments in Belgium
  • · Replies 8 ·
Replies
8
Views
2K
Graduate Distance based opaque to transparent behaviour
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad Polarized light from any suface?
  • · Replies 1 ·
Replies
1
Views
2K
High School Discover the Reason Why Light Moves Slower in Water | Fermilab Video Explanation
  • · Replies 11 ·
Replies
11
Views
2K
High School How would someone see light from something like a flashlight in a tunnel?
  • · Replies 6 ·
Replies
6
Views
2K
High School Why is there a second black ring in Pfund's method with water on the Petri Dish?
  • · Replies 11 ·
Replies
11
Views
3K
Undergrad Light Transmission Through Half-Hollow Sphere
  • · Replies 5 ·
Replies
5
Views
2K
High School Why Does Light Travel Through Glass But Not Opaque Objects?
  • · Replies 6 ·
Replies
6
Views
2K
Graduate Iphone Reflection has a pattern
  • · Replies 2 ·
Replies
2
Views
2K