Fundamental Constants: How Do We Know They're Constant?

In summary, scientists have measured that the gravitational constant, G, appears to be constant, with a 95% confidence limit within (−0.6 ± 1.1) × 10−12 yr-1.
  • #1
PumpkinCougar95
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How do we know that constants in nature like the Gravitational constant or plank's constants are actually "constant" and don't actually change over time? What sorts of experiments have been done which verify these things?
 
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You could try Googling "Measuring G" or "measuring h" and see that such quantities are frequently 'checked'. Somebody could make a real name for themselves if they managed to find that G is increasing. Dark Matter was introduced to explain weird recession speeds of distant galaxies.
 
  • #3
PumpkinCougar95 said:
How do we know that constants in nature like the Gravitational constant or plank's constants are actually "constant" and don't actually change over time? What sorts of experiments have been done which verify these things?
You can just check the BIPM definitions of the SI. These constants are not “in nature” they are in the SI. In other unit systems they may or may not even exist.
 
  • #4
Shadow89 said:
The gravitational constant of earth is roughly 9.81m/s2.
That's not the gravitational constant. It's the gravitational acceleration g (lower case) on Earth and it depends on the Mass of the Earth and the radius.
G (upper case) is constant in
g = MG/d2
Shadow89 said:
Source: This is common, undisputed knowledge.
Whoops! That was really sticking your neck out to say something like that on PF. :wink:
 
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  • #5
PumpkinCougar95 said:
How do we know that constants in nature like the Gravitational constant or plank's constants are actually "constant" and don't actually change over time? What sorts of experiments have been done which verify these things?
Only time will tell if some constants change over time.
 
  • #6

Related to Fundamental Constants: How Do We Know They're Constant?

1. How do we determine the values of fundamental constants?

Fundamental constants are determined through experimental measurements and observations. Scientists use sophisticated instruments and techniques to measure these constants and ensure their accuracy.

2. Are fundamental constants truly constant?

Yes, according to current scientific understanding, fundamental constants are considered to be truly constant. However, there are ongoing experiments and research to test this idea and potentially discover any variations.

3. How do we know that fundamental constants have remained constant throughout history?

Scientists have compared measurements of fundamental constants from different time periods and have found consistent results. Additionally, theoretical models and observations of natural phenomena also support the idea of constant fundamental constants.

4. Can fundamental constants change in the future?

As mentioned previously, there are ongoing experiments and research to test the constancy of fundamental constants. If any variations are discovered, it could potentially lead to a change in our understanding of these constants. However, currently, there is no evidence to suggest that fundamental constants will change in the future.

5. How do fundamental constants impact our understanding of the universe?

Fundamental constants play a crucial role in our understanding of the universe. They are used in various scientific theories and equations to explain natural phenomena and make predictions about the behavior of the universe. Without these constants, our understanding of the universe would be significantly limited.

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