<p>There is no central authority in science. There is no council that sets the standards. The criteria for a discovery are the same: You publish your findings, and your peers accept your results.  </p>

<p>There is the 5 sigma rule in particle physics. Perhaps you were thinking of this. But that is not an official rule, instead it's a convention among particle physics. And it's not applicable to every field. </p>

<p>Things are never cut and dry. What does "Peers" mean. What if only most are convinced. Does it count? Discoveries are usually judged in retrospect. After the dust has settled and the debate s are over.</p>

<p>//edit</p>

<p>Why is the bar set so high in physics?  When "discovering" a particle there is no way to "see" it, instead you observe a mass of data and see a statistical discrepancy. Cern produces masses and masses of data, and it is sifted for anything unusual. And with so much data, the chance of seeing <em>something</em> unusual is actually quite high. (imagine searching for repetitions of '9' in the digits of pi - if you search far enough you can be sure to find a string of 6 9s even though the chance of a random string having 6 9s is very low)</p>

<p>With a mass of data, and the opportunity to repeat experiments it makes sense to set the bar very high.</p>

<p>Compare with an observation, such as the "chirp" at Ligo. We can't repeat it at will, the data is there: something happened that is consistent with a black hole merger. No other theory has been proposed that can explain the observations. The observation is less dependent on a statistical finding after running multiple experiments, but a single direct observation. </p>

<p>In fields in which a result could be explained by chance, then a statistical analysis is done, and published. This contributes to the quality of a finding, and so the number of people you will convince. And convincing your peers is the only criteria that counts in the end. </p>

CC BY-SA 3.0
2016-03-05T14:29:59.547Z
Good point about the $5\sigma$ rule in physics. This actually distinguishes physics a bit from astronomy, as in the latter field, people tend to happily publish a $3\sigma$ result (although they may call it "tentative evidence").
pela
CC BY-SA 3.0
2016-03-05T14:42:53.610Z
@pela - thanks for the comment - this is amazing, since, IMHO, astronomy/astrophysics deals with real physically existing astronomical objects, while the aim of experimental physics is mostly to verify (somewhat abstract) concepts of theoretical physics ...
Alex
CC BY-SA 3.0
2016-03-05T16:42:21.940Z
Would it be worth a comparison with psychology when p=0.05 is "significant" (equivalant to 2sigma) and p=0.1 is "Highly suggestive and tending towards significance")
James K
CC BY-SA 3.0
2016-03-05T16:49:30.983Z
@JamesKilfiger - why not ... I wonder if there already exists some research/publication, covering this issue across variety of science domains.
Alex
CC BY-SA 3.0
2016-03-05T17:21:09.530Z
@Alex: The number of sigmas needed to take a result seriously does depends on the type of observation. But for instance, if one detects something which would be unusual — like a galaxy breaking the distance record — then a $3\sigma$ would make most people happy. After all, this still means that "we're 99% sure it's there". Then better follow-up observations may confirm or reject the observation. And as James Kilfiger mention, we're still doing better than most social sciences :)
pela
CC BY-SA 3.0
2016-03-05T17:28:30.593Z
As for your question about Fortran: It very much depends on the type of task, in particular whether high speed is desired. Object-oriented languages like Python and Java can more easily do much more complex tasks, but for e.g. cosmological simulations where speed and memory are the main wish, C/C++ and Fortran are still the languages of choice, I'd say.
pela
CC BY-SA 3.0
2016-03-05T17:38:25.650Z
@Alex: They would, but many if not most problems simply aren't algebraically solvable. Also, I think precision is usually not an issue. But I guess we shouldn't spam James' answer more on this :)
pela
CC BY-SA 3.0
2016-03-05T19:14:21.113Z
@JamesKilfiger - I'm glad that in your answer update you have referred to the case of LIGO observation, since this generalized question of mine was motivated by more specific case featured in 

  physics.stackexchange.com/questions/236107
Alex
CC BY-SA 3.0
2016-03-05T20:38:09.143Z
@pela To publish something at "3-sigma" significance means you are 99.5% confident. To qualify this as tentative would mean that you don't understand your uncertainties and therefore can't assess the significance at all.
ProfRob
CC BY-SA 3.0
2016-03-07T11:56:00.400Z
@RobJeffries: I'm not sure I understand you. Do you mean that 3 sigma should make you _more_ certain than saying that the evidence is just "tentative"?
pela
CC BY-SA 3.0
2016-03-07T12:30:06.367Z
@pela 3 sigma means that you are 99.5% certain - i.e. you would be wrong only 1 time in 200. To call this "tentative" would be an unusual use of English. What people generally mean when they say "tentative" in this context  is that actually, they don't really know how many sigma it is because they don't understand their uncertainties.
ProfRob
CC BY-SA 3.0
2016-03-07T13:30:09.173Z
@RobJeffries: Okay, I think I misunderstood the word then. Thanks for clarifying.
pela
CC BY-SA 4.0
2021-09-04T16:17:44.307Z
I pretty much share the views of Richard Muller, professor of physics at UC Berkeley: https://www.quora.com/What-lies-ahead-for-General-Relativity-now-that-LIGO-has-detected-gravitational-waves?                                                                              
To claim discoveries of astronomical physical real objects, such as black holes and neutron stars, based singly on the detection of gravitational waves, bearing certain signal signatures, is not acceptable.
Alex
CC BY-SA 3.0
2016-03-05T08:03:29.143Z
2016-03-05T16:58:38.977Z
2016-03-05T16:58:38.977Z
James K
<p>Discovery in Astronomy/Astrophysics (of astronomical objects) vs discovery of physical phenomena in experimental Physics (as such) - do they differ in required burden of evidence (with the notion, that astronomy/astrophysics deals with real physically existing astronomical objects, while the aim of experimental physics per se is mostly to verify rather somewhat abstract concepts of theoretical physics)?</p>

<p>Perhaps answering my question in some definite way would require some analysis with historical perspective and consideration of precedences ...</p>

<p>This generalized question of mine was motivated by more specific case featured in <a href="https://physics.stackexchange.com/q/236107/25575">https://physics.stackexchange.com/q/236107/25575</a> </p>

CC BY-SA 4.0
2019-07-15T15:38:10.317Z
Isn't astronomy a part of physics
user5402
CC BY-SA 4.0
2021-08-09T15:48:30.463Z
https://scitechdaily.com/when-testing-einsteins-theory-of-general-relativity-small-modeling-errors-can-add-up-fast/
Alex
CC BY-SA 4.0
2021-09-04T16:09:05.513Z
I pretty much share the views of Richard Muller, professor of physics at UC Berkeley: https://www.quora.com/What-lies-ahead-for-General-Relativity-now-that-LIGO-has-detected-gravitational-waves?                                                                              
To claim discoveries of astronomical physical real objects, such as black holes and neutron stars, based singly on the detection of gravitational waves, bearing certain signal signatures, is not acceptable.
Alex
<astrophysics><history><resource-request>
Discovery in Astronomy vs one in Physics - do they differ in required burden of evidence?
Alex
# Discovery in Astronomy vs one in Physics - do they differ in required burden of evidence?

(Asked by: username_0 on 2016-03-04)

Discovery in Astronomy/Astrophysics (of astronomical objects) vs discovery of physical phenomena in experimental Physics (as such) - do they differ in required burden of evidence (with the notion, that astronomy/astrophysics deals with real physically existing astronomical objects, while the aim of experimental physics per se is mostly to verify rather somewhat abstract concepts of theoretical physics)?

Perhaps answering my question in some definite way would require some analysis with historical perspective and consideration of precedences ...

This generalized question of mine was motivated by more specific case featured in <https://physics.stackexchange.com/q/236107/25575>

**Tags:** astrophysics, history, resource-request
> **Comments:**
> **username_1**: Isn't astronomy a part of physics  
> **username_0**: https://scitechdaily.com/when-testing-einsteins-theory-of-general-relativity-small-modeling-errors-can-add-up-fast/  
> **username_0**: I pretty much share the views of Richard Muller, professor of physics at UC Berkeley: https://www.quora.com/What-lies-ahead-for-General-Relativity-now-that-LIGO-has-detected-gravitational-waves?                                                                               To claim discoveries of astronomical physical real objects, such as black holes and neutron stars, based singly on the detection of gravitational waves, bearing certain signal signatures, is not acceptable.  

---

## 1 answers

### Answer by username_2 on 2016-03-05. Score: 6

There is no central authority in science. There is no council that sets the standards. The criteria for a discovery are the same: You publish your findings, and your peers accept your results.

There is the 5 sigma rule in particle physics. Perhaps you were thinking of this. But that is not an official rule, instead it's a convention among particle physics. And it's not applicable to every field.

Things are never cut and dry. What does "Peers" mean. What if only most are convinced. Does it count? Discoveries are usually judged in retrospect. After the dust has settled and the debate s are over.

//edit

Why is the bar set so high in physics? When "discovering" a particle there is no way to "see" it, instead you observe a mass of data and see a statistical discrepancy. Cern produces masses and masses of data, and it is sifted for anything unusual. And with so much data, the chance of seeing *something* unusual is actually quite high. (imagine searching for repetitions of '9' in the digits of pi - if you search far enough you can be sure to find a string of 6 9s even though the chance of a random string having 6 9s is very low)

With a mass of data, and the opportunity to repeat experiments it makes sense to set the bar very high.

Compare with an observation, such as the "chirp" at Ligo. We can't repeat it at will, the data is there: something happened that is consistent with a black hole merger. No other theory has been proposed that can explain the observations. The observation is less dependent on a statistical finding after running multiple experiments, but a single direct observation.

In fields in which a result could be explained by chance, then a statistical analysis is done, and published. This contributes to the quality of a finding, and so the number of people you will convince. And convincing your peers is the only criteria that counts in the end.

> **Comments:**
> **username_3**: Good point about the $5\sigma$ rule in physics. This actually distinguishes physics a bit from astronomy, as in the latter field, people tend to happily publish a $3\sigma$ result (although they may call it "tentative evidence").  
> **username_0**: @pela - thanks for the comment - this is amazing, since, IMHO, astronomy/astrophysics deals with real physically existing astronomical objects, while the aim of experimental physics is mostly to verify (somewhat abstract) concepts of theoretical physics ...  
> **username_2**: Would it be worth a comparison with psychology when p=0.05 is "significant" (equivalant to 2sigma) and p=0.1 is "Highly suggestive and tending towards significance")  
> **username_0**: @JamesKilfiger - why not ... I wonder if there already exists some research/publication, covering this issue across variety of science domains.  
> **username_3**: @Alex: The number of sigmas needed to take a result seriously does depends on the type of observation. But for instance, if one detects something which would be unusual — like a galaxy breaking the distance record — then a $3\sigma$ would make most people happy. After all, this still means that "we're 99% sure it's there". Then better follow-up observations may confirm or reject the observation. And as James Kilfiger mention, we're still doing better than most social sciences :)  
> **username_3**: As for your question about Fortran: It very much depends on the type of task, in particular whether high speed is desired. Object-oriented languages like Python and Java can more easily do much more complex tasks, but for e.g. cosmological simulations where speed and memory are the main wish, C/C++ and Fortran are still the languages of choice, I'd say.  
> **username_3**: @Alex: They would, but many if not most problems simply aren't algebraically solvable. Also, I think precision is usually not an issue. But I guess we shouldn't spam James' answer more on this :)  
> **username_0**: @JamesKilfiger - I'm glad that in your answer update you have referred to the case of LIGO observation, since this generalized question of mine was motivated by more specific case featured in     physics.stackexchange.com/questions/236107  
> **username_4**: @pela To publish something at "3-sigma" significance means you are 99.5% confident. To qualify this as tentative would mean that you don't understand your uncertainties and therefore can't assess the significance at all.  
> **username_3**: @RobJeffries: I'm not sure I understand you. Do you mean that 3 sigma should make you _more_ certain than saying that the evidence is just "tentative"?  
> **username_4**: @pela 3 sigma means that you are 99.5% certain - i.e. you would be wrong only 1 time in 200. To call this "tentative" would be an unusual use of English. What people generally mean when they say "tentative" in this context  is that actually, they don't really know how many sigma it is because they don't understand their uncertainties.  
> **username_3**: @RobJeffries: Okay, I think I misunderstood the word then. Thanks for clarifying.  
> **username_0**: I pretty much share the views of Richard Muller, professor of physics at UC Berkeley: https://www.quora.com/What-lies-ahead-for-General-Relativity-now-that-LIGO-has-detected-gravitational-waves?                                                                               To claim discoveries of astronomical physical real objects, such as black holes and neutron stars, based singly on the detection of gravitational waves, bearing certain signal signatures, is not acceptable.  

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