# If GP1 fails to favour GR

1. Jan 12, 2008

### wolram

If this mammoth effort does favour some other model what will the next step be?

Will every one try to find fault first?

2. Jan 12, 2008

### Garth

wolram, what is GP1?

Garth

Last edited: Jan 12, 2008
3. Jan 12, 2008

### turbo

I think we can safely assume he means Gravity Probe B, and it is a pretty probing question.

Last edited: Jan 12, 2008
4. Jan 12, 2008

### wolram

Sorry it is obvious i get things mixed up, i did mean GPB.

5. Jan 12, 2008

### Garth

First it is obvious that there will be room for dispute in the GP-B results. The unexpected errors are being modelled and subtracted from the data to give the signal, however I see that if the final result is inconsistent with GR to greater than a 3 $\sigma$ confidence level then plenty of people will question their error models.

It is interesting to see that the present results are inconsistent with GR to a 1 $\sigma$ confidence level as discussed here.

If the results prove to be inconsistent with GR and consistent with another theory then it will depend on the plausibility of that other theory, but I see a lot of momentum in the standard model so that it will require time to 'turn the ship around'.

Garth

6. Jan 12, 2008

### wolram

Garth, i imagine that the heavens will fall down if GPB favours some model other than GR
I just need to know how much wiggle room there is, could the debate make the test a
nonsense?

7. Jan 12, 2008

### wolram

After looking in the arxives i guess , CL means anything is possible, i mean if one takes all the above 95% CLs , to mean some thing.

8. Jan 13, 2008

### Garth

The GP-B team claim that eventually (May 08) they will be able to reduce the error bars to within 1 mas to, I presume, the 3 $\sigma$ CL.

All the data and their error reduction modelling will be posted by NASA on the internet for anyone else to check.

Just a reminder, the present 1 $\sigma$ result represents an http://colloquia.physics.cornell.edu/11-12-2007/cornellpres_files/v3_slide0426.htm [Broken] at the 68% confidence level.

Garth

Last edited by a moderator: May 3, 2017
9. Jan 13, 2008

### wolram

Thank you Garth, if this CL is reached what will the next step be?

10. Jan 15, 2008

### Garth

To see whether it is consistent with GR, or otherwise.

If inconsistent the next step will be to check and double check everything and see whether the confirmed results lead to a modified GR, or otherwise.

Wait and see, not long now (I hope).

Garth