<p>Having a look on <a href="https://en.wikipedia.org/wiki/Hubble&#39;s_law" rel="nofollow noreferrer">Wikipedia</a> I noticed the following values (of the last 6 years) for the Hubble constant:</p>

<ul>
<li>67.6±0.7 SDSS-III Baryon Oscillation Spectroscopic Survey    </li>
<li>73.00±1.75   Hubble Space Telescope</li>
<li>67.80±0.77   Planck Mission</li>
<li>69.32±0.80   WMAP (9-years)</li>
<li>70.4±1.3     WMAP (7-years)</li>
</ul>

<p>Most of experiments exclude the values of the others so that WMAP excludes the values of SDSS and from Hubble, while Hubble excludes Plank Mission's values, SDSS and WMAP 9.
Can anybody tell what's the problem here and which one is the more reliable source for $H_0$?</p>

CC BY-SA 3.0
2017-01-06T18:31:31.183Z
This is more a guess, so I haven't put as an answer, though I'm fairly certain it is very close to the truth: measuring the Hubble shift of nearby objects gives you a less model-dependent way of measuring H, but the measurement of the Hubble shift is more error-prone. Measurement of the Hubble shift of further away objects is less error-prone, but using them to measure H is much more model-dependent.
John Davis
CC BY-SA 3.0
2017-01-06T22:15:18.910Z
I can assure you, from my many years of experience in this, that the answer to your question is unequivocally -- No.  Some may have strong opinions on this, but scientists differ on this and no one knows for sure.   However, the situation now is better than it was before.
eshaya
CC BY-SA 3.0
2017-01-06T22:19:15.547Z
I was afraid that was exactly the case... thank you eshaya
Dac0
CC BY-SA 3.0
2017-01-07T15:46:26.797Z
There's some controversy over the constant: https://arxiv.org/abs/1512.07364 **and** https://en.wikipedia.org/wiki/Hubble_Bubble_(astronomy)
Wayfaring Stranger
CC BY-SA 3.0
2017-01-11T17:16:06.747Z
illustration of this phenomenon https://www.cfa.harvard.edu/~dfabricant/huchra/hubble/h1920.jpg
samcarter_is_at_topanswers.xyz
<astrophysics><fundamental-astronomy><hubble-constant>
Why the Hubble constant is so inconsistent?
Dac0
# Why the Hubble constant is so inconsistent?

(Asked by: username_0 on 2017-01-06)

Having a look on [Wikipedia](https://en.wikipedia.org/wiki/Hubble's_law) I noticed the following values (of the last 6 years) for the Hubble constant:

* 67.6±0.7 SDSS-III Baryon Oscillation Spectroscopic Survey
* 73.00±1.75 Hubble Space Telescope
* 67.80±0.77 Planck Mission
* 69.32±0.80 WMAP (9-years)
* 70.4±1.3 WMAP (7-years)

Most of experiments exclude the values of the others so that WMAP excludes the values of SDSS and from Hubble, while Hubble excludes Plank Mission's values, SDSS and WMAP 9.
Can anybody tell what's the problem here and which one is the more reliable source for $H\_0$?

**Tags:** astrophysics, fundamental-astronomy, hubble-constant

> **Comments:**
> **username_1**: This is more a guess, so I haven't put as an answer, though I'm fairly certain it is very close to the truth: measuring the Hubble shift of nearby objects gives you a less model-dependent way of measuring H, but the measurement of the Hubble shift is more error-prone. Measurement of the Hubble shift of further away objects is less error-prone, but using them to measure H is much more model-dependent.  
> **username_2**: I can assure you, from my many years of experience in this, that the answer to your question is unequivocally -- No.  Some may have strong opinions on this, but scientists differ on this and no one knows for sure.   However, the situation now is better than it was before.  
> **username_0**: I was afraid that was exactly the case... thank you username_2  
> **username_3**: There's some controversy over the constant: https://arxiv.org/abs/1512.07364 **and** https://en.wikipedia.org/wiki/Hubble_Bubble_(astronomy)  
> **username_4**: illustration of this phenomenon https://www.cfa.harvard.edu/~dfabricant/huchra/hubble/h1920.jpg  

---

## 0 answers

