View Profile: john hunter - Cosmoquest Forum

2017-Jul-23, 11:08 PM

john hunter replied to a thread Supernovae data: Betoule with error bars and statistical packages in Space/Astronomy Questions and Answers

Thanks everyone so far, off line for a few days, but it would be interesting to hear any other suggestions.

5 replies | 162 view(s)

2017-Jul-23, 09:31 AM

john hunter started a thread Supernovae data: Betoule with error bars and statistical packages in Space/Astronomy Questions and Answers

Does anyone have a link to Betoule et al supernovae binned data (31 points, DM against z) including the error bars? ...

5 replies | 162 view(s)

2017-Jul-19, 11:35 PM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

If you mean about 72km/s/Mpc from cosmological measurements and about 69km/s/Mpc from galaxies...this ATM proposal is that a(dot)/a is half those...

70 replies | 2936 view(s)

2017-Jul-19, 11:06 PM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

OK, and when this defined quantity is measured, lets say nowadays, it has a measured value...what would you say that value is?

70 replies | 2936 view(s)

2017-Jul-19, 10:28 PM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

"The Hubble parameter H is defined in textbooks as a(dot)/a", this is agreed, and the ATM proposal is that it is constant (in time) and has half the...

70 replies | 2936 view(s)

2017-Jul-19, 09:55 PM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

You have made it clear that you think the use of the term Hubble constant in the title was wrong. And, from post 7 onwards it's been made clear that...

70 replies | 2936 view(s)

2017-Jul-19, 01:05 PM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

John Mendenhall, Yes, interesting article and your "I'm not a hardnosed mainstreamer; I just like the observations, theories, predictions, and...

70 replies | 2936 view(s)

2017-Jul-19, 08:07 AM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

This ATM thread is about the possibility that the rate of expansion a(dot)/a is half that accepted by the mainstream. 1) Both the v (via redshift)...

70 replies | 2936 view(s)

2017-Jul-18, 07:26 PM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

https://en.wikipedia.org/wiki/Friedmann_equations Just under the section 'Equations' there are two equations and to make the top one have...

70 replies | 2936 view(s)

2017-Jul-18, 11:21 AM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

H as defined in the previous post a(dot)/a is approx. 1*10^-18 . The Andromeda galaxy is about 2.5 million light years away so dt is about 2.537...

70 replies | 2936 view(s)

2017-Jul-18, 08:36 AM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

Reality Check, If you are suggesting that either the data or curve in the graph for the new relation has been falsified - i.e. made up or tampered...

70 replies | 2936 view(s)

2017-Jul-17, 10:29 PM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

Yes, that's right, but the curve which has the best match (i.e for which the extra variable parameter gives the best match) is chosen. That's not...

70 replies | 2936 view(s)

2017-Jul-17, 09:32 PM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

There are a few things here. a) Firstly the redshift due to expansion of the universe isn't really due to a Doppler shift 'velocity', although...

70 replies | 2936 view(s)

2017-Jul-17, 07:56 AM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

Reality Check, regarding the rest of your post 35 on the ISW, the assumptions they have used and put into their model were mentioned in post 33,...

70 replies | 2936 view(s)

2017-Jul-17, 06:32 AM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

Someone needs to be irreverent, to bring todays cosmologists/physicists down to earth! (dark energy! Can you imagine bringing it as a new idea and...

70 replies | 2936 view(s)

2017-Jul-17, 06:02 AM

john hunter replied to a thread How is H(z) measured? in Space/Astronomy Questions and Answers

Thankyou everyone, The straight line has only one parameter H(0), whilst the LCDM has at least two H(0) and omega(m), but maybe it's a topic to be...

10 replies | 636 view(s)

2017-Jul-16, 10:34 PM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

5. Observational Hubble constant data which is measuring the Hubble parameter H(z). this paper https://arxiv.org/abs/1507.02517 has a table...

70 replies | 2936 view(s)

2017-Jul-16, 09:25 PM

john hunter replied to a thread How is H(z) measured? in Space/Astronomy Questions and Answers

Thanks everyone so far...Shaula, did you mean that if the universe were not accelerating the plot of H(z) against z would be a straight line? Would...

10 replies | 636 view(s)

2017-Jul-16, 03:32 PM

john hunter replied to a thread How is H(z) measured? in Space/Astronomy Questions and Answers

Ok, the expression 'Hubble constant' has been changed to 'the Hubble parameter'... In this paper https://arxiv.org/abs/1507.02517 ,page 2 there...

10 replies | 636 view(s)

2017-Jul-15, 05:50 PM

john hunter started a thread How is H(z) measured? in Space/Astronomy Questions and Answers

Hi can anyone answer a couple of questions about this... In this paper https://arxiv.org/abs/1507.02517 ,page 2 there is a table of how Hubbles...

10 replies | 636 view(s)

2017-Jul-14, 09:52 AM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

Dark energy versus a(dot)/a being half the mainstream value... 1) Type 1a Supernovae data: this graph...

70 replies | 2936 view(s)

2017-Jul-13, 06:46 AM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

IF02 https://en.wikipedia.org/wiki/Friedmann_equations IF01 and IF05 matching light curves - which gives luminosity distance and the diagram of...

70 replies | 2936 view(s)

2017-Jul-12, 09:46 PM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

IF01 To find the distance to the galaxy that contains the supernova, scientists just have to compare how bright they know the explosion should be...

70 replies | 2936 view(s)

2017-Jul-12, 07:56 AM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

For IF05: https://arxiv.org/abs/astro-ph/9812133 (Perlmutter 1998) top of page 23 shows how different models with varying matter density...

70 replies | 2936 view(s)

2017-Jul-12, 06:44 AM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

Reality Check, Putting Hubble constant definition as key words brings up many sites e.g....

70 replies | 2936 view(s)

2017-Jul-11, 10:34 PM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

Reality Check P.S. in your post number 8 ..."H0 is Hubble's constant and corresponds to the value of H (often termed the Hubble parameter which is a...

70 replies | 2936 view(s)

2017-Jul-11, 10:05 PM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

From wd40s comments, and the Wikipedia article on Hubbles law https://en.wikipedia.org/wiki/Hubble%27s_law (where is first has Hubble constant in...

70 replies | 2936 view(s)

2017-Jul-11, 08:36 AM

john hunter replied to a thread Halve the Hubble constant! (still apears to be 72km/s/Mpc) in Against the Mainstream

Reality Check, IOF1: "Type Ia supernovae that have a very well-determined maximum absolute magnitude as a function of the shape of their light...

70 replies | 2936 view(s)