— a problem for the biblical creationist model?
In March 2015 it was reported that “[a]stronomers using the NASA/ESA Hubble Space Telescope have, for the first time, spotted four images of a distant exploding star. The images are arranged in a cross-shaped pattern by the powerful gravity of a foreground galaxy embedded in a massive cluster of galaxies.”1 See galaxy in inset in Fig. 1, which has been enlarged in Fig. 2.
Astronomers were looking at a massive elliptical galaxy (Fig .2) and its associated galaxy cluster MACS J1149+2223 (Fig. 1), which is supposedly at a distance in the universe such that the light from the galaxy should take more than 5 billion years to reach Earth. They then found something that has never been seen before. The huge mass of the elliptical galaxy and the cluster is believed to bend the light from a much more distant galaxy where a supernova was occurring. The image of the supernova then is seen as an Einstein cross made from 4 separate images of the same supernova, heic1505, also named Refsdal. In Fig. 1 arrows indicate the 4 images. Fig. 1. shows a wide view of the cluster and the elliptical galaxy with the alleged identical 4 supernova images around it.
Now, a new claim has been made. Because the path lengths for the 4 different images of the supernova are not equal, due to the lensing effect of the massive cluster, the travel time for the light along each path is different. Since some paths are longer than others it has been predicted that the light signal for one of them is greatly delayed (by about a year) over the others. Therefore astronomers are excited by the prospect of seeing the increasing light curve of the supernova explosion once again just like they have already observed.
Using various models of the cluster acting as a lens, astronomers have made a consistent set of predictions for when the next image will appear. Hubble’s gaze will now periodically be fixed on the skies in anticipation of once again observing Refsdal. The next image of this extraordinary event is expected to peak in the first third of 2016.2
Challenge to a creationist cosmological model?
Now I have been challenged via Twitter (see below) that the biblical creationist ASC model3 has a problem because that model says that all incoming light from the cosmos to Earth travels at infinite speed. This is a reference to the one-way speed of light. Therefore if the supernova is the same one for all 4 images how is it possible that the light can be delayed in one path by any amount, let alone a year, when it travels at infinite speed?
The answer to this is straightforward and comes from a correct understanding of the actual one-way speed of light concept. It should be noted that the Anisotropic Synchrony Convention (ASC) is as valid a choice of a timing convention as is the Einstein Synchrony Convention (ESC), which assumes isotropic speed of light, c. Therefore it is only a coordinate transformation and the physics under either the ESC (which is standard in cosmology today) or the ASC is unchanged.
The ASC assumes a particular anisotropy in the one-way speed of light in vacuum. The inbound speed toward the observer is infinite, but light speed incident at an arbitrary angle, θ, to the observer is given by:
c = c0/(1-cosθ), (1)
where c0 is the canonical speed of light (c0 = 299,792 km/s) as determined from a two-way speed of light measurement. Thus θ = 0 degrees means incident on the observer and θ = 180 degrees means moving away from the observer. At 90 degrees or transverse to the observer the speed of light is the canonical speed c0, the same as the two-way isotropic speed of light.
Looking at the trigonometry in the lower image of Fig. 3, with the 4 light paths shown, it is clear to see that the radial components of the paths from the source to the observer are all identical. This is further illustrated by two light paths “A” and “B” in Fig. 4. What is different is their transverse components, which represent the deviations of these paths from a “direct line of sight” geometrical distance. The deviations are produced by the gravitational lens effect of the elliptical galaxy, bending the light around it. These deviations add increased path lengths and longer travel times. The reason the travel times are longer is because the one-way speed of light (as defined by the choice of the ASC convention) is the canonical speed c0 for those components of the distance in those paths. Therefore if the paths were all “straight in” without deviation all 4 light beams would arrive at the same time, instantly, but there would be no gravitationally lensed Einstein cross either. What the ASC model expects in this case is that the relative travel times, at speed c0, along paths transverse (at 90 degrees) to the observer are what makes the differences in the arrival times of the 4 supernova light signals.
This result is the same as under the ESC assumption, as expected. Consider in the case of the ESC the 4 “straight in” without deviation components of the light beams would all arrive at the same time travelling at the same speed c0 and exactly the same distance. Again it is only the relative travel times, at speed c0, along paths transverse (at 90 degrees) to the observer that make any differences in the arrival times of the 4 supernova light signals.
This may be better understood from Fig. 4. The explosion is the supernova source and the eyes are the observer. All observations are in the rest frame of the observer. For both ESC and ASC the travel time along any path, A or B in this case, is the total distance divided by the speed of light along that path. The travel time along path A is tA = a/c, and along path B the travel time is tB = (b1+b2)/c. Under ESC c = c0 regardless of direction (isotropic), but under ASC c is determined from equation (1) above (anisotropic).
It follows from Fig. 4 that any extra-travel time due to a deviation from the straight path (path A) is found only in the transverse component (distance d). Thus irrespective of the simultaneity convention chosen the additional travel time to Earth is,
tB – tA = 2d/c = 2d/c0. (2)
This is because for path B over the segment b1 the light has an additional transverse travel time component d/c0 and over the segment b2 it again has an additional transverse travel time component d/c0 to bring the beam back in line to arrive at the observer. As expected the physics is unchanged regardless of which convention is chosen. This is because under both conventions the transverse speed of light c = c0.
This latest alleged discovery of a gravitational lensed supernova, with separate 4 images and different paths to Earth, even if correct, is not a problem for the biblical creationist ASC cosmology. It is no disproof of an infinite one-way speed of light towards the observer on Earth. Nor should it be, because a different choice of a timing or simultaneity convention, apart from the one that Einstein chose, can have no bearing on the physics. It is simply a different convention and without assuming a convention one cannot know the speed of light, regardless of whether you assume it isotropic or not.
- Hubble sees multiple images of a supernova for the very first time, March 5, 2015
- Astronomers get once-in-a-lifetime opportunity to predict supernova, November 13, 2015.
- Synopsis: A biblical creationist cosmogony, March 9, 2015.
- R. Newton, Distant starlight and Genesis: conventions of time measurement, Journal of Creation 15, no. 1: 80-85, 2001; J.P. Lisle, Anisotropic Synchrony Convention—A Solution to the Distant Starlight Problem, Answers Research Journal 2:191–207, 2010.
- J.G. Hartnett, Synopsis: A biblical creationist cosmogony
- J.G. Hartnett, Expansion of space – a dark science
- J.G. Hartnett, A biblical creationist cosmogony
- J.G. Hartnett, Speculation on redshift in a created universe
- J.G. Hartnett, Supernova remnants and the age of the Universe