Adding “Google is your friend” as if you were schooling him on something didn’t help my impression.
The variable speed of light thing is a hypothesis, not a theory, and it’s not a hypothesis that’s actually all that well-supported by experiment. And even at that, it’s not really meaningful to describe that hypothesis as being about a change in c at all: What they’re really talking about is variation in the fine-structure constant, which could just as easily be interpreted as (say) a change in the charge of the electron. Even the physicists who proposed these models admit that the evidence in favor of them is extremely weak, and that the hypothesis is probably not true.
Gravitational time dilation, meanwhile, is a real phenomenon. It can be quite significant in the close vicinity of a black hole, and is measurable (with very sensitive instruments) even in the paltry gravitational field of the Earth. It is not, however, particularly significant to the problem at hand in this thread. Unless you would like to explain (preferably with calculations) how it is relevant?
That is why i provided a link to black holes for example.
Likewise, as the ‘constant’ for the speed of light is supposed to be for a vacuum, that is hypothetical also. Space is not a perfect vacuum. Hence, depending where/how light is measured, we get a variable speed. Gravity and black holes affect the speed of light, correct?
Here is another article in case yo missed the previous 2:
http://www.foxnews.com/science/2013/04/29/speed-light-may-not-be-constant/
The supposed age of the Universe is relative to the point of observation and its gravity. Therefore, GTD is completely relevant to the topic at hand, as the OP is incorporating the age of the universe within his question.
Okay, now I’m confused.
You said the speed of light might be changing, and gave a link to an article that had to do with how the speed of light changes when passing through a medium.
I said that it’s the speed of light in a vacuum that the changing-speed-of-light crowd is most interested in.
You countered by saying that space isn’t a perfect vacuum.
I replied that the interstellar medium is so incredibly rarefied that its index of refraction (how much light slows down while passing through it) is so close to 1 as for the difference to be practically undetectable.
And you reply with … black holes?
What do black holes have to do with the index of refraction of the interstellar medium? Sure, if a beam of light passes close to a black hole it’s going to be subject to some pretty nasty gravitational lensing, but most of the light that arrives in our telescopes has NOT passed anywhere near a black hole.
If you follow up those articles you’ll discover that they’re highly speculative and unsupported by empirical observation. They’re in “hey, here’s an interesting thing that might be remotely possible” territory. Maybe they’ll turn out to be true and revolutionize physics, but it’s not likely.
It should be noted that Fox News serves a conservative audience with a higher percentage of creationists than the general population. So they have a vested interest in pumping up “Scientists have the speed of light wrong!” stories because a variable speed of light is a key element of many attempts to reconcile observable data about the universe with the Biblical creation story.
Incorrect. Even in a black hole, one is still equal to one.
Yes, but our point of observation is not inside nor anywhere remotely close to a black hole, and so the effect is utterly negligible.
But … but … what about all those cosmologists who say that the Universe is just the inside of a really really big black hole?
I believe this bullshit, but if it helps your worldview of understanding the well known infelicities of science journalism, so be it.
Now I have to wonder about the leftist motives of the home section of the NYTimes.
From that wiki article:
’ The hole is called “black” because it absorbs all the light that hits the horizon, reflecting nothing, just like a perfect black body in thermodynamics.[2][3]’
Then you ask how black holes affect how light propagates through space?
Again from that wiki article on black holes:
’ In this way, astronomers have identified numerous stellar black hole candidates in binary systems, and established that the core of our Milky Way galaxy contains a supermassive black hole of about 4.3 million solar masses.’
Regardless of black holes, the matter in space through which light travels will have some effect on that light before it reaches us. This brings me back to my previous point regarding the assumed speed of light c in a vacuum.
Im sure you have heard of Barry Setterfield, i will defer to him regarding this:
‘In 1738: 303,320 +/- 310 km/second
In 1861: 300,050 +/- 60 km/second
In 1877: 299,921 +/- 13 km/second
In 2004: 299,792 km/second (accepted constant)’
'Setterfield teamed with statistician Dr. Trevor Norman and demonstrated that, even allowing for the clumsiness of early experiments, and correcting for the multiple lenses of early telescopes and other factors related to technology, the speed of light was discernibly higher 100 years ago, and as much as 7 percent higher in the 1700s. Dr. Norman confirmed that the measurements were statistically significant with a confidence of more than 99 percent.
Setterfield and Norman published their results at SRI in July 1987 after extensive peer review.’
A black hole affects light that intersects it or glazes it. Most of the light we receive from stars and distant galaxies has not interacted with a black hole.
Creationist nonsense. Here’s a quote from your link:
*"The theory of evolution requires unfathomable lengths of time – eons … billions and billions of years.
Even with all that time, it’s still hard to imagine how complex biochemicals such as hemoglobin or chlorophyll self assembled in the primordial goo. But to those of us who question the process, the answer is always the same. Time. More time than you can grasp – timespans so vast that anything is possible, even chance combinations of random chemicals to form the stunning complexities of reproducing life.
Modern physics is now considering a theory that could throw into confusion virtually all of the accepted temporal paradigms of 20th-century science, including the age of the universe and the billions of years necessary for evolution. Further, it raises the distinct possibility that scientific validation exists for a (gasp) literal interpretation of the seminal passages of Genesis. Goodbye Scopes trial.
The theory is deceptively simple: The speed of light is not constant, as we’ve been taught since the early 1930s, but has been steadily slowing since the first instance of time. …"*
As I said above, the idea that the speed of light has varied over time is important to creationism because it allows them to handwave away astronomical observations that prove that the universe is ancient. As a result, any marginal scientific research that seems to hint that maybe there’s some variation in the speed of light tends to get blown out of proportion.
That should be “… intersects or GRAZES it …”
A common Young Earth Creationist claim:CE411: Speed of Light Slowing?
The possibility that the speed of light has not been constant has received much attention from physicists, but they have found no evidence for any change. Many different measurements of the speed of light have been made in the last 180 or so years. The older measurements were not as accurate as the latest ones. Setterfield chose 120 data points from 193 measurements available (see Dolphin n.d. for the data), and the line of best fit for these points shows the speed of light decreasing. ** If you use the entire data set, though, the line of best fit shows the speed increasing. However, a constant speed of light is well within the experimental error of the data.** Dolphin, Lambert, n.d. Table 1: Master Set of 193 Values of c. http://www.ldolphin.org/cdata.txt. See also Constancy of the Velocity of Light
Or if talkorigins.org is too biased for you, even the ICR has abandoned this argument:In a non-weighted least squares fit, every data point has equal weight in determining where the best fit straight line should be drawn through the data. For a data set consisting of measurements having error bars of varying lengths, it is not appropriate to give every data point equal weight as Norman and Setterfield have done. It is standard practice to weight the data points in inverse proportion to the size of their error bars. That is, data points with large error bars (greater uncertainty), have less impact on where the best fit straight line should be drawn than do data points with small error bars. This is especially important for the current data set, since the reported error bars range from ± 20,000 km/s to ± 0.0003 km/s. When I analyzed the entire data set of 163 points using the standard, weighted, linear least squares method, the decay of c was determined to be:** decay of c = 0.0000140 ± 0.0000596 km/s/year.**
This result says pretty plainly that there is no discernible decay trend in the data set presented by Norman and Setterfield.
Has the Speed of Light Decayed? by Gerald A. Aardsma, Ph.D.
You were thinking of donut holes. I can’t say that I blame you.
It’s painfully obvious to me, assuming those figures accurate, that it wasn’t the speed of light that changed, but our ability to measure it more accurately.
Also, lets keep things clear: There’s the speed of light taken literally, the velocity of an actual, emitted photon through any physical medium (matter). This is refraction, and is a well known, studied and understood phenomenon.
Then, there’s the speed of light as in the physical constant sense, or c. This is the limit that matter/energy can travel within spacetime, (not matter). Here, there is no evidence yet discovered or uncovered by prediction that claims c has been slowing down. Which, as Chronos states, means it’s a hypothesis, and on thin ice at best.
Concerning black holes, gravity affects both matter and spacetime, but only dilates spacetime, not matter (per se), thus light refraction and GR time-dilation are two fundamentally different things you seem to be conflating, both of which are backed up by mountains of emperical evidence to boot.
Setterfield maintains http://www.setterfield.org/index.htmlGenesis Science Research site. The referenced paper can be found at that site. As the title indicates, it is a creationist website. Although the link to World News Daily in your post will have already told that to anyone familiar with the subject.
What’s the trend then on the slow down? I want to know in time buy new lamps and scatter them around the inside of my living room.
(Honestly, I never knew about this facticiousoid for Creationists.)
All measures must be taken in order to shoehorn observed reality into the confines of the account in Genesis, plus a bunch of made up dogma about its interpretation. People’s faith are on the line here! If the bible’s wrong about something, then… I don’t even want to think of what that might mean for the rest of the book…
I mean, really, how could it possibly be wrong?