Has the speed of light decreased?

You may have caught this news story already - it looks likely that the speed of light may not be a constant, but that it has gotten slower over time.... Here's a link to an article about this....

http://www.newscientist.com/news/news.jsp?id=ns99992650

By the way, one of the researchers who is proposing this (as mentioned in the article) is Prof. Paul Davies. I was lucky to have lunch with him a few years ago.... I actually told this story not long after we started Sowpub.... If you're interested, you can read it here....

http://www.sowpub.com/cgi-bin/forum/webbbs_config.pl?read=1171

Watch the windows of opportunity, since you never know when they will open! :)

- Dien Rice

P.S. Just in the past few days, I've been lucky to spend time with another well-known scientist/businessman, Prof. Dave Warner, and it was an incredible experience.... I might tell that story some time soon (if anyone is interested)....

Hey Dien:

I went to uni with a guy called Paul Davies. He'd probably be in his mid to late thirties now. And he had light colored hair and a big nose. Same guy?

Anyway. From reading that, they never addressed the possibility that it's not an increase in electron charge but maybe more electrons in existence throughout space.

If space is accelerating apart... and as it does small particles pop into existence... and if those particles then add to the volume of space and push it apart some more... then, the more space moves apart the more these energy particles appear. In other words, there is more "stuff" in space and thus more "stuff" that light has to travel through.

The more stuff light travels through the slower it becomes, right?

Light travels at different speeds depending on what it's travelling through, doesn't it? Slower in water and glass, for instance.

So obviously, with more stuff to travel through, or have a gravitational effect on it, light should appear to be slightly slower.

As for seeing light... we can't, can we?

I mean, we can see what light shines on but not actual light - not with our own eyes.

And if we see different colors of the light spectrum, aren't we again merely just seeing the object the light is shining on?

So if light is slowing... and lets assume it is because of the increase in dark energy which means there's more stuff light has to travel through... then could that explain WHY the color of the universe has now changed from what it was believed to be?

In other words... scientists got the color right the first time... and this time... but they didn't realize it was due to a doppler affect.

Interesting.

Michael Ross


This is also interesting

Fascinating discussion Michael -- I never thought about the amount of "stuff" in space increasing.

> As for seeing light... we can't, can we?

> I mean, we can see what light shines on but
> not actual light - not with our own eyes.

I think you've got this wrong . . .

What we see is the light that is reflected off of things. The reflecting item determines the color of the light, but light is the ONLY thing we see.

If this weren't true, wouldn't we be able to see objects even in the total absence of light?

Best,

Paul




eCommerce Software for Digital Products

Hi Paul,

I think you're right about "seeing" light.... In a way, light is all that we see!

Our eyes have photodetectors which detect light, and we "see" the light which is reflected from objects around us.... When photons (you can think of them kind of like "particles" of light) bounce off of objects and enter our eyes, at the back of our eyes our retina has "detectors" which "fire" when the light hits them!

This then sends a signal to the brain, which says "wow, there's something there"! And from that, our brain "reconstructs" the image we see.... :)

Michael's post is pretty thought-provoking though.... I have to think a lot to answer all the issues he raises! :)

- Dien

> What we see is the light that is reflected
> off of things. The reflecting item
> determines the color of the light, but light
> is the ONLY thing we see.

Without objects to reflect the light, we do not see the light.

When I look at a book, for instance, I see the book sitting on the shelf. I do not see the light travelling from the book.

If I shine I light in the dark, I see the light reflecting off the object the light shines on. But I do not see the light travelling between me and the object. I will see it if there are particles like dust or smoke in the air between me and the object. But if there are no objects in the air to reflect the light I do not see the light.

If I stand to the side of you I do not see light entering your eyes.

Good thing we don't see it too. Otherwise we'd be walking around in a color light fog.

Michael Ross


Click here to see the light

> Without objects to reflect the light, we do
> not see the light.

> When I look at a book, for instance, I see
> the book sitting on the shelf. I do not see
> the light travelling from the book.

> If I shine I light in the dark, I see the
> light reflecting off the object the light
> shines on. But I do not see the light
> travelling between me and the object. I will
> see it if there are particles like dust or
> smoke in the air between me and the object.
> But if there are no objects in the air to
> reflect the light I do not see the light.

> If I stand to the side of you I do not see
> light entering your eyes.

Okay, I see (??) what you're getting at -- you're saying we can't see the MOVEMENT of light -- right?

Just for the sake of accuracy, I'll respond to this statement:

> Without objects to reflect the light, we do
> not see the light.

This may be true in certain cases -- if the light were in a narrow enough beam that it wasn't enveloping everything around you. But if your eyes were in the path of the light, you'd see it.

For example, with nothing between you and the sun except the vacuum of space, if you looked at the sun, would you see the light? Of course.

What we refer to as (visible) light is simply a portion of the electromagnetic spectrum which our eyes can convert to electrical impulses. So if our eyes are in the path of those wavelengths, we'll see the light regardless of whether they're reflected or direct.

I feel like I'm back in college -- fun stuff! :o)

Best,

Paul