The speed of light in a perfect vacuum cannot be measured without first obtaining a perfect vacuum. Light has been measured traveling at many different speeds, some of them far in excess of the "textbook" rate.
54 comments
What kind of retard.... no... let me re-phrase
Retards have been measured at many different levels, some of them far in excess of the "textbook" retard.
Nah, I actually trust the folks who went to the trouble of getting PhDs in fields related to space and all that. They know far more about the subject than I do, so they're much more likely to be correct about things like that than I am.
The perfect vacuum was the 1969 Electrolux canister. That thing lasted forever!
Well since that's about their level of understanding, why the hell not
And Evolution has been measured by many scientists and other learned men and found to be accurate.
Oh, and nylon eating bacteria.
And to bring it down to your level, CTD, nylon eating bacteria means we win.
1. The speed of light in a vacuum is a consequence of Maxwell's equations and does not need to be directly measured since it can be calculated by measuring more ameniable electromagnetic systems.
2. The value of c is now defined as a particular value, and the meter and the second are determined from it. Special Relativity predicts that both time and space can vary but not the speed of light. A prediction that has been confirmed time and time again.
3. Light has never been observed to go faster than c , though electromagnetic wavefronts have (phase velocity).
@myheadhurts:
That's faster than light in the medium, not faster than c .
Cherenkov radiation does that. The classic blue glow of radioactive cores in water is actually caused by electrons travelling through the water faster than light can. They are effectively breaking the light barrier (for water) and so throw off a "photonic boom", which is the glow.
image
Are you really that fucking stupid? Have you never taken a real science class or were you homeskooled?
Edit: I just looked at that forum and there is a whole lot of stupid happening on it. The lengths these Creationists will go through to demonstrate a 6000 year old universe is truly mind-boggling. What absolute fail.
So if you were in a car going at the speed of light and you turned the lights on, would they do anything? Can't answer that, can you Mr. Smartypants? Therefore evolution is false and creationism is true.
Light has never been measured far in excess of the textbook rate by anyone in the last 300 years. At this point, our accuracy is so great that any change over time sufficient to support a speed thousands or millions of times faster in 4000BC, if it were still ongoing, could be observed in a matter of weeks.
"Light has been measured traveling at many different speeds, some of them far in excess of the "textbook" rate." Yes, the phase velocity of light can exceed c .
However, the group velocity of light never can.
It's like a spinning barber pole hurtling through space. The stripes on the pole may be moving faster than the pole itself, but it doesn't matter , because the stripes won't arrive anywhere until the pole gets there.
You are arguing if there were no perfect vacuum, light would have different speeds, and since there is no perfect vacuum, it should. Gues what?! That's been tested and debunked! It was formerly believed spacce was filled with the ether, and light would be observed at different speeds at different times in earth's orbit. It wasn't, it was the same all around, and the ether is a quaint idea from the past. Like most of your thoughts.
"The speed of light in a perfect vacuum cannot be measured without first obtaining a perfect vacuum"
that's why we use satellites, in the perfect vacuum of space
"Light has been measured traveling at many different speeds, some of them far in excess of the "textbook" rate."
holy shit, citation SERIOUSLY fucking needed.
Man, this whole site is full of epic fail. I noticed none of the people supporting credible science are actually educated in the field they are discussing. Do all the real intellectuals get banned, to make scientists seem uninformed?
Extrapolation.
We get as close as possible to the ideal conditions, then spot a trend.
However, this doesn't mean guess work. By observing a trend we can predict where it would be at a given time or condition.
PS: We found absolute zero by extrapolation.
You gotta problem Mr. tomatohead. Isnt the fundie claim that the universe is only 6000 years old? And the light from the stars dont say we are older, because the speed of light is SLOWING DOWN (therefore, the stars are actually closer)? Not speeding up as "in excess of the textbook" rate? You and Kent Hovind (and a few other crackpots) need to get together and get your blatant blithering idiot stupid stories to correspond.
Actually...the speed of light may not be a constant.
Australian Paul Davies and his associates have hypothesized that the speed of light may actually have changed over time.
How or why is not clear yet. Davies is a reputable physicist. Just Google "Paul Davies speed of light" for more info.
Of course they're still talking about a universe that is billions of years old.
Um, no.
First of all, we have the technology to create a perfect vacuum...or nearly so.
...secondly, light travels slower in non-vacuum mediums. That is, it's at it's maximum in a vacuum.
Unless you're suggesting that space isn't a vacuum, but some magical material. Well, go up there without a space suit and prove it.
And then the OP goes on to say
"It is a good thing to admit when something is unknown."
Too bad these lying hypocrites can't take their own fucking advice. Especially when it comes to them using "goddidit" as the answer to everything instead of just admitting that they don't know.
Note: I had a look at the original web page, and it was like looking over a cliff into an infinite void of stupidity. Please be careful not to get too close to the edge.
Confused?
So were we! You can find all of this, and more, on Fundies Say the Darndest Things!
To post a comment, you'll need to Sign in or Register . Making an account also allows you to claim credit for submitting quotes, and to vote on quotes and comments. You don't even need to give us your email address.
