"the speed of dark!"

Hey all!
I once heard an episode of Car Talk and cannot figure out what episode number it was. I remember the guys talking about the speed of light, and more importantly & humorously, “the speed of dark”.
I need to find this episode — Please, can anyone help me?!? I’ve searched Google and the Car Talk forums with no luck…

Thanks a ton!

The Lucas klan has the worldwide rights to Darkness and the Tappet brothers are old family friends.

Uhhh… I don’t understand. ??

@JimmyDuane, I’m not sure which episode, but was this the thing they were reading? I’ll try to ask around and see if I can find what show it was.

@cdaquila‌ not sure… the link didn’t work for me.
I know it was while a caller called in and somehow they started talking about the speed of light, then “the speed of dark!” :slight_smile:

@JimmyDuane, for some reason the link is getting mangled. I knew there was a whole list of one-liners that have been read, but it sounds like you’re referring to a particular episode with a particular call. I’ve thrown the question out to the other lackeys to see what they can remember.

I bet it had something to do with this:


See the 4th paragraph from the end.

Thank’s @Shadowfox; that was worth reading just for a good laugh.


@JimmyDuane‌, I got a response from our producer: The bit aired originally in #0025. Aired in encores #0716 and #1322.

Now THAT was funny @shadowfax!

That was an old joke played on students going through electronics training in the Navy. It starts with an explanation of DC and batteries. The students see movies and text books explaining that electrons come out the - end of the battery and flow to the +, which is counter to most peoples logic.

Once they accept this, then the dark sucker theory is easy to pass on, and many student bite. The instructors have a lot of fun with this. I went through this training back in 1970, but I already had a couple years of electronics training and experience under my belt when I joined so I got the joke right away and had fun watching my classmates fall for it.

If you’re traveling at the speed of light,
say on a larger vehicle on which you have a smaller vehicle ( which will also travel at the speed of light ) in which to travel…
Then you launch from the platform …which is already going the speed of light…and your vehicle launches AT the speed of light ( from the platform already going the speed of light…

How fast will you be going ?
light speed TIMES light speed ?
Light speed PLUS light speed ?

Sorry Ken, no part of your Tachypomp machine will be able to exceed the speed of light:

Speed limit: 186,000 miles per second. It’s the law.

Just wondering about unknow theory like space travel because I’ve seen it done with rocket sleds

That sort of thing can be done with rocket sleds at speeds much lower than light speed. But once you approach the speed of light it requires basically an infinite amount of energy to accelerate, making it impossible to break through that speed barrier.

So once your rocket sled reaches the speed of light, nothing on it can be made to go any faster.

@keith yeah, it’s old as the hills. I remember back in high school I flipped the joke on its ear and had a bunch of kids thinking the physics teacher was teaching outdated junk. I ended up organizing a protest outside the front entrance before school one morning demanding that the poor guy be retrained in Darksucker Theory. Fortunately for me, the physics teacher had a sense of humor and thought it was hilarious.

@ken green You’ll be going light speed, both relative to the big ship and relative to a (relative to you) stationary observer. It is impossible to go faster than that within the confines of normal space. At near-light velocities, time slows down and space shrinks for the thing that’s traveling that fast. The ship you are “leaving” will appear to surround you. See the “Aberration in Action” section of this page.

Of course, if you actually hit the speed of light, you will also have infinite mass, be expending infinite energy, and time, for you, will freeze. So you’re basically both pretty amazing, and royally screwed if you try it. :wink:

There was a great PBS show some years ago about relativity. They did a video simulation of what you would see if you were driving at near the speed of light. Because of the warpage of space-time you would see the scenery ahead of you “bend” in such a way that you could see around the corners of buildings ahead of you. It was cool.

Ok, so how about the light itself ? ( no, I don’t know how this is automotive related :wink: )
Say you are on a vehicle traveling the speed of light…
If you project a beam of light forward…does the beam not advance out ahead of you ?
If you project a beam of light directly behind you…does the end of the beam stay stationary as you and the light source advance in the oposite direction ?

The flashlight beam appears to you to be moving away from you at the speed of light. Regardless of your speed, whether zero or 1000 mph or the speed of light, the flashlight beam seems to go the same speed, ie light speed, relative to you, regardless which way you point it.

BUT, to a stationary observer, both you and the light beam would appear to be traveling the same speed, ie the speed of light.

The seeming paradox is that the speed of light appears constant to all observers, no matter what their relative velocities are.


We can relate it to cars (er… loosely…) because the proof that what @jesmed1 is saying is true is that the GPS network works. Because GPS was designed to compensate for relativistic effects, if relativity were false, GPS would not work: