SPEED OF LIGHT!

[Frew]

We are driving done the road at the speed of light. So what happends if I turn on the headlights?
Nothing?


On a side note, can somone answer the question in my signature?

 

[imported_Nail]

We are driving done the road at the speed of light. So what happends if I turn on the headlights?

They shine.

How does the Teflon stick to the pan?

By adhesion.

 

[imgod2u]

Originally posted by: LeadFrog
We are driving done the road at the speed of light. So what happends if I turn on the headlights?
Nothing?


On a side note, can somone answer the question in my signature?

The headlights would shine. You would see them shine just like normally. The thing is, to an outside observer, the beam of light is not moving away from you. To you, it is. This is because time has frozen for you and the light beam is moving away from you at an infinitely slow speed (zero).

I have no idea how Teflon works.

 

[Ryoga]

Originally posted by: LeadFrog
We are driving done the road at the speed of light. So what happends if I turn on the headlights?
Nothing?

You can't have a velocity of the speed of light. As you accelerate toward the speed of light, your mass increases asymtotically. An object travelling at the speed of light would have infinite mass (not impossibly large, infinite). In order to accelerate infinite mass, you would need infinite energy. In the whole of the universe, there is not infinite energy.

A better question is: if photons have mass (and they appear to) how can they travel at the speed of light?

However, ignoring that, the speed of light is relative to the viewer. Whether you're immobile or travelling at 9% the speed of light, the speed of light appears to be the same because your entire frame of reference is travelling that fast.

See also, Straight Dope.

On a side note, can somone answer the question in my signature?

According to more Straight Dope, friction.

 

[frontwards]

Originally posted by: Ryoga
A better question is: if photons have mass (and they appear to) how can they travel at the speed of light?

they don't have mass, but they do have momentum, which is contradictory since momentum=mass*velocity. wierd stuff.

 

[Cogman]

heres an interesting question then, Scientists have made light travel FASTER then the speed of light (something to the effect of 350x the speed of light), So how does that work? after all the speed light in a vaccum was supposed to be the Ultimate speed limit correct?

 

[silverpig]

Originally posted by: frontwards

Originally posted by: Ryoga
A better question is: if photons have mass (and they appear to) how can they travel at the speed of light?

they don't have mass, but they do have momentum, which is contradictory since momentum=mass*velocity. wierd stuff.

But E = mc^2 -> m = E/c^2 so momentum = E*v/c^2 which works fine.

 

[silverpig]

Originally posted by: Cogman
heres an interesting question then, Scientists have made light travel FASTER then the speed of light (something to the effect of 350x the speed of light), So how does that work? after all the speed light in a vaccum was supposed to be the Ultimate speed limit correct?

That's just the sensationalist headline in the newspapers

Normally, photons look sorta like this:

..::||::..

They blur in, have a meaty part, and blur out. When you try to detect a photon, it's a probability function for what part of the photon you have to see in order to detect it. Some photons get detected with the first . some with the last . but most are detected when the || part hits the detector. Now, when you pass a photon through a very very thing barrier (mica for instance), the photons tunnel through the mica and sometimes emerge looking like this:

...:::||:.

So the meat of the photon is shifted forward. It's frontmost point is still in line with the one from above, but as you can see, it's more likely to be detected earlier than the upper photon I drew.

 

[Tiamat]

The steel is sputtered with an interlayer that PTFE adheres to more easily, and then is sprayed with the PTFE after being preheated. Then the Sprayed steel is sintered at high temperature (not high enough to soften the metal).

Edit: The link given above is decently correct. I have done this process myself.

 

[Pulsar]

In case you were wondering, sputtering involves shooting an electron beam through a material to knock the surface of it free - it adhears on a molecular level and provides a very porous (in terms of surface area) coating that let's other materials adhere easily.

 

[jongyoo]

Wow, where you guys goin to school and where did you get your degrees if you are out already? I'm still in the University of Texas in Austin.

 

[f95toli]

LsDPulsar: I am trying to understand what kind of "sputtering" you are describing.
In ordinary magnetron sputtering the conditions are usually choosen so that thr film grows epitaxially on the substrate, so it is definitly not porous.

But I am used to ordinary thin-film technology where we sputter metals or oxides on substrates, depositing sticking layers for PTFE might different.
Do you know what kind of sticking layer is used for PTFE?

 

[Shalmanese]

Google is your friend