Vacuum Tubes and Light - Page 2

A vacuum is also the only place where light can actually travel at light speed, too.  I thought there was something in my theory, but I suck at searching for stuff, and I tried "vacuum tube shining light" and guess what was found?  Just people on the internet asking about why their vacuum tube glows.

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Originally Posted by kevin gilmore 

light definitely travels very well in a vacuum. Much better than it does in air in fact.

Depends what the "air" is made of

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Originally Posted by ramicio 

A vacuum is also the only place where light can actually travel at light speed, too.  I thought there was something in my theory, but I suck at searching for stuff, and I tried "vacuum tube shining light" and guess what was found?  Just people on the internet asking about why their vacuum tube glows.

Light travels at "light speed" (not C) in most mediums under regular conditions - because light speed is the speed of light (duh). It travels at C in a vaccuum - which is said to be the relativistic constnat by which most forces operate (gravity for example). When particles (or whatever) exceed the speed of light in a particular medium (possible) they release cherenkov radiation (think of it as an almost Prandtl–Glauert singularity type of affair). Furthermore, there are instances where light can exceed C (for example if shot through cesium vapour - which has been reproduced in the laboratory). There's also theoretical instances where light can be used to send particles at such high speeds they travel back in time (thought impossible until the emergence of M theory and other issues), without the use of wormholes, cosmic strings etc, due to the equivalency of matter and energy demonstrated by Einstein, wherein large amounts of energy (high powered lasers) instead of a large mass is used to initiate the means of travel at such great speed.

Science is awesome.

Good thing or we'd be nonexistent. How would we have sunshine if photons couldn't pass through vacuum.

Quote:

Originally Posted by MrGreen 

There's also theoretical instances where light can be used to send particles at such high speeds they travel back in time (thought impossible until the emergence of M theory and other issues), without the use of wormholes, cosmic strings etc, due to the equivalency of matter and energy demonstrated by Einstein, wherein large amounts of energy (high powered lasers) instead of a large mass is used to initiate the means of travel at such great speed.

Err what? Have you got a reference for this?

I may be showing my ignorance, but whut th' 'ell...

If light does indeed affect a vacuum tube, would it be possible to regulate the signal with light input instead of the usual grid plates?  Would it sound any better?

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Originally Posted by DanielCox 

 

Quote:

Originally Posted by MrGreen 

There's also theoretical instances where light can be used to send particles at such high speeds they travel back in time (thought impossible until the emergence of M theory and other issues), without the use of wormholes, cosmic strings etc, due to the equivalency of matter and energy demonstrated by Einstein, wherein large amounts of energy (high powered lasers) instead of a large mass is used to initiate the means of travel at such great speed.

Err what? Have you got a reference for this?

Considering it is merely theoretical physics, it's impossible to provide concrete evidence for anything I have said. There's plenty of documents on a man who is currently experimenting with the idea - including a documentary.

Make of it what you will.

Not even a paper reference? I'm not a subscriber to M theory myself.

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Originally Posted by DanielCox 

 I'm not a subscriber to M theory myself.

Me neither. If quantum physics wasn't so reliable for calculations etc, I'd be in the Einstein camp (regarding predictability of the universe). I can't remember the name of the book I first heard about the idea for using energy instead of mass to create a wormhole, I'll see if I can dig it up. The documentary (an awful documentary by the way) is easy enough to find.

Hello all,

Rather than start a new thread, I thought I would post in this existing thread. I've had a Mk II for a year or two now and have loved every moment of music on it. I am wondering if upgrading the tubes will reveal any significant change in sound? David ZheZhe from Little Dot has suggested on his forum the Mullard M8100s or the Mullard M8161s, that seems like the ideal choice (the price is just within my budget too). One n00b question here: judging by the pictures on eBay of both the Mullard tube sets, I presume the M8100s are the smaller tubes that sit nearer the front of the amp, and the M8161s are the larger ones? While I'm at it, can someone explain to me what the smaller and larger ones actually do? (I know how vacuum tubes work in themselves, but I'm not sure how the smaller and larger ones actually differ... apart form size.)

Basically, I want to know if my £40 or so on tubes will actually make a significant difference to the sound coming from my Little Dot Mk II? (I use HD595s headphones, but am probably going to buy either some AKG K702s, or HD650s.)

Thanks!

Quote:

Originally Posted by DanielCox 

Not even a paper reference? I'm not a subscriber to M theory myself.

Personally I think it's tough to subscribe to any unproven theory, especially one as tentative and unexplored as string/M theory! Not that I'm an expert, but I do admire M theory rather a lot. The 'graviton' (the quantum of gravity) isn't shoehorned into the equations, it appears as an inescapable conclusion of the equations. It'a this natural merger of quantum mechanics and relativity that just seems very appealing to me - and to many a physicist. 

I'd like to know why you don't 'subscribe' to M theory? Is there a particular facet that you feel uncomfortable with? (Its inability to prove easy to test is what many abhor I think, but I don't think that should stop progress in theoretical studies since many things have been 'proven' before their discovery, one example being Paul Dirac and anti-matter. Plus it has given the world a lot of new mathematics.)

This is totally relevant to vacuum tubes! :P (Well, sort of.)

I wanted to state that I own a Beseler color analyzer that is used in the dark room that uses an Photomultiplier vacuum tube to measure the color temperature of the light as it pass the negative under the enlarger that would be hitting the photo paper. I would then adjust the color filter pack under the enlarger lamp using the Beseler color analyzer Photomultiplier  tube.

What about Geiger counter tubes?