BS: Can somebody explain in plain English

Subject: BS: Can somebody explain in plain English
From: Mrrzy
Date: 07 Oct 11 - 07:38 PM

How FTL travel means time travel into the past?

The way I see it, if you get somewhere faster than light, when you first get there you're invisible, and when the light catches up to you, you get to see what you looked like when you got there, is that it? So from your point of view you get there before you get there, so you get to watch the past happen?

Subject: RE: BS: Can somebody explain in plain English
From: GUEST,999
Date: 07 Oct 11 - 07:41 PM

Mrrzy,

Is this just a wind-up or is it a serious question?

Subject: RE: BS: Can somebody explain in plain English
From: Bobert
Date: 07 Oct 11 - 07:41 PM

So what's to explain??? You seem to have it correct, Mrrzy...

B~

Subject: RE: BS: Can somebody explain in plain English
From: Mrrzy
Date: 07 Oct 11 - 07:52 PM

No, I'm asking about the neutrino thing. The physicists seem to take if for granted that us scifi readers already understand that if anything could travel faster than light then there could be time travel, specifically into the past. I can't see how, but I can see how you could watch a future (from now now) happen from in front of the light that would appear to be come from the past from the now then when you're watching it...

Subject: RE: BS: Can somebody explain in plain English
From: olddude
Date: 07 Oct 11 - 08:16 PM

Mrrzy
nothing travels faster than the speed of light. To get to the furthest reaches of space you need a worm hole. Think of a sheet of paper on your desk, you could travel across it and take x amount of time, however if the sheet was pushed up in the middle with a pin hole, you could go right to the other side in -x time.

Subject: RE: BS: Can somebody explain in plain English
From: olddude
Date: 07 Oct 11 - 08:17 PM

We use to believe the universe being flat ... now we know there are folds and bends in the fabric of space. If one knows how to find a worm hole what would take light maybe 1 million years you may be able to travel it in 1 year.

Subject: RE: BS: Can somebody explain in plain English
From: olddude
Date: 07 Oct 11 - 08:19 PM

from wiki

In physics, a wormhole is a hypothetical topological feature of spacetime that would be, fundamentally, a "shortcut" through spacetime. For a simple visual explanation of a wormhole, consider spacetime visualized as a two-dimensional (2D) surface. If this surface is folded along a third dimension, it allows one to picture a wormhole "bridge". (Please note, though, that this is merely a visualization displayed to convey an essentially unvisualisable structure existing in 4 or more dimensions. The parts of the wormhole could be higher-dimensional analogues for the parts of the curved 2D surface; for example, instead of mouths which are circular holes in a 2D plane, a real wormhole's mouths could be spheres in 3D space.) A wormhole is, in theory, much like a tunnel with two ends each in separate points in spacetime, or it can be also known as two connecting black holes.

There is no observational evidence for wormholes, but on a theoretical level there are valid solutions to the equations of the theory of general relativity which contain wormholes. The first type of wormhole solution discovered was the Schwarzschild wormhole which would be present in the Schwarzschild metric describing an eternal black hole, but it was found that this type of wormhole would collapse too quickly for anything to cross from one end to the other. Wormholes which could actually be crossed, known as traversable wormholes, would only be possible if exotic matter with negative energy density could be used to stabilize them. (Many physicists such as Stephen Hawking,[1] Kip Thorne,[2] and others[3][4][5] believe that the Casimir effect is evidence that negative energy densities are possible in nature.) Physicists have also not found any natural process which would be predicted to form a wormhole naturally in the context of general relativity, although the quantum foam hypothesis is sometimes used to suggest that tiny wormholes might appear and disappear spontaneously at the Planck scale,[6][7] and stable versions of such wormholes have been suggested as dark matter candidates.[8][9] It has also been proposed that if a tiny wormhole held open by a negative-mass cosmic string had appeared around the time of the Big Bang, it could have been inflated to macroscopic size by cosmic inflation.[10]

The American theoretical physicist John Archibald Wheeler coined the term wormhole in 1957; however, in 1921, the German mathematician Hermann Weyl already had proposed the wormhole theory, in connection with mass analysis of electromagnetic field energy.[11]

    This analysis forces one to consider situations...where there is a net flux of lines of force, through what topologists would call "a handle" of the multiply-connected space, and what physicists might perhaps be excused for more vividly terming a "wormhole".
    —John Wheeler in Annals of Physics

Subject: RE: BS: Can somebody explain in plain English
From: Jeri
Date: 07 Oct 11 - 08:30 PM

You probably know this, but I think it goes back to Einstein. Time slows for an object the faster it moves. It's a theory that if you could go fast enough, time would actually move backwards.

I really don't think events would go backwards. I doubt it. It could be awkward to have a chicken un-lay an egg, for example. I'm hoping I could back up in age 20 years or so. Thing is, everything NOT moving at that speed would go on as normal, so if I was half as old, everybody else would be twice as old.

Of course, this means those Star Trek episodes with them doing a sling-shot around a star are bogus because they couldn't have slammed the whole universe into reverse.

Subject: RE: BS: Can somebody explain in plain English
From: Rapparee
Date: 07 Oct 11 - 08:39 PM

I suspect that if you exceed the SOL you could see what had happened, but not change anything. You would be a spectator, not a participant.

For example, everything we see actually happened in the past. That's because it takes a certain duration of time for the light to reach us, be that nanoseconds or years. In effect, we live in the past because our sensory input has a definite speed limit.

BUT...even if we were to dash through a wormhole we would not exceed the SOL. It would be equivalent to walking through a tunnel instead of climbing over the mountain.

On the quantum level things can be quite different. There is, for instance, the situation where a particle beam is split, but what happens to the left hand split ALSO happens to the right hand one even though they are (on a relative scale) light years apart.

Subject: RE: BS: Can somebody explain in plain English
From: Q (Frank Staplin)
Date: 07 Oct 11 - 09:21 PM

olddude, Mrzzy's question is valid, since a group of European physicists have claimed that they observed neutrinos that were moving faster than the speed of light, and have asked other groups to see if they could verify the observation.
If proven, then Einstein's theories would need revision (and physics textbook, gee whiz science, etc. publishers would make a fortune as they published new ones).

I doubt that any mudcatters are attached to advanced laboratories so definitive answers will not be found here.

To add to the speculation, if one got there (wherever) before light did, would the light crash into him and wipe him out? (And mess up his genealogical family tree).

Subject: RE: BS: Can somebody explain in plain English
From: olddude
Date: 07 Oct 11 - 09:28 PM

cool Q my family tree needs shaken ....

Subject: RE: BS: Can somebody explain in plain English
From: Bobert
Date: 07 Oct 11 - 09:42 PM

Wes Ginny Time Machine Idea:

Go to the North Pole... Walk in circles counter clockwise around it... Every 6 (or so) steps = yesterday... According to the Wes Ginny Slide Rule, any average person can walk off 150 years per day... A couple days walking around the pole and yer back in 1700s...

B~

Subject: RE: BS: Can somebody explain in plain English
From: Mrrzy
Date: 07 Oct 11 - 09:56 PM

Right, I don't see how FTL travel = backwards time travel, I just don't. But I'd like to.

Subject: RE: BS: Can somebody explain in plain English
From: Bobert
Date: 07 Oct 11 - 09:59 PM

Let the FORCE be with you, Mrrzy... You have to believe... I mean, BELIEVE!!!

B~

Subject: RE: BS: Can somebody explain in plain English
From: GUEST,999
Date: 07 Oct 11 - 10:19 PM

The problem is fundamental and multifaceted.

1) What do we mean when we say 'go back in time'? The time we are wondering about going back to doesn't exist. It's gone. We want our memories or recollections to be real, and as those things, they are. But as realities, they aren't there anymore. Did they exist? Probably. DO they exist now, probably not. The difficulty is language. If we talk mathematically (which I am not able to do even in my wildest dreams), it might be possible to explain.

I found a method using arithmetic to 'predict' squares ten ahead. That does not mean I can 'see' into the future. If I can find a way to take that method into negative numbers (read fractions) which I'm having a go at now, that will not mean I can look into the past. The world we humans live in is four dimensional. (It's possible we live in an eleven-dimensional world, but even if we do we'd have no way to 'talk' about it other than through the use of mathematics, and if individuals who don't understand higher mathematics as a way of explaining things try to talk about it, then we're hooped at the start.)

When we say things like 'time travel' (something we're doing as we read/think/breathe) or going forward to the future/backward to the past, we admit that we perceive time to be a linear thing. It goes from here to there, wherever either or all of those things might be. To demonstrate the problem, let me pose the question, "Where is here?" Obviously it's where we are, but neither of us is the other and we do not occupy the same space simultaneously, maybe. So, is here where you are or where I am?

We invent constructs in which to 'imagine' things like time. Barium clocks, quartz crystal clocks, atomic clocks, even tick-tock clocks, all of which tell us the time. And tenses in language like past, present, present continuous, future, all of which assure us that we can think in a three dimensional ((up/down, left/right, front/back) space governed by a fourth dimensional idea (time).

[One of the reasons I suspect that Bill D is a genius--not a word I throw around lightly--is that I also suspect he thinks in more than four dimensions. Don Hackman is another, although there are moments when I am so lost with Don I feel I need a 'Hitchhikers Guide to the Moment'. And then there's Amos Jessup, a man with a vocabulary and insight that may exceed Churchill's.]

So let me ask this: if the BIG clock were to be slowing down, how would we know? The answer becomes a paradox. The problem has been alluded to in words by anthropologists who predated Heisenberg--but one group did it in words and the other person in math.

The real difficulty is found in the perception that time is a constant, and so is the speed of light. I disagree. I think it has to be one or the other.

While I get nailed to that notion, allow me to address Part Deux. Later, or earlier, if time flows in two or more directions.

Subject: RE: BS: Can somebody explain in plain English
From: Mrrzy
Date: 07 Oct 11 - 10:26 PM

I thought time *was* rather than flowed?

Subject: RE: BS: Can somebody explain in plain English
From: GUEST,999
Date: 07 Oct 11 - 10:55 PM

Mrrzy, if you're right, which you may well be, then may I suggest that light *is* rather than moves?

THAT, in your words, has defined the problem. "Cute" guys--and I ain't one of 'em--when asked the speed of light, counter with what's the speed of dark. I counter with 'what's the speed of yesterday, now, tomorrow'? WTF? That's the problem!

You have asked a question that is mind-boggling. (Well, boggles mine anyway, and that isn't too hard to do, no offense.)

Let's say that light--far as we know--travels about 300,000 km/sec. Let's also say the we can measure time as we know it to the trillionth of a second. Without being a wise ass, how do I know where I am without being there?

I've got some sort of wrist watch and some sort of ultimate speed/velocity. So, how do I find out where I am?

Subject: RE: BS: Can somebody explain in plain English
From: Bill D
Date: 07 Oct 11 - 10:59 PM

"Can somebody explain in plain English"\

Not even those who believe in and developed this idea can explain it 'clearly', because some of it depends on complex math, and some of it is merely linguistic....manipulation of terms to create metaphor that we think we understand.

We can create the concept of "traveling back in time", but we can't really imagine what that would be like, or avoid all the contradictions involved. In physics, some of these ideas DO represent some interpretations of odd observations and math...but don't really translate easily into something we can 'explain', the temptation notwithstanding.

   My mother used to say her favorite color was "sky-blue pink", and we all see commonly used terms in that name, but it really makes little sense if you try to imagine it. I once found a ceramic tile that faded from sky-ish 'blue' to a 'pinkish' hue in various areas....but it was only a blending OF colors...not a color. Language can discuss things that are not exactly 'real'.

Subject: RE: BS: Can somebody explain in plain English
From: GUEST,999
Date: 07 Oct 11 - 11:07 PM

See what I mean about Bill?

Subject: RE: BS: Can somebody explain in plain English
From: Bill D
Date: 07 Oct 11 - 11:15 PM

I read this yesterday, and knew you'd say that.

Subject: RE: BS: Can somebody explain in plain English
From: GUEST,999
Date: 07 Oct 11 - 11:33 PM

NO comment!

Subject: RE: BS: Can somebody explain in plain English
From: Jeri
Date: 07 Oct 11 - 11:56 PM

If you're gonna ask where you are, and if you state "I am here", you're not where you were and there's no such thing in reality as "here". We perceive "here", but we aren't there. We WERE there, but now we're somewhere else.

Why?

The earth rotates at almost 1000 MPH
It revolves around the sun at 66,000 MPH
The solar system moves through the Milky Way Galaxy at 43,000 MPH
We spin around our galaxy at 483,000 MPH
The Milky Way is moving through space at 1.3 million MPH

As my astronomy teacher put it "You will never be in exactly the same place you are now."

No such thing as "here and now", because once we say it, it's "there and then". But if we travel back through time, we'll have to travel back through space as well or we'll end up in some rather inconvenient locations.

Subject: RE: BS: Can somebody explain in plain English
From: Stilly River Sage
Date: 07 Oct 11 - 11:57 PM

I heard a speaker discuss the aspects of time travel in this context - but the slowdown of the traveler is so insignificant that someone involved in space travel around the sun or wherever the trip had to go only slowed down by seconds, or fractions of seconds. May have been Neil DeGrasse Tyson I was listening to on this.

SRS

Subject: RE: BS: Can somebody explain in plain English
From: Janie
Date: 08 Oct 11 - 06:27 AM

I think I'll stick with Bobert's method....

Subject: RE: BS: Can somebody explain in plain English
From: Lighter
Date: 08 Oct 11 - 07:49 AM

If I shoot a marshmallow at you at high speed, there will be a measurable delay between the time I fire and the the time it bops you on the head.

The faster the marshmallow goes, the less time between the firing and the bopping.

At the speed of light, the delay is comparatively minimal. (If we're only a few yards apart it's teeniest fraction of a second. If we're billions of miles apart, it's really noticeable, even at the speed of light.

Current physics seems to show that light speed is the top speed possible under normal conditions in the physical universe.

Now, what if my marshmallow were zipping along FTL? In theory, if it were going fast enough, the firing and the bopping would take place at precisely the same instant. And faster than that (this is the point), the sugary confection would hit *even before* it was fired. Looking back on the whole event, it would seem to us that the 'mallow had traveled backwards in time. We'd remember that you'd uttered an otherwise inexplicable "Ouch!" even before the marshmallow was fired.

The effect would have preceded the cause. Voila! A marshmallow that traveled backwards in time!

Of, course how it might have seemed to the marshmallow (which I've just endowed with human consciousness)is another story. It probably wouldn't be much like the movies. SF takes the abstract notion of "going backwards" and adds adventures. That's why it's called science *fiction.*

This was all explained to me when I was a lad by a guy with a huge cranium and skinny arms, wearing a long silvery cape. I never saw him again.

Subject: RE: BS: Can somebody explain in plain English
From: DMcG
Date: 08 Oct 11 - 08:33 AM

Just because time travel is possible (assuming it is) does not in itself mean it is possible for a person to travel in time. For example, the easiest thing to make travel in time is likely to be small amounts of information rather than something corporate, which would appear as nothing more (or less!) mysterious than being able to make accurate predictions of something.

Subject: RE: BS: Can somebody explain in plain English
From: Ed T
Date: 08 Oct 11 - 08:43 AM

Could this be a similar experience?: When a jet travels faster than sound (which occurs every day in air travel), an observer hears the sound in the sky in a slightly different location, opposed to where the jet is seen in the sky. But, the auditory signel does not change the jets actually physical location.

When working on my computer, upstairs, I notice a slight time difference between the sound on the downstairs cable HD TV, and the upstairs cable non-HD TV (when they are both tuned to the same station). Anyone know why? I suspect HD signal takes a slight time longer to process in the HD TV box. I have also noticed that on HD,sometimes when peoiple speak, it seems the sound is slightly off the visuals (it seems like people talking are doing a poor job of lip synchronization).

Subject: RE: BS: Can somebody explain in plain English
From: DMcG
Date: 08 Oct 11 - 09:15 AM

something corporate
I meant, of course, corporal, not corporate. Being indundated with junk mail from companies that don't yet exist would be the stuff of nightmares.

Subject: RE: BS: Can somebody explain in plain English
From: GUEST,John from Kemsing
Date: 08 Oct 11 - 10:14 AM

Recently we have been told that scientific study of ultra small particles suggest that items may be able to travel faster than the speed of light (186000 miles per sec.) It could mean a re-visit to Einstein`s work.

       If one propels, say, a laser torch with the lens at the front, at a speed 1000 miles per sec. away from a fixed datum and then switches on the said torch, will not the light being emitted from that torch be doing 187000 miles per sec.?

DISCUSS!

Subject: RE: BS: Can somebody explain in plain English
From: Paul Burke
Date: 08 Oct 11 - 10:34 AM

J from K: No it won't, that's exactly Einstein's great discovery. The light from the torch travels at 186000 miles a second relative to the torch travelling at 1000 miles a second. It ALSO travels at 186000 miles a second relative to an observer sitting in a deckchair who is watching the torch flash by at 1000 miles a second. The reason that both these statements can be true is that time slows down (relative to the sitting observer) for the torch. If I've got my sums right, "torch" time is slow by about 15 minutes per year.

If you google for the Twins Paradox, you'll see a full explanation of this effect.

That's the interesting thing about things that travel AT the speed of light: although from their point of view, time passes perfectly normally, from our point of view they have no time at all.

Subject: RE: BS: Can somebody explain in plain English
From: Musket
Date: 08 Oct 11 - 10:45 AM

Space / time is a ration and time slows with displacement.

So all the neutrino excitement has proved, (and to be fair the implications are rather fundamental,) is that the constant that other properties are measured against, (formally the speed of photons in a vacuum) now has to be altered to the maximum speed we can get neutrinos to travel, and again, I suspect that although the experiments weren't in a vacuum, a vacuum must allow a higher speed anyway.) We may find other particles that have an even higher velocity in the future and then the constant will alter again.

However, relativity demands that everything is relative, hence the speed of light was used as the constant because we assumed it was the only constant. It still is a constant, and can still be used, but something else has a higher displacement and so in an ideal world, we should now assume that as the constant. (The 3rd string on my banjo is always half a tone flat within 3 secs of tuning it. That is the only other ruddy constant I know of.)

Fascinating, but as the constant is used purely as something that is not relative, it doesn't matter what it is really. E=MC² still holds, just the value of C changes, so the ratio of E to M remains the same. After all, C is just an arbitrary value that has no bearing on the value of either mass nor energy.

Scientists ponder on what happens if you do go beyond the speed of light, but bear in mind this is not "you" and all your corresponding atoms, this is a particular subatomic particle that alone does not become a building block into a physical object. The excitement is, when you boil it down, about now wondering what else can go that fast, and if something does, can it begin to explain the mass of the universe we calculate as existing but cannot detect?

Time is only measured against the speed of light, it is not a property of it...

That's about as far as I go. When I wrote my PhD thesis, quantum mechanics was about to get an explosion of understanding, but luckily for thickos like me, it wasn't altering every week!

Subject: RE: BS: Can somebody explain in plain English
From: Amos
Date: 08 Oct 11 - 10:56 AM

IF the individual particles could be accelerated to FTL individually, it would seem reasonable that some way could be figured to similarly accelerate a whole molecule under some sort of uniform stimulus. If so, then all the molecules of an assembly such as a container of some kind might similarly by driven. If so what happens to a thing contained therein?

Mr Wells, meet Mr Einstein, and vice-versa.


A

Subject: RE: BS: Can somebody explain in plain English
From: Max Johnson
Date: 08 Oct 11 - 11:47 AM

I think that the main indicator that people cannot and never will be able to travel backwards through time is that they haven't.

If they had, then we'd be inundated with time tourists observing major events, and we'd also be swamped by advertising from the future.

This might be because it's impossible, or it might be because mankind is toast. If ants or whales could travel through time, we wouldn't know.

Subject: RE: BS: Can somebody explain in plain English
From: gnu
Date: 08 Oct 11 - 01:14 PM

I am going read this thread later but, you couldn't watch yourself arrive unless you turned on the lights but how could you find the switch in the dark if you've never been there before?

Subject: RE: BS: Can somebody explain in plain English
From: GUEST,999
Date: 08 Oct 11 - 01:35 PM

Follow the marshmallow, Gnu.

Subject: RE: BS: Can somebody explain in plain English
From: Mrrzy
Date: 08 Oct 11 - 01:53 PM

Lighter, that made sense. Thanks!

Follow the marshmallow, indeed.

Subject: RE: BS: Can somebody explain in plain English
From: Q (Frank Staplin)
Date: 08 Oct 11 - 02:37 PM

Discussion of the "finding."

Scientific American.
"Faster-than-Light Neutrinos? Physics Luminaries Voice Doubts." John Matson, Sept. 20, 2011.
http://www.scientificamerican.com/article.cfm?id=flt-neutrinos

*OPERA scientists announced neutrinos made the underground journey from a lab in Switzerland to one in Italy, making the trip 60 nannoseconds faster than they would have traveling at light speed.
*Oscillation Project with Emulsion tRacking Apparatus.

Doubt raised by:
Martin Rees, Univ. Cambridge
Steven Weinberg, Univ. Texas
Laurence Krauss, Arizona State Univ.;
His comments echo those of the other two, expanded. "It is an embarrassment a far as I am concerned. It was not unreasonable for the experimentalists to submit a paper with an unexplained result. But a press conference on a result, shich is extremely unlikely to be correct, before the paper has been refereed, is very unfortunate- for CERN and for science. Once it is shown to be wrong, everyone loses credibility. Neutrino experiments are hard, and systematic errors at the limit of resolution can be significant. Moreover, because the experiment seems to violate Lorenz invariance, which is at the heart of so much known physics, one should be skeptical. One should be additionally skeptical because observations of SN1987A showed, as I wrote in 1998, that neutrinos and photons travel at the same speed to one part in a billion, several orders of magnitude below the claimed effect. Now, the only way out of that is to have some energy-dependent effect, but all the ones that make sense don't wash here."

(Several comments from readers appended)

Subject: RE: BS: Can somebody explain in plain English
From: olddude
Date: 08 Oct 11 - 02:44 PM

wanna step back in time. Just look at the stars ... heck we can see them with our naked eye but the light left there in some cases millions of years ago. If you were looking at earth you would not see the earth today. Nearest star is 4.3 light years away so you are looking back 4.3 years each time you look at it ... see it is all relative... speaking of relatives ... can't stand my sister in law ...

Subject: RE: BS: Can somebody explain in plain English
From: Paul Burke
Date: 08 Oct 11 - 03:03 PM

15 SECONDS per year, not minutes. I did get my sums wrong.

Subject: RE: BS: Can somebody explain in plain English
From: HuwG
Date: 08 Oct 11 - 07:07 PM

I agree with Terry Pratchett's theory that the speed of dark must be faster than that of light, because the dark has to get out of the way when you turn a light on.

Subject: RE: BS: Can somebody explain in plain English
From: gnu
Date: 08 Oct 11 - 07:16 PM

Okay... I read the thread. I ate the marshmallow. But, it's not gone. It will reappear in the future... I'll stop there...

I've seen guys eat mushrooms and have time regression.

No offense meant. Just (trying) joking.

I used to get off on math and related fields but I got sidetracked with day-to-day engineering and never really felt the urge to get back to the theoretical stuff.

Subject: RE: BS: Can somebody explain in plain English
From: Keith A of Hertford
Date: 09 Oct 11 - 04:51 AM

They have not really claimed FTL neutrinos.
The results seem to show it and they have no other explanation, so they have released the data.
At relativistic speeds time slows down for the person moving.
They age less than the rest of us.
This is measurable and an established fact.
At light speed time stands still for the mover, and beyond light speed goes into reverse.
Light speed requires infinite energy, because mass increases with speed and becomes infinite at light speed.
FTL may not be impossible. Just crossing the barrier.

Possible non FTL explanations are errors of measurement distance/time, and extra dimensions providing short cuts.

Subject: RE: BS: Can somebody explain in plain English
From: GUEST,999
Date: 09 Oct 11 - 06:45 AM

"At light speed time stands still for the mover, and beyond light speed goes into reverse."

There is the impossibility. What happens is that time simply ceases to be in our reality. Time cannot work in reverse. The logic we use to measure time no longer applies.

"Light speed requires infinite energy, because mass increases with speed and becomes infinite at light speed."

That is a confusion caused by the term mass. It's based on E=mc2. However, we can see it 'fall apart' when we set the value
of c as 1. It is similar to the conundrum, "I've found a universal solvent but I can't find anything to keep it in."

Subject: RE: BS: Can somebody explain in plain English
From: Keith A of Hertford
Date: 09 Oct 11 - 07:55 AM

That is a confusion caused by the term mass. It's based on E=mc2.

No. Mass increases with velocity, but the increase is only significant at relativistic velocities.
As it approaches c, the mass approaches infinity.
An infinite force would be needed for the last bit of acceleration.
The object would acquire infinite kinetic energy, requiring infinite energy to have been expended.

E = mc^2 refers to converting between energy and mass.
I kg of matter converts to 1X 3X10^8 X 3X10^8 joules of energy.

Subject: RE: BS: Can somebody explain in plain English
From: Keith A of Hertford
Date: 09 Oct 11 - 08:38 AM

Time dilation is real.
Short life particles live longer at great speed.
Two atomic clocks measure different times if one stands still and one flies around the world ina plane.
Fly W to East and time slows.
Fly E to West and time is slower for the clock on the ground, because it is moving faster than the one in the plane.

Subject: RE: BS: Can somebody explain in plain English
From: Paul Burke
Date: 09 Oct 11 - 09:31 AM

It's based on E=mc2. However, we can see it 'fall apart' when we set the value of c as 1

I don't think c is ever 1, except in very special units (light seconds per second?). It's 300000000 metres per second or about 670 million miles per hour. The equation that shows time going "backwards" is actually a bit more complicated, and my HTML isn't up to writing it out here clearly, but the clock slowdown factor is 1/sqrt( 1- (v^2/c^2)).

If v=c, then the divisor becomes zero, and 1/0 is infinity. If v is greater than c, you are taking the square root of a negative number: the result is an imaginary number and I can't think what imaginary time feels like. I certainly don't want it in my back yard.

Subject: RE: BS: Can somebody explain in plain English
From: GUEST,999
Date: 09 Oct 11 - 12:03 PM

Keith, I know that. I'll try once more, no offense--I'm not making myself clear. There is no such thing as infinite energy or infinite mass. The E=mc2 formula doesn't work in all directions. It's a statement meant to 'predict' what one can expect from some 'weight' of matter that is converted to energy. The formula really says, E = m. Choose light as the constant and use whatever measures you wish for energy and (rest)mass. The c2 is for atomic/subatomic particles.

Paul, thank you too. What I'm saying is this: time cannot go backwards. It's I think the same type of proof one would use to demonstrate that you can never reach the wall across the room from you. I'm sure you're aware of it, but in case you're not--

You're in a room that is 20 linear meters from one wall to the other. To get to the other wall you first have to cover half the distance. From that new start point you have to again cover half the distance. The from that new start point, etc. So, you never reach the other wall. However, we both know you will. Proof on paper is not always = to proof in reality.


Course, then again guys, I could be way far out to lunch.

Subject: RE: BS: Can somebody explain in plain English
From: Musket
Date: 09 Oct 11 - 12:09 PM

Hence, as I put above, c2 is just a constant. It has to have a value, to give comparative results for given values to the other variables, as the Manhattan project found in a rather dramatic sense.

Subject: RE: BS: Can somebody explain in plain English
From: Keith A of Hertford
Date: 09 Oct 11 - 01:37 PM

Infinite energy or mass (or anything) are impossible so FTL is impossible.
E=mc^2 does work in both directions, and is true in whatever units you choose.
It is not just for subatomic particles.
Tons of mass is lost every second to keep the sun hot.

Subject: RE: BS: Can somebody explain in plain English
From: Keith A of Hertford
Date: 09 Oct 11 - 01:46 PM

If you choose SI units, mass is in kgs and energy in joules.
The constant is c^2 with c in m/s.

Subject: RE: BS: Can somebody explain in plain English
From: GUEST,999
Date: 09 Oct 11 - 04:36 PM

Dammit, Keith, you want to be the winner, you win.

And, fyi, it's mass in grams = energy in ergs.

BFN

Subject: RE: BS: Can somebody explain in plain English
From: Bill D
Date: 09 Oct 11 - 05:01 PM

Since there are particles which have momentum, but no mass..(physicists differ)... might it be the case that certain particles would not be affected by light speed? The neutrino has very little, if any mass, and it goes very fast.
Since there are particles which go 'almost' C, and there are *theoretical* particles which, if they exist, may have no mass....what would be the *theoretical* speed limit? Photons travel AT C, and have no 'mass' in the usual sense, yet it seems to be accepted that they could be used as a light sail.

I think there is much to be learned yet....including the effect all the "dark matter" that seems to be logically required has on very fast particles...even on photons.

Subject: RE: BS: Can somebody explain in plain English
From: Lighter
Date: 09 Oct 11 - 05:17 PM

Nor have we spoken of going sideways in time.

Subject: RE: BS: Can somebody explain in plain English
From: Keith A of Hertford
Date: 09 Oct 11 - 05:20 PM

(Not in SI units.)


The barman says, "That's impossible!"

A faster than light neutrino goes into a bar.

Subject: RE: BS: Can somebody explain in plain English
From: Bill D
Date: 09 Oct 11 - 05:46 PM

Perhaps the "Red Queen effect" from "Thru the Looking Glass" is relevant.


"Sometimes I have to run ever so fast just to stay in the same place."

Subject: RE: BS: Can somebody explain in plain English
From: Ed T
Date: 09 Oct 11 - 09:23 PM

I see what you mean about the relationship between beer and the speed of light, Keith A of Hertford.

First there was a brand of beer, let's say Nutrino brand. Then there was light (Nutrino Light, of course) , after that. Makes sense to me.

Subject: RE: BS: Can somebody explain in plain English
From: gnu
Date: 09 Oct 11 - 09:45 PM

9... "From that new start point you have to again cover half the distance."

Math guy and an engineer guy at the starting line 100m from a naked woman. Rules are when the whistle is blown they may run half way until the next whistle. Whistle blows and engineer sprints while the math guy just laughs and doesn't run. The starter asks the math guy why he is laughing and not running. The reply is that if one runs half way each time he will never get to the destination.

The starter relates this to the enginner who replys, "For all intents and purposes, I'll get close enough."

Subject: RE: BS: Can somebody explain in plain English
From: Black belt caterpillar wrestler
Date: 10 Oct 11 - 06:45 AM

So, if neutrinos are moving faster than light and have not reached an infinte mass they must therefore have no mass at all!

My wife says that this was the belief of her Physics proffsor at uni back in the 1970s and he was somewhat belittled fr it at the time.

(Discuss) :)

Subject: RE: BS: Can somebody explain in plain English
From: Keith A of Hertford
Date: 10 Oct 11 - 07:58 AM

It was believed they were massless, and so travelled at lightspeed.
They are now believed to have small but not zero mass, so must stay below that limit.

Subject: RE: BS: Can somebody explain in plain English
From: Mrrzy
Date: 10 Oct 11 - 10:44 AM

Could the speed of light be increasing, ever so slightly? That would have made it appear constant to us, who have short lives, but by now we've been measuring it long enough that it's actually a little faster than it was? So all we really have is a better measurement?

Subject: RE: BS: Can somebody explain in plain English
From: Keith A of Hertford
Date: 10 Oct 11 - 11:39 AM

Good idea, but I think it would have been noticed.
c was first measured by the discrepancies in the apparent positions of Jupiter's moons depending on how far away it was.
That would show up any change I expect.
Also absorption lines in the spectra of distant objects have been observed for about a hundred years. They would be changing as c changed.
Radio frequencies would change too.

Subject: RE: BS: Can somebody explain in plain English
From: Keith A of Hertford
Date: 10 Oct 11 - 11:44 AM

Then again, in the neutrino experiment the distance was determined by GPS, and c would be factored into that calculation.
It has been suggested that there are unexpected errors in the GPS calculation.

Subject: RE: BS: Can somebody explain in plain English
From: olddude
Date: 10 Oct 11 - 12:22 PM

Gps calculations are not precise enough to measure this. That is the flaw I think ..

The universe is dynamic in nature. Light travels at a fixed rate but the distortion and path it takes varies.

Subject: RE: BS: Can somebody explain in plain English
From: Black belt caterpillar wrestler
Date: 11 Oct 11 - 08:34 AM

So how much mass does a neutrino have when you slow it down, if it has almost no mass at near light speed?
Is there a quantum amount of mass, and is this it?

Subject: RE: BS: Can somebody explain in plain English
From: GUEST,Patsy
Date: 11 Oct 11 - 09:05 AM

And there was me thinking that Neutrinos was the latest diet aid.