How long does it take for a single photon to travel from the sun?

[White Rabbit]

An easy question, anyone can google the answer, but heres a slightly curly version.

If it takes about 8 min+/- for a photon of light to traval from the sun to here going by our clock, how much flight time does the photon experience by it's own clock due to time dilation?

I was reading the latest issue of Sky and Telescope and the cover story is on Superparticles. One of the blurbs in the article said that some of these particles traveling at near the speed of light are coming from light years away., sometime hundreds of light years but that the actual flight time for the particle was 20 min due to time dilation. This got me thinking about the question above.

Any ideas?

[renormalised]

It's a photon....it doesn't experience any time at all, since it's traveling at the speed of light. However from our perspective, it takes 8.3 minutes for the photon to zip across the distance from the Sun to the Earth. But if you take its flight time to Earth from the time the photon is produced in the core of the Sun, it's several million years. That's because of the density of the core and surrounding gases is such that every time the photon is emitted it only travels a minute distance before it's reabsorbed by another atom.

That travel time of 20 minutes for the 12 million Ly between Centaurus A and the earth was for a cosmic ray of extremely high energy. That's all the time it experiences in that distance due to time dilation.

[sheeny]

Yep. What renormalised said...

Al.

[AGarvin]

I think it goes something like this:

Assuming we're talking within the framework of special relativity, the photon experiencs zero time, in other words, from its point of view it gets there instantly.

It has to do with the concept of spacetime separation as defined by the metric:

dS^2 = c2 dT^2 - dX^2 - dY^2 - dZ^2

where dS^2 is the spacetime separation between two events, c2 dT2 is the time dimension and dX^2 - dY^2 - dZ^2 are the spacial dimensions. This metric will give either a positive, negative or zero result. The time is the proper time experienced by an observer travelling between these two events.

If the time component is greater than the spacial separation, you get a positive result and the two events are causally connected (known as a timelike interval). If you get a negative result, the spacial distance is greater such that not enough time will pass between the two events to allow them to be causally connected (a spacelike interval).

If the answer zero, the events have a lightlike interval, often refered to as null. This would be like two events occuring one light year and one year apart. In the case of the photon from the Sun, the travel time is ~8.3min and the distance equally ~8.3 light min, so the interval is lightlike and the proper time interval experienced by an observer on the photon would be zero.

DOH, hope I've got that right after that ramble.

Andrew

[renormalised]

It would be easier to explain the time dilation using the Lorentz transform equation for time...T = T(obs)/SQR(1-(v^2/c^2)), where T(obs) is the time measured relative to an observer of an event, v is the velocity of the moving object and c is the speed of light. Plug in the numbers for a photon and your answer is T = 0.

[janoskiss]

Yep zilch. When you're a photon everything exists at once - no past - no future - just the Isness of it all :P

[OneOfOne]

I read the same article. They said the particle packed the punch of a baseball travelling at something like 100kph...as I recall? Boy, would that give you a headache. You come in to work in the morning with a black eye and everyone asks you what happened. "I got hit in the head by a cosmic ray!":rofl:

[DJDD]

wouldn't that be T = T(obs)/SQR(0), which is undefined not 0?

[renormalised]

Yes, but undefined is close enough to zero to be zero....it's an example of an infinity (a weird one nevertheless) creeping into an equation.

[DJDD]

I looked up Lorentz Transformation on Wikipedia- no wonder I dropped Physics after second year and maths, as well. Chemistry was always easier...well, except for "theoretical chemistry" but quantum stuff was only for one semester, so... :lol:

[renormalised]

Relativity isn't all that hard....involved, yes, but there's a lot harder maths and physics than relativity. Although, I'd much rather deal with the final equations than try to derive them from 1st principles. That's when you really need to be good at maths.

[AGarvin]

I guess it depends on how you look at it. The Lorentz factor itself goes up to infinity, not down to zero, as you approach the speed of light.



Absolutely, and mine ain't that good :(

[renormalised]

True, however when you try to get the sqrt of 0 (the result of solving the LT for a photon) and you get an undefined answer, that indefinite answer is in itself an infinity and might as well be zero. The equations are renormalised to rid the infinity from the result.

[Zuts]

Hi,

The Lorentz equations only apply to things with mass travelling at less than the speed of light. If you plug in V=c, then the equation is undefined for this value which means it does not give any usefull values.

Basically photons experience no time, maybe thats why they never decay into other particles, but are only absorbed and re-emitted. They dont experience any duration so have no time to decay?

Paul

[renormalised]

Precisely. You can't define the SQRT of 0...it's a meaningless answer.

[Zuts]

I shouldnt be so pedantic but i've had a few :), you can define the SQRT of zero, it's just zero. The value of 1/SQRT(0) though is undefined or infinity.

Paul

[renormalised]

That's what I meant to say:)

[sjastro]

The mathematics behind Special Relativity is nothing more than simple algebra. Deriving the Lorentz equations is a straight forward exercise.

The maths for General Relativity, tensor analysis and Riemannian geometry on the other is not so simple.

Regards

Steven
http://users.westconnect.com.au/~sjastro/small (http://users.westconnect.com.au/%7Esjastro/small)

[renormalised]

I agree. I'd much rather deal with Special Relativity than General. Although compared to some branches of Quantum Theory, even GR is rather simple.

[Brian W]

Moderator, I think this generally fits into this discussion so here goes; It has been decades since my high school math. Could anyone here point me towards on line resources that will enable me to upgrade my math skills so I can at least follow the above discussion? Has to be online as there are no bookstores nor universities near me.
Brian

[AGarvin]

Brian,

Try here (http://www.sosmath.com/).

Andrew.

[renormalised]

Brian, try this site. I use it as part of my Masters course to refresh my maths skills....

http://www.mathcentre.ac.uk/students.php/mathematics/

[White Rabbit]

I used the Mathcentre when I did my UNI prep course a few years back. Their work sheets are really good.

Thanks for the replies but I have a few questions.

When you say"It's a photon....it doesn't experience any time at all, since it's traveling at the speed of light." do you mean this in the sense that because it is a photon it can not experience anything because it is not conscious?

[renormalised]

No, nothing like that (although who's to say what a photon thinks:)). A photon doesn't experience any time because the amount of time dilation that occurs at the speed of light is infinite (which means there's something wrong with the theory....infinities are a curse, but more on that later). Time effectively stands still for the photon, so everything it perceives is NOW. A photon leaving M31 now, would in its world view, have already arrived here.

But for us it's a 2.5 million year long ride:)

[White Rabbit]

Ah, I understand and it makes sense that when traveling at the speed of light the time dilation would be infinite.

I wasnt sure if you were trying to be funny in your earlier post, lol.

Here is another questions.

If it is impossible to travel at the speed of light due to the fact that your mass increases infinitely and the energy needed to propel you at that speed is infinite. How come a photon can? Is it to do with the Wave V's particle nature of a photon that it is able to travel so fast?

Also read somewhere that you shouldn't think of a photon as a particle only a wave.

[White Rabbit]

Yeah, I took chemistry and Biology in school not physics.

[White Rabbit]

Just found this, I'll listen to it tonight it may just have the answers I'm looking for.

http://www.astronomycast.com/physics/ep-83-wave-particle-duality/

[Jeff]

Enjoyed this article (The Life of a Photon):
http://www.propermotion.com/jwreed/Essays/The%20Life%20of%20A%20Photon.htm

Cheers,
Jeff

[sjastro]

From a Quantum Mechanical viewpoint photons are the fundamental particles for electromagnetic radiation, so in fact light is composed of photons. Photons have a zero rest mass hence can be accelerated up to the speed of light.

Regards

Steven
http://users.westconnect.com.au/~sjastro/small (http://users.westconnect.com.au/%7Esjastro/small)

[renormalised]

As has been mentioned, a photon has zero rest mass and therefore can be accelerated to lightspeed.

Photons are both waves and particles....simultaneously. However, they'll act as either depending on the situation they find themselves in.

[renormalised]

Here's something for all of you to think about... there's something seriously wrong with Special Relativity and it should be rather obvious.

Hint....think about the final outcomes of the equations.

[skwinty]

Wow, what a sweeping statement!
If there is something seriously wrong with SRT then Hubbles work must be discarded as he used SRT to determine velocities in all his expanding universe calculations.
As far as what the photon experiences wrt to time and what we see the photon experience wrt time, the point of different inertial frames needs to be considered.

In any event the "obviousness of this flaw" may be a reflection of our lack of understanding. I agree that SRT may not be complete but I cannot agree that it is obviously wrong.:P(As you can see from the icon, I am an Einstein fan)

[renormalised]

That's what's wrong with most people and many scientist.... you seems to think that Einstein is the be all and end all of physics (science almost). He is FAR from it. Considering that he spent most of his career trying to get his head around quantum physics (and rather unsuccessfully at that), he didn't do so well in the end. His whole fame is based on two incomplete theories.

Anyway, here's the problem. Any theory which introduces infinities into its equations, either as part of the workings or as a solution, is meaningless and incorrect in its assumptions. Even Einstein himself knew that, yet just because the rest of the workings seems OK, they persist with the theory in its entirety. Doesn't matter that it can work out masses and lifetimes of objects traveling at substantial fractions of lightspeed, the fact that at lightspeed an object with mass becomes infinitely heavy and zero in size is nonsensical. It's also one of the reasons why relativity breaks down at the singularity in black holes. Precisely because of its characteristics. The results of the equations become nonsensical. Essentially, you get infinities and undefined answers.

Think about it, what do you get when size becomes zero and mass infinite.... a singularity, and if something became infinitely dense and massive, what do you think would happen to the rest of the Universe, regardless of any event horizon?? Yes, a black hole is extremely dense and the gravitational gradient is extremely steep, but it's not infinite. A 10Ms black hole is just that...10Ms, not infinitely massive as you would be led to expect. Something else other than a (true) singularity must reside at the centre of a black hole. It will probably be upto some branch of Quantum Theory to resolve that question.

That's the problem...people don't think. They just blindly accept what's told to them as being gospel and infallibly correct.

It's the same with any theory....Quantum Theories abound with cases where infinities crop up in seemingly elegant equations. The theories then fall to pieces. However, in order to try and preserve face in so far as the theories stand, they use a technique called renormalisation. To put it in simple terms, they add a fudge factor to make the infinities magically disappear. It's usually a long and complicated mathematical abstraction just as complicated as the original equations, but sometimes it can be a simple term, added to counterbalance the infinity. Renormalisation has become the "de rigeur" way of making one's theories seem palatable.

SR maybe elegant, but only upto a point. There's a lot yet to be done before it can be said for certain that it's a complete and totally correct theory. It may never be, and I'd venture to say it won't because I can't see what can be done to overcome the infinities in it's equations. It will probably have to be rewritten in order to become 100% viable. The same goes for GR, but it's less fraught with problems than SR.

My guess is that you'll see some sort of hybrid quantum theory take their place....that will have elements of both classical SR and GR in the theory as part of it's overall structure.

[Brian W]

Thanks for both replies, first I will use SOS and then move on to the more advanced web site.
Brian

[skwinty]

You seem to be implying that Einstein was a failure.
Considering his incomplete theories are still subject to rigorous testing today and so far have not been proven to be false. Sure he was a human and subject to human frailties.
Einstein's self admitted biggest blunder (The piece of fudge called the cosmological constant)may yet prove to be his biggest truimph.
If you look at string theory, the mathematics are also having to be made simpler by making a lot of assumptions and mathematical compromises.
As far as saying that I am not thinking and accepting Einsteins theories at face value without applying any thought, then the same could be said for people like:
1. Owen Gingrich.
2. Steven Hawking
3. Brian Green
4. Jeremy Bernstein
5. Gerald Holton
6. Shimon Malin
7. John Stachel
8. John Archibald Wheeler
9. Richard Feynmann
10.Julian Schwinger
12.Roger Penrose
The list grows much longer and these are well known authorities in Astronomy, Mathematics and Physics of every persuasion.
You make a point saying that any theory that introduces infinities into its equations is meaningless and incorrect in its assumptions.
Well, mathematics introduces infinities as one of its basic axioms (n+1) so does that mean that mathematics is incorrect.
Space as far as we know is infinite so any theory that discards infinity surely then must be incomplete.
The mathematical universe has infinite complexity and is not fully comprehensible to us humans and this is why Godel came up with his theory of incompleteness.
Given that Einstein died in 1955 and never had the benefit of modern technology, which in a lot of cases wouldn't have been available today if it wasn't for his incomplete theories.
Sure he had a problem with randomness, quantum theory and its paradoxes but did that make him unsuccessful?
To quote Richard Feynmann "I can safely say that no one understands quantum mechanics"
Randomness is upsetting to mathematicians but only an outsider to mathematics would venture this statement.
Just because infinities makes things more difficult to understand and compute doesn't make it incorrect and meaningless.
You stated in your post that there is something is "obviously" very wrong with SRT.The hint you gave was to look at the answers derived from the equations.
My question is then why did it take so long before some one could see this obvious mistake.

[AGarvin]

I think this is another common problem, expecting more from a theory than it's capable of. All theories have a framework that they work within and it's is just as wrong to call a theory seriously flawed by expecting more than it is "designed" to do as it is to assume it's the be all and end all.

By this "its seriously wrong" logic even newtonian mechanics is seriously wrong because it's wrong at "relativistic" levels but it works perfectly in everyday life.

[renormalised]

Einstein wasn't a failure, and I never stated that explicitly. What I said was that SR had problems and that he had a hard time trying to understand Quantum Theory.



Yes, and you're correct in that assumption, providing that what we observe as an apparent acceleration of universal expansion is actually occurring. Rather ironic, don't you think??. Einstein would probably laugh about it, if he was still alive.





Yes, there are a lot of assumptions and compromises in String Theory and in other related theories. Much of it due to the appearance of infinities in the equations of the theories. That's why I explained about renormalisation....it's to remove the infinities from the equations, otherwise the equations don't work. They produce nonsense or undefined answers. If the infinities were OK, then the mathematicians and physicist wouldn't bother trying to get rid of them!!!. N+1 is only infinite if you take the value of N to infinity. N can be defined in any way you choose, depending on the system you're working with...and when it approaches infinity, the answer to N+1 becomes undefined, It's an impossibly large number.



So...they can only go by what they have learned and know. However, it doesn't mean that they can't questions Einstein's basic assumptions and the veracity of any formulations he made...and most of those guys have. Why do you think most of these guys have come up with various Quantum Theories.....why the great push for a theory of quantum gravity. It's because Einsteins theories only work so far... it's the same with Newtonian physics. Good for some situations and not for others. Now, even these new theories have run into trouble along various lines. Not just for infinities cropping up in equations, but it's one reason why.



These assumptions are entirely due to our lack of knowledge and understanding. We believe things to be infinite because we can't see any other way that they can be... all due to a lack of the complete facts. Essentially why Godel came up with his theory. It's the old axiom:

"The more we think we know, the more we realise the less we actually know and understand"



I totally agree with him!!!!



The first sentence you wrote here, about randomness, is rather odd. If something is upsetting to someone, then why wouldn't that someone venture the fact that it upsets them??!!. If someone from outside maths said that randomness upsets mathematicians, then he/she is only stating a fact that the mathematicians already concur with!!! Why would mathematicians want to try and renormalise equations that produce infinities if those infinities didn't create problems for them. Since they do try to renormalise their equations, then it's safe to say that having infinities crop up in your theories does cause problems and is a cause for concern amongst mathematicians (and physicists).

Suffice to say, your assumption that it took so long before someone could see the obvious mistake in SR is incorrect itself. They've known for decades about the problems with relativity. However, it doesn't mean that the entire theory should be thrown out with the bathwater, so to speak. Like Newtonian physics, it works...upto a point. But then the problems with the theory crop up and it no longer works (or works rather difficultly) in those situations where the theory is stretched beyond its limitations. Having infinities crop up in your theory is a sign that you're reaching those limits. All mathematicians and physicists recognise this, otherwise they wouldn't try to use methods such as renormalisation to get rid of them.

If you want to read a reasonably well written piece on renormalisation, go here:

http://en.wikipedia.org/wiki/Renormalization

[avandonk]

We can calculate the quantum energy levels for an isolated Hydrogen atom (one proton and one electron) and that is it. Forget a Hydrogen molecule! It is called the three particle problem.

I gave up on fundamental Physics to concentrate on biological molecules as it seemed to be a far more unmined resource for self serving scientific grandeur. It may even give us some insights as nature has been running the experiments for about four billion years.

All jokes aside we nearly have the tools to make the tools to even start to solve the fundamental problems.

Looking at the problem from a perspective we cannot now imagine may solve it. Chucking in a fudge factor is a cop out. We may as well invoke the easter bunny or the tooth fairy!

Bert

[sjastro]

This is not true with SR. If one plots the Lorentz factor 1/sqrt(1-(v2/c2)) against velocity v, an asymptote is found at the line v=c. In this case an infinite Lorentz factor tells us that particle velocity cannot reach or exceed the speed of light c.

Regards

Steven
http://users.westconnect.com.au/~sjastro/small (http://users.westconnect.com.au/%7Esjastro/small)

[sjastro]

Strange how fudge factors are looked at in such a negative light particularly when it brings theory and fact closer together. The cosmological constant is a very successful fudge factor, as was the ad hoc introduction of 1/2 spin numbers in quantum mechanics which were theoretically verified by the application of SR to quantum mechanics.

Regards

Steven

[renormalised]

True, but here in lies the problem. The reason why a particle (except for the photon) cannot reach the speed of light is because of the infinities which crop up. This is why I've been arguing that SR (and even GR, in some respects) is not self consistent and has problems. However, and it may come as a surprise to some, SR doesn't preclude particles traveling faster than the speed of light. People misunderstand what Einstein said, and many scientist misquote him. He originally said that no material object can travel at the speed of light. There are solutions for particles in SR to travel faster than light, but never as slow as light speed. Same problems happen for them when approaching c as occur for those particles which travel slower than c. You'll know them as tachyons. Now, they haven't detected them, but then again there's a lot of things even stranger than tachyons which physicists have said exist but have never detected. Super symmetric particles and the Higgs Boson, for example.

The reason why the fudge factors are looked at in the light that they are is because they take what should be reworked theories and make them palatable by hiding the mistakes made which create the infinities in the first place. Sure, they look good and work well, however they leave a nagging feeling that maybe you should try and get things right in the first place. So far as the cosmological constant is concerned, the jury is still far from giving a verdict on this. It's all been predicated on the observations of about half a dozen distant supernovae, far from being a statistically significant sample. But it's a start. If it works out, great, but then I think we should leave it for awhile until we can say definitively whether it's a fact of life or not. In so far as 1/2 spin numbers goes, it's one area where SR and quantum mechanics have come together rather well. But that is only one application where it actually works. It doesn't mean, then, that it'll work in every other case it's applied. Also, it wasn't so much as a fudge factor than it was a solution which appeared ad hoc, but in actual fact elegantly and self consistently predicted and observationally proved a characteristic of elementary particles. It's not often something like that happens.

[sjastro]

This is the very point I am making. The role of infinity in SR has a definable physical interpretation. It doesn't in anyway compromise the theory.

Particles traveling faster than light (tachyons) need to be looked at in the full context. They are solutions to a symmetrical version of SR. Tachyons cannot travel below the speed of light for the same reasons as "normal" particles cannot travel faster than light. In both cases the speed of light is still a barrier.

[renormalised]

That's what I said:)

But most people wouldn't know this, and so they keep to the popular interpretation.



Yes, and I agree that infinities in SR have a definable interpretation, in that they are the reason for the speed of light barrier. However that doesn't lessen the fact that they're a cause of problems for SR. What needs to be done is more theoretical research into the actual nature of photons and what exactly happens when particles travel at lightspeed.... not just the usual interpretation of "Oh yeah, they reach infinite mass and zero size....SR said so". That makes them singularities (of infinite mass). Wouldn't matter from what inertial frame of reference you observed at, it would be disastrous for both you and the particle (or person in the ship).

[maksutover]

Great discussion people.

I just want to add that Einstein used Reimannian mathematics for most of his work in GR and simply followed the work of Hertz and Plank to "discover" (and i use that term losely) the photoelectric effect which he won the nobel prize for.
Please dont get me wrong, im not belittling the poor guy, in fact i think his contributions were immense, but in no way was he a one man show and as renorm put it, the beginning and end of physics.

[sjastro]

The building of progressively more powerful particle accelerators such as the Large Hadron Collider is more than ample proof of the futility of accelerating particles to the speed of light. It's no coincidence that protons will be accelerated to "only" 99.99% the speed of light using enormous amount of potential energy.

Since m and E are related (E=mc2) most of the increase in mass of a particle approaching the speed of light is in fact taken up by the KE of the particle. If it was possible for the particle to reach the speed the light, the KE would become infinite. The mass won't turn into gravitational sink.

Regards

Steven

[renormalised]

Glad you're enjoying it:)

You know, maybe we should be making Einstein walk the "Planck", until it "Hertz":P:D

Well, at least that's what I'm trying to do:)

[renormalised]

That's true....doesn't matter what they do, they just don't have enough energy to accelerate them to lightspeed. It takes infinite energy.... and there it is again. An infinity....it can't be avoided. That's why SR becomes nonsensical. There wouldn't be enough energy in all the dimensions and parallel universes to accelerate a particle to lightspeed.

About mass and KE.....it could either go two ways. One, the KE becomes infinite, which can't happen....or two, since M and E are equivalent, the mass becomes infinite and you get an infinitely heavy singularity. Either way, the gravity must become infinite. If that particle were to stop (by hitting something, say), the energy has to go somewhere. Since it's infinite, it doesn't matter whether it's transfered to the body it hits or to itself, it becomes mass....an infinite mass derived now from PE. Wam.....instant infinitely heavy black hole. Goodbye universe:)

[skwinty]

What I don't understand about this attitude is:

1. There are no other testable theories at present.
2. No-one implied that Einstein was the be all and end all of anything.
3. The implication being made now is that Einstein was a copy cat who only progessed the work of others.
4 While you are stating facts about the renormalisation of mathematical equations to get rid of infinities, the fact remains that infinities exist and surely should be reflected in any theory or in any equation.
5. You make no distinction between singularities in space and singularities in time.
6. Perhaps we remove the tan function from our calculators as it too produces infinities.

Apart from all this, who is to say what occurs in a black hole or singularity as the mass approaches infinity and the volume approaches zero. Perhaps this is the gateway to the multiverse and this gateway closes after a critical point is reached. ie the blackhole dissappears.

Until such time as the new theories progress into something tangible, you shouldn't toss the baby out with the bath water.:P

[Karls48]

Some couple hundred years ago French Academy of Science has declared that object heavier then air cannot fly. No doubt that, to come to this conclusion they considered all the laws of physic known at that time. If everyone believed to those learned scientists we would not have airplanes today. If we believe that faster then light speed is impossible, then it will be impossible. We never learn from the past.
Use million of horses to pull object to break speed of sound barrier. No hope. Take different approach to it and you will achieve it with power of few thousand of horsepower.

[renormalised]

It's not an attitude, Steve. Everyone has followed Einstein like he's some sort of God (and don't say that people don't, they do) of physics. He's not. It's like all scientist, they come up with an idea that seems to be infallible and they treat them like they can do no wrong. They did the same to Newton and they've done the same to Hawking, but now quite a few scientist have questioned Hawking's premises. He's even gone back on a few of his ideas himself!!!!. But now he's looking at other ways to prove himself right. It's all ego and hubris.

All scientist work on the assumptions of others and try to progress science by extending those assumptions. Sometimes, they come up with some of their own. In any case, that wasn't my point.

Yes, the infinities do exist, but only as mathematical constructs. No physical observation or experiment ever carried out has proved the existence of an infinity. Why??, because an infinity by its very nature is an incalculable sum, hence it's nonsensical. That's the reason why renormalisation is used. To negate the infinities.

It doesn't matter whether it's a singularity in space or time. Because space and time are coupled, there can be no distinction between either. They both look the same.....in fact they are the same, given what we know of either.

All mathematical functions will produce infinities if you take the maths to its limits....it doesn't mean that the maths is wrong altogether, it just has serious problems when it reaches certain conditions (like SR and other theories do), and should be revised and/or discarded when it no longer works, for those conditions. It may work fabulously up until that point.

I'm not tossing any baby out with the bath water....all I'm saying is that the water has gone cold and should be changed, the baby stays in the bath:P:D

At least until Mother decides to take him/her out:P:D

[sjastro]

No it doesn't. Relativistic mass = Rest mass + KE. Rest mass is constant. KE is tied up in the velocity of the particle. There will be no increase in the "mass component" of relativistic mass.

If you are so against infinities why do you readily accept infinite mass in your argument.:shrug:

Regards

Steven

[sjastro]

:lol:

[AGarvin]

Yes. The full equation is:

E2 = p2c2 + m2c4

where m = rest mass and p = momentum. The shortened version of the equation is just to illustrate the relationship between mass and energy.

[skwinty]

If this is indeed correct, then there is no difference between the singularity described in the big bang and the singularity or black hole in the middle of our galaxy or omega centauri.
My understanding is that there is a subtle distinction between space and time singularities

[renormalised]

I didn't accept infinite mass in my argument except as a postulate of SR. When I mention an infinite mass or energy, it's in relation to SR postulates.

If rest mass is constant (invariant), and it's only the relativistic mass which becomes infinite, then any mass increase is nothing more than "relative" and therefore is a perspective illusion based on one's PoV. It's an apparent mass based on the addition of energy of motion (KE), not the real or proper mass of the system. It means that whilst it has measurable physical effects and can be confirmed by experiment, it's still nothing less than an illusion and that we don't really understand what we're looking at.

[maksutover]

STEVE! Dude take it easy! No matter what anyone says, it only their opinion! You seem to be very defensive in regards to this topic.
I totally agree that Einstein was a genius! But what renorm (i think) and I are stressing is that he is slightly over exemplified in physics (for God knows what reason). If you study the biography of people like Sir Issac, you'll see that he became the greatest mathematician in the world in about 18 months from scratch!

Also I recommend reading "The Infinite Book" by John Barrow. As impossible, nonsensical and outrageous as infinity might be, the basic principles of calculus and other mathematical branches will cease to exist without it.

So my children, learn to embrace it :)

[AGarvin]

Yes, that's why it's called relativity. Regardless of what you observe my (relativistic) mass as, in my reference frame my mass doesn't change. I'm not actually gaining more atoms. The total energy of the system increases with momentum relative to the observer.



It sounds like your trying to equate spacetime with something physically real (????). Spacetime is not a real thing, it's just a construct that in the mathematical framework or relativity theory has 3 spacial dimensions and one temporal. M-Theory has it's own version of spacetime that has 10 spacial and one temporal.

Also, the concept of spacetime is not Einsteins, it was developed by Hermann Minkowski 3 years after Einsteins paper in 1905 and it was Minkowski who took SR and first placed it in a geometric framework - spacetime.

[renormalised]

And I agree with everything you have said here, so we have no differences. Einstein never even came up with relativity in the first place. Galileo was the first to theorise about relativity. Einstein's theories just built on that earlier work (along with Newton's work as well, of course).

But that still doesn't change what I have written. I'm trying to get people to look at different theories (in this case SR, etc) in a critical manner and not just take what's said at face value. I'm not saying that SR should be turfed out in the garbage....upto a point it works brilliantly, but it has problems with strong gravitational situations, accelerated motions (the reason why AE formulated GR) and with infinities in the equations. Heck, quantum physics has enough problems of its own with infinities and other oddities, but it still works in most situations. We just need to be more critical with the answers we come up with, the theories we formulate and how we overly place great scientists on impossibly high pedestals.

I'll bet, in 50 or 100 years time, someone is going to find our conversations here rather quaint. They'll probably laugh at our ignorance and end up filing our posts on their holocrystal storage device, just before they board Flight 251 for the Interdimensional Mechanics conference at the Hawking Institute on Rigel 8:D:)

[skwinty]

Hi Maksutover
Not getting defensive, just expressing my opinion wrt to the comments that are being made in this discussion.
I call it robust debate.:thumbsup:

[skwinty]

The outstanding problem requiring resolution wrt to relativity is how to unite gravity with the WNF,SNF and EMF.
In the beginning of the universe, the universe was massive(Einstein's theory of gravity) and smaller than an atom(Quantum Theory).
Herein lies the problem as these two theories do not overlap or concur.

String Theory resolves these issues by saying that the "string" is the indivisible building block of the universe and the "unification" of gravity, WNF,SNF and EMF are contained within the "vibration" of the "string".

This leads to the Quantum Theory of Gravity. Einsteins Theory can predict the future with 100% certainty(ie the planet is here today and there tomorrow) whilst Quantum Theory only predicts possible futures or probabilities.

So the holy grail is to combine certaintities with uncertaintities.
Now, gravity pops ups in the string theory by virtue of the math and initial assumptions and it is not neccesarily Einsteins version of gravity.

Now, one dimensional strings are not the only strings that occur.
Single dimensional strings are called branes and multidimensional strings are called p-branes where p denotes the number of dimensions.

These branes exist in a multidimensional space time.
The implication of this is, our universe may not be the only universe around.

Now, if there are more then the possibility exists that these universes will collide with each other. This may well explain the big bang, singularities,black holes and infinite mass in zero volume. These conditions are not permanent and may well exist only for a "short period".

Well, thats my 2 cents worth.:P;):thumbsup:

[renormalised]

Nothing wrong with anything you said there , Steve. Why not try to expand on it and come up with a hypothesis, then go on from there:)

The only thing I'd disagree with is the infinite mass/zero volume part. You could say that something might be masquerading as such, so it could be an "apparent" construct. A "smoke and mirrors" type of thing. Could even have something to do with strings:)

[astroron]

I am enjoying this thread even though the math flies over my head,but please cut down on the abbreviations or at least say what they mean somewhere in the discussion.
I know you are discussing this among yourselves but you have a lot of people following this thread.
Steve what is wrt?
Ron

[sjastro]

It's not a perspective illusion at all. The effects are very real.

In nucleur fusion involving the inelastic collisions between nuclei, the fused nuclei has a mass greater than the sum total of the colliding nuclei as the kinetic energy has been converted into mass. In the periodic table, are the atomic weights listed illusionary?

Regards Steven

[renormalised]

Even illusions can have real effects, if the causes of those illusions have properties which are based in physical reality. Take a mirage, for instance. Refraction of light caused by a hot layer of air just above the ground, magnifying a distant mountain range and making it appear closer than it actually is...or even distorting the image of an object till it appears something it isn't. Very real physical effects, nothing but illusions seen.

No, the atomic weights of the elements are not illusions. Not as you would define them, although I can imagine there's probably a quantum theory somewhere out there which maintains they are:P:D

[renormalised]

You know, I could've sworn I saw another post of AGarvin here on page 4!!!!. Now it's gone, or appears to be gone.

An effect of SR!!!!:P:D

Also, you know I'm wondering about what White Rabbit is making of all of this. All he asked for was for the travel time of a photon from the Sun to here and we're going on about SR and all that!!!!!:eyepop::P

Poor guy must be lost:)

[skwinty]

My apologies
wrt = with respect to
WNF = weak nuclear force
SNF = strong nuclear force
EMF = electromagnetic force:thumbsup:

[renormalised]

It's all in the GUT's of the matter:P:D

[AGarvin]

Nah, QM, my uncertainty in it's validity lead to a complete breakdown in its wavefunction.

Seriously though, there was but I deleted it. After I re-read it I felt it was kinda pointless :doh:.

Andrew.

[renormalised]

It got caught in the "quantum foam" beyond the Planck Scale:)

It was "randomised":D

[skwinty]

:rofl:I assume thats the "Great Unknown Theory".
On a more serious note though, in mathematical terms, infinity occurs at a very specific point. ie at exactly tan of 90 degrees, not 89.9999 for example.
So I suppose that the singularity approaches infinity but does not quite get there.

Now, if it does, space time ruptures, the laws of physics disintegrate and something really big happens.
Now consider the hypothetical particle the tachyon. This particle supposedly travels faster than the speed of light. This implies that it then travels backwards in time. Perhaps this hypothetical particle is only created in these infinite mass zero space structures

So, perhaps when infinite mass is contained within zero volume or close enough to this, the process is reversed, but in a different direction leading to another space time. Once the process has reversed all is restored, but unfortunately its happens to be somewhere else. So, the mass has done a Buzz Lightyear and gone to infinity and beyond.;)

[Kokatha man]

I'm (almost!) staying out of this thread topic: but felt cheeky enough to comment on the above, r/n.....

There are a number of perspectives re your comments above, several of these subscribing to nothing tangible, re quantifiable; as opposed to the inferences intimated by your statement....!

Not necessarily disputing the validity of your comments in this discussion per se, but just picking on your particular post from amongst a sea of speculators, swimming in a sea of speculation....!

The Macquarie Dictionary:

"specular" - pertaining to, or having the properties of, a mirror

"speculate" - to engage in thought or reflection, or meditate or to indulge in conjectural thought

" speculation" - (2) a single instance or process of consideration

"speculator" - (2) one devoted to mental speculation

There is an intent/perspective to my specific ordering of the above definitions that has more (possibly) to do with some of my own intimations, rather than their alphabetical order: cheers, Darryl!;):P:)

ps - what about the Stephen Hawking program on SBS last Sunday night....?

[sjastro]

Analogies don't make good scientific arguments.

Let's go back to your original statement.



Unfortunately you just can't pick and choose what's real and what's an illusion. Why should the energy contribution from mass be considered "more real" than the KE.

In fact your line of reasoning contradicts the conservation of relativistic mass.

Regards

Steven

[renormalised]

That's about the way it is...the number of GUT's theories about you'd think they'd settle on one at some stage!!!!. It loses most people:)

That first idea of yours is a very good point. It's entirely possible that infinities, in real life terms, can never be reached, despite the machinations of theoretical physicists. The singularity might come damn close to diving off the edge of the wacky abyss but just pulls up by the skin of it's toenails.

Now whilst tachyons are supposed to have properties which are time reversed according to SR, we still don't really know enough about space and time itself to really be definitive about this. Who knows what the real properties of tachyons are...and given what they've come up with in many quantum theories it's become debatable whether time itself even exists as we seem to know it. But, you maybe right. Tachyons may need extreme circumstances to come into existence.

That could be how infant universes form. Once a singularity gets to being close to an infinitely dense and small point, spacetime might rupture and unfold into it's original 11 dimensional state, at that point. That, I should imagine, would generate more than enough energy to start another bubble in Superspace expanding into another universe. It probably needs to reach a critical threshold in energy density before it can initiate an expansion of a new 4D spacetime bubble (spike, membrane or whatever shape it is).

If you look at brane theory, it's possible that the agency which causes two branes in Superspace to collide might be the formation of a black hole in one of them. The singularity might be where both of them touch one another. The problem with visualising that, if you look at the conventional way they portray branes colliding is that you have to visualise a 11 dimensional object interacting with another of the same type. The thing is, two 11 dimensional objects could intertwine with one another without even necessarily touching at any stage, except when a new universe is formed, so it's entirely feasible that the conventional interpretation of interacting branes might not be totally correct, if at all. Given that the Calabi-Yau manifolds they're proposing have 11 dimensions, the number of degrees of freedom of movement within those 11 dimensions is staggering. Almost unquantifiable. It'll be damn interesting to see what they can come up with:)

[skwinty]

Which is probably just as well otherwise the life span of any given universe could be measured in femtoseconds rather than billions of years.
Where would that have left us,regardless of our perspective of time!
A multitude of Omega points every femtosecond would certainly put some truth into the old adage of the only constant being change!!:screwy:

[renormalised]

I probably didn't word my original statement as good as I should've:).

Analogies quite often are the only things you have to go by until evidence comes to light which either proves or disproves what you've found. They're only used as examples of what is likely, not what is certain.

I wasn't picking and choosing what was real or illusion. I said that the relativistic mass was illusional...an so was the infinite mass value. The KE is real, but the increase in mass due to the motion of the body in question was illusional and only based on the PoV of an outside observer.

[renormalised]

Precisely, because every time the two universes touched it'd set off all sorts of fireworks which would destroy anything in either of them. We'd be nothing more than road kill!!!:scared:

It'd leave any universe completely uninhabitable.

[sjastro]

The basis for SR are observers making measurements in different frames of reference. Relativistic mass is NOT illusional because it is a measurable parameter for each observer. (Example:Inelastic collisions of atomic nuclei).

Infinite mass on the other IS illusional for the following reasons.

(1) It is not a measurable parameter.
(2) SR has an operating range of 0 <= v < c. Mass is finite in this interval.

The fundamental postulate of SR, supported by the mathematics and observation, is that a mass particle cannot obtain the value v=c. So why have this debate in the first case?

To argue that SR "is basically OK" except for the infinities is a total contradiction because it brings into question that fundamental postulate on which SR is built on.

Enough of my ramblings I will now go quiet on this subject.

Regards

Steven
http://users.westconnect.com.au/~sjastro/small (http://users.westconnect.com.au/%7Esjastro/small)