Eistein and Hawking

[Wayne]

Hi everyone...
last time i read some books about relativity and theory of everything...and i hav to admit,i was quite blurred by all the theories...warping space..fourth dimesions..wau! :?:
Are we going to learn all those things in states later?
i am very interested to know deeper about all these theoritical physics theories and i think all of you can help me..
But juz explain in easier way, cuz i am juz a beginner...
Thanx a lot!! :)

[Wayne]

Hi everyone...
last time i read some books about relativity and theory of everything...and i hav to admit,i was quite blurred by all the theories...warping space..fourth dimesions..wau! :?:
Are we going to learn all those things in states later?
i am very interested to know deeper about all these theoritical physics theories and i think all of you can help me..
But juz explain in easier way, cuz i am juz a beginner...
Thanx a lot!! :)

[chenchow]

Wayne, thanks for being very interested to learn about a lot of additional knowledge.

On whether you will learn it in US, the answer is it depends on You.

You will decide whether you will learn it. You have 4 years in US and you have pretty flexible schedule to work around and I am sure if you want to learn, you can definitely choose those courses to take. There is no limit in what you can take, but it is just yourself that is the limitation. How much workload you are able to take? Everyone learns differently and everyone has different priority.

There are people here who are obsessed with research, some who like to learn a lot of advanced stuff on certain topic, some who likes to learn very broadly, but not deeply, and of course there is a group of engineering students who have shallow interest in engineering and they take a whole lot of other courses.

Just give you an instance of me, I am an Electrical And Computer Engineering Major. I have taken the course from Financial & Managerial Accounting, Industrial System Analysis, Negotiation, Business Law, Entrepreneurship, Quality Control, Information Technology, Managerial Leadership, Managerial Economics, Micro Econ, Macro Econ, Communication, International Relations, Debates & Argumentative, Webpage Design, Decision Analysis, Enterprise Engineering, Equestrian, Riflery, Archery, Ballroom Dancing, etc and I have a year more to go... So, you can see the flexibility available. I have to admit that I take the most minimum Electrical & Computer Engineering course, I did not do research, no honors, practically nothing... I take what I like and every course I take there is a personal reason why I choose those courses...

It very much depends on your interest. Think of what you want to gain from your education in US, and then go ahead and make it a reality. There are many ReCom members who can help guiding you, but it is you that need to make the main first step...

[chenchow]

Wayne, thanks for being very interested to learn about a lot of additional knowledge.

On whether you will learn it in US, the answer is it depends on You.

You will decide whether you will learn it. You have 4 years in US and you have pretty flexible schedule to work around and I am sure if you want to learn, you can definitely choose those courses to take. There is no limit in what you can take, but it is just yourself that is the limitation. How much workload you are able to take? Everyone learns differently and everyone has different priority.

There are people here who are obsessed with research, some who like to learn a lot of advanced stuff on certain topic, some who likes to learn very broadly, but not deeply, and of course there is a group of engineering students who have shallow interest in engineering and they take a whole lot of other courses.

Just give you an instance of me, I am an Electrical And Computer Engineering Major. I have taken the course from Financial & Managerial Accounting, Industrial System Analysis, Negotiation, Business Law, Entrepreneurship, Quality Control, Information Technology, Managerial Leadership, Managerial Economics, Micro Econ, Macro Econ, Communication, International Relations, Debates & Argumentative, Webpage Design, Decision Analysis, Enterprise Engineering, Equestrian, Riflery, Archery, Ballroom Dancing, etc and I have a year more to go... So, you can see the flexibility available. I have to admit that I take the most minimum Electrical & Computer Engineering course, I did not do research, no honors, practically nothing... I take what I like and every course I take there is a personal reason why I choose those courses...

It very much depends on your interest. Think of what you want to gain from your education in US, and then go ahead and make it a reality. There are many ReCom members who can help guiding you, but it is you that need to make the main first step...

Chen Chow is right on the aspect of the flexibility of a US undergrad education. You can do virtually anything your college offers.

And there are quite a few smart people around too. At top colleges, it is not unusual for some students to be able to produce research-quality work before they graduate. All it takes is interest and persistence.

Chen Chow is right on the aspect of the flexibility of a US undergrad education. You can do virtually anything your college offers.

And there are quite a few smart people around too. At top colleges, it is not unusual for some students to be able to produce research-quality work before they graduate. All it takes is interest and persistence.

BTW, I took a physics class my freshman year which dealt with Einstein's special theory of relativity.

This page provides a good introduction to the special theory:
http://www2.slac.stanford.edu/vvc/theory/relativity.html

The really cool and exciting stuff I learnt in that class is that electromagnetism is actually a relativistic phenomenon.

While we know from classical physics that a wire carrying current is neutral (same +ve and -ve charges), if you put two wires together with the current moving in the same direction, they attract. In high school, your teacher might describe this as some "magical" magnetic attraction.

Call the first wire A and second wire B.

But in fact, the wires A and B appear neutral only in our perspective. The electrons in both wires are moving very fast, say around 1/100 the speed of light. So, the electrons in wire A do not see wire B as neutral and vice versa. Therefore, the electrons moving in wire A are attracted to wire B (and vice-versa), and the two wires attract.

I guess this kinda a hand-waving explanation of the special theory of relativity. The general theory involving gravity is even more complicated.

BTW, I took a physics class my freshman year which dealt with Einstein's special theory of relativity.

This page provides a good introduction to the special theory:
http://www2.slac.stanford.edu/vvc/theory/relativity.html

The really cool and exciting stuff I learnt in that class is that electromagnetism is actually a relativistic phenomenon.

While we know from classical physics that a wire carrying current is neutral (same +ve and -ve charges), if you put two wires together with the current moving in the same direction, they attract. In high school, your teacher might describe this as some "magical" magnetic attraction.

Call the first wire A and second wire B.

But in fact, the wires A and B appear neutral only in our perspective. The electrons in both wires are moving very fast, say around 1/100 the speed of light. So, the electrons in wire A do not see wire B as neutral and vice versa. Therefore, the electrons moving in wire A are attracted to wire B (and vice-versa), and the two wires attract.

I guess this kinda a hand-waving explanation of the special theory of relativity. The general theory involving gravity is even more complicated.

[chenchow]

Fully agree with Prince.

Wayne, I am sure you will be able to learn and follow the footstep of Prince. He has done a great deal of research and definitely many people, including me, really admires him for his interest, dedication, persistence and geniusness.

Prince, you should share some of the learning techniques, so that there will be more people of your talents emerge~!

[chenchow]

Fully agree with Prince.

Wayne, I am sure you will be able to learn and follow the footstep of Prince. He has done a great deal of research and definitely many people, including me, really admires him for his interest, dedication, persistence and geniusness.

Prince, you should share some of the learning techniques, so that there will be more people of your talents emerge~!

[Wayne]

Thanx for your explanation, Prince. :D
Btw, i like theoritical physics a lot but my major is Aerospace Engineering. So, i wonder if any courses about this will help me in my major.
From what i know,Engineering is more to practical purposes.So theoritical physics seems not very helpful.
Anyway, i am also interested in time travel reseach.
Wonder if anyone of you have come across such things in US, or anyone of you are involved in this kind of reseach, and can enlighten me with it..... :)

[Wayne]

Thanx for your explanation, Prince. :D
Btw, i like theoritical physics a lot but my major is Aerospace Engineering. So, i wonder if any courses about this will help me in my major.
From what i know,Engineering is more to practical purposes.So theoritical physics seems not very helpful.
Anyway, i am also interested in time travel reseach.
Wonder if anyone of you have come across such things in US, or anyone of you are involved in this kind of reseach, and can enlighten me with it..... :)

[tree007]

yo wayne! remember the MIT talk at INTEC? remember the fresh graduate? he mentioned sth like some1 did some research to disprove the possibility of time travel sth like that in MIT..

so maybe can call upon some1 from MIT who heard of this reserach to explain lor..

gee, btw, where r the MIT students?!! how come none at Recom wan? where's ching hao? where's jin hock? too busy? :P

[tree007]

yo wayne! remember the MIT talk at INTEC? remember the fresh graduate? he mentioned sth like some1 did some research to disprove the possibility of time travel sth like that in MIT..

so maybe can call upon some1 from MIT who heard of this reserach to explain lor..

gee, btw, where r the MIT students?!! how come none at Recom wan? where's ching hao? where's jin hock? too busy? :P

[yekban81]

yeah, I read that before very long time ago; someone has attempted to prove that time travel is impossible. but I forget liao. I wish someone can shed some light on this.

[yekban81]

yeah, I read that before very long time ago; someone has attempted to prove that time travel is impossible. but I forget liao. I wish someone can shed some light on this.

[tree007]

i think most science fiction movies that involve time travel will say that they create a machine that can "tear through the frabic of space time'... in other words, they see space time continium as a "thing"... is it really a thing that can be teared? and how do we access this "thing"? i guess that's the question..... correct me if i'm wrong.. 'cos.. i only learnt this from "back to the future" series.. hehe...

oh yeah! back to the future rox!!! hehe :P

[tree007]

i think most science fiction movies that involve time travel will say that they create a machine that can "tear through the frabic of space time'... in other words, they see space time continium as a "thing"... is it really a thing that can be teared? and how do we access this "thing"? i guess that's the question..... correct me if i'm wrong.. 'cos.. i only learnt this from "back to the future" series.. hehe...

oh yeah! back to the future rox!!! hehe :P

[SpRInG]

hm.... i have an interesting question here...

so far, we have this theory of relativity and quantum mechanics and so on.... by our uncle Einstein.....

so well, my question is, well, they are all theories, isn't it? And if i'm not mistaken (if i am, correct me), his theories' consistency were based on a constant, which is the speed of light. Again, if I'm not mistaken, some people had tried to prove that the speed of light is no longer a constant?

well, the real question is, all of these are just theories.... so well, actually what is the whole real truth about the universe, and even science itself has not been truly revealed.... so, hmm.. why don't we try somehting fun like posting our own theories.....????

Just a thought :D

[SpRInG]

hm.... i have an interesting question here...

so far, we have this theory of relativity and quantum mechanics and so on.... by our uncle Einstein.....

so well, my question is, well, they are all theories, isn't it? And if i'm not mistaken (if i am, correct me), his theories' consistency were based on a constant, which is the speed of light. Again, if I'm not mistaken, some people had tried to prove that the speed of light is no longer a constant?

well, the real question is, all of these are just theories.... so well, actually what is the whole real truth about the universe, and even science itself has not been truly revealed.... so, hmm.. why don't we try somehting fun like posting our own theories.....????

Just a thought :D

[yekban81]

Einstein's theory of special relativity results from two statements -- the two basic postulates of special relativity:

1. The speed of light is the same for all observers, no matter what their relative speeds.

2. The laws of physics are the same in any inertial (that is, non-accelerated) frame of reference. This means that the laws of physics observed by a hypothetical observer traveling with a relativistic particle must be the same as those observed by an observer who is stationary in the laboratory.

I wonder how Einstein came out with such idea from scratch. Did he reveal any formula which represent his two basic postulates of special relativity? I am really out of my common sense to apprehend his first basic postulates of special relativity 8O
There must be more explanations which should make his theory acceptable within our common sense.

[yekban81]

Einstein's theory of special relativity results from two statements -- the two basic postulates of special relativity:

1. The speed of light is the same for all observers, no matter what their relative speeds.

2. The laws of physics are the same in any inertial (that is, non-accelerated) frame of reference. This means that the laws of physics observed by a hypothetical observer traveling with a relativistic particle must be the same as those observed by an observer who is stationary in the laboratory.

I wonder how Einstein came out with such idea from scratch. Did he reveal any formula which represent his two basic postulates of special relativity? I am really out of my common sense to apprehend his first basic postulates of special relativity 8O
There must be more explanations which should make his theory acceptable within our common sense.

[yekban81]

Possibly time travel does not exist; else we could have had hot news about people from future coming here at the present time long time ago. But we may be able to see what was happening at a particular place and time; i mean we can see the past if we have a space ship which can travel at many times X light speed velocity and a high power telescope. NASA did the same thing before but they did not need such kind of space ship except a powerful telescope to capture the scene of our universe at its birth.

[yekban81]

Possibly time travel does not exist; else we could have had hot news about people from future coming here at the present time long time ago. But we may be able to see what was happening at a particular place and time; i mean we can see the past if we have a space ship which can travel at many times X light speed velocity and a high power telescope. NASA did the same thing before but they did not need such kind of space ship except a powerful telescope to capture the scene of our universe at its birth.

[USSDefiantNX74205]

Possibly time travel does not exist;

No one could be sure about that. However, one must wonder about the implications time travel will bring. Here are two interesting examples of paradoxes that might happen:

Paradox 1:
A time traveller goes back in time and kills his grandfather. The time traveller's father will therefore cease to exist and so will he. But if the time traveller never existed, how can he go back in time and kill his grandfather?

Paradox 2:
An old man from the future gives me the secret to time travel, enabling me to invent a time machine. Years later, when I'm an old man, I go back in time and give my younger self the secret to time travel, enabling my younger self to invent the time machine. Question: who discovered the secret to time travel in the first place?

Its paradoxes like these that lead people like Einstein to conclude that time travel can never happen. But some physicists are offering alternative theories. One of them involves a universal foolproof device or constant: that if you try to kill your grandfather, somehow, something will stop you from doing so in order to preserve the timeline. Like maybe you get run down by a truck or something while on the way to kill your grandfather. Another alternative involves multiple timelines. For example, when you go back in time to kill your grandfather, you create a whole new timeline independent of your own. This means in your original timeline, your grandfather was never killed while in the new timeline you just created, your father, you and your future generations will never exist.

Interesting huh?

But that's not all. Come to think of it, either way, what happens in your life is already set and whatever will happen to you will happen no matter how you try to avoid it. With the first alternative, imagine this:

Someone from the future tells you that you are going to be run over by a truck and die the next day. So you try your best to avoid all roads and motorized vechicles the next day and walk to work in the safest route you know. But these very actions of yours in trying to avoid being run over by a truck will ultimately lead to a series of events that will end up with you being run over by a truck, hence fulfilling the prophecy.

The second alternative is more complicated, but your life is still set. Why? Because all timelines will end with different outcomes. But due to the almost infinite number of timelines (created by the almost infinite number of choices along the way), all the outcomes are eventually accounted for. You belong to one of these timelines. But why do you belong to this particular timeline and not the others? Shows how your life is set isn't it, because you are stuck in this timeline due to the past decisions of other individuals and decisions that you will make and have made. What happens if you make a decision halfway through the timeline? Lets say you make a decision to choose A (thus creating timeline A) over B (you create timeline B if you choose this) in an event - it still makes no difference. The person in timeline A is you (and hence you're stuck in timeline A) whereas the 'you' in timeline B is not really you as you made the choice to choose A.

But there's another argument put forward by others: the you in timeline A and 'you' in timeline B are still the same person, though they made different choices. Therefore, the two are actually a single person with no difference in them except their choices.

So does this prove the concept of fate? Seriously I don't know. And if none of you understand what I'm crapping about then its ok. Sometimes I don't understand myself too...

But no matter how complicating or fascinating all this may sound, in the end it all still boils down to whether or not it can be proven in math - which is what physics is all about.

[USSDefiantNX74205]

Possibly time travel does not exist;

No one could be sure about that. However, one must wonder about the implications time travel will bring. Here are two interesting examples of paradoxes that might happen:

Paradox 1:
A time traveller goes back in time and kills his grandfather. The time traveller's father will therefore cease to exist and so will he. But if the time traveller never existed, how can he go back in time and kill his grandfather?

Paradox 2:
An old man from the future gives me the secret to time travel, enabling me to invent a time machine. Years later, when I'm an old man, I go back in time and give my younger self the secret to time travel, enabling my younger self to invent the time machine. Question: who discovered the secret to time travel in the first place?

Its paradoxes like these that lead people like Einstein to conclude that time travel can never happen. But some physicists are offering alternative theories. One of them involves a universal foolproof device or constant: that if you try to kill your grandfather, somehow, something will stop you from doing so in order to preserve the timeline. Like maybe you get run down by a truck or something while on the way to kill your grandfather. Another alternative involves multiple timelines. For example, when you go back in time to kill your grandfather, you create a whole new timeline independent of your own. This means in your original timeline, your grandfather was never killed while in the new timeline you just created, your father, you and your future generations will never exist.

Interesting huh?

But that's not all. Come to think of it, either way, what happens in your life is already set and whatever will happen to you will happen no matter how you try to avoid it. With the first alternative, imagine this:

Someone from the future tells you that you are going to be run over by a truck and die the next day. So you try your best to avoid all roads and motorized vechicles the next day and walk to work in the safest route you know. But these very actions of yours in trying to avoid being run over by a truck will ultimately lead to a series of events that will end up with you being run over by a truck, hence fulfilling the prophecy.

The second alternative is more complicated, but your life is still set. Why? Because all timelines will end with different outcomes. But due to the almost infinite number of timelines (created by the almost infinite number of choices along the way), all the outcomes are eventually accounted for. You belong to one of these timelines. But why do you belong to this particular timeline and not the others? Shows how your life is set isn't it, because you are stuck in this timeline due to the past decisions of other individuals and decisions that you will make and have made. What happens if you make a decision halfway through the timeline? Lets say you make a decision to choose A (thus creating timeline A) over B (you create timeline B if you choose this) in an event - it still makes no difference. The person in timeline A is you (and hence you're stuck in timeline A) whereas the 'you' in timeline B is not really you as you made the choice to choose A.

But there's another argument put forward by others: the you in timeline A and 'you' in timeline B are still the same person, though they made different choices. Therefore, the two are actually a single person with no difference in them except their choices.

So does this prove the concept of fate? Seriously I don't know. And if none of you understand what I'm crapping about then its ok. Sometimes I don't understand myself too...

But no matter how complicating or fascinating all this may sound, in the end it all still boils down to whether or not it can be proven in math - which is what physics is all about.

[cquayhl]

Wayne et al.,

I don't know very much, but I'll tell you what I know.

First, I agree with everything Chen Chow said. :-)

Yes, yes, I actually have some things to say. SR is a relatively accessible subject to the lay engineer. :-) If you only want to know about SR and not any other physics, I would recommend a book by AP French by the same title. The normal time for most physics undergrads to learn SR is at the end of the upper-level Electrodynamics class, but SR is quite a 'stand alone' subject, so maybe you can try looking at Chapter 12 in David Griffiths's Introduction to Electrodynamics and see whether it's helpful. Prince, what physics class did you take? Maybe Wayne can take a similar one. :-)

I've also found the following lecture notes on SR helpful. http://www.maths.ox.ac.uk/teaching/lecture-notes/ (See section b.) There are also GR notes in section c, which I keep meaning to look at have only glanced through. They seem quite well-written as well, although it may require more maths to understand.

About time travel, one person I know of who is doing research in this area is Alan Guth. http://web.mit.edu/physics/facultyandstaff/faculty/alan_guth.html He gave a talk here about how he showed that time travel is not possible in one very specific way. Needless to say, I didn't understand most of his talk. :-) As far as I understand nobody has proven that time travel is absolutely impossible; I think it will be quite difficult to do.

About how Einstein came up with SR, according to legend, he noticed some inconsistencies in classical electromagnetic theory. Don't ask me what inconsistencies...I took quals too long ago. :-P

About 'theories', most of them agree very well with experiment/nature. :-) (Well, otherwise they get thrown out.) When you combine SR with quantum mechanics, you get quantum field theory. One of the very sucessful QFTs is quantum electrodynamics, which has made predictions about things like the electron dipole moment which agree with experiment down to lots of decimal places. (Again, I forget specifics. If anyone is interested, I can go and look it up.) An interesting 'non-technical' book to read is QED, by Richard Feynman.

OK, I hope this is helpful. Wayne, when you get to the states, try taking a few physics classes and see how you like them. You can double major as well, but with Aerospace Engineering and Physics, that would be a very heavy workload. Good luck.

Cheers,
Charis.

[cquayhl]

Wayne et al.,

I don't know very much, but I'll tell you what I know.

First, I agree with everything Chen Chow said. :-)

Yes, yes, I actually have some things to say. SR is a relatively accessible subject to the lay engineer. :-) If you only want to know about SR and not any other physics, I would recommend a book by AP French by the same title. The normal time for most physics undergrads to learn SR is at the end of the upper-level Electrodynamics class, but SR is quite a 'stand alone' subject, so maybe you can try looking at Chapter 12 in David Griffiths's Introduction to Electrodynamics and see whether it's helpful. Prince, what physics class did you take? Maybe Wayne can take a similar one. :-)

I've also found the following lecture notes on SR helpful. http://www.maths.ox.ac.uk/teaching/lecture-notes/ (See section b.) There are also GR notes in section c, which I keep meaning to look at have only glanced through. They seem quite well-written as well, although it may require more maths to understand.

About time travel, one person I know of who is doing research in this area is Alan Guth. http://web.mit.edu/physics/facultyandstaff/faculty/alan_guth.html He gave a talk here about how he showed that time travel is not possible in one very specific way. Needless to say, I didn't understand most of his talk. :-) As far as I understand nobody has proven that time travel is absolutely impossible; I think it will be quite difficult to do.

About how Einstein came up with SR, according to legend, he noticed some inconsistencies in classical electromagnetic theory. Don't ask me what inconsistencies...I took quals too long ago. :-P

About 'theories', most of them agree very well with experiment/nature. :-) (Well, otherwise they get thrown out.) When you combine SR with quantum mechanics, you get quantum field theory. One of the very sucessful QFTs is quantum electrodynamics, which has made predictions about things like the electron dipole moment which agree with experiment down to lots of decimal places. (Again, I forget specifics. If anyone is interested, I can go and look it up.) An interesting 'non-technical' book to read is QED, by Richard Feynman.

OK, I hope this is helpful. Wayne, when you get to the states, try taking a few physics classes and see how you like them. You can double major as well, but with Aerospace Engineering and Physics, that would be a very heavy workload. Good luck.

Cheers,
Charis.

[oshmelvin]

It is interesting to see this topic online! Yeah, we could actually go back to our own past (the real past) or we could go back to the past in another reality (which has no effect to our future if we change the past in another reality). I think that time travel is possible. It has been proven that time slows down when we are moving really fast (for example on the jet plane). A research has been done... if i'm not mistaken it was in maryland or something. Read that two years back. One researcher (Professor Carol Allie) placed one atomic clock on a jet plane and another one on earth. The two clocks had been synchronized. The jet plane took off at high speeds and after a few hours, the two clocks were compared. There was a very small difference in the time though. (that is why it's only detectable with an atomic clock) The time showed on the clock which was onboard the plane was a bit slower compared to the one on earth. This is known as time dilation according to einstein's theory. So if a rocket were to be able to work up it's speed to the speed of light, we would see that time has indeed frozen for those in the rocket but to them there's no difference to their surrounding or our surrounding. So, one of the ways that we could actually travel to the future is by travelling at high speeds (speeds at the speed of light, 300 000 000 m/s). There is another way according to einstein's special and general theory of relativity. That is by creating a closed time like curve. Einstein's theory combined the three dimensional space with time to form a four dimensional space-time. So any points and location in space would represent a particular place at a particular time. If one could create a worm hole (which is a tear in the space-time fabric which is connected at two points), you'd come out at a different place in space at a different time (which means that you've either travelled to the past or future. So a worm hole is actually like a short cut to another point in space which has a different time which is also a short cut to the future or past. If we were to create a worm hole that could link to another distant place, we could be able to create a closed time-like curve that distorts our world line which is a straight line that links the past and future. SO, Einstein's theory PROVES that TIME TRAVEL IS INDEED POSSIBLE!

[oshmelvin]

It is interesting to see this topic online! Yeah, we could actually go back to our own past (the real past) or we could go back to the past in another reality (which has no effect to our future if we change the past in another reality). I think that time travel is possible. It has been proven that time slows down when we are moving really fast (for example on the jet plane). A research has been done... if i'm not mistaken it was in maryland or something. Read that two years back. One researcher (Professor Carol Allie) placed one atomic clock on a jet plane and another one on earth. The two clocks had been synchronized. The jet plane took off at high speeds and after a few hours, the two clocks were compared. There was a very small difference in the time though. (that is why it's only detectable with an atomic clock) The time showed on the clock which was onboard the plane was a bit slower compared to the one on earth. This is known as time dilation according to einstein's theory. So if a rocket were to be able to work up it's speed to the speed of light, we would see that time has indeed frozen for those in the rocket but to them there's no difference to their surrounding or our surrounding. So, one of the ways that we could actually travel to the future is by travelling at high speeds (speeds at the speed of light, 300 000 000 m/s). There is another way according to einstein's special and general theory of relativity. That is by creating a closed time like curve. Einstein's theory combined the three dimensional space with time to form a four dimensional space-time. So any points and location in space would represent a particular place at a particular time. If one could create a worm hole (which is a tear in the space-time fabric which is connected at two points), you'd come out at a different place in space at a different time (which means that you've either travelled to the past or future. So a worm hole is actually like a short cut to another point in space which has a different time which is also a short cut to the future or past. If we were to create a worm hole that could link to another distant place, we could be able to create a closed time-like curve that distorts our world line which is a straight line that links the past and future. SO, Einstein's theory PROVES that TIME TRAVEL IS INDEED POSSIBLE!

[__earth]

SO, Einstein's theory PROVES that TIME TRAVEL IS INDEED POSSIBLE!

actually, einstein's theory postulates that. It proves nothing.

[__earth]

SO, Einstein's theory PROVES that TIME TRAVEL IS INDEED POSSIBLE!

actually, einstein's theory postulates that. It proves nothing.

[oshmelvin]

Earth,

Thank you for the correction. It has been proven that time slows down (dilates) at high speeds, so this is a mile stone in time travel. Also, all of Einstein's theories have been proven right so far due to research in high energy physics. :D

[oshmelvin]

Earth,

Thank you for the correction. It has been proven that time slows down (dilates) at high speeds, so this is a mile stone in time travel. Also, all of Einstein's theories have been proven right so far due to research in high energy physics. :D

[yekban81]

I am impressed with the informations u guys offer. Thanks cquayhl
for your recommended website. And also thumbs up for oshmelvin for bringing on the time dilation and "worm hole-space & time" as a possible milestone to time travel. Very interesting indeed. 8O

[yekban81]

I am impressed with the informations u guys offer. Thanks cquayhl
for your recommended website. And also thumbs up for oshmelvin for bringing on the time dilation and "worm hole-space & time" as a possible milestone to time travel. Very interesting indeed. 8O

[Ic3b3rg]

yeah...thanx wayne for posting this topic... gives uninformed ppl like me a chance to increase my "limited" knowledge...hehe...

[Ic3b3rg]

yeah...thanx wayne for posting this topic... gives uninformed ppl like me a chance to increase my "limited" knowledge...hehe...

[tree007]

even though travelling close to the speed of light can enable time travel, is it possible to achive such speeds?

ahhh.. using worm holes as means of transportation.. ala star trek.... talking about star trek, if c (speed of light) is the universal speed limit, then, star trek warp speeds mah impossible lor? dang... if only can really create star ships of warp 9 speeds.. oooo.. chun..

[tree007]

even though travelling close to the speed of light can enable time travel, is it possible to achive such speeds?

ahhh.. using worm holes as means of transportation.. ala star trek.... talking about star trek, if c (speed of light) is the universal speed limit, then, star trek warp speeds mah impossible lor? dang... if only can really create star ships of warp 9 speeds.. oooo.. chun..

[SpRInG]

hmm.. hmm... see? we're all talking about theories... and postulations again....

an interesting question: can anything practical come out of this? such as time travel?

[SpRInG]

hmm.. hmm... see? we're all talking about theories... and postulations again....

an interesting question: can anything practical come out of this? such as time travel?

[oshmelvin]

Travelling at the speed of light is not achievable at the moment but one day we might develop technologies such as star ships that are nuclear- powered and can travel close to the speed of light. Besides, black holes are unexplored yet and even light can't escape the black hole. Presumably, we will be able to travel at the speed of light or even faster if a space craft were to be sucked up by a black hole.

[oshmelvin]

Travelling at the speed of light is not achievable at the moment but one day we might develop technologies such as star ships that are nuclear- powered and can travel close to the speed of light. Besides, black holes are unexplored yet and even light can't escape the black hole. Presumably, we will be able to travel at the speed of light or even faster if a space craft were to be sucked up by a black hole.

[yekban81]

"Besides, black holes are unexplored yet and even light can't escape the black hole. Presumably, we will be able to travel at the speed of light or even faster if a space craft were to be sucked up by a black hole."

An interesting assumption you have made, oshmelvin. But in my opinion, light being absorbed into black hole doesn't mean that a space craft will be sucked by black hole at a velocity greater than light speed. I believe that light does not exist in a black hole because it's simply being absorbed by black hole in a same process as light being absorbed by any black surfaces around us.

[yekban81]

"Besides, black holes are unexplored yet and even light can't escape the black hole. Presumably, we will be able to travel at the speed of light or even faster if a space craft were to be sucked up by a black hole."

An interesting assumption you have made, oshmelvin. But in my opinion, light being absorbed into black hole doesn't mean that a space craft will be sucked by black hole at a velocity greater than light speed. I believe that light does not exist in a black hole because it's simply being absorbed by black hole in a same process as light being absorbed by any black surfaces around us.

[oshmelvin]

An interesting assumption you have made, oshmelvin. But in my opinion, light being absorbed into black hole doesn't mean that a space craft will be sucked by black hole at a velocity greater than light speed. I believe that light does not exist in a black hole because it's simply being absorbed by black hole in a same process as light being absorbed by any black surfaces around us. [/quote]


Dear YekBan,

Thank you for your opinion on the black hole. I really do appreciate it. Anyway, I'd like to correct the statement that I've made yesterday that light could not escape the black hole. Actually, there is exception. There is something called a black hole evaporation which does release a certain amount of light from the black hole (which logically means that the black hole must contain light in order to release it). So I assume that light does indeed exist in the black hole. A black hole is not like a black coloured object that you see around. Yes, they both asorb light but in my opinion, light is trapped as light in the black hole where as light is converted into heat energy after being absorbed by a black coloured object (because light is an electromagnetic wave which carries energy). On a space craft travelling faster than the speed of light in a black hole, I must say we do not know for sure. Since light travells at the speed of 300 000 000 m/s the suction velocity of the black hole must far exceed the speed of light which means that there is such a possiblity for a craft (star craft) to travel at speeds unimaginable by men if it goes through a black hole. :D

[oshmelvin]

An interesting assumption you have made, oshmelvin. But in my opinion, light being absorbed into black hole doesn't mean that a space craft will be sucked by black hole at a velocity greater than light speed. I believe that light does not exist in a black hole because it's simply being absorbed by black hole in a same process as light being absorbed by any black surfaces around us. [/quote]


Dear YekBan,

Thank you for your opinion on the black hole. I really do appreciate it. Anyway, I'd like to correct the statement that I've made yesterday that light could not escape the black hole. Actually, there is exception. There is something called a black hole evaporation which does release a certain amount of light from the black hole (which logically means that the black hole must contain light in order to release it). So I assume that light does indeed exist in the black hole. A black hole is not like a black coloured object that you see around. Yes, they both asorb light but in my opinion, light is trapped as light in the black hole where as light is converted into heat energy after being absorbed by a black coloured object (because light is an electromagnetic wave which carries energy). On a space craft travelling faster than the speed of light in a black hole, I must say we do not know for sure. Since light travells at the speed of 300 000 000 m/s the suction velocity of the black hole must far exceed the speed of light which means that there is such a possiblity for a craft (star craft) to travel at speeds unimaginable by men if it goes through a black hole. :D

[__earth]

nothing can travel faster than light. that's an acceptable physics theory.

[__earth]

nothing can travel faster than light. that's an acceptable physics theory.

[oshmelvin]

Yes, in every day circumstances, nothing can travel faster than the speed of light. Light is a remarkable electromagnetic wave that carries energy but no mass so it enables it to travel up to the fastest speed possible which is almost 300 000 000 m/s. But light can travel faster than the speed of light (which is the now acclaimed speed). In an experiment in Princeton, New Jersey, physicists aimed a pulse of laser light through cesium vapor and amazingly, it exited the chamber before even finished entering it. And after some calculations, the light travelled 310 times the distance it would have travelled if the chamber was a vaccum chamber instead. Which means that light can travel so much faster than it actually does!

[oshmelvin]

Yes, in every day circumstances, nothing can travel faster than the speed of light. Light is a remarkable electromagnetic wave that carries energy but no mass so it enables it to travel up to the fastest speed possible which is almost 300 000 000 m/s. But light can travel faster than the speed of light (which is the now acclaimed speed). In an experiment in Princeton, New Jersey, physicists aimed a pulse of laser light through cesium vapor and amazingly, it exited the chamber before even finished entering it. And after some calculations, the light travelled 310 times the distance it would have travelled if the chamber was a vaccum chamber instead. Which means that light can travel so much faster than it actually does!

[Ic3b3rg]

Physicist Hawking debunks astrology and Einstein

British physicist Stephen Hawking has been debunking astrology and some of Albert Einstein's theories in a lecture in the capital of India.

Most Hindus consult star charts and astrological signs for decisions on marriage and other matters but Professor Hawking said the practice is not compatible with science.

Delivering a lecture in New Delhi, Prof Hawking said Einstein had been confused about quantum theory and wrong about the existence of black holes.

In his Albert Einstein Memorial Lecture for the Centre for Philosophy and Foundation of Science, the scientist added that some theories about the ability to predict the position and velocity of particles in space or time may be no better than astrology.

He said: "When it was discovered that the Earth was not the centre of the universe, astrology became impossible.

"The reason most scientists don't believe in astrology is because it is not consistent with our theories that have been tested by experiment."

At the end of the lecture, Hawking was given a standing ovation and presented with a Hindi language translation of his blockbuster physics book, "A Brief History of Time."http://www.ananova.com/news/story/sm_176752.html

hehe.... i c tht this topic is idle for quite some time......
so i jus added some food for tot.....

[USSDefiantNX74205]

At last, a famous science figure steps fore to debunk astrology. Shouldn't it be obvious already that astrology doesn't work?

[yekban81]

No astrology discussion over here. You may post anything relates to astrology in this forum:

http://www.recom.org/modules.php?name=Forums&file=viewforum&f=36


Well, I am surprised to know that Hawking said Einstein had been confused about quantum theory and wrong about the existence of black holes. I thought he has been researching and proving Einstein theory in quantum mechanic and black hole.

mmm...thought that I can read more about that in the link which you provide here, ic3b3rg.

[USSDefiantNX74205]

Oops...sorry I didn't notice there was a thread on astrology already.

Anyway, I have the same feeling as yekban81. I thought Hawking was a strong supporter (or at least believer) in black holes? I remembered reading somewhere though that Einstein himself didn't believe in the existence of black holes although his calculations supported their existence...

[Ic3b3rg]

sorry :oops: ..... read this page for more info about stephen hawking's response to einstein's theories...

http://www.hawking.org.uk/lectures/lindex.html

click on "public lectures"
then click on "the beginning of time"....
he explains it with day-to-day language....easier to understand....


btw, i am not an expert on the theories of hawking and einstein.... jus wanna read more about this topic.... :wink:

[yekban81]

Thanks a lot, Ic3b3rg for providing the info link.
I have downloaded before the lectures but lost them including the link. Never expect that I can access again those interesting lectures. :D