The science threads - Physics

chemistry_geek said:
In the PBS television special, the physicists themselves said that unless there is "real world testing of this theory, it is philosophy, not science, YET". Please note, I'm not making that statement, but someone else in the television special did.
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That is exactly why TV is the wrong medium to teach this in. Any dictionary can tell you that they were wrong for saying that. A theory is as much valid science as is experimentation.

When you put people, their ideas and their egos on TV your going to get mostly ego. And actually this is the problem with Physics today. A few people have made a name for themselves and are now finding it so important to defend what got them there that they don't care about the alternatives to their ideas.

A great example is the way they all (and now all of them do it) explain extra dimensions in space-time. The roll-into-a-tube-which-looks-like-a-line-from-a-distance party line is sad. Totally doesn't actually tell people what is going on and now some physicist actually think that is the way it is because they don't have the mathematics background to truly understand what is going on.

The most important part of science is being lost because if you don't have a name your ideas are not important. If someone like Hawking says something, question it. Your a scientist, that is what you are supposed to do... question it! Is it right? is it complete? What is the whole story? Ask the questions and then find out for yourself.

chevy said:
Back to the theme of the thread. I was not so much discussing philosophy against science, but more about the implications and significations of the string theory.
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As with most theories, there is a modeling period. That is to say you rework the theory over and over again to match nature as you know it. There are a number of theories right now that cover most of the same things as strings. As I said, I like Gauge Theory the best of those which provides for everything via a 10 dimensional space-time (6 of those being group-like degrees of freedom and not space-like dimensions as we are use to).

It is hard to talk about these things at these types of levels. I know from my personal experience in my research that once you pass a certain level of understanding which most of the people around you have you become isolated from them. I was very fond of many of my professors and loved sharing my research with them, but after a point certain point in time it became very hard to convey everything that I was so excited about. They saw that I was excited and listened all the same, but I soon realized that they weren't following me.

That was with people who had the levels of experience to maybe understand what I was doing. With other people it was even harder to talk about stuff.

Most of what is significant of string theories has direct effects on other theories in ways that are hard to understand. And (as with most physics today) there is going to be egos and posturing involved. Watching the PBS show on it I was reminded of why I got out of physics to begin with... the egos are incredible.

That is not to say that they aren't there in mathematics. I ran straight into someone's ego back in 1994 when I reframed a discovery of his in a way that made the discovery less of a break threw in the field and more of a break down in the definitions being used.
 
RacerX said:
It is hard to talk about these things at these types of levels. I know from my personal experience in my research that once you pass a certain level of understanding which most of the people around you have you become isolated from them. I was very fond of many of my professors and loved sharing my research with them, but after a point certain point in time it became very hard to convey everything that I was so excited about. They saw that I was excited and listened all the same, but I soon realized that they weren't following me.
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I think that the effect of science can be explained when we understand it correctly.

It's just difficult to always understand it correctly.
 
I'm sorry chevy, for partailly hijacking the thread, but I really disliked that quote. I don't know enough about string theory to partecipate. However, maybe I can humbly suggest that you somewhat change the nature of this thread. Science is not synonymous with physics, and string theory may be a bit far-fetched for a forum discussion. I think that allowing for more breadth would be good, because it would elicit more partecipation.
 
I'm a little bit late to the game here, but I thought I'd throw in a comment, which I don't believe has a lot to do with string theory, but is in response to a previous post.

There is actually an escape velocity faster than light according to Stephen Hawking. He has proven that there is some radiation emitted from black holes. So this either proves that what is coming from the black hole has no mass so it's not drawn into the gravity of the black hole or that the velocity is high enough as to escape the pull.
 
Captain Code said:
There is actually an escape velocity faster than light according to Stephen Hawking. He has proven that there is some radiation emitted from black holes. So this either proves that what is coming from the black hole has no mass so it's not drawn into the gravity of the black hole or that the velocity is high enough as to escape the pull.
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Hawking's theory (known as Hawking Radiation) does not require anything to go faster than the speed of light.

The theory works like this:

Every where in the universe virtual particles are popping into and out of existence. These are done in pairs, in which one particle is matter and the other is antimatter. Hawking theorized that on the edge of an event horizon (the boundary between a black hole and the rest of the universe found at R=2M, where M is the mass of the black hole) if these particles popped into existence, one might fall into the black hole while the other escapes as radiation. In keeping with the fact that something can't come from nothing, Hawking said that gravitation from the black hole provided the energy to keep the virtual particles from disappearing. In a sense, the black hole is bleeding away it's mass-energy in the form of gravitational tidal forces. Given that, Hawking theorized that black holes would eventually evaporate unless fed by some other source.

Note: by definition a black hole is any large body whose radius r is less than R where R=2M and M is the mass of the body. As I recall Hawking came up with this theory around 1974-76.
 
That's a good topic... what are we going to do about space travel if we can never go faster than the speed of light? We may hypothetically be able to get within kilometers of it (which, according to the Google calculator, is 299,792,458 m / s), but we can't pass it.

At that rate, it will take a space vessel at least 5 years to just get to the nearest star to our system, much less a system with an inhabitable planet. Will we choose to suffer the wait, possibly freezing our bodies to preserve our nature or inhabiting a colony ship until it arrives at its destination? Will we consign to stay put on Earth, or at least colonize our local friendly neighboring planets and moons? Will we discover a way to break the laws of physics? Who knows?

The answer, no matter how you argue it, is nobody right now. But we'll see.
 
RacerX: now that you explained it, I remember how it worked, and it was what you said, and not exactly what I thought. But, Cat is right about going faster than the speed of light. Those scientists in the articles he listed have proved it. It may just so happen that when you go faster than light you go back in time as well.

I think someone will discover how to fold space-time and we will not really go faster than light, but only have to travel a short distance, as we pull 2 parts of space very close together and go from one point to another that is "physically" hundreds or thousands of light years away in a matter of seconds.
 
I think the problem lies in trying to imagine it now. It would be like going back 300 years and asking someone, one of the colonists perhaps, what they think a good design for a computer would be. You'd have a hard time even explaining the basics of computing without a working model because that's so out of their league, just as space travel beyond the conventional means is out of our league.

I say this because I was thinking about how we'd accomplish what the cap'n described, folding space and time. Then I realized that we can never accomplish it until we understand the problem, and what's a better way to understand a problem than to compare it to something you already understand? Some say it's as if space and time were a piece of paper, and you simply fold the paper to connect A to B. It may be, but until we can understand the concept of extending this to the 3rd or 4th dimension, we can never really know.
 
IIRC som etime ago scientists succeeded in encoding information in a beam of light. The let it pass through a gas or crystal (can't remember) and the beam would store information about this (will look for links).
BTW. can't you store information in a beam of light through polarization? IT would be enough to encode 1 & 0 so technically enough for anything...

EDIT: link for the crystal

EDIT2: link one and two for polarization.
 
Cat said:
IIRC som etime ago scientists succeeded in encoding information in a beam of light. The let it pass through a gas or crystal (can't remember) and the beam would store information about this (will look for links).
BTW. can't you store information in a beam of light through polarization? IT would be enough to encode 1 & 0 so technically enough for anything...

EDIT: link for the crystal

EDIT2: link one and two for polarization.
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Of course information can be encoded in a light beam.
 
I'm not sure I understand you.

No information, no mass, no information travels faster than light for a long time/distance.

Phase can be faster than light.
And we know that quantum states can be "unlocal". As of today, it is still impossible to tranfer any information from point A to point B in a time shorter than the distance between A and B divided by c (the speed of light constant).

Can we fold space to travel faster ? We may be able to localy fold space, but doing that on a large scale to accelerate interstellar travel will probably require more energy than what we can ever produce.
 
Ok, we are probably both nit picking here: if you can make light go faster than light in vacuum, then you can transmit information faster than light in vacuum speed. However, there's a whole bunch of encoding and decoding which probably cannot take place at the speed of light, so if I want to send you the message "no worries?" through a telegraph operating with the super-light speed light, the pulses would obviously travel faster than light in vacuum. However, I need to tap the telegraph and you need to decode the lines and dots, etc. So what do you consider as "time to transmit information"? All from encoding to decoding? Or just the time the message spends in the channel? I cinsidered the second option and if indeed light can go faster than light in vacuum then the time the message spends in the channel will be shorter than the distance between A and B divided by c. Maybe it depends also on what exactly you call information, but things get rather fuzzy there.

I wholehartedly agree on your amended statement "... for a long time/distance". :)
 
Cat said:
Ok, we are probably both nit picking here: if you can make light go faster than light in vacuum, then you can transmit information faster than light in vacuum speed. However, there's a whole bunch of encoding and decoding which probably cannot take place at the speed of light, so if I want to send you the message "no worries?" through a telegraph operating with the super-light speed light, the pulses would obviously travel faster than light in vacuum. However, I need to tap the telegraph and you need to decode the lines and dots, etc. So what do you consider as "time to transmit information"? All from encoding to decoding? Or just the time the message spends in the channel? I cinsidered the second option and if indeed light can go faster than light in vacuum then the time the message spends in the channel will be shorter than the distance between A and B divided by c. Maybe it depends also on what exactly you call information, but things get rather fuzzy there.

I wholehartedly agree on your amended statement "... for a long time/distance". :)
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Here we must differentiate the speed of light as being the speed of any part of light (a photon or a group of photons) and the physical constant "c" that is equal to the speed of light in vacuum. No physical entity can go faster than "c" over a long distance (I use long distance because over short distances other phenomena can happen like tunneling that obey other, non strictly causal, rules... the "long distance" limit is normally microscopic but may be quite large in places of extreme gravitation). Phase of a phenomena can be faster than "c". This does not mean that the phenomena is faster than "c".
 
Well, I would ask you to define "phenomenon" then, because that concept is probably just as fuzzy as "information".
If the phase can travel faster than c and I can consider the phase as information, then information can travel faster than c.

chevy - I am no physicist, so if I am right out wrong, please tell me so. I may have misunderstood some concepts or treating them as meaning something different. I still suspect that we probably both agree, but are having linguistic issues of how some concepts are defined.
 
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