Scientific 'things you've always wanted to know' thread
Discussion
Einion Yrth said:
MOTORVATOR said:
Only for you that are left behind surely, in my frame of reference time is all still good. Speed of light is ony at C when measured locally.
You would not perceive it, but your journey, however long, even infinite, would be over before you could take a single step. <tongue in cheek> there is only one photon, for it is everywhere at once </tongue in cheek>When I meet myself this afternoon you won't even have noticed that I've been anywhere.
MOTORVATOR said:
Einion Yrth said:
MOTORVATOR said:
Only for you that are left behind surely, in my frame of reference time is all still good. Speed of light is ony at C when measured locally.
You would not perceive it, but your journey, however long, even infinite, would be over before you could take a single step. <tongue in cheek> there is only one photon, for it is everywhere at once </tongue in cheek>When I meet myself this afternoon you won't even have noticed that I've been anywhere.
MOTORVATOR said:
Einion Yrth said:
BarnatosGhost said:
MOTORVATOR said:
If I take a round the universe flight on the latest Branson virgin challenger thingy that travels at the speed of light and during the flight move from the back seat to the front.
Will I have travelled faster than the speed of light and hence will there be more than one of me in existence?
You (and the challenger) have mass. So no speed of light travel.Will I have travelled faster than the speed of light and hence will there be more than one of me in existence?
And doesn't my mass become irrelevant as long as I have escaped any gravitational fields or at least found a position where gravitional fields are so weak as to render the acceleration due to gravity to be so low that it's combined effect with my mass is similar to that on earth?
So it may take a long time to get to where we can accelerate to speed of light but once there if I move seats and we return to where we started I would expect to meet myself?
http://edge.org/3rd_culture/hillis/hillis_p3.html
Einion Yrth said:
MOTORVATOR said:
Einion Yrth said:
MOTORVATOR said:
Only for you that are left behind surely, in my frame of reference time is all still good. Speed of light is ony at C when measured locally.
You would not perceive it, but your journey, however long, even infinite, would be over before you could take a single step. <tongue in cheek> there is only one photon, for it is everywhere at once </tongue in cheek>When I meet myself this afternoon you won't even have noticed that I've been anywhere.
BarnatosGhost said:
That's just explaining mass in relation to energy. Mass has no local effect unless a gravitional field acts upon it. So take myself outside of gravitional effect and it matters not a jot to me other than the accelerative power required to get to C. Weight now does not exist.
So Branson just needs to come up with the infinity drive and we are away.
MOTORVATOR said:
BarnatosGhost said:
That's just explaining mass in relation to energy. Mass has no local effect unless a gravitional field acts upon it. So take myself outside of gravitional effect and it matters not a jot to me other than the accelerative power required to get to C. Weight now does not exist.
So Branson just needs to come up with the infinity drive and we are away.
BarnatosGhost said:
No, it explains why you can't do it. Your mass increases hugely as you approach c, such that you won't have the energy to get there. Did you actually read it?
Yes that's why I pointed toward the infinity drive. Saying we can't get there is based upon our current understanding of drive capability which will no doubt change in the future. Possibly in the form of gravitational drives to make use of the increase in mass.
But that veers from my original question. If travelling at the speed of light in someone else's frame of reference not necessarily your own and you move across a ship's deck when you return to that viewers frame of reference would you there be more than one of you?
Einion Yrth said:
MOTORVATOR said:
Mass has no local effect unless a gravitional field acts upon it.
Does the word 'inertia' mean anything to you?As I understand it you as an observer can only explain my 'inertia' by utilising fictious forces.
Am I travelling at the speed of light or is everything else travelling away from me at the speed of light?
MOTORVATOR said:
Einion Yrth said:
MOTORVATOR said:
Mass has no local effect unless a gravitional field acts upon it.
Does the word 'inertia' mean anything to you?As I understand it you as an observer can only explain my 'inertia' by utilising fictious forces.
Am I travelling at the speed of light or is everything else travelling away from me at the speed of light?
R300will said:
MOTORVATOR said:
Einion Yrth said:
MOTORVATOR said:
Mass has no local effect unless a gravitional field acts upon it.
Does the word 'inertia' mean anything to you?As I understand it you as an observer can only explain my 'inertia' by utilising fictious forces.
Am I travelling at the speed of light or is everything else travelling away from me at the speed of light?
Therefore to them we are also travelling at higher than the speed of light and we haven't flown apart.
MOTORVATOR said:
R300will said:
MOTORVATOR said:
Einion Yrth said:
MOTORVATOR said:
Mass has no local effect unless a gravitional field acts upon it.
Does the word 'inertia' mean anything to you?As I understand it you as an observer can only explain my 'inertia' by utilising fictious forces.
Am I travelling at the speed of light or is everything else travelling away from me at the speed of light?
Therefore to them we are also travelling at higher than the speed of light and we haven't flown apart.
MOTORVATOR said:
R300will said:
They aren't travelling away from us, the space between us and them is expanding faster than light, which is can as it has no mass.
Agreed but from our frame they are still travelling faster than C just that we can't see them obviously.R300will said:
MOTORVATOR said:
R300will said:
They aren't travelling away from us, the space between us and them is expanding faster than light, which is can as it has no mass.
Agreed but from our frame they are still travelling faster than C just that we can't see them obviously.A bit of a diversion from the speed of light and stuff.
What is the physical basis of long term memory? For instance when you have a dream and something pops up from donkey's years ago that you have literally not thought about for maybe decades, but is there in what seems to be great detail. Somewhere in your brain is that memory - what is it made of?
And how accurate is that memory? Do I just have the idea of a place that I once was and fill it in convincingly from the "palette" of places that I have in my brain enough to think it's an accurate memory or am I really remembering it the way it was?
What is the physical basis of long term memory? For instance when you have a dream and something pops up from donkey's years ago that you have literally not thought about for maybe decades, but is there in what seems to be great detail. Somewhere in your brain is that memory - what is it made of?
And how accurate is that memory? Do I just have the idea of a place that I once was and fill it in convincingly from the "palette" of places that I have in my brain enough to think it's an accurate memory or am I really remembering it the way it was?
Shaolin said:
A bit of a diversion from the speed of light and stuff.
What is the physical basis of long term memory? For instance when you have a dream and something pops up from donkey's years ago that you have literally not thought about for maybe decades, but is there in what seems to be great detail. Somewhere in your brain is that memory - what is it made of?
And how accurate is that memory? Do I just have the idea of a place that I once was and fill it in convincingly from the "palette" of places that I have in my brain enough to think it's an accurate memory or am I really remembering it the way it was?
A mixture of both depending on the circumstances. Truth is nobody really knows much about how the brain works. What is the physical basis of long term memory? For instance when you have a dream and something pops up from donkey's years ago that you have literally not thought about for maybe decades, but is there in what seems to be great detail. Somewhere in your brain is that memory - what is it made of?
And how accurate is that memory? Do I just have the idea of a place that I once was and fill it in convincingly from the "palette" of places that I have in my brain enough to think it's an accurate memory or am I really remembering it the way it was?
MOTORVATOR said:
R300will said:
MOTORVATOR said:
Einion Yrth said:
MOTORVATOR said:
Mass has no local effect unless a gravitional field acts upon it.
Does the word 'inertia' mean anything to you?As I understand it you as an observer can only explain my 'inertia' by utilising fictious forces.
Am I travelling at the speed of light or is everything else travelling away from me at the speed of light?
Therefore to them we are also travelling at higher than the speed of light and we haven't flown apart.
On a side note, If you're travelling on a fast-moving rock towards an observer and someone else is stood on another stationary* rock and you both shoot a beam of light at someone 5 light-minutes away, the observer will see both beams at exactly the same time. The first one hasn't travelled at "c+speed of the rock". They both travel at 300,000,000 m/s, but the "moving rock" beam has doppler shifted to a higher frequency so will look blue. Assuming the right amount of shift, of course!
* yes, yes, relativity and all that! Let's say they're both taken from the standpoint of a completely seperate observer OK? Jeez, you lot and your scientific accuracy.
I stand to be corrected as I'm not a proper physicist
crofty1984 said:
I've given the book back now (Why does E=MC2?) so I can't check, apologies if I'm wrong, but IIRC, "c" isn't the speed of light and nothing can go faster than light. "c" is the speed limit for the universe. full stop. Because light has no mass, it can travel at the speed limit of the universe (I'm on shaky ground here, but I think it actually HAS to in a vacuum) but it boils down that "c" is a hard and fast limit whether we're talking about light or not.
On a side note, If you're travelling on a fast-moving rock towards an observer and someone else is stood on another stationary* rock and you both shoot a beam of light at someone 5 light-minutes away, the observer will see both beams at exactly the same time. The first one hasn't travelled at "c+speed of the rock". They both travel at 300,000,000 m/s, but the "moving rock" beam has doppler shifted to a higher frequency so will look blue. Assuming the right amount of shift, of course!
* yes, yes, relativity and all that! Let's say they're both taken from the standpoint of a completely seperate observer OK? Jeez, you lot and your scientific accuracy.
I stand to be corrected as I'm not a proper physicist
Some German bloke once said.On a side note, If you're travelling on a fast-moving rock towards an observer and someone else is stood on another stationary* rock and you both shoot a beam of light at someone 5 light-minutes away, the observer will see both beams at exactly the same time. The first one hasn't travelled at "c+speed of the rock". They both travel at 300,000,000 m/s, but the "moving rock" beam has doppler shifted to a higher frequency so will look blue. Assuming the right amount of shift, of course!
* yes, yes, relativity and all that! Let's say they're both taken from the standpoint of a completely seperate observer OK? Jeez, you lot and your scientific accuracy.
I stand to be corrected as I'm not a proper physicist
“The velocity c of light in vacuum is the same in all inertial frames of reference in all directions and depend neither on the velocity of the source nor on the velocity of the observer”
But went on to further say.
“The results of the special relativity hold only so long as we are able to disregard the influence of gravitational fields on the phenomena”
So as long as you aren't accelerating C is a constant but as soon as you apply any form of acceleration or 'G' then C is no longer at 299792km/s and will increase or decrease along the vector of the gravitational field.
I think.
A few questions
1) i heard they did an experiment at manchester uni using a very very cold gas they could slow and almost stop proton, so is the speed of light in space not variable to temperature?
2) I find it hard to grasp space being a perfect vacuum, i.e devoid of matter, it's obviously full of stuff, anti matter whatever, sowhy do we say C is speed of light in a vacuum?
3) isn't the reality that C is just a handy constant for the maths but in reality it's not constant?
1) i heard they did an experiment at manchester uni using a very very cold gas they could slow and almost stop proton, so is the speed of light in space not variable to temperature?
2) I find it hard to grasp space being a perfect vacuum, i.e devoid of matter, it's obviously full of stuff, anti matter whatever, sowhy do we say C is speed of light in a vacuum?
3) isn't the reality that C is just a handy constant for the maths but in reality it's not constant?
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