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# Who's familiar with the conversion? - "In 15 years' ship-time they could reach Andromeda

layman

0
Sat 14 Nov, 2015 09:17 am
@layman,
The premise here is that the ship will CONSTANTLY accelerate at the rate determined by a force of 1g. At that rate the ship would reach the speed of light in less than 1 year (353 days, they say). And then, it just keeps on accelerating at an exponential rate year after year. Yet it never reaches the speed of light.

Apart from mathematical equations and insubstantial "appearances," how can that make even the least bit of sense?
oristarA

1
Sat 14 Nov, 2015 10:14 am
@layman,
layman wrote:

The premise here is that the ship will CONSTANTLY accelerate at the rate determined by a force of 1g. At that rate the ship would reach the speed of light in less than 1 year (353 days, they say). And then, it just keeps on accelerating at an exponential rate year after year. Yet it never reaches the speed of light.

Apart from mathematical equations and insubstantial "appearances," how can that make even the least bit of sense?

If space can be distorted, it also means that there are wormholes, through which the ship can in effect travel faster than speed of light.
layman

0
Sat 14 Nov, 2015 12:44 pm
@oristarA,
Quote:
If space can be distorted, it also means that there are wormholes, through which the ship can in effect travel faster than speed of light.

This claim had nothing to do with wormholes, Oris, but never mind that. I'm not even going to ask you what "wormholes" are, how you know they exist, how they "work," or anything else. I can see that you are determined to try to "make sense" of this claim, by whatever means. If that's the case you will certainly succeed in convincing yourself, at least.

Keep the faith, Baby.
oristarA

1
Sat 14 Nov, 2015 07:47 pm
@layman,
layman wrote:

Quote:
If space can be distorted, it also means that there are wormholes, through which the ship can in effect travel faster than speed of light.

This claim had nothing to do with wormholes, Oris, but never mind that. I'm not even going to ask you what "wormholes" are, how you know they exist, how they "work," or anything else. I can see that you are determined to try to "make sense" of this claim, by whatever means. If that's the case you will certainly succeed in convincing yourself, at least.

Keep the faith, Baby.

You don't see my point there, which actually sticks to the central question discussed here. Because new knowledge is involved that is by far not expressed here. And all clues show that you seem to be unaware of the new knowledge.

First you get to clarify what you want to show us or what you want to know. Your view is here:

layman wrote:

Anyway, Oris, it seems to me that all this talk about "inflation" for an infinitesimal amount of time doesn't relate to the question I asked at all. The question was:

Quote:
The basic proposition is that, theoretically at least, a space ship can go 13.7 billion light years in 23 years and never travel faster than the speed of light.

Does anybody see a problem with this claim? Isn't there "something" inconsistent here?

What assumptions underlie such a claim? How would carrying those same assumptions over to other areas of physics mandate a reassessment of our "knowledge" in those other areas?

Now answer me the question: On what theoretical ground do you inquire us "Does anybody see a problem with this claim"? When it says "theoretically", it refers to Einstein's special relativity. Do you agree to this theory of Einstein's and do you make it your theoretical ground when asking such question?

maxdancona

2
Sat 14 Nov, 2015 08:57 pm
@oristarA,
I just want to point out that the basic point that someone in a spaceship travelling at near C will experience less time going to the nearest star than someone on Earth watching is not theoretical.

Lorentz contraction has been demonstrated by experiment, both by particles (see https://en.wikipedia.org/wiki/Time_dilation_of_moving_particles) and by experiments with Atomic clocks.

This is something that we have shown really happens.
layman

0
Sat 14 Nov, 2015 08:57 pm
@oristarA,
Quote:
Do you agree to this theory of Einstein's and do you make it your theoretical ground when asking such question?

If you insist, no, and yes. I was hoping to get some analysis from others, but it doesn't seem to be forthcoming.

A lot of people seem to assume that "whatever the scientists tell us MUST be right," and don't try to see if what the scientists are saying actually makes sense. They see it as their "obligation" to uphold "science" as they're told it is.
layman

-1
Sat 14 Nov, 2015 09:01 pm
@maxdancona,
Quote:
I just want to point out that the basic point that someone in a spaceship travelling at near C will experience less time going to the nearest star than someone on Earth watching is not theoretical.

You're right, Max, but you're wrong about what the spaceship is required to "see." The spaceship will see EVERYONE else in the universe as "experiencing less time" (if applying SR, anyway).
layman

0
Sat 14 Nov, 2015 09:04 pm
@layman,
Under the mathematical rules and procotols which SR requires for calculating time and distance, a ship could be going completely back and forth across the universe 25,000 times every second, and it would STILL be required to "see" itself as completely motionless--with everything else moving, but not it. Hence it is REQUIRED, by theory, to NEVER see it self exceeding the speed of light (because it's not moving at all). This applies to inertial motion only, of course (which is another problem here).
maxdancona

2
Sat 14 Nov, 2015 09:36 pm
@layman,
Quote:
Under the mathematical rules and procotols which SR requires for calculating time and distance

If you are now explaining what these mathematical rules and procotols (sic) say... could you please express that mathematically? Which mathematics exactly are you talking about?
layman

0
Sat 14 Nov, 2015 09:44 pm
@maxdancona,
I'm talking about the Lorentz transformations, Max, and the adjustment for the bogus "relativity of simultaneity" which has been added to them. I thought you knew all this, eh?
0 Replies

layman

0
Sat 14 Nov, 2015 09:48 pm
@maxdancona,

Quote:
If you are now explaining what these mathematical rules and procotols (sic) say

I suggested a long time back, Max, that you analyze the implications of a "frame of reference" (a term YOU brought up), but of course you would never do that.

Tell me, if I am in an inertial frame of reference, do I make any calculations regarding the LT based on the assumption that I am moving? EVER? Or does the very concept of a "frame of reference" (in SR) mean I am NOT moving (for LT purposes)?
maxdancona

3
Sat 14 Nov, 2015 09:53 pm
@layman,
Once you use the word "mathematical" in your argument, you need to be prepared to talk about the mathematics.

Any frame of reference is equally valid. You can choose a frame of reference and make all of the calculations from there, and you will get a correct answer. In an undergraduate physics class you will do exactly that (it is a shame that you haven't let yourself do this). This is very useful to see, where you calculate things in a couple of different frames of reference and see that all of them make predictions that you can then confirm by experiement.

At any given time, there will always be exactly one inertial frame of reference in which you are not moving. Sometimes it is useful to make your calculations based on this frame of reference.

That is all I can say... unless you want to start diving into the math.

layman

0
Sat 14 Nov, 2015 10:00 pm
@maxdancona,

Quote:
That is all I can say... unless you want to start diving into the math

That's just the kind of ignorance that PREVENTS you from understanding anything about what you're doing or why, Max. And, of course, by saying it, you AVOID all questions. Just answer the question:

Quote:
Tell me, if I am in an inertial frame of reference, do I make any calculations regarding the LT based on the assumption that I am moving? EVER? Or does the very concept of a "frame of reference" (in SR) mean I am NOT moving (for LT purposes)?
oristarA

1
Sat 14 Nov, 2015 10:05 pm
@layman,
layman wrote:

Quote:
Do you agree to this theory of Einstein's and do you make it your theoretical ground when asking such question?

If you insist, no, and yes. I was hoping to get some analysis from others, but it doesn't seem to be forthcoming.

A lot of people seem to assume that "whatever the scientists tell us MUST be right," and don't try to see if what the scientists are saying actually makes sense. They see it as their "obligation" to uphold "science" as they're told it is.

It seems that you've answered nothing to me.
What is "no" and what is "yes"? And when is your no and when yes? Be concrete, not this trick used in Halloween days.
A real scientist always leaves room for doubt, because nothing is absolutely certain due to the Principle of Uncertainty. I don't give a fig for those who have superstition on what scientists say.
0 Replies

maxdancona

2
Sat 14 Nov, 2015 10:07 pm
@layman,
I answered the question. You either didn't understand the answer, or you ignored it.

You can make valid calculations from any frame of reference. They are equally valid. At any instance of time, there is exactly one inertial frame of reference in which you are motionless. It may be more simple to make the calculation from that frame of reference, but any other frame of reference would be valid too.

If we want to talk about mathematics in any more detail than that, we need to be doing math.
layman

0
Sat 14 Nov, 2015 10:13 pm
@maxdancona,

Quote:
You can make valid calculations from any frame of reference. They are equally valid

That's not what you said the first time, Max. I'll come back to that. For now, let me phrase the question a different way:

1. Assume that I am on earth. Assume that from *my* frame of reference, I see an object going clean across the universe, and back, 25,000 times a second. Let's skip the math and just say, for now, that, from *my* perspective it's goin "purty fast," eh? NOW, THEN

2. Let's say I want to calculate it from the way the spaceship "sees" it. Let's say I am now on the ship, instead of the earth, OK. Now that's *my* frame of reference. Under SR, am I moving now?
maxdancona

2
Sat 14 Nov, 2015 10:19 pm
@layman,
You realize that from any inertial frame of reference, including yours, the speed of light is a limit. The situation you propose is impossible.

Assuming that you come up with a possible situation, then you would use the Lorentz transformation to make the calculation. Take a look at the Lorentz transformation and see what happens as v approaches c. You might find you need to use L'hopital's rule.

Of course, if you refuse to study any college level math because it doesn't make sense to you, this might be a problem.
layman

0
Sat 14 Nov, 2015 10:22 pm
@maxdancona,
Quote:
You realize that from any inertial frame of reference, including yours, the speed of light is a limit.

I realize that that is what SR says, yeah. We trying to analyze the claim made in the article Oris started with, right?

Quote:
Let's say I want to calculate it from the way the spaceship "sees" it. Let's say I am now on the ship, instead of the earth, OK. Now that's *my* frame of reference. Under SR, am I moving now?
maxdancona

3
Sat 14 Nov, 2015 10:26 pm
@layman,
This is simple mathematics Layman, the definition of frame of reference is well-defined. When you accelerate, your inertial frame of reference has changed. This means that what you are now calling "*my*" frame of reference isn't the same mathematical frame of reference as it was before you got onto the space ship and accelerated.

There is no mathematical contradiction (other than the fact that you haven't taken the time to understand the mathematics).

layman

0
Sat 14 Nov, 2015 10:28 pm
@maxdancona,
Quote:
This is simple mathematics Layman, the definition of frame of reference is well-defined. When you accelerate, your inertial frame of reference has changed. This means that what you are now calling "*my*" frame of reference isn't the same mathematical frame of reference as it was before you got onto the space ship and accelerated.

That's not what I asked you.