Speed of light revisited yet still again

@parados,

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then why would she see our clocks standing still

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Because that is how relativity works.

But Para you had us ignoring relativity. That means halfway through her journey hasn't she has encountered at 2c that entire 10 seconds of photons; so during her entire 10-second trip she passes thru two such bundles, in effect 20 seconds worth of photons

Thus if she leaves at noon (earlier we had synced) when she sees our clock reading 11;50 she arrives here at 12:10

Con, canya help me

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@dalehileman,

Bran, '"as that" s/b "in that"

I wonder if it bugs anyone else how soon a2k withdraws permission to edit

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@dalehileman,

dalehileman wrote:

hasn't she has encountered at 2c

Nobody, and nothing, can travel at 2c.

1 Reply

@dalehileman,

dalehileman wrote:

dalehileman wrote:
"...how do we know that our little visible area moves at c with respect to the rest of the Universe..."

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I'd really like to know what you mean by this.
Sorry Bran, it was a typo; I meant to ask,

How do we know that what we now call The Visible Universe in its entirety is not moving at velocity c with respect to a much larger body, the actual Universe...

This indicates a lack of familiarity with the single most basic concept of relativity, and, indeed, the reason it is called relativity. "The Visible Universe in its entirety" is not moving at any one speed. To believe that it is is to believe that there is a preferred coordinate system. The most fundamental concept of relativity is that there isn't a preferred coordinate system. Speed has no meaning except as a comparison between two objects. I can see that you've picked up a lot in your year posting about relativity here.

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@dalehileman,

dalehileman wrote:

"...hasn't she has encountered at 2c that entire 10 seconds of photons..."

Another of the most basic concepts of relativity is that all observers measure light as travelling at c.

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@contrex,

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Nobody, and nothing, can travel at 2c

But Con we're ignoring relativity. I presume what Para meant by that is, that the rules wouldn't apply, there wouldn't be a limit to relative speed through the cosmos

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The person on the spacecraft would see 10 minutes pass while observing that the clocks on earth would stand still. (If we ignore acceleration and general relativity.)

So maybe I misunderstood; that is, the rules still apply but we simply forget them; in which case: Because, Para, if her the trip is almost instantaneous, wouldn't she instead see (virtually) no time elapse, while observing a jump in the clocks on Earth from 11:50 to 12:00

Because in Para's proposal we are pretending there's no such thing as relativity, we must assume that we'd have assumed she assumes that those photons must have been passing her at 2c

But in ignoring Einstein we must assume that her trip being instantaneous and on her arrival her watch still reading 11:50, we must assume there's something wrong with our notion of time-at-a-distance, that it's not now on the distant planet but ten minutes earlier

….which by the sheerest coincidence explains intuitively the apparently relativistic changes in the moving object (about which we're assuming we know nothing) now easy to explain: the apparent stopping of her watch obviously because her trip was almost instantaneous; the apparent shortening of her ship because we see its nose and exhaust port at the same time; the apparent increase in mass because we're underestimating her speed, etc etc

So Co maybe Para has stumbled on something we should further investigate

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@dalehileman,

There are two kinds of relativity, general and special. I only had you ignore one of them.

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@dalehileman,

dalehileman wrote:

But Con we're ignoring relativity.

Why, exactly? I seem to have missed this step. What are we going to ignore next? Gravity? Common sense? Please explain.

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@contrex,

Para, please explain

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@dalehileman,

I gave you a link.

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@parados,

Quote:

I gave you a link.

Sorry but can't remember. Please resend

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Brandon, Hileman is just an octogenarian troll, with the emotional maturity of an adolescent. He's an attention whore, and when people get bored and leavae this thread, he'll start the entire topic again, so that he can, briefly, be the center of attention.

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@Setanta,

And Brandon believes everything that he reads, because, since it is in a book it has to be real. I once read that microwave ovens cook from the inside out, then I put an apple in my first microwave oven for 1 minute, sliced it open to reveal a cold interior and a hot exterior. I then deduced that microwave ovens cooked from the outside in like conventional forms of cooking, and that the book and all of the people that I have heard spew this nonsense, were fools.

E=MC2, is theory, not real.

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@Setanta,

Setanta wrote:

Brandon, Hileman is just an octogenarian troll, with the emotional maturity of an adolescent. He's an attention whore, and when people get bored and leavae this thread, he'll start the entire topic again, so that he can, briefly, be the center of attention.

Let us hope that he never finds out about the Wikipedia article about the Tachyonic Antitelephone, or even worse, starts a thread about it. It has those two old thought-experiment friends Alice and Bob (who should get a room, maybe, except that they usually can't), and some bad shrimps.

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

1 Reply

@Setanta,

Setanta wrote:

Brandon, Hileman is just an octogenarian troll, with the emotional maturity of an adolescent. He's an attention whore, and when people get bored and leavae this thread, he'll start the entire topic again, so that he can, briefly, be the center of attention.

Certainly, reading a reputable exposition of special relativity so that he actually learns something doesn't appear to be in his make-up. Obviously, I don't mind that everyone doesn't have a degree in physics. What I do mind is when people talk about it as though experts but cannot be persuaded to do the work to actually learn something.

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@dalehileman,

It seems you can't read, you can't remember and you can't think. What do you do for fun?

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

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@Brandon9000,

Brandon9000 wrote:

Obviously, I don't mind that everyone doesn't have a degree in physics.

(I suppose I know the answer to this.) Why don't you get people filling forum threads saying that (say) chemistry is all wrong, that the molecular weight of glycerine is some different value than the books have it, etc?

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@dalehileman,

The speed of light has never been visited, at least not by any human.

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@Brandon9000,

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Certainly, reading a reputable exposition of special relativity so that he actually learns something doesn't appear to be in his make-up

And yet Bran nobody hereabout specifically controverts my assertions

In my own defense when I was a kid I r read alotta such stuff. If my mems at 84 are dead wrong however, my most sincere apologies; I assure all I'm not trolling

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@parados,

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It seems you can't read, you can't remember and you can't think

Para, whattya mean I can't read

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What do you do for fun?

Friday and Sunday, popcorn. Tuesday three exotic imported brews

Thanks Para for that link but where, specifically, anywhere, have I posted anything contrary to what's revealed in the Wiki article

1 Reply

Speed of light revisited yet still again

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