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# Speed of light revisited yet still again

Mon 29 Dec, 2014 12:28 pm
In another thread Marty and some of the rest of us discuss the means of travel of the photon and its speed

http://able2know.org/topic/263281-1

Somewhat OT Marty but I've often wondered how relativistic effects come to happen at velocity c. I understand they have to, mathematically; yet your Middling Dumbbell (me) can't help wondering whether they couldn't be accounted for using ordinary language

In this connection it's interesting to note that it all falls in place if we assume that somehow we're underestimating the speed of light, that it's not c but many times c. That easily explains for instance if Polly leaves her home planet Mars at light speed that to her the trip to visit us here seems to her instantaneous; the reason being of course that it is instantaneous

The apparent shrinking of a moving object in the direction of travel another instance in point. If the reflected light reaches us from the front and back of her ship at the same instant, then its thickness would seem to be zero

Yes this makes the assumption that somehow the time on Mars isn't now but ten minutes earlier, very hard for the intuition to accept

I could elaborate on this line of thought but instead of quiet consideration or reasoned rebuttal I'd probably be encountered by outright insult from most every quarter

Be happy to discuss it with anyone else tho
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contrex

1
Mon 29 Dec, 2014 01:34 pm
A spaceship travelling at the speed of light would indeed have zero length, but if you tried accelerating a spaceship to the speed of light you would find that as you got nearer to c that more and more of the energy you were putting in was going to make the mass larger. You woulkd never get to c. Also, if a spaceship was moving at even 99.999998 percent of the speed of light, any stray hydrogen atoms it met (and there are lots in space) would strike with an energy of around 7 TeV (tera electron volts), right about what the Large Hadron Collider can generate.
dalehileman

1
Mon 29 Dec, 2014 02:05 pm
@contrex,
Quote:
A spaceship travelling at the speed of light would indeed have zero length,
At least to the bystander

Quote:
...you would find that as you got nearer to c that more and more of the energy you were putting in was going to make the mass larger
Yes the apparent mass, again to the bystander. But we might note at this point that the apparent increase in mass could also be accounted for if were underestimating its velocity

Quote:
You would never get to c.
Again I've argued that this limit might be also be accounted for if the speed of light were infinite. However the suggestion entails certain contradiction and paradox. More likely (if my nutty theory has any validity at all) since it has the least mass, it simply goes fastest. Maybe some day some other sort of particle will be shown lighter and thus a tiny bit faster, who knows

…. at even 99.999998 percent of the speed of light, any stray hydrogen atoms it met…...would strike with an energy of around 7 TeV (tera electron volts)…….Or one might postulate that our little visible corner of things is for some reason traveling at that rate and the H atom is stationary w resp the rest of the Whole Megillah so it's we who impart the energy

….brings up the possibility of a stationary ref. I know there isn't supposed to be one, but certain crucial aspects of Einstein not yet abundantly clear occasionally intrude in our thinking tho we subliminally but instantly reject 'em
contrex

1
Mon 29 Dec, 2014 02:08 pm
Dale, you are just waving your hands about. There is nothing to discuss.
0 Replies

contrex

1
Mon 29 Dec, 2014 02:09 pm
@dalehileman,
dalehileman wrote:

Quote:
A spaceship travelling at the speed of light would indeed have zero length,
At least to the bystander

To everybody, including its occupants, however, physical objects can't travel at the speed of light.

dalehileman

1
Mon 29 Dec, 2014 02:29 pm
@contrex,
Quote:
A spaceship travelling at the speed of light would indeed have zero length,
At least to the bystander

Quote:
To everybody, including its occupants,
I'm not so sure about that Con. You might be right of course, I'm no physicist; but then according to present theory we'll probably never know, will we

Quote:
...however, physical objects can't travel at the speed of light.
Yes, no, I understand, Con. But might it not turn out that the photon does indeed have a little mass, that someday some other particle will be discovered that's a tiny bit lighter so will go a tiny bit faster

Slightly OT but I'm still puzzled by c. Assuming my crazy imaginings are totally off base and Einsteinian Math aside, why this particular velocity and not some other
contrex

1
Mon 29 Dec, 2014 03:06 pm
@dalehileman,
dalehileman wrote:
why this particular velocity and not some other

It comes out of the Clerk Maxwell equations.
dalehileman

0
Mon 29 Dec, 2014 05:51 pm
@contrex,
Quote:
It comes out of the Clerk Maxwell equations.
Thanks Con and I'm sure you're right but I was wondering if there isn't a non-mathematical explanation that would better suit the intuition of your Everyday Clodpate (me), that is in short sentences of everyday words arranged in their usual order

Alright yes, no, maybe that's impossible; everything is the way it is to make the formulas work
roger

1
Mon 29 Dec, 2014 07:01 pm
@dalehileman,
Someone once said that some non mathematical descriptions were like describing a symphony without using notes. I don't know about either one, of course.
0 Replies

contrex

1
Tue 30 Dec, 2014 02:05 am
@dalehileman,
dalehileman wrote:
I was wondering if there isn't a non-mathematical explanation that would better suit the intuition of your Everyday Clodpate (me), that is in short sentences of everyday words arranged in their usual order

http://www.theguardian.com/science/2014/jan/12/einstein-theory-of-relativity-speed-of-light

dalehileman wrote:
everything is the way it is to make the formulas work

Nope, you have it exactly reversed: the formulas "work" because of the way things are.

Much of modern physics, from relativity (over 100 years old) to quantum mechanics (nearly 100 years old) is not "intuitive".

somewhatsolved

0
Tue 30 Dec, 2014 04:59 am
@dalehileman,
Dudes The poster asked for laymans terms and Tera doesn't quite meet that standard.

So basically the faster you go the more you weigh. The more you way the slower you go. You can't reach the speed of light. C. Also it takes 30min for light from earth to reach mars on a good day. Add in G force of such travel means death. There is the star trek travel which is similar to the Halo series Travel. But not even I can brake that down easily.
roger

1
Tue 30 Dec, 2014 05:01 am
@somewhatsolved,
Not even you? Sounds serious.
somewhatsolved

0
Tue 30 Dec, 2014 05:15 am
@roger,
Okay you want me to expla
In the math I Will but Be Warned I'm a college dropout who only took one class and got an F in that as well so are you sure.
0 Replies

timur

1
Tue 30 Dec, 2014 06:15 am
somewhat unsolved wrote:
Also it takes 30min for light from earth to reach mars on a good day.

You got that wrong "dude"..

and wrote:

only took one class and got an F

Oh! This explains it..
0 Replies

Setanta

1
Tue 30 Dec, 2014 06:19 am
The time needed for a radio signal to get from the Earth to Mars depends, of course, on their relative positions. It can be less than five minutes, or as long as 21 minutes.
somewhatsolved

1
Tue 30 Dec, 2014 07:36 am
@Setanta,
Okay then why did NASA state that thier rover bots need to be able to guide themselves for up to an hour do to the back and forth relay of information that is traveling at light speed. Cut the time in half and you have 30min. And your making fun of me but I don't really care about that. Meet me on jeopardy and we'll tango till then just be professional. Mr. Put down the fully provable mathematics even though you quote theories that can't be proven. You probably still think a theory can become a law. Or that E=MC^2 is the correct equation. 😝
contrex

1
Tue 30 Dec, 2014 07:41 am
@somewhatsolved,
somewhatsolved wrote:
Okay then why did NASA state that thier rover bots need to be able to guide themselves for up to an hour do to the back and forth relay of information that is traveling at light speed. Cut the time in half and you have 30min

Cut "up to" an hour in two and you get "up to" 30 minutes.

People will make fun of you if you spell like a dick and plainly don't think before you post.

rosborne979

1
Tue 30 Dec, 2014 08:36 am
@dalehileman,
dalehileman wrote:
But might it not turn out that the photon does indeed have a little mass

No, it won't. Things that have zero mass exist at infinite velocity, and things that have mass cannot move at infinite velocity.

Just take F=ma and replace the "m" (mass) with a zero and you can see how the lack of mass and the speed of light are related.

And since you like intuitive things, just think of it this way: If you had an object floating near you and you gave it a tiny push (applied a force) it would accelerate away slightly. But if you imagine the mass of that object approaching zero then less and less force would be required to move it, until finally at zero mass, even the tiniest force imaginable would send it accelerating away at infinite velocity instantly. So things that have zero mass must exist at the speed of light, and things which have mass cannot move at the speed of light. The speed of light isn't just an arbitrary velocity, it's an artifact of space-time boundary conditions.
dalehileman

0
Tue 30 Dec, 2014 11:34 am
@contrex,
Thanks Con for that link but I'm afraid it didn't tell me anything I didn't already pretty well know. I still find the limit c mysterious

Quote:
Nope, you have it exactly reversed: the formulas "work" because of the way things are.
Okay, well, I was being sort of facetious. But it's entirely possible that in cases where the way things are isn't well understood, that another phenom yet undiscovered might better explain things in terms more acceptable to the intuition

To mine anyway

Quote:
Much of modern physics…. is not "intuitive"
True but it might be made so were an alternate way of analyzing or describing the phenomena eventually proposed

For instance I'd proposed to explain "relativistic" changes in the moving object not mathematically but buy the introduction of an alternate way of looking at time-at-a-distance more satisfying to the intuition. Conceding I might be 'way off base but on the other hand I might be onto something with a note of validity that might bear looking into

Hitler remember, made fun of Einstein
0 Replies

dalehileman

1
Tue 30 Dec, 2014 11:46 am
@somewhatsolved,
Quote:
... faster you go the more you weigh...the slower you go. You can't reach the speed of light. C
Yes Some, I understand the basic theory in this regard

Quote:
Also it takes 30min for light from earth to reach mars on a good day.
My book says 3 - 22 min

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