Would Religion still continue if....

[Upchurch]

Hehehe … funny how you A-Theists can imagine “No Time Existing”, or a present not based on the past, or acausal magic occurring for no objective or logical reasons,

Just because it bears repeating from time to time (appologies to Arthur C. Clarke):

"Any sufficiently advanced science is indistinguishable from magic."

 

[Franko]

Allow me to restate my calculation:

Relativistic composition of velocities: u = (v1 + v2) / (1 + (v1 v2)^2 / c^2)
Where,
u = total velocity between v1 and v2
v1 = velocity of one ship in reference to Earth = 0.7c
v2 = velocity of the other ship in reference to Earth = 0.7c

u = (0.7c + 0.7c) / (1 + (0.7c 0.7c)^2 / c^2)
u = (1.4c) / (1.49)
u = 0.94c

Noting that u < c, which is consistant with Relativity.

Mathematics don't lie unless the theory behind them are wrong. If you can find no error in my mathematics, then the only conclusion is that the Theory of Relativity is wrong. If you see an error in my math, please point it out. If you do not, do you see an error in the Theory of Relativity? If so, what?

I’m not sure we are disagreeing Upchurch. I’m not even sure what you are arguing at this point?

If I am heading in one direction, and you are headed in another direction and we are each traveling at 0.7 x C relative to a common point of origin we are separating at a rate of 420,000 kms relative to an observer on the Earth.

Furthermore, once one of these “asteroid ships” is out in deep space I see nothing in Relativity that would stop them from launching their own “mini-rocket” in the original direction of travel at a speed of 0.5 x C relative to the asteroid. Now at that point … wouldn’t the asteroid ship just be a “stationary” platform like the Earth was when the asteroid ship originally departed? Wouldn’t the little mini-ship be heading away from the asteroid at the apparent relative speed of 0.5 x C, with the Earth in the opposite direction still receding at 0.7 x C?

I realize that from the POV of someone on Earth, or someone on the mini-ship the speed would appear different, but from someone on the asteroid wouldn’t the mini-ship be headed off one direction at 0.5 x C and the Earth would look like it was headed in the opposite direction at 0.7 x C?

 

[Upchurch]

I’m not sure we are disagreeing Upchurch. I’m not even sure what you are arguing at this point?

If I am heading in one direction, and you are headed in another direction and we are each traveling at 0.7 x C relative to a common point of origin we are separating at a rate of 420,000 kms relative to an observer on the Earth.

Okay, how best to explain this...

How about this:

0.94c is different than 1.4c. Specifically, 0.94c is less than 1.4c. I am saying that the combined velocity of the two ships is former, you are saying that it is the latter. Therefore, we are, what is commonly known as, "disagreeing" about the combined velocity of the two ships.

Furthermore, once one of these “asteroid ships” is out in deep space I see nothing in Relativity that would stop them from launching their own “mini-rocket” in the original direction of travel at a speed of 0.5 x C relative to the asteroid. Now at that point … [1.] wouldn’t the asteroid ship just be a “stationary” platform like the Earth was when the asteroid ship originally departed? [2.] Wouldn’t the little mini-ship be heading away from the asteroid at the apparent relative speed of 0.5 x C, with the Earth in the opposite direction still receding at 0.7 x C?

1. From the asteroid ship's frame of reference, yes.
2. Yes.

I realize that from the POV of someone on Earth, or someone on the mini-ship the speed would appear different, but from someone on the asteroid wouldn’t the mini-ship be headed off one direction at 0.5 x C and the Earth would look like it was headed in the opposite direction at 0.7 x C?

Again, yes. Very good. Now, how do you figure out what the velocity of the mini-ship is from the Earth's frame of reference?

Bonus Question: How fast would an observer on the asteroid ship say the rocket is moving away from the Earth?

 

[Franko]

0.94c is different than 1.4c. Specifically, 0.94c is less than 1.4c. I am saying that the combined velocity of the two ships is former, you are saying that it is the latter. Therefore, we are, what is commonly known as, "disagreeing" about the combined velocity of the two ships.

It depends on who’s observing doesn’t it?

Franko:
I realize that from the POV of someone on Earth, or someone on the mini-ship the speed would appear different, but from someone on the asteroid wouldn’t the mini-ship be headed off one direction at 0.5 x C and the Earth would look like it was headed in the opposite direction at 0.7 x C?

Upchurch:
Again, yes. Very good. Now, how do you figure out what the velocity of the mini-ship is from the Earth's frame of reference?

Bonus Question: How fast would an observer on the asteroid ship say the rocket is moving away from the Earth?

Well if the one ship is moving away from Earth at 210,000 kms, and the other ship is moving away from that one at 150,000 kms then isn’t the first one moving away from the Earth at 360,000 kms?

 

[The Fool]

Frank.
I see you are still having problems letting go of your clockwork universe.....
I have cut-n-pasted part of my previous post, you really have to let go of this newtonian addition of velocities....spooky things happen at high speed, you should do some reading about it.

Get over it frank, relative velocities are just a concept, You can fire imaginary objects in any damn direction you like but C is still the speed limit. A photon emitted from any object traveling at any speed up to C will always be able to reach the other object traveling in any other direction traveling at any speed up to C. You could always put a stationary dot in between them that neither of them are traveling from at greater than C...The photon simply travels to the dot then from the dot to the other object...Dammit, you don't even need the Dot! I just thought it would help you get your head around the problem....get over it.

 

[Upchurch]

Well if the one ship is moving away from Earth at 210,000 kms, and the other ship is moving away from that one at 150,000 kms then isn’t the first one moving away from the Earth at 360,000 kms?

hint: u = (v1 + v2)/(1 + (v1 v2)/c^2), not u = v1 + v2.

What do you think Theory of Relativity says? How do you think it works? What are the consequences of Relativity?

 

[Solitaire]

Two futuriestic rockets are on a collision course. The rockets are moving
with speeds of 0.800c and 0.600c and are initially 2.52E+12 meters apart
as measured by Liz, an Earth observer. Both rockets are 50.0 meters in
length as measured by Liz. (a) What are their respective proper lengths?
(b) What is the length of each rocket as measured by an observer in the
other rocket? (c) According to Liz, how long before the rockets collide?
(d) According to rocket 1, how long before they collide? (e) According to
rocket 2, how long before they collide? (f) If both rocket crews are capable
of total evacuation within 90 minutes (their own time), will there be any
casualties? (g) What if Franko is right?

 

[evildave]

Originally posted by Franko

Hey! Congrats evildave you officially have more balls that Upchimp. It would have taken me at least 12 posts to get a straight answer out of him.

Nope, he appears to have answered it right away.

Yeah, but remember we are trying to keep things simple so we can see what is really going on. That is how Logic, Philosophy, and Science ALL work. You reduce the complexity and focus your perception on one single puzzle at a time. Otherwise, you’ll never see squat.

It's not how space travel works. Try to talk a non-suicidal astronaut into operating a space craft you deisgned by "simplifying" in this way.

Ohhh, yes we could think of all kinds of nonsense to make the example MORE complex, and that is exactly what you would do if you didn’t want to find anything out more than what you already know. Maybe they were traveling at 0.69642028754 x the speed of light instead of just 0.7 x C? Maybe instead of both planets being exactly 7 light years away one was 7.8986386 light years away, and the other was 15.875328976.

The formula D=RT, works no matter what the numbers are. What could be simpler?
11.341769821067036630746226695428 years and 22.795615320279099978386020239057 years, respectively.

Arrival notification to be received on Earth in
19.24040842106703663074622669542 years and 38.67094429627909997838602023905 years, respecively. Given the additional speed-o-light delay in message transmission that the observers would experience.

Does that really make the example BETTER for you evildave?

Doesn't appreciably change it. Still over-simplifies the stated problem. If you said trains were going 6000 miles at 60MPH, the D=RT math would even work. Still the planetary arrival announcement of the original problem would occur in 17 years (assuming space craft are pre-accelerated, and just fly past the planets without slowing down).

Ahhh, so in other words, you Hate simple examples where it is easy to see the point?

Ahh, I see. So this shortcut to understanding you prefer to use is to ignore all the pesky details that reality contains and simplify problems into silly and unrealistic models that don't work at all?

I understand your problem, but if detail-free and unrealistic models are the key to understanding the universe, the theists would have had it nailed down centuries ago. What with all of "god's help" and all.

...


So, as you can see LucyR, Franko wasn't interested in the actual relativistic effects at all.

People here probably even spotted that I got the backwards radio reception problem backwards. Not that it would work at all, since EM signals won't propagate at the ship's speed + C, as the doppler effects on the signal should indicate to anyone who'd have the sense to wonder why the signal changes frequency.

Oh well....

 

[LucyR]

evildave,

As I said I was in a good mood yesterday. No longer. The gentleman in question did not respond to my posts so I'm now officially Frankophobic.

By the way, are you really a games programmer? How did you get involved? What type of games?

 

[evildave]

Really am.

Started programming as a kid, applied for a game programmer job in 1990 when I got out of the USAF, got hired. The rest turns into a resume, dropping lots of dead compant names of lots of "Bargain Bin" content I helped to pollute shelves with all over... well, wherever it got sold. I seldom saw a copy of it... at least without dust on it. Even the N64 and PSX stuff. The joy of helping to make other people's dreams "real".

Mostly worked in networked games. Though a few bouts of crappy single-player PC games, console arcade ports, even a crappy palm pilot game.

Currently working on a new server back-end for an MMORPG. Currently working out how to recover when one of the servers/processes/elements dies, and idly wondering why we're reinventing the wheel... but from what we saw at GDC, the wheel we want isn't properly invented AND for sale at a reasonable price that makes not reinventing it look attractive. One IBM was pushing barely seemed to work at all (IBM Rep Quote: "We make chips for Sony and Nintendo, so we are experts in the industry!" - My question: "So the people who make the boxes they put the consoles in are experts too, right?"). Another Aussie one seemed to work, but all they could show was a "year old" demo that had some apparent issues. We're still waiting to see if they're full of technology or something else. Another one was pushed by SUN in a "boot camp" seminar, whose pitch people seemed to believe that having a "pretty" (with neon lights and a clear side-window) blade server makes all the difference.

I might look more seriously at cel phone games "off the clock". Little projects one or two people can do. Readily available APIs. Easy distribution channel. That's the ticket.

 

[Upchurch]

Two futuriestic rockets [R1 and R2] are on a collision course. The rockets are moving
with speeds of 0.800c [v1] and 0.600c [v2] and are initially 2.52E+12 meters [Lo] apart
as measured by Liz, an Earth observer. Both rockets are 50.0 meters [L1' and L2'] in
length as measured by Liz.

Quick calculations
R1: gamma = g1
g1 = 1 / Sqrt(1 - (0.8)^2)
g1 = 1.67

R2: gamma = g2
g2 = 1 / Sqrt(1 - (0.6)^2)
g2 = 1.25

(a) What are their respective proper lengths?
L1' = 50m = L1 / g1 = L1 / 1.67
L1 = 50m * 1.67 = 83.5m
L2' = 50m = L2 / g2 = L2 / 1.25
L2 = 50m * 1.25 = 62.5m

L1 = 83.5m
L2 = 62.5m

(b) What is the length of each rocket as measured by an observer in the other rocket?

As given above:
L1' = 50m
L2' = 50m

(c) According to Liz, how long before the rockets collide?

u = (0.8c + (0.6c))/(1 + (0.8c 0.6c)/c^2)
u = (1.4c) / (1.48)
u = 0.95c = 285000 m/s

To = Lo / u = (2,520,000,000,000 m) / (285,000 m/s)
To = 8,842,105 s
To = 147,368 min
To = 2,456 hours
To = 102 days

(d) According to rocket 1, how long before they collide?

L1 = Lo / g1 = (2,520,000,000,000 m) / (1.67) = 1,509,000,000,000 m

T1 = L1 / u = (1,509,000,000,000 m) / (285,000 m/s)
T1 = 5,295,000 s
T1 = 88,250 min
T1 = 1,470 hours
T1 = 61 days

(e) According to rocket 2, how long before they collide?

L2 = Lo / g2 = (2,520,000,000,000 m) / (1.25) = 2,016,000,000,000 m

T2 = L2 / u = (2,016,000,000,000 m) / (285,000 m/s)
T1 = 7,073,000 s
T1 = 117,883 min
T1 = 1,965 hours
T1 = 82 days

(f) If both rocket crews are capable of total evacuation within 90 minutes (their own time), will there be any casualties?

R1 has time to totally evacuate 980 times.
R2 has time to totally evacuate 1,309 times.

Edited to add: I doubt there will be any casualties. In fact, they probably have enough time to get other ships up there and tow each ship out of collision course or even just to steer out of the way of each other...

(g) What if Franko is right?

If he is, watch out for falling satelites, because NASA has been caclulating their trajectories incorrectly for the last 40 years.

"I love the smell of physics in the morning..."

 

[MRC_Hans]

COOL!

Hans

 

[Upchurch]

John?

Am I right or were you just asking for the fun of it?

 

[Akots]

COOL!

Hans

UpChurch has my vote for coolest science guy on the forum for this. Physics rocks.

 

[whitefork]

Sadly, the individual who started this highly instructive diversion seems to have lost interest.

Upchurch, you get another thumbs up.

 

[LucyR]

OH YEAH?!!

I offer to derive the fcuking theory from first principles - and does anyone respond?! Of course not!

Upchurch plugs a few numbers into some very simple equations and lo, he's everyone's hero!

This is grossly unfair!

 

[Upchurch]

Hans, Akots and 'fork,

Thank you very much, but all I did was answer the man's questions. The concepts have been around for nearly a century.

Touching back on the philosophy side of things (this being the R&P forum, after all), I'd like to point out that this stuff isn't common sense and it takes some effort to learn. As I told Soubrette in a PM:

To [study physics], I had to break free from a lot of my preconceptions about the universe because the universe is the way it is, not how I think it is.
[snip]
Essentially, I learned to change my common sense to match the universe rather than trying to change the universe to match my common sense.

I think this is a trap that we all tend to run into in philosophy & religion. Because we only want to see the universe one way (i.e. our own way), we tend to forget that just because an argument is logically consistant that doesn't mean it can't be dead wrong.

Newton, for example, had a very self-consistant set of rules about how the universe worked dynamically. People believed it for over 200 years. At some point, someone noticed that the laws of electromangetics predicted that light propageted at a speed based on constants, meaning the speed of light was constant. This lead to some serious paradoxes as far as Newton's laws of motion were concerned. To fix the problem, It was suggested that light propegated through a substance called aether and that when objects moved through space, it drug the local aether along with it. Thus, they allowed light to travel at a constant speed (relative to the local aether) and still work with Newtonian mechanics. However, aether later caused all sorts of problems.

Finally, instead of trying to force the universe to behave Newtonianly (is that a word?), they finally realized it was time to scrap Newton and relearn how the universe actually works rather than how they thought it works.

So, my question is: Going back to the actual topic of the thread, Would religion survive if we talked about the universe as it is?

 

[Upchurch]

Lucy,

I'm sorry you feel that way. I didn't see where you offered to derive it.

Edited: okay, I found where you offered. My appologies for missing it. Would you care to give it a go?

Once again, I appologize if I stepped on your toes.

 

[whitefork]

evildave,

Well, I could be wrong but he seems to have the idea that the concept of relativity, as defined by Einstein, is an atheist plot designed to pull the wool over his eyes. His questions are couched in such a way as to suggest that he's trying to force the atheist posters on this board to admit it. If we're nasty to him it'll only reinforce his prejudice.

What I would like to do is start with the empirical observation that c is constant independent of reference frame, and carry on from there. We can explain to him the history of the theory: the failure of the Michelson-Morley experiment, and the observation that the form of the Maxwell equations is not invariant when transforming between reference frames in the Newtonian universe, and the significance thereof. We can present the Lorentz transformation, and describe time dilation and length contraction, and also obtain the expression for the composition of velocities. We can even derive E = mc^2! Perhaps that'll impress him.

My point is that it should be possible to convince him of the validity of SR, if we take things step by step.

PS thanks for correcting my spelling - that was silly of me.

I missed this one too, or I filed it away under "irony/sarcasm". There must be a receptivity for learning at work before learning can take place, and I've not observed such receptivity in the subject in question, yet.
Reading a couple of books would be a nice sign of sincerity.

 

[Upchurch]

Based on the conversation at that point, I imagine I was focusing on how to explain it all to Franko that I just skimmed over the dialogue between Dave and Lucy. Not intentionally, I assure you, Lucy.