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I'm looking forward to Kelseymh's next Instructable... Answered


"How to Make a Universe"

I'm making space in my shed this very weekend...

Discussions

Kiteman, if you're already making space, then you've beaten me to it. Hopefully you don't end up with an inflationary epoch....

I'm just not sure I've got enough copper for the electromagnets, and the local photo-developers did a double-take when I told them how many old camera flashes I might need to get enough capacitors...

not to the subject i have an idea about time travel well i think lighning bolts time travel because you need 1.21 gigawatts and be moving at the speed of light your telling me it just disseapers in to metal? how about ''When this thing hits 670,616,629 mph your gonna see some serious stuff"' or ''Where the heck are they. ''The correct question is when are they''

Please don't tell me you are using a 1980s teen movie as a scientific text...

no i saw somewhere that you would need that to travel in time but where (.......)
was it on discovery for the light speed part?) oh and im not reffering to bttf (sorta)

Actually, you were. And "I saw somewhere" is an amazingly useful citation. Almost as good as your "girlfriend's brother's cousin's best friend had it happen to them once, and they died!"

yes i was but look at this: Einstein believed that all you needed was something that would go at the speed of light, and wormholes
ps i never said girlfriend's brother's cousin's best friend had it happen to them once, and they died
and ur starting to get offencive

How do you know what Einstein believed? I would be most appreciative if you could provide actual information (title of a book, publication reference, whatever) for what you think Einstein believed about whatever it is you're talking about (time travel, I think, but I can't tell from anything you've written).

Ah, you mean this book? That's an excellent starting point. Do you have the reprint, or did someone give you an original edition?

Where in there does he talk about or mention wormholes, or time travel? I'm very interested, because so far as the published literature is concerned, Einstein never mentioned either of those features of his theory.

The first wormhole solution to the field equations was found by Hermann Weyl in 1921 (though he didn't call it a "wormhole"; Wheeler coined that name in the 1950s). Closed timelike curves as valid solutions to GR were first found by Kurt Godel in 1949.

no book just science shows on the history channel what sciencetists say is that einstein had a therory and that the therory of reletivity allows it

.  The History Channel does a reasonably good job of checking facts and presenting them, but one should never have just one source of information. Don't even accept kelseymh's word alone for anything (and certainly not mine). Check and re-check your information and your sources.

Indeed, as the theory of relativity does demonstrate that time "slows" during rapid movement over a period of time, but slowing time is not the same as traveling THROUGH time.

but the theroy of reletivity allows it, and sciencetists think that if you're in an area being slowed by time, (a black hole for example) and the rest of the world is not then when you step out you have barely aged while the rest of the world has. (the the theroy on going at lightspeed is if you are on a rocket, and you travel to outer space when you return everybody on earth has aged 500 years, but you have only aged what your journey took)

You are confusing a lot of different issues, and misunderstnding many of them.

1) Relativity may allow closed timelike curves, but that is not yet proven.
2) Time dilation is not time travel.
3) Time dilation occurs at any speed, not just close to c. The effect grows with velocity [1/sqrt(1+v2)], so it's easier to see as you go faster.

Well 1. its a theroy
2. technicily you phisicly travel through time because all your friends have died because you're 500 years in the future
3. yes i know because when they tes this in aircrafts it's slightly slower on the ground then in the air

1. Do you know what "theory" means as a scientific term?

2. That's pointless sophistry. You are "travelling through time" right now (at the rate of one hour per hour), but nobody calls it that. If you want to engage in an intelligent, scientific discussion, then use correct terminology, not word games.

3. Well, making those measurements with aircraft and satellites (for example, GPS), combines two different effects -- the special relativistic time dilation, and gravitational red shift. You can see the special relativistic effect on its own most clearly with unstable subatomic particles (the lifetimes we measure when they are moving are longer than the lifetimes we measure for the same kinds of particles at rest). Also, a great recent experiment used a high-precision atomic clock to measure the frequency difference due to time dlation between a single atom at rest, and another atom that was bouncing back and forth at about 4 m/s (that's jogging speed!).

1. THEROY: a thought that has yet to be proven.

2. I AGREE.

3. Let me read out of a book: Nobody knows what it is, but the best guess is that it's just another direction. This was Einsteins theroy anyway. In the same that we have up, down, left, right, forward, and backward we also have past, and future. Time is thus a forth "dimension". (skip a few sentences) We may not be able to move through time, but there are ways of changing how fast we move through it. Einsteins theroies of Special, and General Reletivity proved using simple mathmatics, that speed and gravity both alter time. Expereiments have shown that clocks placed in fast moving aircraft run slower, than clocks standing still, and clocks on the ground run very slightly slower than clocks in orbit in a spacecraft high above the earths surface. The differences are so small, that it takes very senceitive equipment to detect them, but they are real. Einsteins theroy suggests that anything moving close to the speed of light (186,000 miles per second) will find time slowing down for them. So in sence they are time traveling.
 

1. Not correct. What you wrote is called a "hypothesis." First, you need to spell correctly if you want to be able to look things up: T H E O R Y (the 'r' comes after 'o', not before). Second, try the following for an explanation of what a scientific theory is: a principle or body of principles for explaining a class of phenomena.

2. Good.

3. Is the last sentence in your comment your, or theirs? Also, what book is this from? I'm not challenging, I'm curious what you're using as a reference. I might be able to recommend others that would be appropriate for you.

It just sounded like some of the things they post there...

In the last sentence it's my comment. Funny thing its from a book called: Back To The Future Annualy, this was in the info for "real" time travel

Okay, it's that comment that's causing our disagreement. "Time travel" usually means something fairly specific, in particular, the ability to move between any arbitrary points in spacetime, not connected to the "speed limits" imposed by relativity.

When we talk about the way our measurement of time slows down as a result of velocity, or speeds up when farther away from a large mass (gravity),the term that is used, universally, is "time dilation."

By conflating the two terms (there's a word for you to look up :-), you are making it harder for you to be understood, and more likely that others (me and Kiteman, for example) to think you don't understand something that maybe you actually do.

I hope that helps you to understand where our confusion lies, and why we were getting a bit impatient with your comments.

Lets see 34 hours later it's resolved, and yes it does help
:-)


Not really. Forward motion by this means or by means of suspended animation aren't really time traveling in the strictest sense. The only "method" of traveling back in time known would be to pass back through a wormhole to an earlier time, but it is also theorized that nothing larger then a subatomic particle cold pass through such a wormhole...per Mr. Hawking

Light goes at the speed of light, and it doesn't go back in time.

I don't think Einstein mentioned wormholes (Kelseymh?)

The "girlfriend's etc comment was what is known in the real world as "humour by exaggeration".

I think kelseymh's years of expert work entitle him to get a bit sniffy at a child who tries to dismiss thousands of man-years of work with a half-remembered quote from a quarter-century-old fictional movie.

Why are you not responding to my messages to you? Thanks to your wisdom I settled down a bit

Sorry, I didn't think they needed a reply.

Well done, though.

Ohh.... Well I'm currently trying to get a free ipod touch without refferals, surveys, or offers.

Ohh.. my mistake i ment to say black holes (I was reffering to an einstein rosen? bridge)

Ah, thank you! The Einstein-Rosen bridge is just one type of wormhole, discovered as a solution by Rosen and Einstein in 1935 (and hence was not "part of" his original theory, though obviously implied by it). Weyl's solution predates it by 14 years. Interestingly, it took another 27 years for Wheeler (1962) to show that the E-R solution was unstable, with a pinch-off time shorter than the light transit time.

Ok... so what I said is wrong (when you said pinch off did you mean milisecond, second, or some other (frame?) of time

Not wrong! Just incomplete. Depending on what books you read (or shows you saw on TV), you might have gotten the impression that the E-R bridge was the only kind of wormhole.

By pinchoff, Wheeler showed that it was nearly instantaneous. If such a wormhole were to open, it would immediately collapse (pinch off) faster than a light beam could make it through and reach the middle. How long that is depends on how big is the spacetime involve

After the collapse, you end up with the same old spacetime, with two black holes, one at each end of where the wormhole used to be.

Question, would the black holes (fuse?) together forming a bigger black hole if they where that close together.

Good question! No, they wouldn't; explaining why gets a bit complicated. There are some good diagrams in the Wikipedia article on wormholes, so I'll assume you've got access to that and can look at them.

So, first, the wormhole throat is not a measure of distance between the blackholes, it's just a connection. The "distance" for purposes of interaction (gravity pulling them together, for example) is the separation across ordinary spacetime; the "long way around" in the diagram in Wikipedia.

Black holes do merge (yes, "fuse" is a correct word, but not what you'll find in the literature), forming a larger one. That happens when you have a pair of black holes orbiting one another (like binary stars) in ordinary space time. Their orbits decay, and they spiral together until they merge. They give off gravitational waves during this process.

In the case of a classic (non-traversable) wormhole, the pinch-off is part of the reason they wouldn't (couldn't) merge through it. The wormhole's throat collapses, breaking the connection, sooner than light or anything else can pass through it. Gravity propagates at the speed of light (that pesky "speed limit" again :-), so any gravitational "signal" that could pull the black holes together through the throat can never actually get across.

Does that make sense? I used a fair amount of technical terminology. Please try using Wikipedia or something to look up as much as you can, and feel free to ask me questions.

Well one question I read somewhere at school 1 year ago about white holes are those part of an E-R bridge?

Yes. The original model of an ER bridge (before Wheeler proved their instability) was that one side was a black hole and the other a "white hole." However, white holes violate the second law of thermodynamics. That was noticed very soon after Rosen and Einstein's work, so the interpretation of the solution became one of two black holes connected by a throat.

A white hole violates the laws of thermodynamics because (classically) it produces energy from nothing. Those conservation laws are local (that is, they apply at each point in space), so having energy come from a black hole far away, and spew out of a white hole, violates those laws.

are you referring to hyperbole Kiteman?

Yes, but to a child with less-than-complete language skills.

FYI I got my report card today I got an A in all the grammer and language subjects.

Congratulations. However, you still need some help with punctuation and spelling, or maybe just with proofreading :->

"FYI, I got my report card today. I got an 'A' in all the grammar and language subjects."