h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Entry: Into the Abyss(es) - A1034803
Author: Intersturber - U199002

This is a research paper I wrote for a course. My prof is grading it probably as you read it, but I just wanted to see if it was actually any good. A writer cannot critique his or her own writing, you know...

Quite interesting reading, being someone who has no knowledge of such things. I'm sure as a research paper for a class on the subject where the professor and other classmates know exactly what you're talking about this is prime stuff . And it is far superior to the existing Edited Entry concerning black holes.

As far as being Edited Guide material, I think this is a fantastic start. Actually it's probably a little too good -- I'm sure someone will come along and disagree with me, but I'll explain

Of course, to be edited, you would want to remove the specific references. If you would like to credit your sources a brief paragraph at the bottom stating what those sources were would suffice(I realize the references are a requirement of the research paper).

You've been very thorough, but for an average layperson with no prior knowledge (myself) there are still some questions to be answered. Like:
How did Wheeler change the field, and what field did he change - dark stars or general relativity?
How did Eddington cause Chandrasekhar to forsake work?
Why did Wheeler want to annoy the French so much? (I think this bit is one of the more interesiting bits of the paper and could do with a bit more explanation)
When did Penrose calculate how to use black holes for energy? Was this recent research?

I particularly liked the demonstration of what would happen to a person crossing the event horizon . Very descriptive and graphically gets the point across.

And, finally, if you're serious about having this in the Edited Guide (you said you were wondering if it was any good, so I don't know if you're even curious about what changes to make for editing), you would want to break it up a bit with some headings and subheadings. This would make it more accessible to the average layperson as well.

On the whole, a great effort!

I only have a couple of minor criticisms of this entry.

first, you express the problems of time travel as facts, but the theory still seems heavily disputed at this time, especially as regards travelling backwards in time.

secondly, you repeat yourself a couple of times, using a phrase, and within a pararaph or two, using it again.

thirdly, your current method of citing references doesn't seem to work very well. while "author, pages" is traditional in some journals, in others, you footnote the same references, and in others you only quote the specific work as a footnote, and leave it as a reference to the reader (using the references index) to find the page numbers. something different to what you are currently using seems in order, but I don't know what to suggest.

Thanks for all of the suggestions, I'll get on with them as soon as I'm done with a huge graphing project on rational functions I have to get done. Understand, of course, that this had requirements for a class, so I apologize for the format. I'll work on making more "Guide Suitable" and describing the ticking off of the French I can do right now, and then you can see if you want it in the paper. Apparently, the translation had, and I quote, "dubious sexual" connections. The book didn't go any farther than that, but I'm sure you can work it out for yourself. Thanks again, I'll get right on it after I'm done with fun fun fun functions!

Hey, it's fixed up now if anyone would care to go over it again!
Intersturber

Oh, one more thing.
If anyone would care to look over for grammar and spelling errors, that'd be nice. I've gone over it several times, but I happen to be the world's worst speller. (Or some denomenation thereof)

A much smoother read Not too techie, not too elementary. Well done!

I do have a quibble about your case for the impossibility of reverse time travel. In one paragraph you state "This can only go one way, though. Time travel backwards would be very difficult if not impossible." then begin the very next paragraph with "Time travel to the past would be impossible and here’s how." Later in that same paragraph you go on to say "These contradictions prevent time travel to the past impossible." which doesn't seem to make a lot of sense (sentence structure-wise). Besides, everyone knows you can travel anywhere in time using a flux-capacitor at the leisurely pace of 88 mph (spot the joke)

At the very end of your segment about time travel you have a bit about the possible compounding effect of minor changes to the timeline which I feel is somewhat excessive. I'm not sure I can pinpoint the exact problem, it just doesn't seem to flow well.

Overall it looks much better though

First off, fantasic entry! Now, you said you wanted a grammar check, so here we go: 'its' is the possessive adjective, ie 'its gravitational force' refers to 'the gravitational force of the black hole'. 'it's' means 'it is', so in general yo should change 'it's' to 'its' in this entry, though i'm probably nitpicking and am sure the editor will do this for you. I also have one question: if indeed it is possible to travel extra fast through time by orbiting a black hole, this would seem useless, because how the would you escape? You could wait until it evaportes, I guess, but then I imagine the explosion would annihilate your spaceship. Could you please clear this up for me?

It would be possible to orbit it without falling in (as the earth orbits the sun). If anything gets too close to too large and massive a stellar body, it will fall in, there is always a safe distance. I believe the event horizon is discussed somewhere in that mob of a research paper! I'll try and get you some more facts!
Intersturber

Though kudos to you for remembering the Hawking research that showed black holes evaporate over time!(unless I added that in the paper at the last minute and have forgotten about it...)
Kudos to you anyway for helping me spell correctly!

Intersturber

While I generally like the article, I would have to dispute the entire section based upon hawking proposition that time travel to the past is impossible.

it is stated as fact, yet it is only a proposal, based upon hawkings personal severe dislike for all the explanations that allow time travel.

considering the fact that he has been wrong before, it is risky to asume that just because he says so, he must be right.

I will say it again.

noting that I have come across which has been published so far actually bans time travel into the past.

a few people have proposed various methods to limit the possibilities for encountering the paradoxes, but as yet none of them actully show time travel into the past to be impossible.

Would it help if I added that it is entirely theory?

I put that in and mentioned that some people have theorized that wormholes might be able to take one back in time.
I am entirely open to any other suggestions anyone may have!

Intersturber

Well, from a sub's point of view, here's the view:

You repeatedly use quote marks - the Guide uses single marks, rather than double. Also, be careful of where you put punctuation marks with the quote marks - they're supposed to go on the outside, unless part of the quote.

In the History section - third paragraph, dealing with Scwartzchild, you talk of his theory as
' In 1916, Karl Schwartzschild found a way to fit the dark stars into general relativity. Not many people believed him'.

If this is a theory, why didn't they believe him? My point is, did they doubt that he'd come up with this theory or did they just not agree with his conjecture? If it was the latter, as I suspect, this would need to be clarified accordingly.

Also, be careful of the way you use it's instead of its - as in it's circumference instead of its circumference...

All in all, this is very readable, and I haven't really got any serious complaints...

cheers ismarah

I like it!

As a non-physicist, I found this entry very readable and understandable.

There are a couple of non-physicist type questions I found asking myself, though...

"More people became interested in the 1960s when technology became more modern." - An example here might be helpful.

"The star will then commence to collapse to a tiny point called singularity, which represents zero size and infinite density. Therefore, a black hole isn’t a 'hole' in space, but an immensely dense object pulling in and devouring everything in it’s path," is immediately followed by "Once not even believed to exist, black holes are now known to be found all throughout the universe. Very large black holes are found at the centers of galaxies, whereas smaller ones are scattered just as unevenly as the stars all around." - This seems to be saying that the centers of galaxies may contain something that is both very large and of zero size.

On to the picking of nits!

"Each particle of the fuel would be broken in to two pieces at the even horizon." - "even horizon" should be "event horizon."

"the nearest black hole is well over15 light years away" - need a space between "over" and "15."

"These contradictions prevent time travel to the past impossible." - needs to lose the word "impossible" for the sentence to make sense.

0

"This seems to be saying that the centers of galaxies may contain something that is both very large and of zero size." -0

I felt I understood what was meant by this, though. I understood this to mean that the singularities at the centers of galaxies would have more far-reaching event horizons, meaning they have a stronger gravitational pull. If my interpretation is correct I don't see much reason to change it... no matter how contradictory it may *sound* it adequately demonstrates the point.

I'll get right on those comments... possibly the day after today seeing as I'm supposed to be doing something else and not "waste time" as some would call it whilst I believe that there is an art to procrastination.

Sorry for my horrible spelling and grammar, I'll fix that as well.

It is very hard to imagine something so huge yet so small all at once, but you know, some things in life were meant to be confusing (as in my entire life)!

Keep your head in the game and I'll keep mine in the clouds!
Intersturber

" "More people became interested in the 1960s when technology became more modern." - An example here might be helpful."
When you think about it, technology is always perfectly modern, as it's the latest at the time. However, Intersturber may have meant more modern relative to us, in which case I'm almost certain he's talking about telescopes. Am I right?

Well....
I was referring to our ability to detect unseeable objects by observing the x-rays black holes emit from their poles and observing the intensive gravitational forces on surrounding objects (telescopes... bingo!) despite the fact that they themselves are invisible.

I'll put that in as well!

Intersturber

I have fixed up everything I could find, which means it still needs a lot of work! I'm going to need specifics on where the grammar problems are, because I tend to look over things. Just section and paragraph would be nice (thank you ismarah for helping me find exactly where the problems were instead of generalizing it)!

Thanks for all of the input, it's been great fixing up this misspelled, improperly typed, miserable entry into a slightly less misspelled, improperly typed, almost-not-miserable entry!

Cheers!
Intersturber