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by Drastic on October 26th, 2007
Where exactly is the Ionian Nebula located in the universe?
by Kevisaurus is a Carnotaurus today on March 28th, 2008
| 3 people like this
How is the siza of a nebula determined three dimensionally when it is viewed only as a cloud?
by Dark Warrior on November 18th, 2007
| 3 people like this
What is special about the Boomerang Nebula?
by Dr. Scientist on July 29th, 2008
| 1 person likes this
How is a nebula's size determined three dimensionally when is is visible only as a cloud?
by Dark Warrior on November 12th, 2007
| 2 people like this
How can you see Boomerang Nebula since it's 5000 light years away? if you do see it than there's something else that is traveling faster than the speed of light since you'll be dead before you see it yet you can find images of the Boomerang Nebula online.
by answerbeggar on October 26th, 2007
| 5 people like this
You're reading How can you see Boomerang Nebula since it's 5000 light years away? if you do see it than there's something else that is traveling faster than the speed of light since you'll be dead before you see it yet you can find images of the Boomerang Nebula online.
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Comments
Actually, 5000 light years ago..but you probably meant that.
by WildCoastAmbler on October 26th, 2007
A light year is how far light travels in one year. So if something is 5,000 light years away, it takes 5,000 years for it's image to reach us here on Earth. So it's 5,000 years.
by Drastic on October 26th, 2007
Aargh of course! What was I thinking...time I went to bed..sorry!
by WildCoastAmbler on October 26th, 2007
Haha, no problem.
by Drastic on October 26th, 2007
If that's so, 5000 years ago there's no camera to capture the images and they got no good technology.
by answerbeggar on October 26th, 2007
Lol, the pictures weren't taken 5,000 years ago. They were taken in the 80's with the most detailed taken in 1998.
by Drastic on October 26th, 2007
But how can you take the pictures in the 80's without the light first travel to it before 5000 years? Would someone back then in 3020 B.C. already developed a technology so that light could travel and let the 1980's people take the picture?
by answerbeggar on October 26th, 2007
You're not getting what I'm saying. If you look up at the sky and see something that is 5,000 LIGHT YEARS away, then that means you're seeing something that has happened 5,000 years ago. People 5,000 years ago would not have been able to see it, because the light from the nebula has not reached Earth yet. When you look up and see the nebula, you're not looking at it as it is presently, but rather from 5,000 years ago.
by Drastic on October 26th, 2007
Drastic...you have your work cut out here..good luck.
by WildCoastAmbler on October 26th, 2007
In other words, the boomerang nebula happened 5,000 years ago, but WE have just recently been able to view it because that's how long it took for the light to reach us here on Earth.
by Drastic on October 26th, 2007
Lol, thanks! I might give up if he still doesn't get it.
by Drastic on October 26th, 2007
And I thought the nebula was there all the time and we use light to emit to it specifically so we can see it. I thought our light shines on it not nebula's light shine on us.
by answerbeggar on October 26th, 2007
No.
by Drastic on October 26th, 2007
Everything emits light, as given by the Black Body Spectra law.
What happens is that the nebula emits light at a time t, and the photons travel at the speed of light away from it, taking a time dt to reach the earth. That means we recieve the light of time t and time t+dt, so we're seeing what happened time dt ago, but only at time t+dt!
You actually experience this universially,e .g. the time for the light to reach your eyes from the sun is 8 minutes, the time for the reflection off someone's body to you is fractions of a nanosecond, etc. You never perceieve something directly, but always a 'past' image of it.
by H on October 26th, 2007
The thing is, how can you be sure that it is 5000 years? How can you tell?
by answerbeggar on October 26th, 2007
The actual age of it is debatable, but it's x number of years in the past anyway.
The age is an estimation, a 'best guess' with some rough science thrown in, but the error bars are huge.
by H on October 27th, 2007
i think scientists figgure it by comparing the distance of it w/ something we realy know the distance of and just do the math
by rudirs on August 24th, 2008
There are plenty of things faster than the speed of light. The Big Bang must have occurred at faster-light-speeds because the galaxy is about 14.2 billion years old and unless we're at the very dead center of where the big bang happened, looking 14.2 billion light years in any direction proves that early expansion took place at far greater speeds.
Otherwise, if we looked 14.2 billion light years to the left and then to the right, one would yield no starts beyond a few million light years.
To say that light is the fastest thing in the universe is like saying that since we haven't discovered aliens today they must not exist. Or saying in 1998 that a 333mhz computer is the fastest computer that will ever exist.
by A shout without knowledge is a protest on December 25th, 2011
Another fundamental misunderstanding..
The speed of light is a theoretical maximum speed that information can travel at (Though neutrinos appear to have potentially shattered this). The big bang is slightly different because it relates to the expansion of space itself, and thus, how do you measure that in a simple speed? Its not so easy. Theres no Einstein violation there.
I challenge you to name one thing, aside from hyperinflation (which is a special case) which travel with a bunch velocity faster than the speed of light. The only known potential exception so far are the tachyons (hypothetically) & neutrinos (result waiting confirmation from other scientific experiments).
Complete misunderstanding.
by H on December 27th, 2011
Being impolite when you think you're right doesn't make it so.
And why remove the expansion of the big bang from the potential violators of such an absurd universal speed limit? The simple fact is that if the universe expanded at no faster than the universal speed of light then it would be the age of the universe wide in one direction (from a given point).
Put a small balloon at the center of your kitchen. Now, blow it up to the size of your entire home. The balloon still started at somewhere (or nowhere) specific.
You can't say that the Universe was subatomic and then expanded to our known universe and still argue that it did not have a point of origin, even if that point of origin was not realized until it expanded.
And even if you did argue that, the spacing between the furthest two opposite galaxies is obviously over 28 billion light years. The simple fact that the universe is, as we know so far, 14ish billion years old proves that at one point, MATTER must have moved faster than the speed of light to create a universe that is, so far, 28 billion light years apart.
by A shout without knowledge is a protest on December 27th, 2011
My point is that you clearly dont understand how this works. Your understanding is, well, interesting for a layman, but thats all it is.
The speed of light relates to the speed at which information can transverse. When space itself actually expands, then there is, in the first instance, no information is travelling any distance.
There's also no concept of any 'centre' of the Big Bang - if you read any astronomer/cosmology text, this will be immediately clear. Your analogy fails because you are still expanding into something that already exists. The universe creates its own spaec as it expands - there is not a specific place it began from. What you can do, though, is 'collapse' it back into a singularity (note you cannot assign this singularity geometric coordinates).
As I said, read up on hyperinflation. Its an interesting cosmological mystery - one that is still being worked on - but the ieda that c is ever violated is incorrect.
The easiest, simpliest, and as such, somewhat incorrect analogy is if you assign point 1 to (0,0,0), point 2 to (1,1,1). If you change the meaning/significance of 0,0,0 and 1,1,1 to, instead, 0,0,0, x,x,x (NOTE: Not through motion on point 2 itself, but an actual expansion of the subset you're looking at), point 2 hasnt technically moved, though its distance from point 1 has increased.
Thats why dark energy is so fascinating, it seems to be an inherent expansion on space itself.
by H on December 28th, 2011
Also, I feel sorry for you if you think anything I said there is rude :)
by H on December 28th, 2011
To quote from one of your other threads:
Unfortunately, my math skills are lacking so severely that I wouldn't stand a chance.
-------
This particular aspect of cosmology is actually non-trivial. Its been a few years since I did courses on this (as a note, I'm doing a PhD in Particle Physics), and I'd have to re-look at my notes to give you the full glory latest and greatest on hyperinflation, so in itself it isnt entirely trivial mathematically, however, I can assure you no one juggles the theory that this comes down to some c-violation.
by H on December 28th, 2011
Not bothering to read anything but the insulting part of your poorly written comment (implying that I lay bricks and am stupid) and the fact that you think "light speed" refers to how fast information travels ends this conversation. I mean, how dumb can you be?
And my math skills make it impossible for me to calculate, for example, triangulation. It has nothing to do with understanding the theory behind light speed and the fact that light speed has nothing to do with data or information.
by A shout without knowledge is a protest on December 28th, 2011
Au contraire, I wouldnt claim to have any indepth understanding of, for example, QED or QCD. I understand and can converse with people what they entail and what they confer, but to claim any understanding of any physics without being able to do the maths is erroneous and proves a misunderstanding on your account.
Plenty of things can exceed the speed of light - the 'lighthouse' example is a great one - but the important thing is that information, travelling from A to B, can never occur at a rate faster than the speed of light.
My quotation of your comment in another thread is simply to relate to the four points posted above.
I have not (& hence my posting on this website) EVER had a problem with people not understanding things, being curious, or even being wrong. What I do have an issue with is people who openly admit they arent qualified to study a subject that involves indepth maths (and, to be honest, if you cant even triangulate, I hesitate to see the effects if you ever tried to understand ANY quantum mechanics, or start solving the Schroedinger equation) tries to claim any TRUE understanding of anything that is harder to explain than "Every action has a reaction" is erroneous.
If you feel so confident in your knowledge of physics, why dont you demonstrate solving a Lagrangian, or solving Schroedingers Equation for a n=1 sin wave in a square well? I would argue no one can even begin to make a claim to understanding quantum physics if they cant do that. Cosmology is more complicated (Quantum mechanics generally deals in vectors, only when you get to QCD and QED you have to worry about tensors... whereas cosmology is basically entirely tensors (my own lack of mathematical comfort is why I have avoided doing any maths in this thread - and as I stated, I'm doing post-grad particle physics - a testimony to the complexity of it).
If you dont understand that, then sadly, you dont understand science. You might be able to get a few things right, but you are getting something VERY FUNDAMENTAL, COMPLETELY WRONG in this thread.
And what I object to there is someone passing on false information about the world - educating the people incorrectly is just as bad a crime as not educating them :)
by H on December 28th, 2011
There are a few things you are bassackward on here, but I suppose you are right about the rest.
1) Because I have trouble with math I can't understand principles? From what we have discussed here, it is pretty obvious that you have been found lacking. And that is the fundamental error in your presumptuous, rude, and generally incorrect assertion. Do you need to know how a computer uses electricity to preform computations in order to understand the fact that it does?
Do I need to know how to determine where gold that arrived on Earth came from to know how it arrived on Earth?
2) It does not take someone who can teach advanced math to know that light speed does not have anything to do with data transfer. Imagine how many conversations you made yourself look stupid during by saying that.
3) Spreading lies (or at the very least poorly considered information)
is far worse than not educating people. For you are not only not helping with their education, but you are making it worse. How did you screw that theory up, too?
4)You would make a terrible theorist and an even worse teacher. The fact that you can't present a sound or logical argument and you cant even keep up with me, who apparently lays bricks, proves you are just trying to compensate for an inferiority complex here. And I was just kidding about you being right. You got tricked into reading what I wrote. Not bad for a layman, huh?
by A shout without knowledge is a protest on December 28th, 2011
1 - Clearly some principles are easy to understand, but if you're going to start discussing cosmological theory, you definitely need to do at least vector calculus before you can claim any real understanding of it.
To take your computer analogy - its much more like programming. You might be able to understand the basics of some programmes, you might be able to state even briefly how they work, but unless you can actually programme, you will never have a deep understanding of it (and, thus, more importantly, never be able to TEACH it to someone).
2 - Once again, its sad to say, if you think this is true, then you are very ignorant of some fundamental physics. What exactly do you think photons do? They transfer information. I wouldnt know the sun was there unless a photon from the sun reached my eye. That is information transfer. And the rate at which information can be transferred can not exceed the speed of light. As I stated, a lot of cases have been done where this is broken (via the phase velocity of the wave, rather than the group velocity) - however information is never transferred faster than the speed of light.
Here's a link. The very first line demonstrates your ignorance:
http://physicsworld.com/cws/article/news/41378
3 - Great, so you agreed with what I said.
4 - I've never once insulted what you perform for a living. Not once. Simply stated that if, by your own admission, you can not possibly fully understand physics. I salute you for trying, and am happy to provide a guiding hand for the areas where you get things wrong.
Now, please, go read up a bit more - most of what I've stated above has been known since the 19th century (back when people thought there was ether even!). You have a wonderful world of 20th and 21st century quantum mechanics to go through still :)
by H on December 29th, 2011
One last example:
If I take an electric-field free region of space, and turn on an electric field (there are conservation issues with this, but I think you get the principle), what speed do you think the 'information' of this field existing propagates through space? Because something 100 light years away will not find out instantly, it doesnt even know until the first photons reach it. Thats what scientists call information transfer. If you think I'm talking about reading and writing on hard drives, then I'm going to go cry to myself a bit.
Put it like this, I'm glad you're in law enforcement, and not in my field :)
by H on December 29th, 2011