Do they have Jesus?

Seems like a really short time for a galaxy to form doesn't it?

It's a great big universe and we're all really puny.

 

Clickit

dragonchild: I'm talking about the Cosmic Microwave Background Radiation, of course, which XKCD turned into his "SCIENCE. It works, biatches" comic. You really don't want to question the CMBR findings as "a whole bunch of educated guesses" if you don't want to look like an epic idiot.



R.A.Danny: Science really can't be wrong, it only reports the evidence it has. Scientists that translate the evidence are just human though.

Then there's Dragonchild. You can't question Dragonchild, cause Dragonchild is delicate about questions.

dofus: Let's suppose the astronomers turned their equipment in the exact opposite direction and discover galaxy 'B' at the same distance.

If they did that, they would see the ground.

AdolfOliverPanties: Clash City Farker: AdolfOliverPanties: Big Bang happened. What came before it or caused it? Still up in the air, if they can even be answered.

Wait, are you saying The Big Bang Theory is a now The Big Bang Law, or are you saying you believe it happened?

Big Bang Theory is a TV show.

Big Bang is not Big Bang Law. It is just Big Bang. It happened. Go sell your religion somewhere else.

Sounds like you're the one preaching here.

Ishkur: The Universe doesn't have an edge anymore than the Earth has an edge. Go in any direction far enough and you'll just wind up where you started. Moreover, wherever you go, the Universe will look exactly the same to you. You will perceive everything as moving away from your position in space. Add the Theory of Relativity and things get pretty wibbly wobbly, timey wimey....

The Eath, and the Universe both have edges, called the surface, or outer edge.

RedVentrue: Eath

= Earth

Quantum Apostrophe: there their theyre: I'd do it for a chance to see another world. Who's with me?

Why do you feel that urge? We already have pictures of other worlds. And? They'll look pretty much like features of this planet, since we are, like, in the same universe and made of the same matter and obeying the same rules. Unless you don't believe that, in which case, how can you trust the pictures we take with instruments built here?

You never had the "What's going on over there?" urge?

Ishkur: Alright, time for Lawrence Krauss' "Universe From Nothing" lecture, which should be required viewing for every participant in every Fark Big Bang thread. There's something you're not grasping and I think he can explain it better (with visual aids).

Fun talk. "Woody Allen" of physics indeed. I don't think it addressed my point head-on but I gather my general misconception was considering expanding space in a purely 3D framework. I still think that the lack of edge requires a closed, or at least flat, if not strictly the former universe. I do find the idea of the total energy of the universe being totally balanced by the energy of the gravitational potential to be very compelling from a 'beauty' perspective myself.

Ishkur: Maybe the reason why we think the Big Bang happened 13.72 billion years ago is because that's as far as our instruments can observe.

The age of the universe is not determined by the farthest thing we can see, and the edge of the observable universe is about 46 billion light years away.

Ishkur: subfactorial: Fun talk. "Woody Allen" of physics indeed. I don't think it addressed my point head-on but I gather my general misconception was considering expanding space in a purely 3D framework. I still think that the lack of edge requires a closed, or at least flat, if not strictly the former universe. I do find the idea of the total energy of the universe being totally balanced by the energy of the gravitational potential to be very compelling from a 'beauty' perspective myself.

I just watched it again too. I wish someone would have asked him (and if I was there I would have) about where he asserts that since the expansion of the Universe is accelerating that it will eventually blink out of our ability to observe it..... what is the likelihood that this isn't occurring already?

Maybe the reason why we think the Big Bang happened 13.72 billion years ago is because that's as far as our instruments can observe. There might be more Universe out there but we can't see past that point and we got it all wrong. Krauss even states that in the far distant future humans will have a completely different picture of the Universe and it will be wrong. But what if we are too because we arrived to late to observe the full big picture? In a billion years, we'll see the CMBG radiation will only go as far back as 10 billion years ago. And then in a couple billion years, it will only go back 8 billion years.....etc.... slowly shrinking as the expansion exceeds C and pulls everything away from us.

It's useless speculation of course (I mean, how can we really know?), but I would have liked to hear his thoughts on it.


But as for the expansion/edge/center argument, I think the best way to describe it is to say that the galaxies are not moving. In fact, they are stationary. It is the space BETWEEN the galaxies that is filling up with more space, pushing them away from one another equidistantly. If you can conceptualize that, then you can understand why the Universe has no edge nor a ...

Don't galaxies crash into each other from time to time?

Ever since I was a little kid I've been interested in space. All those galaxies, planets and stars waiting to be discovered.

So last week, I finally did it. I went down and enrolled in cosmotology school!

It costs $32,000 a year and I had to take out a bunch of student loans, but it will be worth it. I can't wait to start!

subfactorial: Ishkur: subfactorial: Bottom line being that I would disagree with the statement that 'everywhere is the center of the universe". Some are more center than others.

No, because everything came from the same point at the beginning. That point is the center. Since that point was everything, then everywhere is the center.

Yeah, still no. If everything was in *exactly* the same spot then everything would continue to be in *exactly* in the same spot. Expanding universe or no. At some point there was some daylight (haha) between matter//energy to occupy some space for it to expand away from everything else. There should still be an edge to this somewhere.

To consider the idea that space extends for 13B years in every direction from every point (and that there are visable things in every direction) implies that there is an infinite amount of space with a correspondingly infinite amount of matter/energy in total. I don't think any well accepted theory of cosmology makes that argument... so what am I missing then?

06wildcat: Don't galaxies crash into each other from time to time?

Certainly. Galaxies are mostly empty space so they tend to pass through each other like two fist-fulls of sand thrown on crossing trajectories. Gravitationally they swirl and disrupt any structures effectively blurring or smearing any arms or heterogeneous aspects. One can look at a galaxy and estimate it's age visually. A galaxy like the Milky Way is probably young since it still has definite arms. Globular fuzzy homogenous galaxies are likely older having had a disturbing interaction with another galaxy in the past.

RedVentrue: You can't question Dragonchild, cause Dragonchild is delicate about questions.

You ought to see me when someone on Fark questions my sexuality.

/ In which case I'll type something as if I care, although I'm just sitting at my keyboard

Begoggle: dofus: Let's suppose the astronomers turned their equipment in the exact opposite direction and discover galaxy 'B' at the same distance.

If they did that, they would see the ground.

Heh

Serious question - What's in the other direction? Surely not another galaxy another 13 billion light years away, right?

If I draw a circle that's the entire universe in 2d (which I know is a horribly inaccurate way to depict it) are we.. like.. towards the edge and these are on the opposite side, or is it just that this is as far as we can see with our technology?

Also, it makes me somewhat depressed when I think about where, as a race, we would be if not for those hundreds of years of near-zero scientific progress due to religious zealots being nuts. Think where we'll be in 500+ years.. we'd be there now, maybe..

/deep sighs

MessinAr: Serious question - What's in the other direction? Surely not another galaxy another 13 billion light years away, right?

If I draw a circle that's the entire universe in 2d (which I know is a horribly inaccurate way to depict it) are we.. like.. towards the edge and these are on the opposite side, or is it just that this is as far as we can see with our technology?

Also, it makes me somewhat depressed when I think about where, as a race, we would be if not for those hundreds of years of near-zero scientific progress due to religious zealots being nuts. Think where we'll be in 500+ years.. we'd be there now, maybe..

/deep sighs

You mean like when they killed the Aztecs and the Incas? Totally.

Oddly enough there was a show on TV from 2010 about the universe last night. It seems the universe is expanding faster than the current theory says it should. In order to explain this, science has 'discovered' certain missing factors like 'dark energy' and 'dark matter'. See, that explains it. Right?

Clearly they mean its 5,900 years old

MessinAr: Serious question - What's in the other direction? Surely not another galaxy another 13 billion light years away, right?

That depends on the topology of the universe, which isn't all sorted out. We honestly don't know that, if you keep going in one direction, you'll go on forever or wind up where you started. Gravity warps space, which complicates matters somewhat. Think of it this way: pretend that the direction you go on Earth is locked in an east-west direction. If you face east at the equator, you can go 25,000 miles and wind up back where you started. If you do the same near (but not quite at) the north pole, you could wind up where you started by lunchtime -- on the exact same planet. That's one of the wonky things about the Earth's surface being curved. Space-time is even more complex.

MessinAr: If I draw a circle that's the entire universe in 2d (which I know is a horribly inaccurate way to depict it) are we.. like.. towards the edge and these are on the opposite side, or is it just that this is as far as we can see with our technology?

Again, the "inflating balloon" analogy is limited but you have to imagine all that there is, is on the surface. "Ant on a balloon" is the phrase often used, because it won't work unless you imagine you're the ant. There is a "center" to the balloon, but it's in a dimension that is irrelevant to you and thus may as well not exist. There is no "center" to the surface of a sphere. We know the Earth has a physical center (the core), but what's the "center" of the Earth's surface? I know some people think it's NYC, but geometrically no point is any more or less "center" than another. Similarly, there is no "center" to space.

Clash City Farker: It seems the universe is expanding faster than the current theory says it should. In order to explain this, science has 'discovered' certain missing factors like 'dark energy' and 'dark matter'. See, that explains it. Right?

No, it doesn't, and nobody says it does. Dark matter and dark energy are testaments to the integrity of the scientific process. When astrophysicists calculated the rotation rate of galaxies, they realized that even the wildest estimates of their mass didn't create enough gravity to prevent them from flying apart. They admitted they were missing something, something that didn't emit visible light, so they coined the term "dark matter" (because it's dark and has gravity and thus mass) as a placeholder while they tried to figure out WTF it was. If an MBA was in charge of this process they'd say, "Well I know everything so this can't be right," and fudge the numbers, chalking up the mystery of galactic rotation to Intelligent Design. Dark matter and dark energy are admissions that scientists don't know everything, so calling them out for not having an explanation to an area of active research is, by definition, premature.

nekom: 1. Why did it not collapse almost immediately? Scientists believe it could of it not for
2. Hyperinflation. Sure it as space itself violating the speed of light, but it's still weird.

It is weird, and the math here is very, very hard. I wish I could explain but I don't necessarily think it's modest to say that Stephen Hawking is a much smarter fellow than I am.

nekom: 3. No symmetry whatsoever. If everything came out of a singularity, wouldn't there be some recognizable patterns somewhere? Instead, utter chaos.

The afterglow is actually very, very smooth. So smooth, in fact, that galaxies and "all this chaos" emerged from the mere quantum fluctuations that occurred within the Big Bang. Matter has since clumped together in rather messy ways, but cosmic microwave background radiation readings show the expansion to have been the most symmetrical event in our known timeline.

Maybe the universe suddenly imploded 13.7 billion years ago, shrinking entirely into a singularity, where we are now.

Ok. Maybe not. But I was listening to a radiolab episode the other day where a physicist was saying that evidence seems to indicate that the universe is, if not "flat", infinite. Not curved back on itself. I had always thought that prevailing scientific opinion was that it was finite but unbounded.

What if dark matter/energy are huge super-luminal things/forces from a parallel universe overlapping ours such that their time travels backwards through ours, causing negative gravities which mess with our gravity which explains it all.

/takes another bong hit

If people have eternal souls, it will be possible to fly at .00000000^A miles per hour and still visit every galaxy in the known universe an infinite number of times.

/sounds boring

everytime I see one of those deep field pics of galaxy's I think of

Rent Party: No, we could do it if we could develop a working Broussard drive. What it would mean is that you could jet about the universe exploring stars, but you could never come home, as everyone you know would be centuries dead.

You don't need FTL. You need relativistic velocity and a willingness to abandon every single thing on Earth forever.

Sorry, but you'd still have to obey the laws of physics, and c is a hard, cold biatch.

It's going to take you years to get to the closest stars, and centuries to leave our galaxy. You're not going to get anywhere outside of our neighborhood during your lifetime (even according to your clock).

nekom: That makes sense, actually. But the `afterglow' isn't what is typically visible to us. . . I only vaguely understand things like quantum physics, but it's mind boggling stuff for sure.

The story of discovering the Big Bang is quite fascinating and on a conceptual level doesn't require quantum physics.

It starts with the knowledge that if you heat something enough, it'll eventually glow. A piece of metal, for example. At low temperatures, it doesn't look like it's glowing at all. At high temperatures it starts glowing red, then eventually white. But you know how certain substances glow in different colors (as anyone who's seen fireworks has witnessed)? Sodium, for example, glows yellow. Well, as anyone who's seen a rainbow would know, you can break up light into its component colors. So one day a guy made a device called a spectrometer, which would break up a glowing substance's light and squiggle (like those seismograms they use to monitor earthquakes) when it detected a color. So he heated a substance and ran the light through the machine, which squiggled right through the colors of the rainbow. . . and kept going. It was picking up "colors" that were literally invisible to humans.

The above tale is apocryphal, but here's the factual lesson -- our eyes are blind to over 99% of what goes on in the universe. Radio waves, microwaves, infrared -- these are all, in a sense, just different colors of light we can't see. So let's go back to the piece of hot metal. . . if there are colors we can't see and a metal of a certain temperature can glow red. . . what happens when it cools down? It turns out it's still glowing -- just in an invisible color, infrared light. In fact, it turns out anything of a certain temperature glows -- it's not a yes/no thing, but just a question of what color. "Thermal" goggles don't actually detect heat directly; they're sensitive to the infrared light -- the color humans glow.

Now, by the 1940s we knew for some time that the universe was expanding because everything was moving away from each other, but scientists then asked. . . what if you traced all this expansion backwards in time? What happened? It's almost like the universe originated from some sort of explosion. . . but if it did, wouldn't there be an afterglow? Well, 20 years later, some fellows were experimenting with microwave communications when they picked up a background signal. They originally thought it was a design flaw, because it was uniform in strength no matter where they pointed the antenna. It seemed like the signal was coming from everywhere in the sky -- which, to communications engineers, was logically preposterous. In order for a signal to come from everywhere it'd have to be everywhere, like the Force or something. The scientists, when asked about it, decided this just might be exactly what they were looking for. So, the scientists launched a spectrometer into space to measure this background radiation, when they got the results, they overlaid them with the mathematical expectation of what the afterglow of a hypothetical "Big Bang" that created the universe would look like after being stretched out by the expansion of space. Here are the results:

Broom: Rent Party: No, we could do it if we could develop a working Broussard drive. What it would mean is that you could jet about the universe exploring stars, but you could never come home, as everyone you know would be centuries dead.

You don't need FTL. You need relativistic velocity and a willingness to abandon every single thing on Earth forever.

Sorry, but you'd still have to obey the laws of physics, and c is a hard, cold biatch.

It's going to take you years to get to the closest stars, and centuries to leave our galaxy. You're not going to get anywhere outside of our neighborhood during your lifetime (even according to your clock).

Thank you for letting me know you don't know how time dilation or relativity works.

At 1 G constant acceleration, 1000 light years would only be 13 years of ship time to cover. 100,000 light years (enough to go from edge to edge of the Milky Way) can be done in 22 years ship time. Increase acceleration to 1.5G, and that time drops to 15 years. At 2G, it's only 11 years ship time to span the entire galaxy.

There's math involved in this. You should check it out. Then you can participate in the conversation.

How much energy does it take to get 1G acceleration?

Clash City Farker: How much energy power does it take to get 1G acceleration?

That depends upon your mass and your frame of reference.

Rent Party: Broom: Rent Party: No, we could do it if we could develop a working Broussard drive. What it would mean is that you could jet about the universe exploring stars, but you could never come home, as everyone you know would be centuries dead.

You don't need FTL. You need relativistic velocity and a willingness to abandon every single thing on Earth forever.

Sorry, but you'd still have to obey the laws of physics, and c is a hard, cold biatch.

It's going to take you years to get to the closest stars, and centuries to leave our galaxy. You're not going to get anywhere outside of our neighborhood during your lifetime (even according to your clock).

Thank you for letting me know you don't know how time dilation or relativity works.

At 1 G constant acceleration, 1000 light years would only be 13 years of ship time to cover. 100,000 light years (enough to go from edge to edge of the Milky Way) can be done in 22 years ship time. Increase acceleration to 1.5G, and that time drops to 15 years. At 2G, it's only 11 years ship time to span the entire galaxy.

There's math involved in this. You should check it out. Then you can participate in the conversation.

Cute, kid. Unfortunately, I set the curve in A-Bomb, and corrected the professor's key for the final - I got more right than he did, and he was allowed more than 2 hours.

Time dilation between any two observers is given by the Lorentz Factor, which is always >= 1.
t' = gamma*t
As velocity increases, the dilation of time increases, until at V=c the Lorentz Factor "gamma" is infinite.

If you were right, and gamma could decrease with velocity, one could cross the universe in a true "instant" by traveling at the speed of light. But this is not what photons do. Go check the article for an example: photons that left the galaxy 13.3 billion light years away have spent... wait for it... 13.3 billion years in transit.

Broom: Rent Party: Broom: Rent Party: No, we could do it if we could develop a working Broussard drive. What it would mean is that you could jet about the universe exploring stars, but you could never come home, as everyone you know would be centuries dead.

You don't need FTL. You need relativistic velocity and a willingness to abandon every single thing on Earth forever.

Sorry, but you'd still have to obey the laws of physics, and c is a hard, cold biatch.

It's going to take you years to get to the closest stars, and centuries to leave our galaxy. You're not going to get anywhere outside of our neighborhood during your lifetime (even according to your clock).

Thank you for letting me know you don't know how time dilation or relativity works.

At 1 G constant acceleration, 1000 light years would only be 13 years of ship time to cover. 100,000 light years (enough to go from edge to edge of the Milky Way) can be done in 22 years ship time. Increase acceleration to 1.5G, and that time drops to 15 years. At 2G, it's only 11 years ship time to span the entire galaxy.

There's math involved in this. You should check it out. Then you can participate in the conversation.

Cute, kid. Unfortunately, I set the curve in A-Bomb, and corrected the professor's key for the final - I got more right than he did, and he was allowed more than 2 hours.

Time dilation between any two observers is given by the Lorentz Factor, which is always >= 1.
t' = gamma*t
As velocity increases, the dilation of time increases, until at V=c the Lorentz Factor "gamma" is infinite.

If you were right, and gamma could decrease with velocity, one could cross the universe in a true "instant" by traveling at the speed of light. But this is not what photons do. Go check the article for an example: photons that left the galaxy 13.3 billion light years away have spent... wait for it... 13.3 billion years in transit.

Photons do not experience time, Nor does any object traveling at C.



What does gamma equal when v=c?

ambassador_ahab: buck1138: What does gamma equal when v=c?

*Raises hand*

1/SQRT 1 = 1

So if v=c what does v^2/c^2 equal?

buck1138: ambassador_ahab: buck1138: What does gamma equal when v=c?

*Raises hand*

1/SQRT 1 = 1

So if v=c what does v^2/c^2 equal?

42?

Shazam999: buck1138: ambassador_ahab: buck1138: What does gamma equal when v=c?

*Raises hand*

1/SQRT 1 = 1

So if v=c what does v^2/c^2 equal?

42?

ambassador_ahab: buck1138: So if v=c what does v^2/c^2 equal?

I'm pretty sure that if v=c then v^n/c^n will always equal 1.

So if v=c and v^2/c^2 = 1 then 1 - v^2/c^2 is what?