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On September 15 2011 05:13 Whitewing wrote:Show nested quote +On September 15 2011 05:04 Poseidonsc2 wrote:On September 13 2011 09:19 hotbreakfest wrote:Currently we can see up to 42 billion light years into space. We are an insignificant speck dust on a speck of dust on a speck of dust on a speck of dust on a grain of sand in the Sahara Desert. I think that says just about enough.  So you explain to me, how a universe that is 13.9 billion years old, can see up to 42 billion light years it takes light a year to travel a light year(duh) so 42 billion light years it would take 42 billion years. So if the big bang happened only 13.9 billion years ago, how can we see up to 42 billion light years? we can't? I think the last figure was 13.5 billion light years Imagine how life on another planet 3.6 times as large as earth would look! The muscles on those animals! http://everyjoe.com/technology/how-can-we-see-galaxies-47-billion-light-years-away-when-the-universe-is-only-13-billion-years-old-191/Short answer as to why we can see around 47 billion light years away (the furthest image taken so far): The speed at which the universe is expanding is not constant. Rather, everything in the universe is expanding away from each other linearly proportional to the distance between the objects. The rate at which the universe is expanding is increasing.
I can understand the universe itself being 47 billion light years old the problem i'm having is how can we SEE something 47 billion light years away since the light coming from it would have to travel longer than the age of the universe...
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The speed at which the universe is expanding is not constant. Rather, everything in the universe is expanding away from each other linearly proportional to the distance between the objects.
The rate at which the universe is expanding is increasing.
so..What happen when they reach the speed of light?..i mean after 13 000 000 000 000 years of acceleration,something has to hit 300 000km/s..what now?
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On September 15 2011 06:13 whitelly wrote:Show nested quote +The speed at which the universe is expanding is not constant. Rather, everything in the universe is expanding away from each other linearly proportional to the distance between the objects.
The rate at which the universe is expanding is increasing. so..What happen when they reach the speed of light?..i mean after 13 000 000 000 000 years of acceleration,something has to hit 300 000km/s..what now?
Actually the expansion of the universe can exceed the speed of light. This doesn't conflict with theory of relativity.
EDIT: To clarify; objects can never travel faster than the speed of light. But the expansion of space into "nothing" can happen at a rate faster that that of the speed of light.
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On September 15 2011 06:15 SpiffD wrote:Show nested quote +On September 15 2011 06:13 whitelly wrote:The speed at which the universe is expanding is not constant. Rather, everything in the universe is expanding away from each other linearly proportional to the distance between the objects.
The rate at which the universe is expanding is increasing. so..What happen when they reach the speed of light?..i mean after 13 000 000 000 000 years of acceleration,something has to hit 300 000km/s..what now? Actually the expansion of the universe can exceed the speed of light. This doesn't conflict with theory of relativity. EDIT: To clarify; objects can never travel faster than the speed of light. But the expansion of space into "nothing" can happen at a rate faster that that of the speed of light.
i allways though "space" is The matter,not something imaginary,like..empty void?isnt empy void the"nothing"?
thx
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People look at expansion of the universe in the wrong way. Its not that the edges of the universe are growing out into nothingness, its that space is being added homogeneously between everything.
Basically, space isn't expanding into nothingness - there's nothing beyond space, space is just getting bigger.
I think it's Feynman's example, but imagine the universe is a loaf of bread. Our galaxy and another galaxy are 2 raisins in the bread. As it bakes and rises, they get further apart, not because they're "moving" away from each other - they're both essentially static to their surroundings. But it appears as if they're getting further away.
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On September 15 2011 06:20 whitelly wrote:Show nested quote +On September 15 2011 06:15 SpiffD wrote:On September 15 2011 06:13 whitelly wrote:The speed at which the universe is expanding is not constant. Rather, everything in the universe is expanding away from each other linearly proportional to the distance between the objects.
The rate at which the universe is expanding is increasing. so..What happen when they reach the speed of light?..i mean after 13 000 000 000 000 years of acceleration,something has to hit 300 000km/s..what now? Actually the expansion of the universe can exceed the speed of light. This doesn't conflict with theory of relativity. EDIT: To clarify; objects can never travel faster than the speed of light. But the expansion of space into "nothing" can happen at a rate faster that that of the speed of light. i allways though "space" is The matter,not something imaginary,like..empty void?isnt empy void the"nothing"? thx Lets just leave it at that astrophysics is complicated ^_^
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On September 15 2011 06:12 Poseidonsc2 wrote:Show nested quote +On September 15 2011 05:13 Whitewing wrote:On September 15 2011 05:04 Poseidonsc2 wrote:On September 13 2011 09:19 hotbreakfest wrote:Currently we can see up to 42 billion light years into space. We are an insignificant speck dust on a speck of dust on a speck of dust on a speck of dust on a grain of sand in the Sahara Desert. I think that says just about enough. So you explain to me, how a universe that is 13.9 billion years old, can see up to 42 billion light years it takes light a year to travel a light year(duh) so 42 billion light years it would take 42 billion years. So if the big bang happened only 13.9 billion years ago, how can we see up to 42 billion light years? we can't? I think the last figure was 13.5 billion light years Imagine how life on another planet 3.6 times as large as earth would look! The muscles on those animals! http://everyjoe.com/technology/how-can-we-see-galaxies-47-billion-light-years-away-when-the-universe-is-only-13-billion-years-old-191/Short answer as to why we can see around 47 billion light years away (the furthest image taken so far): The speed at which the universe is expanding is not constant. Rather, everything in the universe is expanding away from each other linearly proportional to the distance between the objects. The rate at which the universe is expanding is increasing. I can understand the universe itself being 47 billion light years old the problem i'm having is how can we SEE something 47 billion light years away since the light coming from it would have to travel longer than the age of the universe...
Relax and read what he posted. The universe does not need to be 47 billion years old for 2 objects to now be located 47 billion light years away. Imagine that you stand 1 foot away from your twin. Now imagine that you both instantaneously are launched in opposite directions at a speed near that of light when observed by a person stationary in the frame of reference that the experiment began in. At the exact time you are launched, your twin begins shining a laser beam in your direction.
In one year, as measured by the original reference frame, you see the laser that your twin shined at you at time 0. However, you are now 2 light-years (minus 1 foot) away from your twin even though the light was shined 1 year ago.
Hopefully that example makes enough sense.
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United States7483 Posts
On September 15 2011 06:12 Poseidonsc2 wrote:Show nested quote +On September 15 2011 05:13 Whitewing wrote:On September 15 2011 05:04 Poseidonsc2 wrote:On September 13 2011 09:19 hotbreakfest wrote:Currently we can see up to 42 billion light years into space. We are an insignificant speck dust on a speck of dust on a speck of dust on a speck of dust on a grain of sand in the Sahara Desert. I think that says just about enough. So you explain to me, how a universe that is 13.9 billion years old, can see up to 42 billion light years it takes light a year to travel a light year(duh) so 42 billion light years it would take 42 billion years. So if the big bang happened only 13.9 billion years ago, how can we see up to 42 billion light years? we can't? I think the last figure was 13.5 billion light years Imagine how life on another planet 3.6 times as large as earth would look! The muscles on those animals! http://everyjoe.com/technology/how-can-we-see-galaxies-47-billion-light-years-away-when-the-universe-is-only-13-billion-years-old-191/Short answer as to why we can see around 47 billion light years away (the furthest image taken so far): The speed at which the universe is expanding is not constant. Rather, everything in the universe is expanding away from each other linearly proportional to the distance between the objects. The rate at which the universe is expanding is increasing. I can understand the universe itself being 47 billion light years old the problem i'm having is how can we SEE something 47 billion light years away since the light coming from it would have to travel longer than the age of the universe...
Because the distance the light is traveling is also increasing, at an ever increasing rate (second derivative is positive). Let's say a ray of light leaves point A for point B, and point B is exactly one light year away when the ray of light leaves point A. Now, if the distance remains perfectly constant for one year, the light will reach point B after precisely one year. But what if point A and point B are moving away from one another? Then it would take longer than a year for the ray of light to reach point B, this is what is happening in our universe. Because light has a finite speed (it's bloody fast, but it's finite, it doesn't instantly move from one location to another regardless of distance), it is affected by changes in distance just like anything else. We can see this through redshifts.
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I knew it, although habitable eh:
A planet with two suns may be a familiar sight to fans of the "Star Wars" film series, but not, until now, to scientists. A team of researchers, including Carnegie's Alan Boss, has discovered a planet that orbits around a pair of stars. Their remarkable findings will be published Sept. 16 in Science.
This is the first instance of astronomers finding direct evidence of a so-called circumbinary planet. A few other planets have been suspected of orbiting around both members of a dual-star system, but the transits of the circumbinary planet have never been detected previously.
The team, led by Laurance Doyle of the Carl Sagan Center for the Study of Life in the Universe at the SETI Institute, used photometric data from the NASA Kepler space telescope, which monitors the brightness of 155,000 stars.
They found the binary star system by detecting a system where the stars eclipsed each other from the perspective of the Kepler spacecraft. These stars have two eclipses: A primary eclipse when the larger star is partially blocked by the smaller star and a secondary eclipse where the smaller star is fully blocked by the larger star.
But the researchers also noticed other times when the brightness of the two stars dropped, even when they were not in an eclipse position. This pattern suggested that there was likely a third object involved. The fact that these so-called tertiary and quaternary eclipses recurred after varying intervals of time, and were of different depths, indicated that the stars were in different positions in their orbit at each instance. This result showed that the tertiary and quaternary eclipses were being caused by something circling both stars, and not an object circling one or the other star.
Source
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On September 15 2011 07:05 Whitewing wrote:Show nested quote +On September 15 2011 06:12 Poseidonsc2 wrote:On September 15 2011 05:13 Whitewing wrote:On September 15 2011 05:04 Poseidonsc2 wrote:On September 13 2011 09:19 hotbreakfest wrote:Currently we can see up to 42 billion light years into space. We are an insignificant speck dust on a speck of dust on a speck of dust on a speck of dust on a grain of sand in the Sahara Desert. I think that says just about enough. So you explain to me, how a universe that is 13.9 billion years old, can see up to 42 billion light years it takes light a year to travel a light year(duh) so 42 billion light years it would take 42 billion years. So if the big bang happened only 13.9 billion years ago, how can we see up to 42 billion light years? we can't? I think the last figure was 13.5 billion light years Imagine how life on another planet 3.6 times as large as earth would look! The muscles on those animals! http://everyjoe.com/technology/how-can-we-see-galaxies-47-billion-light-years-away-when-the-universe-is-only-13-billion-years-old-191/Short answer as to why we can see around 47 billion light years away (the furthest image taken so far): The speed at which the universe is expanding is not constant. Rather, everything in the universe is expanding away from each other linearly proportional to the distance between the objects. The rate at which the universe is expanding is increasing. I can understand the universe itself being 47 billion light years old the problem i'm having is how can we SEE something 47 billion light years away since the light coming from it would have to travel longer than the age of the universe... Because the distance the light is traveling is also increasing, at an ever increasing rate (second derivative is positive). Let's say a ray of light leaves point A for point B, and point B is exactly one light year away when the ray of light leaves point A. Now, if the distance remains perfectly constant for one year, the light will reach point B after precisely one year. But what if point A and point B are moving away from one another? Then it would take longer than a year for the ray of light to reach point B, this is what is happening in our universe. Because light has a finite speed (it's bloody fast, but it's finite, it doesn't instantly move from one location to another regardless of distance), it is affected by changes in distance just like anything else. We can see this through redshifts.
What are you a professor?
I had this same question in my head for a long time and i thank you for making it so simple to understand. Seems so obvious now.
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United States7483 Posts
On September 16 2011 04:40 Darkdeath3 wrote:Show nested quote +On September 15 2011 07:05 Whitewing wrote:On September 15 2011 06:12 Poseidonsc2 wrote:On September 15 2011 05:13 Whitewing wrote:On September 15 2011 05:04 Poseidonsc2 wrote:On September 13 2011 09:19 hotbreakfest wrote:Currently we can see up to 42 billion light years into space. We are an insignificant speck dust on a speck of dust on a speck of dust on a speck of dust on a grain of sand in the Sahara Desert. I think that says just about enough. So you explain to me, how a universe that is 13.9 billion years old, can see up to 42 billion light years it takes light a year to travel a light year(duh) so 42 billion light years it would take 42 billion years. So if the big bang happened only 13.9 billion years ago, how can we see up to 42 billion light years? we can't? I think the last figure was 13.5 billion light years Imagine how life on another planet 3.6 times as large as earth would look! The muscles on those animals! http://everyjoe.com/technology/how-can-we-see-galaxies-47-billion-light-years-away-when-the-universe-is-only-13-billion-years-old-191/Short answer as to why we can see around 47 billion light years away (the furthest image taken so far): The speed at which the universe is expanding is not constant. Rather, everything in the universe is expanding away from each other linearly proportional to the distance between the objects. The rate at which the universe is expanding is increasing. I can understand the universe itself being 47 billion light years old the problem i'm having is how can we SEE something 47 billion light years away since the light coming from it would have to travel longer than the age of the universe... Because the distance the light is traveling is also increasing, at an ever increasing rate (second derivative is positive). Let's say a ray of light leaves point A for point B, and point B is exactly one light year away when the ray of light leaves point A. Now, if the distance remains perfectly constant for one year, the light will reach point B after precisely one year. But what if point A and point B are moving away from one another? Then it would take longer than a year for the ray of light to reach point B, this is what is happening in our universe. Because light has a finite speed (it's bloody fast, but it's finite, it doesn't instantly move from one location to another regardless of distance), it is affected by changes in distance just like anything else. We can see this through redshifts. What are you a professor? I had this same question in my head for a long time and i thank you for making it so simple to understand. Seems so obvious now.
:D
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On September 15 2011 07:05 Whitewing wrote:Show nested quote +On September 15 2011 06:12 Poseidonsc2 wrote:On September 15 2011 05:13 Whitewing wrote:On September 15 2011 05:04 Poseidonsc2 wrote:On September 13 2011 09:19 hotbreakfest wrote:Currently we can see up to 42 billion light years into space. We are an insignificant speck dust on a speck of dust on a speck of dust on a speck of dust on a grain of sand in the Sahara Desert. I think that says just about enough. So you explain to me, how a universe that is 13.9 billion years old, can see up to 42 billion light years it takes light a year to travel a light year(duh) so 42 billion light years it would take 42 billion years. So if the big bang happened only 13.9 billion years ago, how can we see up to 42 billion light years? we can't? I think the last figure was 13.5 billion light years Imagine how life on another planet 3.6 times as large as earth would look! The muscles on those animals! http://everyjoe.com/technology/how-can-we-see-galaxies-47-billion-light-years-away-when-the-universe-is-only-13-billion-years-old-191/Short answer as to why we can see around 47 billion light years away (the furthest image taken so far): The speed at which the universe is expanding is not constant. Rather, everything in the universe is expanding away from each other linearly proportional to the distance between the objects. The rate at which the universe is expanding is increasing. I can understand the universe itself being 47 billion light years old the problem i'm having is how can we SEE something 47 billion light years away since the light coming from it would have to travel longer than the age of the universe... Because the distance the light is traveling is also increasing, at an ever increasing rate (second derivative is positive). Let's say a ray of light leaves point A for point B, and point B is exactly one light year away when the ray of light leaves point A. Now, if the distance remains perfectly constant for one year, the light will reach point B after precisely one year. But what if point A and point B are moving away from one another? Then it would take longer than a year for the ray of light to reach point B, this is what is happening in our universe. Because light has a finite speed (it's bloody fast, but it's finite, it doesn't instantly move from one location to another regardless of distance), it is affected by changes in distance just like anything else. We can see this through redshifts.
Award for best answer to a science question on TL goes to.... (drumroll)
Whitewing!
Thanks for your effort
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United States7483 Posts
On September 15 2011 06:30 Thorakh wrote:Show nested quote +On September 15 2011 06:20 whitelly wrote:On September 15 2011 06:15 SpiffD wrote:On September 15 2011 06:13 whitelly wrote:The speed at which the universe is expanding is not constant. Rather, everything in the universe is expanding away from each other linearly proportional to the distance between the objects.
The rate at which the universe is expanding is increasing. so..What happen when they reach the speed of light?..i mean after 13 000 000 000 000 years of acceleration,something has to hit 300 000km/s..what now? Actually the expansion of the universe can exceed the speed of light. This doesn't conflict with theory of relativity. EDIT: To clarify; objects can never travel faster than the speed of light. But the expansion of space into "nothing" can happen at a rate faster that that of the speed of light. i allways though "space" is The matter,not something imaginary,like..empty void?isnt empy void the"nothing"? thx Lets just leave it at that astrophysics is complicated ^_^
The math is quite complicated by the actual basic theory isn't that bad, and while explaining WHY it is the case in detail is probably beyond most people who don't have a degree in the subject, you can give a very basic explanation that most people can understand quite well.
Space itself refers to the vacuum, the area that is not matter of any sort that surrounds and actually contains all matter. A good example that's easy to picture would be a gelatin dessert with fruit inside of it. The fruit are objects in space like stars and planets for example, and the gelatin is space.
Now, what's important to know about the speed of light barrier is that in order for an object with a mass greater than 0 to reach and pass the speed of light, it requires infinite energy. Space itself is not matter, it is in fact an area that lacks matter of any sort, so space does not have a mass. Because it has no mass, it does not have a mass greater than 0, so it can expand faster than light can move.
One should note however, that as far as we can tell, it is not moving faster than twice the speed of light (at least not yet). This makes sense if you think about it, because if object A and B in the example I gave above (one light year apart when the ray left point A) are moving away from one another at precisely two times the speed of light, then point B is moving away from the spot where point the ray originated from (no longer point A, point A has left) at the speed of light, so the ray will never reach point B no matter what.
Keep in mind that the verb "move" doesn't really apply to space, since space is not an object, although it's difficult to explain properly without attributing to it some traits that it doesn't technically have. Abstract ideas are very difficult to grasp without something real to picture.
However, it is interesting to note that the rate at which the universe is expanding is increasing, it's expanding faster and faster. One of the greatest questions of science right now is whether that trend will continue, or whether eventually it will begin to decelerate.
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On September 13 2011 05:55 ampson wrote:
Now let's get to work on that faster-than light travel? Looks sweet. But why is it called SUPER EARTH?
agreed, if you calculate the distance from light years, which is 18,000 miles/second. it is still a staggering 19,867,680,000,000 miles away :x
let that scale stuff for everyone, this is possibly the closest star to us that resembles us and its 19 trillion??(i cant remember xD) miles away, ill find this display on how truely big the universe is "estimated" to be and its something like 24,000,000,000x10^6000 light years to get to where the light hasnt reached yet :x(dont take that as literal, i vaguely. remember the numbers)
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United States7483 Posts
On September 16 2011 11:43 tsukiumi wrote:Show nested quote +On September 13 2011 05:55 ampson wrote:
Now let's get to work on that faster-than light travel? Looks sweet. But why is it called SUPER EARTH? agreed, if you calculate the distance from light years, which is 18,000 miles/second. it is still a staggering 19,867,680,000,000 miles away :x let that scale stuff for everyone, this is possibly the closest star to us that resembles us and its 19 trillion??(i cant remember xD) miles away, ill find this display on how truely big the universe is "estimated" to be and its something like 24,000,000,000x10^6000 light years to get to where the light hasnt reached yet :x(dont take that as literal, i vaguely. remember the numbers)
Yeah, essentially, you either need to be able to teleport to get there, or you need to be able to bend space. In the future, we may be able to enter and travel through wormholes without getting killed, and then possibly even temporarily create our own, which would allow for near instantaneous travel from any point to another.
This is tech that, assuming it's possible, is probably more than a thousand years from being developed.
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On September 16 2011 11:48 Whitewing wrote:Show nested quote +On September 16 2011 11:43 tsukiumi wrote:On September 13 2011 05:55 ampson wrote:
Now let's get to work on that faster-than light travel? Looks sweet. But why is it called SUPER EARTH? agreed, if you calculate the distance from light years, which is 18,000 miles/second. it is still a staggering 19,867,680,000,000 miles away :x let that scale stuff for everyone, this is possibly the closest star to us that resembles us and its 19 trillion??(i cant remember xD) miles away, ill find this display on how truely big the universe is "estimated" to be and its something like 24,000,000,000x10^6000 light years to get to where the light hasnt reached yet :x(dont take that as literal, i vaguely. remember the numbers) Yeah, essentially, you either need to be able to teleport to get there, or you need to be able to bend space. In the future, we may be able to enter and travel through wormholes without getting killed, and then possibly even temporarily create our own, which would allow for near instantaneous travel from any point to another. This is tech that, assuming it's possible, is probably more than a thousand years from being developed.
i agree with this post completely. einstein's theory on space was on the right track about bending space etc etc. but with wormholes, scientists are running frantic because the formulas are failing. it will NOT be in this lifetime(without divine or outside intervention) that we discover the technology or even the beginnings of how to travel and bend space to our will.
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1019 Posts
everything is meaningless until we develop the ability to travel at the speed of light
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United States7483 Posts
On September 16 2011 12:03 white_horse wrote:
everything is meaningless until we develop the ability to travel at the speed of light
As far we know, it's theoretically impossible to achieve that. What is theoretically possible though is bending space to literally shorten the distance between two points, and thereby travel at a normal speed to the location. It has a similar effect, in that it gets you to where you're going very fast, but FTL travel is theoretically impossible due to actually having mass.
There are other ways we might cheat it, quantum entanglement comes to mind.
BTW, topics like these are the coolest thing ever. <3 science
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If there is other intelligent life out there, it's kind of naive to think humans are the most intelligent. I can't help believing that another planet will find us before we find them.
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On September 13 2011 05:55 ampson wrote:
Now let's get to work on that faster-than light travel? Looks sweet. But why is it called SUPER EARTH?
probably cus it's a lot bigger than actual earth?
It's great. now our parasitic race can take other planets and pollute the hell out of them after we overpopulate this one to the point of death =/
what a depressing thought
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EPT
