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Hubble vs. Webb - How Far Back Will They See?
Roland Piquepaille writes "According to Forbes, reporting in "Peering Back At The Universe's Past," space telescopes are really acting as time machines. They can watch objects which are so far from us that light has taken billions of years before reaching their mirrors. The Hubble telescope is able to look at events that took place 13.3 billion light-years ago. But the James E. Webb space telescope, currently under construction, and scheduled to be launched in 2011, will be able to see even further and catch phenomena which happened 13.5 billion light-years ago. The astronomers think the Webb telescope might even be able to see up to 13.7 billion light-years ago, when our universe was just 200 or 300 million years old. We are used to see fantastic images from Hubble, without paying too much attention to the characteristics of the telescope itself. So here is a thorough comparison between the two space telescopes."
As I'm sure everyone will be quick to point out, lightyears isn't a measure of time, rather of distance.
It is more accurate to say that the hubble could see images 13.3 billion years ago, and the Webb telescope may be able to see images 13.7 billion years ago.
Somebody place a mirror on the other end!
Then we can look into the history of our own Earth!
"We can confirm that Debian does *not* ship the version with the trojan horse. Our version predates it." [CA-2002-28]
13.3 billion light-years ago
So time IS a spatial dimension after all.
13.5 billion light years ago? Maybe I am being stupid, but I always thought that a light year was a measurement of distance?
if they could only see a few days back and tell me where I left my mobile phone.
Do not try to read the dupe, thats impossible. Instead, only try to realize the truth
What truth?
There is no dupe
I think the imagery provided by Hubble to date has been phenominal and expect that imagery from Webb will just as good or better. Looking back that far in the past though is just that ... the past. When we look back and see light that is 13.3, 13.5, or 13.7, or whatever billions of years old, it is exciting and adds more to the knowledge base. However, when I see galaxies that old I can't help wonder if they're still there (probably not) and what has taken their place. What's there now ...
light-years ago
Wouldn't that just be years ago? A light-year is a measure of distance, not time. It's like saying 'I can see three inches into the past.' The only reason I can think of to say this is if you also want to indicate how far away the event was when it happened.
-Colin
13.7 / 13.3 = 1,030075188 => 0.03 % performance increase with the new, latest, more expensive system.
Nahh, I'll maybe void my warranty, but I'll just increase the fsb of my old Hubble...
Anyone has tips on deep space overclocking ?
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Not trying to offend, I'm genuinely interested. How do they know how far in time they can look with those telescopes? Have photons lost too much energy after that distance?
All that money/time for a measly 1% increase in performance!?!
... that we'll eventually see the big bang? Assuming of course that the theory of the big bang is correct.
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is the fact that while Hubble can view things in the optical, James Webb will be looking at things in the infra-red. The two Wiki links (from the article) provide much more information.
e scope
p e
/. is screwing up the text, but the links should still work.
http://en.wikipedia.org/wiki/James_Webb_Space_Tel
http://en.wikipedia.org/wiki/Hubble_Space_Telesco
Grr...
It's rather more complicated than you think. The light reaching the telescopes is x billion years old, meaning that the objects that emitted the photons have long since moved elsewhere and are no longer there where the telescope sees them. So, when looking out into the universe, you are seeing mirages of the past. The more distant the object, the older its light. So yes, telescopes are time machines in that regard because such is the nature of spacetime - if you look over any given distance you are in effect looking into the past.
----- One learns to itch where one can scratch.
I'm not a that great with science, but isn't the speed of light not actually a constant but changing with the expansion of the universe (only page I could find).
I know many people here are better at science (not to mention spelling, grammer, coding, e.t.c), than I am, so i ask does this not make a lot of these predications less accurate than they might think?
Avontech | Play dirty! They started it!
well, if hubble could actually see as far as (light speed * age of the universe) light years than we could gain new knowledge about the big bang theory and the creation of the universe.
as it is, knowing what the universe looked like at age 300Million is quite nice by itself and simply saying that it "ain't nuttin' new" is quite ignorant!
as the light has traveled millions of light years, we ARE actually seeing something that existed millions of years before our time and thus you could call it some kind of "looking into the past"!
Instead of 13.5 billion years back, why not make the mirror/etc a little bigger and see to the "beginning"? Or better yet, have the resolution to see farther than that, and see what happens? I'd be way more interested in that than a lame 500 million light-years farther than the hubble. Furthermore, is Arecibo unable to reach that far because of the atmosphere?
stuff |
Dear Sir,
Some of us prefer the universe the way it is, more mature and filled out. I think its disgusting that these perverts want to spend so much money to ogle at the universe when it was a young hottie.
No doubt they are also hoping to get a glimpse of some of the banging the universe got up to in the exuberance of youth.
Shame on you all I say.
Yours etc.
Outraged
Do not try to read the dupe, thats impossible. Instead, only try to realize the truth
What truth?
There is no dupe
Hubble is 375 miles from Earth, the article has Webb listed as 1 *million* miles from us. Where is it going to be located, and how is it getting there? (I'm guessing that there will be no opportunity for service calls, as there was for Hubble!)
-J
...how long ago/far away is that in Libraries of Congress?
http://www.astronomycafe.net/qadir/acosmbb.html
Just for the record, the Big Bang theory is becoming as accepted in cosmology as the theory of evolution is in Biology.
There will eventually be a limit to how far back we can look in time. The Big Bang itself will just appear to be an incredible brilliance everywhere.
That same brilliance has cooled to the point that nowadays, it's only detectable as an almost-universal background microwave radiation.
The detection of that radiation is considered one of the strongest "proofs" of the Big Bang theory, by the way.
13.7 / 13.3 = 1,030075188 => 0.03 % performance increase with the new, latest, more expensive system.
As another poster has pointed out, it's actually a 3% improvement.
The point is, that's only 200 or 300 million years from the very beginning of the universe, and it gets exponentially more difficult the further back you want to see.
Rather than 13.7 vs. 13.3 billion years back from now, think 200/300 million years from the start versus 600/700 years from the start. That's a pretty good improvement.
I've got it. Here you've got a project that has produced some very good data and yet the creators have decided to stop maintaining it while they completely redo it from the ground up because they think the old base has gotten too "messy" to properly maintain anymore, disenfranchising the user base in the process. That's right all the signs are there, we must have just not noticed before, Hubble must be an open source project.
Don't mess with the bunny, outsideworld.org
The article states that the new 'scope costs about the same as Hubble, but will only have a 10-year lifetime, while Hubble is expected to be in service for 20 years.
Surely modern manufacturing etc should be able to improve on Hubble's lifetime for the same money? What am I missing?
A light year is a valid distance measurement since the speed of light is a constant. It's as valid as defining the distance between home and work as "10 minutes in my car travelling at a constant 60 mph".
It's the "Woodlands" theme/stylesheet by Bryan Bell.
...is an interesting thing, but a problem remains: it can't see events in the present (at far distances, obviously).
According to the comparison Webb is able to see 13.5 billion light years back in time, not 13.7. And Hubble able to see 13.3 not 13.5.
Mohahah!
I don't understand how we can see so close to the beginning of the universe, unless we have been travelling at a significant portion of lightspeed. Surely the light from events 200 million yrs into the length of the universe should have long since passed this point in space?
***You learn something Every day. And then you die.***
... one make a telescope powerfull enought to see arround the curvature of the universe? Would it see our own future?
not another tiny writeup from bloody piquepaille. whats the point of clicking through to his article when you have to click on the links in that before you get anything worth reading?
SURELY NOT!!!!!
I could just image.... Viewing the universe billions of years ago... It was a stange place, where beings like GOD knew that we would be looking, so he mooned us!
It's not dying....
It's just in the stages of decay lead to stgnation and then finally death.
Servicing missions to the Hubble added about 4-5 years of operational life to the telescope and this was possible because being only a couple of hundred miles above the earth, it was accessible.
Obviously, we are human and we can make mistakes. So what happens if there is a problem discovered on the Webb telescope after its launch?
Actually, the speed of light is not constant. They have done various tests and proved that light an slow down.
That's exactly the question I have as described in the parent. The light should have overtaken us long time ago and the earth can'y "out-run" the light from the original bang.
What are we missing?
The orbit is about 1.5 million km distance from the earth, at something called the L2 Lagrangian. The Webb wiki page has a link to the Lagrangian page, but for the lazy people, it's here. The orbit was chosen to keep the position of the sun constant relative to the telescope, so that the big 'parasol' can be used to shield the infra-red sensor.
As for Hubble, it's been able to give some awesome images, but it has its limits. I was hoping that the JW (henceforth called J-Dubya?!) would be able to start spotting planets around other stars, but it's not designed for that. I'd like to know if it's theorically possible to keep both in orbit and use them in parallel somehow, in the same way that ground-based radio telescopes have been linked together in arrays. Probably not worth the hassle?
The 'infra-red only' sensor troubles me. Since the telescope's aim is to study the Big Bang, the light/photons it'll be receiving will have travelled for a long time/distance and I guess be red-shifted way down to the IR band. This is all very well, but it means that the telescope shouldn't be considered as a replacement for Hubble, which carries out a wider range of observations.
As an aside, I believe that there is a limit to how far back we can look. At some point, probably less than 1 million years (a guess, can anyone help?), the universe was just too dense for photons to travel around unhindered as they seem to these days. Who said it was better back in the old days eh?
Now two questions. First why beryllium? I know that it's lightweight so easier to lift into orbit. Any other reasons? And secondly what happens if a micro-meteor hits this shield? Do we get a permanent bright spot on all subsequent images, like a broken pixel on an LCD display?
This is not a sig
No telescope will be able to look further back than about 300 kyr after the Big Bang. Before this period, background photons were energetic enough to ionise very rapidly any hydrogen atoms that formed, so the universe mostly consisted of free electrons and protons. These are very efficient at scattering light (mean free path very short ~ O(centimetres) ). The universe was opaque to radiation - a glowing fog of photons and plasma.
After 300kyr, the universe had cooled sufficiently for recombination. Virtually all the electrons and protons combined to form neutral hydrogen, which scatters radiation far less well, and the universe became effectively transparent to radiation.
Any attempt to look back will be unable to see anything before this decoupling. We can still see the radiation from the decoupling period in the form of the cosmic microwave background.
Maybe yes, maybe no. We won't know until we look. We've already found structures that weren't supposed to be existing at their 'distance'.
mankind has divided time and space, cause the concept of spacetime hurts their little brain...
according to einstein space and time should be space-time, so it is definately a measurament for distance, and time.
mass "curls" space around it, creating time in the process.
This is still if we have the space shuttles still flying and there are any left by 2010.
Maybe there's nothing left out there. And the darkenss is closing in on us. We wouldn't even SEE it coming.
Evolution or ID?
I understand the concept of light reflected from an object that's been traveling for billions of years granting us a look into the past. But what I wanna know is, does this mean we are looking away from the center of the universe? I imagine the light furthest from the center would be the oldest.
If this is the case, what do we get by pointing our telescopes toward the center? Is there some crazy ball of energy still expanding outward or something? (Assuming the big bang theory is right.)
Oh yeah, I assume the light has to be of some relatively high magnitude to be able to do this? Am I wrong? Is it possible to point a telescope at say a distant planet of some kind and oberve it's birth.. or even in theory a guy planting a tree 10 billion years ago?
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Come one - slashdot editors regularly seem to believe that "foot", "ounce", "gallon" and "mile" are metrics used in the modern western world.
;)
If they could start changing the little things, they can use light-year as a time measure for another year for all that I care
Well right and wrong, everything is relative.
3/4 of the Universe as we know it was put in place in less than 1 second. End to end, that would be faster than the speed of light, but in relation to other objects, it was not.
Brain hurt?
The fabric of space was bent by the event.
A poet and didn't know it.
Let there be light, and there was!
Actually, the speed of light is not constant. They have done various tests and proved that light an slow down.
Light can slow down. In an open vacuum it is at it's highest speed. Going through materials it slows down a little. The speed change is different for different materials.
An example is that light slows down going though glass.
Evolution or ID?
One day Hubble will find the Death Star - after all, it was long, long ago in a galaxy far, far away.
When I am king, you will be first against the wall.
It's not inconceivable to use it as a measure of the radius of a 'cone' of space time which can be viewed from a certain point. Kind of a synthesis of distance and time.
In that sense, it's implied in almost ALL astronometrical comments like "we saw this 15 light years away"; it's are really saying "we saw this event happening 15 years ago because that's as recent as we can see anything from that target".
So yeah, basically you're right, but it's faintly arguable.
-Styopa
But how is it that we can see images of objects just 2-300 million years old by being able to increase magnification?
Sure, I can see that increasing the magnification allows us to see further in the distance; and light that travelled to us further started off earlier, hence being able to "see into the past"
But doesn't this only work if objects were further away too?
Where is the point where we can't see any further into the past - because the universe hadn't expanded enough to see the objects there?
Earth can't have expanded from the center faster than the speed of light, so I'm just getting utterly confused!
Webb has nothing to do with space shuttles.
Patrick Doyle
I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....
Today's lesson: Forbes is only a news source in the sense that ketchup is a vegetable.
Hubble is close to earth which means it's easy to maintain - easy in space terms anyway. Webb is a million miles away I gather? What happens if there is a screw missing or some other minor ailment? As I remember Hubble needed new refractors(?) on it's launch.... if history repeats itself NASA is going to look a bit of an arse
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Of course, the article is flawed in the sense that it's meaningless to talk of a view of "the past".
No flaw there.
It's as valid as defining the distance between home and work as "10 minutes in my car travelling at a constant 60 mph".
Looks like you agree that you can't say "the distance is 10 minutes" without specifying the speed. In the expression "13.5 billion light years" the word "light" is specifying the speed. Just like "13.5 billion snail years" is specifying another speed, which would give another distance. Saying "13.5 billion snail years ago" doesn't make sense, which is the point of the grand-parent.
http://news.bbc.co.uk/1/hi/sci/tech/3732157.stm
http://slashdot.org/~GuyFawkes/journal
A light year is a measure of distance not time,
_ ________
saying 13 billion light years ago is like saying
something like 100 km ago, it doesn't make sense
all you gotta say is 13 billion years ago, also
you should note that its been proven that the
general speed of light is actually decreasing,
so you can't really make an exact or near exact
estimation about the time period for which something
that occurred many thousands of light years away
occurred.
Arash Partow
_________________________________________
http://www.partow.net
Arash Partow's Philosophy: Be a person who knows what they don't know, and not a person who doesn't know.
if you completely discount that whole "faster than light" thing. Possible in the sense that there's no currently conceivable way to do it?
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...can I use it to club my grandfather to death before he fathers my father?
Now my head hurts.
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Anybody else notice that Webb is expected to have a lifetime ten years shorter than Hubble?
I'd have expected a more recently built telescope to last longer than an older one.
Also, anybody have a clue exactly what happens when a telescope dies?? (Visions of Hubble slowly growing incontinent etc.....)
Do we know what direction to point these telescopes in? Presumably we have to point towards the big bang, otherwise we'll see the expanding edge of the universe (which will be closer than 13.3 billion light years)?
Wasn't it Cobe which showed that the background radiation wasn't that smooth ? Your reference seems older than the picture from COBE (I think).
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That they named the new telescope after some obscure NASA bureaucrat instead of a great scientist?
Insert witty sig here.
One thing the comparison chart doesn't mention is the type of scope Webb is. Hubble is a Ritchey-Chretien, as are (AFAIK) all recent big scopes.
Insert witty sig here.
Astronomers have a whole range of different ways to measure distances, each of which works in a different regime. They form a "cosmological distance ladder" - you attempt to calibrate each new method during its overlap region with the previous method.
Parallax is the method for the very shortest distances (nearby stars).
For intermediate distances (distant stars in our own galaxy, relatively nearby galaxies), most of the methods come down to finding some sort of "standard candle" - something that you know the intrinsic brightness of, so you can use its apparent brightness and the inverse square law to calculate its distance. Astronomers tend to use particular types of variable stars (stars with a well-defined cycle of brightness changes) for this purpose. For galaxies, you can sometimes use averaged properties of all the stars to estimate the distance.
For cosmological distances (very distant galaxies) the most common trick is to use redshift. Because of the universe's expansion, an object twice as far away is receding from us twice as fast, and so its light is Doppler-shifted twice as much. Ideally, you look for known features of the object's spectrum and see what wavelength they have ended up at. This is what people are talking about when they measure the distance to Hubble's latest find.
There is also a complementary method that uses standard candles at cosmological distances. In this case, you use Type Ia supernovae, a particular type of exploding star that looks pretty much the same every time. They're bright enough to be seen very far away, and again you can get the distance using the inverse square law (modified by general relativity). It's the difference between this method and the redshift method that provides the strongest evidence for dark energy - it shows us that the universe is expanding faster than we expect, and that this expansion is accelerating.
The Hubble telescope is able to look at events that took place 13.3 billion light-years ago. But the James E. Webb space telescope, currently under construction, and scheduled to be launched in 2011, will be able to see even further and catch phenomena which happened 13.5 billion light-years ago. The astronomers think the Webb telescope might even be able to see up to 13.7 billion light-years ago, when our universe was just 200 or 300 million years old.
OOOooooK. Well, if we're seeing the light from 13.7 billion years ago, and we're expecting that to be when our universe was 300 million years old, does that mean that our universe would be at LEAST 27.4 billion years old? 13.7 billion + 0.3 billion doesnt equal 27.4 billion, or am I missing something?
I know there was a period of hyper-expansion following the Big Bang, but during this hyper-expansion, were the laws of physics GROSSLY broken so that particles with mass (anything besides photons) travelled at faster-than-light speed?? Someone explain this to me!
--Confused in Katmandu, J
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I just read an article (BBC) about a study that claims the measurement for the age of stars is incorrect and that the universe is 1 billion years older than originall thought. If that is the case, we either have been looking alot further back or have alot further to go to look closer to the beginnings of the universe.
I believe there is a book by this title,
have you read it?
when the universe was 200-300 million years old
:)
that seem's like a small amount left out of the universe's total age..
I can't help but wonder what the end of the universe looks like...
and what would happen if they could see further back in time than the universe is old?
-judging another only defines yourself
there are many speculative positions here. Despite the symantic arguments, you're not looking into the past, as much as "at" the past. But not relative to time. You're simply seeing an image of the past, though not as static as say a picture since it will take time for the light reaching the mirror to spend itself. Even so, to assert that time itself is distance and to imply that we theoretically could travel this medium to Earth's past is perhaps entertaining as a fantasy but is ultimately an excersize in futility given the nature of speed, space, and time as we know it. Throw in the highly speculative age of the universe and the arrogance it takes to assert a knowledge of the universe's age and dynamics and at best you have a good Star Trek episode....TNG, of course.
Very young objects in the universe are characterized by their redshift "z value" which is approximately the wavelength stretch of light:
.53 microns would be brightest at 5.8 microns, which is deep infra-red. You need a good infra-red telescope to see very young objects then. The Hubble IR camera goes out to 2.5 microns while the Webb will see as far as 28 microns, or redshifts up to 50. This combined with the greater light gathering capabilities will allow viewing even younger objects.
z = lambda-shift / lambda-ref - 1
The largest z values observed so far are about "10" implying a 11-fold stretch of the wavelength. An object with the black body wavelength of our Sun at
Redshift values can be translated into relative ages and apparent universe expansion velocities. For z=10, the age is 5% of age of the universe and appears to recede at 98% the speed of light. The interpretation of very large redshift values starts to become complicated. The formulas must include effects like the cosmological constant and acceleration for proper interpretation. Theys are hotly debated topics currently.
"Obscure NASA bureaucrat," my ass! James Webb was the NASA administrator during the development of Project Apollo, arguably the most complex and difficult endeavor in human history. They ought to name the whole damn agency after him, not just one little telescope.
I noticed thta in a lot of these comments, people say that you have to go at a very high speed (near or at light speed) to get far enough away fast enough to see into the past. And that's only a couple of days into the past.
Wouldn't it then be logical that our galaxy, to be able to see near the beginning of the universe in space-time, had to be traveling at way above light speed to get to where it is today? If no, then we shouldn't technically be able to see that far into the past.
-[EPSILON]-
I understand that the light took 13.x billion years to reach us, but how can we actually see something that happened that long ago if the "universe" was fairly new? I mean, did we travel faster than the speed of light to reach the spot in the universe that we currently reside? If not, I would think the light would have passed us by long ago. Perhaps we could see objects that traveled away from us, but it still seems like the light from those wouldn't be near the beginning of the universe. I'm just a little puzzled on this. Can anyone explain?
This item raised my curiosity on something - I had always thought that a light-year was used as a measurement of distance with a light-year being the distance that light travels in the span of a year. I was under the impression that the year was a year - based on our 1 earth year. So if the light we are seeing is coming from 13 billion light-years away, then what we are seeing would be 13 billion years old. Am I right or did I miss something in the glossary on this one?
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... to drop a camera X light years from us is a horrible kludge. FTL violates causality by definition, therefore it is physically equivalent to time travel. You may as well just go back in time directly and observe our past at arbitrary closeness.
Supposedly all matter in the universe was present in the big bang, right? This means that conceivably, the amorphous blob of plasma or whatever that the earth eventually cooled from was also present and perhaps reflected some light back then. Now certainly the earth-plasma didn't travel faster than light, so this is where I get confused. The distance between earth and the big bang is X number of light years, correct? Now the earth couldn't have traversed that distance at the speed of light because then it would, lose all its mass into energy or whatever(here I show my total ignorance of this whole concept). So how does this work. Wouldn't the light from the big bang have passed the earth by the time the earth gets to wherever it is? Meaning there is some limit on how far we can look back?
I'm sorry but I find it really funny that someone has made the Universe as being some 13 billion years old. True enough that in science you make your postulates and then try to prove it wrong, and as long as it appears to be workable - you use it.
The problem I guess I have is the authoritarian teachings in school where people are blindly followed is, well... naive.
Statistically it's the few who branched out following their own logic who has written history. Most people seem to be followers, which may or may not be the way to go.
Just say something that is aligned with popular belief, however foolish, like nothing can travel faster than light, and you have it made.
I'm glad we have these great telescopes, I'd just wished we took it a bit easier before accepting an idea as "law". Only to find exceptions which immediately shows it's not a "law", but at best has a limited workable application.
I shouldnt have to add to the subject.
emt 377 emt 4
Note that in the comparison box, the launch vehicle for the Webb isn't a shuttle. It's an Ariane rocket.
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I only look human.
My mother is a halfling and my dad is an ogre, so that makes me an Ogreling
A larger optical telescope will not just see deeper than the HST, it will also have higher resolution. According to Rayleigh, the resolution of a telescope is directly proportional to the diameter of it's aperture. The JWT will give us prettier pictures than HST, resolving even finer details.
burris
... Just because there is evidence of a big bang doesn't mean God didn't cause the big bang.
Nobody can say whether God invented Mexican food before everything else...
Hopefully you can fill in the rest.
I only look human.
My mother is a halfling and my dad is an ogre, so that makes me an Ogreling
It's pronounced 'Churengkof' but it's spelled Cerenkov. And it occurs when a charged particle is moving faster than the speed of light within a medium other than a vacuum (light travels slower in non-vacuums). Nothing can travel faster than the speed of light in a vacuum.
"I'm so moist I'm sticking to the leather." -Kermit the Frog on The Late Late Show
Sounds like eventually we'll have to figure out where the center of the universe is, so we can see light from the universe's beginning. How tricky is that?
If only there was a way to somehow "trap" light emitted at a certain scene or event. We could take the trapped light, and release it at a latter time, effectivelly allowing anyone nearby to literally see history! Maybe we could even find a way to convert the light into electrical signals so we could transmit it at great distances. Better file a patent quick!
Tsunami -- You can't bring a good wave down!
...anybody have a clue exactly what happens when a telescope dies?
Usually it runs out of money. IUE was supposed to go for five years; instead it went along for 18. It was ailing some toward the end, but ultimately it was funding that killed it.
Exit, pursued by a bear.
The original evidence for the fine structure constant changing are now in question with recent observations released this year. New limits put tighter constraints on the constant further back in time.
A good summary can be found here with the recent press release here.
mh
It's nice to see there are so many experts putting there two cents' worth in here for us all to enjoy and ponder on. I particularly appreciate it when the writer provides links to supporting or opposing arguments (which, as we all know, there are many). As examples, since there seems to be such wide agreement here as to the validity of the "Big Bang" Theory, check out what Astronomer Thomas VanFlandern has to say about it http://www.metaresearch.org/cosmology/cosmology.as p
and as for the constancy of the speed of light, check out Barry Setterfield's work:
http://www.setterfield.org/scipubl.html
and as for ...
oh, never mind. Sorry to have disturbed your sleep.
Heard any good sigs lately?
Hubble/Webb are supposedly looking at stuff 13+ billion years ago since it now supposedly takes the light from that stuff 13+ billion years to get to us. But 13+ billion years ago the universe was a lot smaller than it is now, so whatever these telescopes are looking at ya gotta wonder: what has it been doing all that time? Has it been ricocheting back and forth from the expanding edge of the universe? If so, how reliable is what we're finally able to see? Maybe it's so red-shifted by now that any calculation of distance/time is useless. Has the expansion of the universe acted as a kind of distance/time cop, such that no matter when you see this stuff it always seems to be 13+ billion years away/ago? If so, it doesn't really tell us much about the beginning state. Maybe in the early history of the universe time didn't "run" at the same "velocity" it does today. Who knows?
So many questions, so little time.
</hat>
"A great democracy must be progressive or it will soon cease to be a great democracy." --Theodore Roosevelt
IIRC the saga of Webb Hubbell goes back to 1994 or thereabouts.
(Hey, what good is karma if I can't burn it with wildly offtopic lame jokes?)
Your fantasies contain the seeds of important concepts.
what happens when they can see 14.5b years in past?
does that mean they will see before the universe began?
the mind boggles....
This has always puzzled me: if light from a galaxy takes 13.7 billion light years to reach us, and the universe was a singularity 14 billion years ago, then we must be moving away from that galaxy at a speed of 13.7/14c = 0.98c.
Is this right? If so, isn't time dilation from moving at a speed of 0.98c quite significant? To an observer in the remote galaxy wouldn't our age of the universe be only (1-0.98)x14=0.28 billion years?
Thanks
Troll? Man I wish I had mod points today. This should be at least a +1 Funny. There's nothing funnier than a goo AOHeller joke.
Who is Twirlip of the Mists?
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Heard any good sigs lately?