How do they know how old the universe is?
492240
you propose a theory and convince people to side with you. ;-)
1140994
I like your spirit. Keep it up!!\n\nAfter reading a few of the answers I can't help but break out in laughter. Is this 2006? or is it before Renaissance?\nMight I mention a few things: radio carbon dating, cosmic background radiation, speed of light, distance of some galaxies from us, the time to form heavy elements from hydrogen, half life of uranium...\nI think any one of these things will prove the age of the earth. Incidentally, the Hindu scriptures, Vedas are about 6000 years old. The last ice age ended 13000 years ago...\n\nI can't believe these same people boast about space travel. LMFAO.\n\nIncidentally for the person who said something about matter and energy. No matter and energy can't be created or destroyed. Matter and energy are actually the same thing in different forms. One is a more stable form, the other is a transient form.\n\nAnd the person who said the Bible is the truth. Well the bible didn't arrive by fax from heaven. It was written by men. The laws of physics, on the other hand, was written by God. Scientists merely discover them.
629421
Age of the "world," taking Earth as the "world"...scientists estimate about 4.54 billion years.  Estimate was confirmed by radiometric dating using rubidium (and other decay series).  Radiometric dating is something I study, so that's why I trust this estimate.
420014
the big bang happened 13.7 billion years ago.  also, i have something else for you to think about.  the universe is 13.7 billion years old, yet we can observe parts of the universe that are about 46 billion lightyears away.\n\nhttp://www.sciam.com/print_version.cfm?articleID=0009F0CA-C523-1213-852383414B7F0147
1167352
Totally, completely, 100% incorrect information!  Where do you get this nonsense from?\n\nThe oldest observatory in the world was excavated in north China's Shanxi province, and is believed to be 4,100 years old, predating the formerly oldest known observatory from South America.\n\nWhat is well known is that the Arab world gave us our current number system, and the concept of zero.
134220
We believe the universe to be infinite in size.  In some ways, we know how small the universe is not.\n\nThe universe is atleast 13 billion light years in radius from the earth. The furthest galaxy seen to date dates from 13 billion years ago.  This means that the light from that galaxy took 13 billion years to reach us and so, at the speed of ... uh ... light, it was 13 billion light years away from earth.  This is 76,424,219,300,000,000,000,000 miles away or 76 sextillion miles away.\n\nThe problem is seeing past that distance because Hubble discovered that light keeps shifting toward the red part of the spectrum and beyond as the universe continues to expand.  There could be stuff past where we can see but we don't know because we can't see it.\n\nAnother reason I say minimum is because after the light left that galaxy 13 billion years ago, we believe that the galaxy continued to move away from us during that 13 billion year period due to the expansion of the universe.  So, it is over 13 billion light years away from us today and the light from that galaxy "today" would take over 13 billion years to reach us.\n\nBut in reediting this just now, I realized that there might actually be a stretching effect for the distance due to the time that has passed.  In otherwords, the distance that the light travelled in the first year (13 billion years ago) has since expanded (causing the redshift) and so will be more miles in distance than the light year travelled in the most recent year till now.  Which may be why articles on the oldest galaxies seen never mention distance but only mention time or age.  They never say the observed galaxy is 13B light years away, they say that it is 13B years old and leave it at that. Let's just ignore this plausible issue for the moment.  \n\nWith out extrapolating, you might calculate the volume of a sphere that is 13 billion light years in radius and use that as a lower bound for the size of the universe:\n\n4/3 radius^3 => 5.9*10^68 cubic miles.  Don't know about you but I can't even comprehend how big that is.\n\nAs for who or what created it, well, that depends on what you believe and what evidence you allow to modify that belief.\n\nI liked the article in March 2005 Scientific American on the "Misconceptions of the Big Bang".
382215
The Earth is assumed to be about 4.6 billion years old, and unlike what everyone else said, it's not based solely on anything contained on Earth, including carbon dating. The oldest solid material found on Earth is about 4.1 billion years.\n\nThe guess -- and that's all it is, a guess -- is based on the rate of radiological decay of material on Earth and in meteorites found on Earth and around the solar system.\n\nIf you assume that the entire universe is formed from a common pool of matter (the essence of the Big Bang theory is that all material in the universe came from a single, supercondensed source that exploded); if you assume that therefore, all the matter in the universe has been equally distributed in all directions; if you assume that the rates of decay in all radiological material in the universe are consistent regardless of time, their position in the universe, etc.; then you can derive, by comparing the same kind of radiological material from celestial bodies that were not formed in our solar system, bodies that were part of our solar system when it formed, and that material now on Earth, the age that the Earth must be at the time it began to take solid form.\n\nThe paticular materials used to get that age is Lead-206 / Lead-207, which are the products of decay in Uranium-238.\n\nThis is further supported by temperature measurements of the universe and the evidence of background radiation from the timing of the Big Bang, which is assumed to have occurred about 15 billion years ago; given the rate of expansion of the universe visible to us, and the rate of change in both the speed of that expansion, the temperature of the universe and the density of space, we can verify the assumptions of the Earth's age to be within the estimation of a "young Earth" of 4.6 billion years old.\n\nAlso, to the person who said "The Bible": If you derive the history of the Earth from the Bible, as countless theological scholars have done through extensive research, it's about 6,000 years old; no scholarly Biblical research places the age of Earth at more than 10,000 years old.\n\nIf you want to believe that, in the face of overwhelming evidence to the contrary, that's fine. But you should at least agree with your evidence before citing it.
1072258
First consider some scientific estimates or guesses. Not all scientists are going to agree. The Universe or heavens 20 billion years old. The Earth 4.6 billion years old. The Moon 200 to 300 million years younger than the Earth. Dinosaur extinction 65 million years ago. The Ice Age 2.5 million years ago. Oldest evidence of flesh man 7000 to 14000 years old.\n\nThere are 3 earth ages (II Pet.3:5-7), same earth but different ages. We are now in the 2nd earth age. Between Gen.1:1 and Gen.1:2 is a vast amount of time, if time existed. Between these 2 verses is Satan’s rebellion (Rev.12:3-4) and “his tail” drew 1/3 of God’s children. Between these 2 verses also belongs all fossils and remains, such as Dinosaurs.\n\nIn Gen.1:2 we have the of the end of the 1st earth age and the beginning of the 2nd. For clarity Gen.1:2 needs to be divided (see below).\n\n(A) Gen.1:2 And the earth was without form, and void; and darkness was upon the face of the deep. \n\n(B) Gen.1:2 And the Spirit of God moved upon the face of the waters.\n\nIn (A) Gen.1:2 the first occurrence of the word “was” has been corrupted and is “became”. It reads “And the earth became without form, and void”. The end of the 1st earth age.\n\nIn (B) Gen.1:2 we have the beginning of 2nd earth age, the one we live in now. Man did not exist in flesh till this earth age.\n\nBetween (A & B) Gen.1:2 is also a vast amount of time, if time existed. Between (A & B) Gen.1:2  is; a global flood (not Noah’s which was a local flood), the destruction of Atlantis, the breakup of Gondwana Land, and the Ice Age.\n\nTime means nothing to our Father. He is very patient and loves His children. Instead of destroying Satan and 1/3 of His children, He destroyed that first earth age. Now in this 2nd earth age we all are born innocent in the flesh. Father came in the flesh Himself, Jesus Christ, and paid the price for all. Father defeated Satin, that is death, legally. So now His children have a decision, to choose life or to choose death. It’s your decision. Choose life!!
61902
Earth is thought to be between 4.5 and 4.8 billion years old. The age of Earth is found by measuring the age of very old Earth rocks. This is done by measuring the rate at which elements of the radioactive metal uranium decay (break down) into lead. Scientists have also measured the age of meteorites which have fallen onto Earth's surface, and the age of moon rocks brought back by the Apollo astronauts. Both the meteorites and the moon formed around the same time as Earth, and they show similar ages.\n\nIf you want a break down of that timespan in terms of Geologic Periods, see:\nhttp://www.cotf.edu/ete/modules/msese/earthsysflr/geotime.html
1092532
according to mr. wikipedia... the age of earth is... geologists have determined the age of the Earth to be around 4.55 billion years (4.55x109 years). This age represents a compromise between the oldest-known terrestrial minerals – small crystals of zircon from the Jack Hills of Western Australia – and astronomers' and planetologists' determinations of the age of the solar system based in part on radiometric age dating of meteorite material and lunar samples.\n\nThe radiometric age dating evidence from the zircons further confirms that the Earth is at least 4.404 billion years old. Comparing the mass and luminosity of the Sun to the multitudes of other stars, it appears that the solar system cannot be much older than those rocks. Ca-Al-rich inclusions – the oldest known solid constituents within meteorites which are formed within the solar system – are 4.567 billion years old, giving an age for the solar system and an upper limit for the age of the Earth. It is assumed that the accretion of the Earth began soon after the formation of the Ca-Al-rich inclusions and the meteorites. Since the accretion time of the Earth is not exactly known yet, and the predictions from different accretion models vary between several millions up to about 100 million years, the exact age of the Earth is difficult to define.\n\nIn the centuries preceding the scientific revolution, the age of the Earth was determined from the accounts of creation by religious authority. Today some religious groups continue to accept only theological accounts regarding the age of the earth, rejecting scientific evidence which contradicts their beliefs.\n\n\nHope this helps... ^^
730967
The earth is BILLIONS of years old. That's 4500 Million years old , (about).\n\nPeople think know this because of four ways of thinking about it.\n\n1. We know about how old the sun is. \n\nThink of a soda with ice. when we start drinking theres plenty of soda and a the ice is frozen and the soda is cold, when the soda gets "older" it is more watery because the ice has all melted, when the soda gets really "old" the soda becomes flat and doesn't taste good. \n\nIt's kinda like that with the sun, we can see other stars, some that are young and some that are old and when we look at them all we can know the sun is about 4.5 billion years old based on how it behaves. \n\nStars are also a little bit like people in how they behave. Very young sun-like stars are bright and white or yellow and very active. Adolesent stars are not as active but are still bright and usually yellow or light orange in color. Middle age stars are orange and not quite as active. Old stars are darker colors of orange and even less active,and may start to get fatter and very old stars will grow bloated , turn redish and then become more dim and evenually end up becoming nurserys for other stars or planets after they die.\n\nWe think the earth formed at the same time as the sun, so that is about 4.5 billion years ago. \n\n2. Some elements on earth "decay" at a certain rate, think of it like a rusting tool in a shed or work area. One of the metals, Uranium decays over billions of years , almost all of the Uranium on the earth is of the same "decaying" age. That age is about 4.5 billion years ago. Oxygen and other elements have other "decay" rates and these also tend to support the fact that the earth has had oxygen in the atmosphere for about 3 billion years.\n\n3. We know the earth is old because of fossils , some fossils are of shells of sea animals that are very simple. Some of these shells are found on the highest mountains in the world. So if we say these shells were once deep in an ocean "how often do earthquakes move this mountains" and "how much does the mountain move up or down up each time", if we then say ok "we've been here watching this mountain for 200 years and there were two earthquakes and each earthquake  moved the mountain 1 inch. How long would it take to move 100 miles and 3 miles up. \n\nBy answering questions like that we can figure out how old certain mountains are, by doing this all over the earth the oldest mountains/rocks are in Australia and Canada and they are were formed a little less than 4 billion years ago.\n\n4. We think the moon formed from the earth being hit by another planet about the size of the planet mars, and we think that this happened about 4 to 3.5 billion years ago based on how far the moon is moving away from the earth and the incline of the earth and the moon.\n\nSome religions, notably the evangelical movement in the US, believe the earth was formed by God in 6 days. They figure based on the Bible backwards from when someone dies or was born backwards from Jesus , to King David, to Noah, to Adam and Eve and based on that math the Earth is only 6000 years old.  \n\nThis is not supported by any scientists as a good, reasonable date as the planet's surface is too large and would still be mostly molten rock if it was only 6000 years old and there would be no oceans or life just a big molten radioactive lava ball in space like a red hot bigger version of the moon...\n\nOther religions say that the earth was the result of a giant fight amongst the Gods and almost every society of man has what is called a "creation myth" which is how primitive people explain good questions when they don't _know_ or can't figure out the answers.
1021140
WHAT MAKES YOU THINK THE EARTH ISNT 6,000 YEARS OLD BECAUSE SCIENCE SAYS SO ?? AND WHERE DO THEY GET THEYRE INFO FROM LIKE THE CARBON DATING WHERE DO THEY GET THAT INFO FROM I MEAN DONT YOU NEED TO COMPARE SOMETHING WITH SOMETHING EVEN I CAN SAY OH YEA THIS ROCK IS 2 YEARS OLD OR 2 MILLION SCIENCE IS JUST THAT ITS SCIENCE I BELIEVE IN GOD MAYBE THIS WORLD IS 6,000 YEARS OLD MAYBE IT ISNT BUT DOES IT ACTUALLY MATTER ANYWAY?  SCIENCE PROVES THAT GOD EXISTS BUT DONT WANT TO ADMIT IT I WAS THINKING ONE DAY IF ALLLLLLLLLL THIS UNIVERSE STUFF JUST HAPPENED ----BAMMMMMMMM----  WHY DOES THE WEATHER BEHAVE THE WAY IT DOES OR THE SUNSETS OR RISES ????  IT ISNT BY ACCIDENT IT IS FROM INTELLIGENT DESIGN .   I DONT BELIEVE SCIENTIFIC DESIGN NOR DO I BELIEVE THE ICE AGE HAPPENED THERE WAS A FLOOD YOU KNOW & THAT REALLY MESSED THINGS UP .
47368
First we have to distinguish between the "observable" ("known") universe and the absolute (all) universe. We can only speculate about the size of the entire universe, but for the observable universe most scientists have agreed that it's 13.7-billion light years in size.
741387
In the first place, god did not create the world in 7 days -- or any other period of time.  The universe is 13.7 billion years old; the earth is about 4.5 billion years old.
54811
According to the US Geological Survey (USGS), the Earth is approximately 4.5 billion years old.\n\nThe articles below discuss the evidence for this estimate.
488633
What is time? We tend to measure everything by our learned standards.  Can you even try to imagine the Big Bang?  We as a race (human) know so little.
268021
According to current estimates, roughly 400,000 years.  This is what we can tell from the data from WMAP, which was launched to measure the microwave background radiation.  It is this radiation that is the leftover glow from when light decoupled from matter, which is the point at which the universe would have "turned black".