The Naked Scientists

The Naked Scientists Forum

Author Topic: How old is the Universe?  (Read 30136 times)

Offline jeffreyH

  • Global Moderator
  • Neilep Level Member
  • *****
  • Posts: 3927
  • Thanked: 55 times
  • The graviton sucks
    • View Profile
Re: How old is the Universe?
« Reply #25 on: 18/04/2015 02:40:14 »
Alice and Bob have a specimen of uranium, and the ability to date it with extreme accuracy.  It has been dated at 20 million years.  They break it in half.  Bob stays on Earth with one half while Alice goes on a trip at close to the speed of light.  When Alice returns Bob’s half is dated at 20m+20 years, while Alice’s is dated at 20m=5years.  Is that accurate reasoning?

From Bob's perspective the half life of Alice's uranium has also increased and that is the most pertinent point.
 

Offline Bill S

  • Neilep Level Member
  • ******
  • Posts: 1830
  • Thanked: 12 times
    • View Profile
Re: How old is the Universe?
« Reply #26 on: 18/04/2015 02:47:36 »
Quote from: Jeffrey
From Bob's perspective the half life of Alice's uranium has also increased and that is the most pertinent point.

Why would the half life alter?
 

Offline jeffreyH

  • Global Moderator
  • Neilep Level Member
  • *****
  • Posts: 3927
  • Thanked: 55 times
  • The graviton sucks
    • View Profile
Re: How old is the Universe?
« Reply #27 on: 18/04/2015 03:11:14 »
Quote from: Jeffrey
From Bob's perspective the half life of Alice's uranium has also increased and that is the most pertinent point.

Why would the half life alter?

Because Alice is traveling at near light speed everything is undergoing time dilation. Including the decay of the uranium. When they meet up Bob's uranium will have decayed faster than Alice's. Dating the uranium will depend upon the decay rate.
 

Offline chris

  • Neilep Level Member
  • ******
  • Posts: 5339
  • Thanked: 65 times
  • The Naked Scientist
    • View Profile
    • The Naked Scientists
Re: How old is the Universe?
« Reply #28 on: 18/04/2015 09:03:37 »
Incidentally, regarding the age of the Universe, I think ESA's Planck mission returned a slightly altered age measurement of 13.8 billion years compared with the present best guess of 13.7
 

Offline Bill S

  • Neilep Level Member
  • ******
  • Posts: 1830
  • Thanked: 12 times
    • View Profile
Re: How old is the Universe?
« Reply #29 on: 18/04/2015 12:59:42 »
Absolutely right, Chris, and some other interesting stuff that may find its way into future TNS threads.

    The Universe is 13.82 billion years old.
    The Universe is expanding a bit slower than we expected.
    The Universe is 4.9 percent normal matter, 26.8 percent dark matter, and 68.3 percent dark energy.
    The Universe is lopsided. Just a bit, just a hint, but that has profound implications.

I specially like the lopsided idea.  :)

 

Offline Bill S

  • Neilep Level Member
  • ******
  • Posts: 1830
  • Thanked: 12 times
    • View Profile
Re: How old is the Universe?
« Reply #30 on: 18/04/2015 13:07:07 »
Quote from: Jeffrey
Because Alice is traveling at near light speed everything is undergoing time dilation. Including the decay of the uranium. When they meet up Bob's uranium will have decayed faster than Alice's. Dating the uranium will depend upon the decay rate.

OK. My misinterpretation.

Suppose it were possible to have a radioactive specimen dated with this ridiculously high accuracy to the birth oh the Universe – 13.82 billion years. (Howzat for up to date figures?) Bob’s half would show 15 more years than Alice’s for the age of the Universe.
 

Offline jeffreyH

  • Global Moderator
  • Neilep Level Member
  • *****
  • Posts: 3927
  • Thanked: 55 times
  • The graviton sucks
    • View Profile
Re: How old is the Universe?
« Reply #31 on: 18/04/2015 22:12:05 »
Quote from: Jeffrey
Because Alice is traveling at near light speed everything is undergoing time dilation. Including the decay of the uranium. When they meet up Bob's uranium will have decayed faster than Alice's. Dating the uranium will depend upon the decay rate.

OK. My misinterpretation.

Suppose it were possible to have a radioactive specimen dated with this ridiculously high accuracy to the birth oh the Universe – 13.82 billion years. (Howzat for up to date figures?) Bob’s half would show 15 more years than Alice’s for the age of the Universe.

That is why either the velocity of an observer or the strength of the gravitational field he sits in is important. At non-relativistic velocities or low strength gravitational fields it is not a problem.
 

Offline PmbPhy

  • Neilep Level Member
  • ******
  • Posts: 2762
  • Thanked: 38 times
    • View Profile
Re: How old is the Universe?
« Reply #32 on: 18/04/2015 23:06:50 »
Quote from: Bill S
The Universe is expanding a bit slower than we expected.
Why would you say this? It was discovered that the universe is expanding at an accelerating rate. Before that we thought it was expanding at a decelerating rate. For that reason the universe is expanding faster than we expected.

Quote from: Bill S
The Universe is lopsided. Just a bit, just a hint, but that has profound implications.
Please explain.
 

Offline Thebox

  • Neilep Level Member
  • ******
  • Posts: 3164
  • Thanked: 46 times
    • View Profile
Re: How old is the Universe?
« Reply #33 on: 18/04/2015 23:43:29 »
Absolutely right, Chris, and some other interesting stuff that may find its way into future TNS threads.

    The Universe is 13.82 billion years old.
    The Universe is expanding a bit slower than we expected.
    The Universe is 4.9 percent normal matter, 26.8 percent dark matter, and 68.3 percent dark energy.
    The Universe is lopsided. Just a bit, just a hint, but that has profound implications.

I specially like the lopsided idea.  :)

what?

 ''The Universe is 13.82 billion years old.''  not fact, a guessed prequel


''26.8 percent dark matter, and 68.3 percent dark energy''   completely made up and not fact, neither are presently detected,

   '' The Universe is lopsided. Just a bit, just a hint, but that has profound implications.''  false , there can not be a lobsided when we observe a black background of space, lobsided relative to what?


 

Offline Bill S

  • Neilep Level Member
  • ******
  • Posts: 1830
  • Thanked: 12 times
    • View Profile
Re: How old is the Universe?
« Reply #34 on: 19/04/2015 00:16:17 »
Quote from: Pete
Please explain.

Perhaps giving the link would be better than trying to explain: then Thebox can ridicule the original. 

http://www.slate.com/blogs/bad_astronomy/2013/03/21/age_of_the_universe_planck_results_show_universe_is_13_82_billion_years.html
 

Offline PmbPhy

  • Neilep Level Member
  • ******
  • Posts: 2762
  • Thanked: 38 times
    • View Profile
Re: How old is the Universe?
« Reply #35 on: 19/04/2015 10:08:23 »
Quote from: Pete
Please explain.

Perhaps giving the link would be better than trying to explain: then Thebox can ridicule the original. 

http://www.slate.com/blogs/bad_astronomy/2013/03/21/age_of_the_universe_planck_results_show_universe_is_13_82_billion_years.html
Thanks. I understand now.
 

Offline PmbPhy

  • Neilep Level Member
  • ******
  • Posts: 2762
  • Thanked: 38 times
    • View Profile
Re: How old is the Universe?
« Reply #36 on: 19/04/2015 12:34:22 »
Quote from: Thebox
what?

 ''The Universe is 13.82 billion years old.''  not fact, a guessed prequel


''26.8 percent dark matter, and 68.3 percent dark energy''   completely made up and not fact, neither are presently detected,

   '' The Universe is lopsided. Just a bit, just a hint, but that has profound implications.''  false , there can not be a lobsided when we observe a black background of space, lobsided relative to what?
It's posts like this that have all of us rolling our eyes. We've constantly told you to learn more about physics, especially the philosophy of physics, and you continue to refuse. Then you post nonsense like the above as a result of your ignorance.

If you have any understanding whatsoever about physics then you'd know, like the back of your hand, that physics is not about what you think of as "facts" because that implies someone has exact knowledge and knows some sort of "truth" whereas nothing like that exists in physics. Physics is all about observing nature, formulating theories and then testing those theories. The more our predictions are borne out by experiment the more faith we have in the theory. We use these theories to make calculations based on data obtained from observations and that means we use the theory to make the calculations. That's where those numbers come from.

You, on the other hand, keep making countless claims that you've never made a serious attempt to support. E.g. all you did here is make an unsupported claim that those numbers are but mere guesses. That's a complete load of horse-hockey.
 

Offline Thebox

  • Neilep Level Member
  • ******
  • Posts: 3164
  • Thanked: 46 times
    • View Profile
Re: How old is the Universe?
« Reply #37 on: 19/04/2015 14:08:51 »
Quote from: Thebox
what?

 ''The Universe is 13.82 billion years old.''  not fact, a guessed prequel


''26.8 percent dark matter, and 68.3 percent dark energy''   completely made up and not fact, neither are presently detected,

   '' The Universe is lopsided. Just a bit, just a hint, but that has profound implications.''  false , there can not be a lobsided when we observe a black background of space, lobsided relative to what?
It's posts like this that have all of us rolling our eyes. We've constantly told you to learn more about physics, especially the philosophy of physics, and you continue to refuse. Then you post nonsense like the above as a result of your ignorance.

If you have any understanding whatsoever about physics then you'd know, like the back of your hand, that physics is not about what you think of as "facts" because that implies someone has exact knowledge and knows some sort of "truth" whereas nothing like that exists in physics. Physics is all about observing nature, formulating theories and then testing those theories. The more our predictions are borne out by experiment the more faith we have in the theory. We use these theories to make calculations based on data obtained from observations and that means we use the theory to make the calculations. That's where those numbers come from.

You, on the other hand, keep making countless claims that you've never made a serious attempt to support. E.g. all you did here is make an unsupported claim that those numbers are but mere guesses. That's a complete load of horse-hockey.

You really should consider what you write,  you have just admitted in essence that science makes up a lot of things with no actual truth's.  Science is about truth's of physical process and not fallacy of unicorns.   Absolute proof is essential to state that it is complete absolute truthful fact, science insists a continuation of fallacy lies with no absolute truths, that is called make believe on my planet.

''because that implies someone has exact knowledge and knows some sort of "truth" whereas nothing like that exists in physics. ''


Utter rubbish, fact an object falls to the ground, fact water evaporates, fact water turns into ice, fact we have a sun, fact we are in orbit, etc,etc, this is real science, not make believe, science needs to stop doing this.

fact- you can not see or measure dark energy ,

fact- any percentage given is made up without foundation

fact - matter is expanding out into space and space does not expand.

fact- the age of the universe is unknown.

 

Offline chiralSPO

  • Global Moderator
  • Neilep Level Member
  • *****
  • Posts: 1879
  • Thanked: 145 times
    • View Profile
Re: How old is the Universe?
« Reply #38 on: 19/04/2015 14:30:43 »
No, Box, physics is NOT about absolute truth. It is as he said: we observe the world passively, or by experiment; formulate models or theories based on that evidence; test logical predictions of those models or theories against reality; based on those results we discard, tweak or share said model/theory with others; this cycle is repeated over and over.

Our measly human minds probably cannot fathom "absolute truth," but if we can make up a model that is easily understood and helps us make predictions about the universe around us, that are shown to be accurate, then the model is useful.

All of our models are wrong (I think I have said this before). They are based on assumptions, on approximations and definitions that are created by people, and don't necessarily have a "real" meaning. But if one understands the limitations of the model, and when to use it or when to use a different model, then these models help us engineer incredible technologies and further refine our understanding of the world. The fact that we know our models are incomplete allows scientists to have open minds, and we are always looking for ways to refine or expand our understanding.

One point about technology (jccc, I hope you're reading this too): The fact that we can design, build and use bridges, power plants, electronics, computers, satellites, medicines,  etc. proves the usefulness and self-consistency of physics as we know it now. We may not have access to "absolute truth" but we know enough to rationally design a specific arrangement of atoms to do our bidding.
 

Offline Thebox

  • Neilep Level Member
  • ******
  • Posts: 3164
  • Thanked: 46 times
    • View Profile
Re: How old is the Universe?
« Reply #39 on: 19/04/2015 14:42:30 »
No, Box, physics is NOT about absolute truth. It is as he said: we observe the world passively, or by experiment; formulate models or theories based on that evidence; test logical predictions of those models or theories against reality; based on those results we discard, tweak or share said model/theory with others; this cycle is repeated over and over.

Our measly human minds probably cannot fathom "absolute truth," but if we can make up a model that is easily understood and helps us make predictions about the universe around us, that are shown to be accurate, then the model is useful.

All of our models are wrong (I think I have said this before). They are based on assumptions, on approximations and definitions that are created by people, and don't necessarily have a "real" meaning. But if one understands the limitations of the model, and when to use it or when to use a different model, then these models help us engineer incredible technologies and further refine our understanding of the world. The fact that we know our models are incomplete allows scientists to have open minds, and we are always looking for ways to refine or expand our understanding.

One point about technology (jccc, I hope you're reading this too): The fact that we can design, build and use bridges, power plants, electronics, computers, satellites, medicines,  etc. proves the usefulness and self-consistency of physics as we know it now. We may not have access to "absolute truth" but we know enough to rationally design a specific arrangement of atoms to do our bidding.

I really do understand the concept of models to give a person a starting point and premise for argument.   What I will never understand is why nearly every science forum on the internet have banned me, when I am talking about, debating the models from a different context, models being defending as if they are the sole truth, it is this about science that makes it look like a religion, defending the words taken in faith to have truth and be the truth.
I have never argued a true fact on any forum up to date in my eyes.

My point is , when someone ask's a question like how old is the Universe, the truthful answer is we do not know for sure, but we accept a context for our own use of about 13.8 billion years, and this subject is open to debate by any individual because relatively we have no absolute proof to prove we are correct.   So a person can not be ''wrong'', or deluded, or a crackpot, who as their own ideas about something.


 

Offline Bill S

  • Neilep Level Member
  • ******
  • Posts: 1830
  • Thanked: 12 times
    • View Profile
Re: How old is the Universe?
« Reply #40 on: 19/04/2015 18:45:39 »
Pete & Chiral, I admire your patience, but if Box really doesn't know why nearly every science forum on the internet has banned him/her, there's a serious lack of understanding there somewhere.  Alternatively, if he/she does understand, then you are just troll feeding.  Either way your respective talents could probably be better employed. 
 

Offline PmbPhy

  • Neilep Level Member
  • ******
  • Posts: 2762
  • Thanked: 38 times
    • View Profile
Re: How old is the Universe?
« Reply #41 on: 20/04/2015 22:00:07 »
Quote from: Bill S
Pete & Chiral, I admire your patience, but if Box really doesn't know why nearly every science forum on the internet has banned him/her, there's a serious lack of understanding there somewhere.  Alternatively, if he/she does understand, then you are just troll feeding.  Either way your respective talents could probably be better employed.
I can't speak for Chiral but if you may have noticed, I have ceased all of my attempts at trying to help him. To he's simply unteachable. He's far too arrogant to be able to learn.
 

Offline chiralSPO

  • Global Moderator
  • Neilep Level Member
  • *****
  • Posts: 1879
  • Thanked: 145 times
    • View Profile
Re: How old is the Universe?
« Reply #42 on: 20/04/2015 22:53:05 »
At this point I don't expect Box to understand, but I feel obligated to present answers to his questions for the sake of the rest of the readership.
 

Offline yor_on

  • Naked Science Forum GOD!
  • *******
  • Posts: 12001
  • Thanked: 4 times
  • (Ah, yes:) *a table is always good to hide under*
    • View Profile
Re: How old is the Universe?
« Reply #43 on: 20/04/2015 23:15:12 »
Box :)

One good reason to how we define a age is the use of light as a constant. When you combine that with distances (standard candles, etc), as well as counting on the different types of redshift, you can give a age to the earliest light reaching us. Science is alike a puzzle, whatever idea one get needs to fit the pieces we already have proven, preferably also giving birth to a prediction that will be unique for it to be true. That prediction of an earliest light, combined with you placing yourself somewhere else, measuring the age in all directions again, becomes a proof both of the age being correct as well as a proof of the universe being 'infinite'. So the age might be finite everywhere, but the scale of the universe should be something else. We still prefer finite things though, as one and one becoming two, because that has been the way we expected things to be practically, until rather recently.
 

Offline jccc

  • Hero Member
  • *****
  • Posts: 990
    • View Profile
Re: How old is the Universe?
« Reply #44 on: 21/04/2015 11:13:50 »
i think box is right on this 1. so far science gives the universe an age of 13.7B, but that is not absolute correct.

what's before the bang? have we see time end before? where is the evidence?

if you believe all things science says, if you live in older times, you will think earth is flat and box is wrong as now.

isn't in fact, most of the science was progressed by someone challenging older theories?

 

Offline jccc

  • Hero Member
  • *****
  • Posts: 990
    • View Profile
Re: How old is the Universe?
« Reply #45 on: 21/04/2015 12:29:50 »
Quote from: Bill S
Pete & Chiral, I admire your patience, but if Box really doesn't know why nearly every science forum on the internet has banned him/her, there's a serious lack of understanding there somewhere.  Alternatively, if he/she does understand, then you are just troll feeding.  Either way your respective talents could probably be better employed.
I can't speak for Chiral but if you may have noticed, I have ceased all of my attempts at trying to help him. To he's simply unteachable. He's far too arrogant to be able to learn.

Pete, i think
you can say that again, to yourself.

box's last 2 comments are very true, if you able to debunk, you will not hesitate.
 

Offline jccc

  • Hero Member
  • *****
  • Posts: 990
    • View Profile
Re: How old is the Universe?
« Reply #46 on: 21/04/2015 12:34:40 »
Pete & Chiral, I admire your patience, but if Box really doesn't know why nearly every science forum on the internet has banned him/her, there's a serious lack of understanding there somewhere.  Alternatively, if he/she does understand, then you are just troll feeding.  Either way your respective talents could probably be better employed.

Bill,

i thought you are a good thinker. till this 1.
 

Offline chiralSPO

  • Global Moderator
  • Neilep Level Member
  • *****
  • Posts: 1879
  • Thanked: 145 times
    • View Profile
Re: How old is the Universe?
« Reply #47 on: 21/04/2015 14:54:22 »
have we see time end before?

What would this question even mean? Self-referential questions like this are hard to think about, and almost always lead down the wrong path.

If time stopped before, then it would need to have started again, since we observe it now. But time couldn't just stop and then start--how long would it be stopped? (if no time, then it would be stopped for no time--never stopped)
 

Offline jccc

  • Hero Member
  • *****
  • Posts: 990
    • View Profile
Re: How old is the Universe?
« Reply #48 on: 21/04/2015 15:08:26 »
have we see time end before?

What would this question even mean? Self-referential questions like this are hard to think about, and almost always lead down the wrong path.

If time stopped before, then it would need to have started again, since we observe it now. But time couldn't just stop and then start--how long would it be stopped? (if no time, then it would be stopped for no time--never stopped)

how could someone says, yeah, i saw crashing birds all the time while in fact maybe just 1 time?
 

Offline chiralSPO

  • Global Moderator
  • Neilep Level Member
  • *****
  • Posts: 1879
  • Thanked: 145 times
    • View Profile
Re: How old is the Universe?
« Reply #49 on: 21/04/2015 15:48:14 »
That I see birds killing themselves on windows "all the time" may have been a slight exaggeration. But I can recall witnessing birds crashing into windows on at least 7 different occaisions.

Still, birds do crash into windows with startling frequency:
http://www.allaboutbirds.org/Page.aspx?pid=1184
"According to the U.S. Fish and Wildlife Service, 'One of the greatest hazards to birds is plate glass, with windows in homes and offices killing as many as one billion birds each year.' "
(that is the American billion, 109)

But this is besides the point. Your question was logically flawed, and my statement was a slight exaggeration of a true phenomenon.
 

The Naked Scientists Forum

Re: How old is the Universe?
« Reply #49 on: 21/04/2015 15:48:14 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums