Age Definition and 590 Threads

I've pondered a hypothetical problem Take as time perspective "A" as being relative time dilation of Earth Time dilation "B" being half of "A" slower due to relativistic effects. assuming both "A" and "B" were both formed at the same time say 5 billion years ago. If you were to...

I've been thinking I want to go back to school to get a degree in a science field, I don't know if I will pursue physics or biology, they both seem so interesting. At first I was dead set against it, but then I asked earlier if you have to have a natural ability to do this, and someone answered...

According to the wikipedia entry, the latest values for the Lambda-CDM model parameters for the age of the Universe, t_0, and the Hubble constant, H_0 are t_0 = 13.75 \pm 0.11 \times 10^9 \mbox{ years} H_0 = 70.4 \pm 1.3 \mbox{ km s}^{-1} \mbox{Mpc}^{-1} If you combine the errors this implies...

Hi! Is it possible to start a PhD in US universities when you are 27? Having a Master from a major university. Is it too late? I mean, if you are not focused on an academic career, and you want to get a PhD to get the higher possible degree and then get a job that is somewhat related to...

Hubble's law states that the speed of a distant object is proportional to it's distance (this implies an expanding universe). By finding the distance and speed (via redshift) of various distant galaxies you can produce a graph displaying the linear relationship. The gradient of the line is...

Just did a test today (so no results back yet) (year 12 physics) and it annoyed the heck out of me, in part because to answer these questions you had to make preposterous assumptions, assumptions which in hindsight I probably should have just stated as opposed to writing out explanations as to...

I understand that the ~14.6 billion year age of the universe is in the cosmological frame, i.e., representing the coordinate time elapsed in a comoving reference frame. Of course this means (as has been discussed plenty of times here) observers in different frames would measure a different age...

Ok first off, its nice to meet you all. :smile: Second, my knowledge of physics is limited to 5 seasons of The Universe on Netflix. :rolleyes: This will be my only question though so bare with me. Physicists seem to be SURE (at this time at least) about the age of the universe being around...

With some students I've tutored lately we've come across quite a bit of word problems that can be a headache to set up, so for all of you younger high school students here is a common medium-level of difficulty problem you might see in algebra class or on college entrance exams. A father is...

Is there any boundary of age for any jobs such as International labs, an academic carieer in university ? The reason why i ask you is that I'm at 29 and I still major in MSc physics or physics enginnering. To you, Is it a logical ? So,i have been lated to apply any job in U.S or Europe ...

Hello everyone, I'm a masters student(engineering) and interning at a lab (robotics) for the summer. The senior PhD students and post-docs in the lab are all in their 30s and even in their late 30s mostly because they worked a while, or changed fields etc. Most of them say that they would...

Hi All.. I have a basic doubt in time dilation theory. As per time dilation theory, when an object moves with the velocity of light, then relatively its time becomes zero. In that case, light is traveling at 'velocity of light'. So for light, there is no age? Or I misconcepted time dilation...

I'm just wondering does age really matter or is love the only that matters? :shy:

It seems that suddenly the last of the actors I watched in my teens are dying now. I will always rember Borgnine in the Comedy tv show McHale's Navy. R.I.P. http://news.yahoo.com/blogs/upshot/oscar-winning-film-star-ernest-borgnine-dies-la-212606632.html

Iron Age coins discovered in Jersey after 30-year search http://www.guardian.co.uk/culture/2012/jun/26/iron-age-coins-discovered-jersey About 50,000 silver and bronze coins uncovered by men who spent decades exploring one field...

Quantum Confusion -- "Does not exist until it's observed" and age of universe Hi. I ran across this: http://physics.jamesbaugh.com/quanta.html QUOTE: "It is a problem of assuming values of properties are "out there" independently of the acts by which the values are determined. The...

I will be starting a PhD (if all goes well) at the age of 26. I know this is not much older than the average, but how much do graduate admissions (particularly at top programs) see students that did not have the standard "4 year bachelors out of high school to PhD" route? For some reason I...

I've once read an article about a team of scientists who were about to (or wanted to) clone a mammoth with the aid of using elephants. I have two questions on this topic: 1. Is that possible? (I assume they're using a recovered mammoth genome and in vitro fertilization) 2. If it's possible...

A while back I posted a thread about the probability that someone who is alive at 12 years of age will be alive at age 82. This person could only die if he were murdered or if he died when he was greater than 82 years old. Now, let's assume this person will live forever if he's not murdered...

Hello World! I am going to college to do physics this year, and there is a issue I have. I have a pretty logical, critical thinking, creative, investigative mind and pretty good imagination of the possibilities that reality can hold. I love how science works and how it helps us to understand...

I apologize if this has been discussed before. I haven't been able to locate an adequate answer to my question through searches. I enjoy debating with creationists; it's a bit of a cheap thrill. I'm sure many of you can relate. One of my favorite topics is the supposed unreliability of...

In this Article there is a remark by biologist "It's one of the basic lessons in biology: Reproduction is very costly, and if you don't use it, you can live much longer". Can someone give few examples of species that live longer if they don't reproduce?

hello, I'm wondering how to calculate, even approximately for the relatively mature universe, what the CBR wavelength was as a function of age of the universe. I get that the CBR began during recombination, though have read different values for the black body temperature at that...

How many half lives have passed since a particular rock was formed if a sample of the rock contains 31 times as much lead-207 than uranium-235? I know that I need to do a table and calculate I know how to do this question but the thing I need help on is how do I know the number of atoms in order...

Do atoms age?? I ve read in many articles that most of the atoms which we see are made initially during big bang..And most of them concluded that atoms won't age..Is it true?

Homework Statement The age of the dead sea scrolls was measured using radiocarbon dating. If the measurement gives a ratio of 0.78 for the ratio of the activity in the sample to the activity in a sample of corresponding live material of similar mass, calculate the age of the scrolls...

Homework Statement I need a rock solid proof. Is it possible to be half someones age more than once? Eg. I was born at 0 while my dad was born at 20, he will be 40 when I am 20 hence I am half his age. Is this possible more than once?

Hi all, Does the age we assign to the Universe depend on how we define distances in space? I've read that there are a whole host of ways that cosmologists can define distance in the Universe, and that no particular way is *correct* as such. Another factor is that General Relativity implies...

The other day, I was calculating the age of universe dominated by vacuum energy and it turned out to be infinity. What does age of the universe being infinite mean? On explanation I thought of is that may be this implies that such a universe has no beginning. Is it a proper explanation?

Hi, I know very little about quantum physics so I need some help here, but recently I have seen lots of new agers claiming work on Quantum physics "refutes" materialism and either supports dualism or that mind is the basis of reality, they cite people like gowami or even Bohr or Heisenberg...

I'm going to go ahead and put this to the board, figure I might as well. I'm 30 years old, and a pretty quiet person. Friendly, polite, but stand-offish with most people. Anyway, enough with the background. There's a girl at my work who I think is great. She's gorgeous, a little reserved, and...

I'm a yr 12 student doing a full year research assignment and i have decided to find the age of the star, Sirius. I have access to a pretty good telescope and equipment but I am not sure where to start. Suggestions anyone?

Could "TIME" or the age of matter be a factor? From my very basic "understanding" of particle physics and our search for hidden particles something keeps nagging at me; is it possible that quantity/quality of particles/boson are tied to time? In other words can the absolute age of any...

nah I'm just really curious, cuz PF seems to possesses a much wider varities of age groups compared to similar forums like Aops, CC, etc...(mostly 10s~20s unless instructors/staffs, etc) aw well :D so hey guyz, I'm new here

Hello all, I am sure this has been asked before, but just can't seem to find a thread. To make a long story short I have been on the 10 year track to my Bachelor's degree; there are a lot of outside factors. I am getting my BS in mechanical engineering and want to go on to a PhD in...

How is the age of the universe measured? Is it by the distance light has traveled since the big bang? Does that imply a closed universe?

Wanted to Change over careers to Physics Research at Age of 22 is it too late?? Hey I am 22 yrs old and graduated from School with pretty good grades, but due to certain problems had to discontinue my education and had to start working. Although i tried not to lose touch with the books. I...

Good job parents Hooked on chicken nuggets: Girl, 17, who has eaten nothing else since age TWO rushed to hospital after collapsing Stacey Irvine has breathing problems and anaemia Only other food she eats regularly are fries But despite warnings cannot resist McDonald's...

Hi, Age of Earth is equal to A solar day A lunar day An astronomical day None of these Which is the correct one and how?

People always say the Universe is 14 billions year old. But what does that mean? What is the time of the Universe relative to?

Homework Statement The equilibrium concentration of C14/C12 ≈ 1.5×10−12 A 2.5 g sample of Carbon from an old tree fragment has an activity of 4.57 decays per minute. How old is the sample? Homework Equations I'm pretty sure I use A(t)=λN(0)*exp(-tλ) but I am having trouble calculating N(0)...

Universe age!?, I never really understood that Hi, there is one thing I really never got. they say the universe is 13.7 billion years old. That is because Hubble couldn't see any further!? Now this is the part I do not get: "hubble cannot see any further??" WOW! What does it see? Its...

The relativity of time and defining the "age" of the universe I have been doing searches on the relativity of time and its relation to the "age of the universe," among other things. I have come across some insightful Q&A, but I have yet to really see a "solid" response to my innate question...

http://www.tecca.com/news/2011/01/26/nasa-announcement-details-hubble-discovery-of-oldest-galaxy-ever-seen/ How is the age of the Universe most accurately estimated and is it possible there is a discrepancy between the Oldest observed Galaxies and the estimated Age of the Universe...

I have recently been watching the series "Into the Universe with Stephen Hawking" and I have a question (commence eye-rolling of anyone reading this). I don't think the series is supposed to be an educational tool necessarily, its more of a horizon expanding view of some high level topics with...

Hi, and thanks for making such a great forum! My question is as the title proposes. Would Einstein's Theory of Relativity - Time Dilation, mean that racing drivers age (all be it, small) slower than say a usually stationary human? (couch potato ;)) Thank you in advanced. Which leads me...

Hi, I am currently reading Liddles Introduction to Modern Cosmology (2nd Ed) and having trouble with problem 8.4, about the age of the universe with a cosmological constant. The question asks to derive the formula for the age by first writing the Fridemann equation in such a model as...

The experts say the age of the universe is known with considerable accuracy. What frame of reference are they using and why doesn't it violate the idea of relativity to claim to have a preferred frame?

Hi everyone, I'm finishing up at a community college right now as a physics major. I've got a 4.0 GPA and absolutely love physics! Problem is I'll be 27 by the time I transfer to UC Berkeley as a junior. So I'll pretty much be 30 by the time I start grad school. I've asked myself why it took me...

When I was in Kindergarten I took some tests to get into my school's gifted program. I did very average on the quantitative skills portion, but I scored well in the other sections. Does this mean that I lack the inherent math gift? Can this gift be acquired through hard study?