Years Definition and 634 Threads

Hi. I'm not a student of physics, so please forgive me for my ignorance. I only have a very simple question. If the observable universe is about 93 billion light years in diameter, how could the universe have reached that size in only 13.7 billion light years? Doesn't it stand to reason...

I was wondering, if you where going at 0.16c how fast would it take you to get 4 light years?

http://www.space.com/entertainment/090515-apollo-snoopy.html 40 years! OMG! It is hard to believe that what was once the cutting edge of technology is now all but ancient history.

I decided to come back to the small town where I grew up because there is a lot of work in the gold mines. I haven't been here in almost twenty years, but I've got several people who have offered me a place to stay while I'm here. I've also been offered trucks to drive even though I have a...

Ok, here's my problem... In the EPR experiment it is described that if entangled particles are required to be able to cancel each others spin's then no mater how far apart these particles are, if one is measured you can instantly infer the state of the other particle. Why would the other...

By and large, it has been retreating glaciers, ice shelves and a general reduction in the thickness of ice masses over the last century, and more particularly, the last 25 years, that has alerted the world to the global warming. Is it known by how much, approximately, the worlds store of ice...

We current abbreviate this year as 09, however abbreviating 2010 as "10" just doesn't sound right. Does "010" work?

I can't believe that she was only sentenced to 6 years, she can probably get released in 2 with good behaviour. Just incredible that people can be this stupid. Paying bills while driving? http://news.yahoo.com/s/ap/20090404/ap_on_re_us/text_crash

Homework Statement The expected lifetime of a battery is 0.5 and the standard deviation is 0.5. At the end of battery's lifetime, the battery will be changed so that different batteries are independent of each other. How many batteries do you need such that at least one of them is alive...

Wow it's been forever since I've been around here! I blame school... so who is still hanging around these here forums after all these years? :D

this is my 1st post, and its a question that i had developed, most likely out of ignorance, so please save me from my sad paradox. lol Thank you, in advanced. I understand if i where floating in the bulk of space with no visual queues to give me aid in telling me if I were moving, i could...

Suppose that a binary-star system consists of two stars of equal mass. They are observed to be separated by 350 million {\rm km} and take 5.4 Earth years to orbit about a point midway between them. I got 1.1x10^29 as my answer, but it is incorrect. Can anyone help me out?

Hey everyone, I happen to be at an interesting juncture in my education thus far. I am a third-year undergraduate student studying physics, mathematics, and astronomy at my (somewhat small) university, and the notion of attending graduate school is quickly approaching. I'm having trouble...

I can't decide between wanting to become a neurosurgeon or an engineer/computer programmer. I will be able to enjoy either one, equally, I'm pretty sure. But will there be any advantage for me if I decide on one as soon as possible, or will the first few years of college require me to take the...

This hypothesis was put forward some years ago Bill Ruddiman 2003 report. It's an interesting idea. Is this the reason why we're not currently in the early stage of advancing ice sheets?

Is neuroscience a profitable job in the future of about 10-15 years? What kinds of things can you do with a degree in neurosci?

New years chat is open... Come in! I was all alone there last night while stoking the wood stove, and so far it's just Kurdt and me today. https://www.physicsforums.com/chat/flashchat.php

Me for one :(

Homework Statement Mars orbits the sun at 1.52 Earth's orbital radius. What is the period of Mars in Earth years? Homework Equations ΣFc = mac The Attempt at a Solution I am unsure how to do this problem as this is the first "orbital period" question that I have encountered. Do I...

Homework Statement a particular nuclear power reactor operates at 1000MWe (megawatts electric) with an overall efficiency in converting fission energy to electrical energy of 30%. what mass of 235 U must fission in order for the power plant to operate for (a)one day, (b)one year?(c) if the...

After having read a big part of "Who wants to be a Physicist" I was quite surprised that it is possible to apply for a Ph.D. with "only" a Bs.Sc. It is the same here in Argentina so now I'm guessing that Argentina took US example. I'm currently finishing the first year of University and...

Does anyone know how the supercomputers did it rather than the empirical approach? Also, energy can also be converted to mass, but how? Is there any evidence of this occurance? http://news.yahoo.com/s/afp/20081120/sc_afp/sciencephysicseinstein_081120235605

arXiv:0811.2402 [ps, pdf, other] Title: A Realistic Cosmological Model Based on Observations and Some Theory Developed Over the Last 90 Years Authors: Geoffrey Burbidge Comments: 21 pages, conference Subjects: Astrophysics (astro-ph) This meeting is entitled "A Century of Cosmology."...

With unemployment fore casted to hit 8% or higher by next year? How are you going to prepare for the strong possibility that you might get the pink slip and see your 401 k(s) become completely worthless?

AOL reported that OJ Simpson was found guilty on 12 counts...13 Years to the Day of his other famous verdict...any thoughts on the irony? I'm not attempting to judge (or comment) on his guilt/innocence. It merely occurred to me that if he WAS found guilty the first time...he MIGHT have...

I'm listening to an astronomy lecture by Prof. James B. Kaler. He keeps pronouncing Pisces like Pee Cees. I've always pronounced it Pie Cees. How do you pronounce it?

apparently, and was replaced by the American mammoth, That's the result of mitochondrial DNA research: http://www.msnbc.msn.com/id/26545527/ There is something with that excellent picture of the Yarkov mammoth mummy, heavy copyright fights. I hope this is the right place to post it.

What do you think will happen in that span of time? Will we find some wonderful discoveries or will we come across a global war over resources? Time to get your eight ball out...

A nice story on PBS tonight: Japanese Americans who were forced out of college and into internment camps, during WWII, were graduated last weekened at Oregon State University [Integral's and my alma mater]...

Hi. I was an undergrad at MIT 1996-1997, but dropped out because I couldn't pay for it, and to do startups. Now, I'm thinking about going back to MIT (they have a fairly liberal readmission policy). Going anywhere else is a little complicated because I also dropped out of high school (to go...

In some cultures and especially in the past boys at age 9 or 10 choose their wife that they will marry later on. Why? An example is in Mongolia in the olden days. Not sure if it still happens now.

Ok this is a pretty simple concept and in the electronics field I use it on a monthly basis, I can do it but I do not understand how it works and It is bugging the crap out of me. EXAMPLE: I have a pressure sensor, it reads pressure from 0 psi to .73 psi, and outputs a corresponding voltage...

Hi All, I understand that Einstein pursued the Unified Field Theory for the last 30 years of his life, pretty much going against mainstream physics. Of course he never succeeded because the necessary foundation was not yet in place for this pursuit. Does this mean that the last 30 years...

question as above, entering this fall, I wouldn't really want to buy one if I didnt really have the need to, btw, I am not staying on campus, i have my own place.

I was just watching the weather news. They showed the last six years of weather on May 2-4 Mondays: Sun, rain, sun, rain, sun, rain. So, they say, next year, expect sun. Idiots. People will trust this. Flip a coin 6 times: heads, tails, heads, tails, heads, tails. What can you expect...

Masters degree? One of my friends has a B.S in physics, and a masters in mechanical engineering. He did it all in 6 years. Now surely an appreciable amount of physics relates to mechanical engineering, but is it typically that easy to complete another "separate" major like that? If I do 4...

This is probably an elementary exercise, but my head spins trying to think about it. Assume that on Earth we see something 1 billion light years away (i.e. light took 1 billion years to reach us). To simplify, assume no relative proper motion, although the distance will change due to universe...

Would a galaxy 7 billion LY away appear to be twice the expected size (angular size) as a consequence of the expansion of the universe? (Assuming the universe is 14 Billion years old). My math says yes. But of course, I am just using trig and geometry. Just curious.

Hi everyone ! I got the weird idea of revisiting my old math books from 20 years ago and I got stuck on an problem that is probably super easy for most of you. It's from the chapter where we learn about how to solve limits of the form 0^0, \infty^0, 1^\infty by transforming an...

Assuming we're not extinct, what will maths be like in one million years. Can the language be improved in any way? Would we be more efficient with fewer/more digits than 9. Imagine if we we're using roman numerals how crap everything would be...

For the first time in twenty-five years I made a mistake that damaged a customer's piece of equipment. I was doing a last minute I/O check as there had been some discrepancies, and I inadvertently started a piece of equipment that provides no indication that it's running. My first clue was the...

what will be development of computer in next 20 years?

Hi all, after 10 years without any physics, I have trouble solving the following problem: "If your mean surface temperature is 28 C, what is your emittance? If the mean wall temperature in the room in which you are standing is 20 C, what is the average thermal irradiance at your surface...

Here is the part that I am confused on. I have to calculate the number of years the employees have been working for us, I believe the function I need to use is TODAY but it is not working, how can I get that function to work? I also need to figure out how to use the functions when looking at...

I had posted this in the wrong thread before I believe, so I moved it here. This is my first post, so I hope I am following the guidelines. I have a bachelors degree in Physics and a minor in math which I completed back in 2000. Back then I was sort of an average student, but I also did laser...

The contents of this forum has, for me, made the prospect of becoming a theoretical physicist very intimidating. I now find myself wishing that I had become interested in the field at the beginning of high school, instead of at the end. But instead of dwelling on what I cannot change I have...

Hello everyone, If you meet a person who graduated with a degree in 6 years. What would be you first impressions or you impressions in general about it? Will it be diffirent if the person did graduate with a degree in Engineering? I need some guiadance in this regard. Thank you.

Hello, everyone. From what I understand at universities there are three terms in one year and students are required to take 5 subjects per term for 2 of these terms (ie. 10 subjects per year). So, if a student wanted to go to school for all three terms that would be 15 courses per year...

Hi, This is probably a beginners question, but ill ask it anyway as it has me confused.I have read quite a few posts from clever people here (so I assume its correct) that the closer to light speed you get, the slower time gets, and also distances get shorter. Effectively meaning that, say for...

Is it possible to build an ion cannon(it's a super weapon that orbits around the Earth in space) with the technology we currently have or will have within the next 5-10 yrs?