Years Definition and 634 Threads

Hi everyone! Nowadays, our Universe has a 47 Billions light-year long radius, but the tricky thing is that its expansion rate is increasing, so could you tell me how its radius was a couple of thousand years ago? Thanks and happy new year!

Please forgive me if this fell into the wrong forum. I thought this would be the right place to ask. 500 million years have past since humanity came in control of a device that could send ships at great speeds across the universe, from the edge of one galaxy to the edge of another in weeks...

Couldn't there be a more boring subject for a thread? However Sterre is the daughter of our national hero Andre (yes common name) Kuypers (lower right), who happens to be in ISS right now and stays there for half a year. She keeps singing all the way despite the applause...

Hi there, I am planning on going back to graduate school to get a PhD in Physics. I plan on applying during the fall of next year, and then going back the year after. However, I still need letters of recommendations, and its already been a while since I've last communicated with any of my...

i remember the French came up with metric meter by measuring the distance between equator and north pole and then divided by an integer to come up meter. it that still the defintion for meter? also, it seems now that a second is defined by the integer number of oscillation of atomic clock...

Since I was 14 I've been in the restaurant business. Even if I had another job I still worked part time in restaurants. I've worked for Morrimoto when he was the executive chef at POD, Mark Vettri, Chris Bellino and other big name chef's. It's really the only thing I am actually qualified to do...

So I put together a plan for the final five semester of my four year plan. It includes a physics major, math minor, and music minor. Looking to get feedback on its layout from anyone who has already finished a semi-similar program. Do any of the semesters look particularly overwhelming? Spring...

Hello Folks I am a 43 year old guy with only a high school diploma and I am very much considering going back to school for physics. Can I still do it and have a career or am I wasting my time and money?

I'm only an ME undergraduate right now, but I'm pursuing this path that may lock me in industry (CAD/CAM/machine design/etc.) for a minimum of 3 years after graduation. It's not quite the technical path that I wanted to go into, but the opportunity seems too great to pass up for now. How...

I would like to know how many stars are within 150 light years of Earth. There must be a website somewhere that has the number, or perhaps a graph correlating distance with number of stars. I've done some searching, but you folks are much smarter than I am. Thanks

I'm a high school senior and I'm toying around the idea of double majoring in cs and physics, as I incredibly enjoy both fields. I aced AP Computer Science and AP Physics C(both Mechanics and EM). With AP credit, will I be able to complete a cs physics double major in 4 to 5 years without...

When I was in high school and first learned about the laws of thermodynamics, I independently postulated the heat death of the universe (of course I didn't know it was called that at the time). A few years later and I find out that some guys in the 1800s beat me to it. What do you think...

Oks, I've always been a passive reader of forum...Until now =) Im a ME student, finishing my 2nd year AND I am working 20hours/week at a well renown technology institue at my country. Working only 20hours per week gives enough time to study, so I am doing ok. Yesterday, another job was offered...

Homework Statement A light-year is the distance that light travels in one year. Find this distance in both miles and meters. Homework Equations Speed of light (c) = 3.00x10^8 m/s The Attempt at a Solution 10^15 m/s __________ 3.00x10^8 m/s That is to find meters...I think I can only find...

It's been a long time from my childhood. I'm almost 40, so I thought I'd try to find some people from my past. In particular, two guys who had the most significance and bearing on who I would become. The first was a guy who was a friend of mine for a few years before we simply stopped hanging...

Don't remember seeing this. Does NASA do September fools jokes? I cannot imagine anything so CGI being for real.

So, five years ago, at a pretty prestigious North American univ, I was accused of cheating on a take home exam. I hadn't cheated, but unluckily, I made careless mistakes that were similar to where I was supposed to be cheating from (and this was on a predominantly maths based paper) and so I...

And man has technology in the classroom advanced at breakneck speed. I've only been away for 5 years and I'm having trouble trying to learn it. Is it me, or has technology actually made learning worse? Why can't things be simple anymore? All I want is a lecture, an assignment, and test. Now...

This is a follow-up to some of the advice I was given at the thread I created called "Shortest Path to a PhD in Math or Theoretical Physics" and here it is for reference: https://www.physicsforums.com/showthread.php?t=521408 After looking around on the internet here is a path which I could...

How come AI never makes an progress? OK this may be slightly over stated but it has been 50 years since we thought we could make an AI soon and we are no where near an AI.

I got a bachelors in physics in '08 at an upper liberal arts college. Intended to take a year off but fell into a depressed rut (father died, girlfriend left, etc etc) and just worked a low-skill job / volunteered / played wow for two years. Cleaned my act up a year ago. I'd surfed through...

I know this question has been asked a million times,but i haven't been able to find an answer for this. I am a Physics Undergrad and looking forward to pursue MS in Physics from US,but I have only 15 years of education (10+2+3). Most schools require qualifications comparable to a U.S...

Greetings all. I apologize for the lengthy intro; I shall try to be brief. For those who don't think any background is necessary, you can skip to the last paragraph if you would like to save some time. For all of my younger life, I was always a math freak. Gifted with a knack for the...

Not sure where this goes. I like math but this is a little over my head. Can somebody do this for me and what branch of math is used? Our town has a goose manure problem so I'm gathering facts for my presentation. Here's the problem- If two geese produce 8 babies each year what would the...

When Greg changed the members list awhile ago to show only members with 500 posts (I just looked and it appears he changed it back), I thought, hmm... how close am I to that magic number, and it turned out (at that time) I had quite a few to go to break 500. I did it this morning, and it took me...

Is it coincidental that the Hubble Sphere, in light years, is approximately the age of the universe computed as 1/Ho (13.7 billion years)? If the recession speed exceeds the speed of light, the photon would never reach the observer, this is why there exists a horizon of the visible Universe...

According to the legend, the island of Manhattan was purcased from the native indian population in 1626 for 24 dollars. Assuming this money was invested in a Dutch bank paying 5 % simple interest per year, costruct a table in C++ showing how much money the native population would have at the...

Will the big bang be seen as 13.7 billion years ago by all observers in the universe regardless of their velocities ? I mean I read that in SR one has to abandon notions of simultaniety. And an event which has already occurred for one observer may be in future for another observer. I guess...

Okay, If Uranium's half life is 4.5 billion years, why does it become waste at a reactor before it decays 4.5 billion years later... Forgive me if my question is badly worded or really stupid; I am a high-school student who has just finished the topic of "Nuclear Energy" in my physics class...

A star is 40 light years from Earth. (a) How far would you measure this distance to be if you traveled it in a spaceship moving at 1.00X10^8 m/s (b) How long would the trip last (for you)? Can someone please help me out with this question and what equations I should use to solve this...

I've been posing this question to physicist folk for 10 years, mySpace 6 years ago, and here (don't know when, when I had an older account), and I see that others bring it up on occasion. I will refine it to meet current objections. You have a photonic drive spaceship. It has a (classical) mass...

I'm currently in my third year of a 4 year masters course, however I've been offered a place on a PhD scheme which would mean me graduating with a Bsc instead of a masters and starting the PhD right away. My question is: Does having a masters as well as a PhD differ significantly from having a...

Recently I saw this in the news...any thoughts on this? jhd as joesmith

Huguette Clark, daughter of Las Vegas founder and second richest man in the US at his time, William Clark (Rockefeller bested him) is dead, at 104 years old. It is said that compared to her, Howard Hughes was an outgoing&sociable man...

Currently I am doing my MSc in Physics with a focus on Condensed Matter Theory. I have about one more year to go, after which I will have to decide how to carry on. By the time I finish my Masters I will be 23 years old. This summer I will do a well-paid internship in the financial sector at...

I don't remember specifically where I read this, I think in a post here, but is it true that PhD programs prefer admitting students who completed their BS in 4 yrs over those who took longer? Ive already been working on my BS for 4 years and am trying to decide whether to cram and finish in...

Hello, I am a mechanical engineering and mathematics undergraduate, and am looking at the Navy's NUPOC (nuclear propulsion officer candidate) program as a potential right-out-of-college job prospect (well, technically, while in college, but for all practical purposes, it starts after I...

Hello, I would appreciate advice, preferably from people with families. I am currently plodding through a degree in physics\math at a snail's pace, due to working part-time at unconventional hours (in informal education) and raising a 1.5 year old. I also observe the Jewish sabbath, so...

For years I have mastered the art of simulation and testing, but I almost never seem to be able to find SPICE models for real devices. For example, the TI OPA548. It's a high-current power op-amp. I would love to run some simulations...but I can't find a model of it anywhere to use in...

Hello folks, I graduated 10 years ago with a PhD in theoretical atomic physics and went into the IT industry. My career to date in IT has been successful, however it has never challenged me and recently I have had a great yearning to get back into research. So I have been getting out all my...

Long story short: I got admitted to a top 20 physics grad program. I'm thrilled about finally working towards my PhD in Physics, but I've been out of physics for nearly five years now. So, I'm looking for advice on what I can do between now and September to "catch up." My current game plan...

In the UK, following the Bologna process, any undergrad degree taking 4 years, assuming sufficient amount of credits is obtained, one is awarded a Masters degree. A 3 year course results in a bachelors. Why is it that in the US, one is awarded with BS after 4 years of study? Is it because of the...

Hi, I am worried my son probably going heading down hill with absent/missing ACA A1 segment. He is also has very poor vision (OA) with nystagmus. He has hemiplegic event last years by treating his sinus issue somehow has positive effect for 8~10 months no hemiplegic events. Last week he had...

What will be happening 10^(trillion) years from now? Sorry if this is posted in a wrong section.

Hi, I've just been wondering about something so if anyone coudl explain it that'd be great. You often come across the statement that we believe the universe to be 13.7 billion years old, but I was wondering how this calculation is made? My main problem is that I'm confused as to whether every...

According to the Milankovitch 100,000 years cycles, there is a problem. The orbit of the Earth will change to a gradually more ecliptic orbit, and it will be a bit colder when this happen. But the problem is that this is not enough to explain ice ages. How much is missing. I mean how much...

The universe is said to be 13.7 Billion years (http://en.wikipedia.org/wiki/Age_of_the_universe" . So, for the present galaxy UDFj-39546284 and the present Earth to have traveled as far as they are now, and even if we assume that the big bang occurred right between Earth and UDFj-39546284, it...

I hear a lot about astronomers using type IA supernovae to accurately measure large scale distances over billions of light years to do things like measure the rate of expansion of the universe. I doubt that the calculation of this distance is simply based on the inverse square law. So my...

Not sure if this is the right forum but i'll ask here anyway. I'm a student going into a mathematics program in the fall but I'm wondering if i can still do a hobby. But here's the thing. To understand math, i literallly have to do all the homework my teacher assigns each class. This is roughly...

I was a mechanical engineering major that recently switched into physics. Given my late start, I'll be taking most of the physics curriculum in 2.5 years. Is this enough time to adequately prepare for PhD work? Since I'll be taking quantum my senior year, I probably won't take the GRE until...