Want to become an astrophysicist, hopefully this video will seal the deal either that you definitely should or definitely should not
Today's episode is a bit different. I'm going to tell you how to become an astrophysicist
I have a slightly unique perspective on this not because I did it myself but because I spent the past several years
Sitting on and then running the physics PhD admissions committee for one of the largest universities in the u.s
I have an idea of what it takes
So I thought I'd share some of the stuff I've learned
Maybe some of this will be useful to anyone thinking of chasing this silly path
But also to those of you just curious about the process
You might come out of this even happier that you didn't go down this rather unforgiving rabbit hole
I'm gonna end with some astrophysics that we can all try a
Challenge question for our recent episodes on the eternally inflating universe
Let me start by telling you about my own path. It was typical enough
I started out with a deep fascination in physics in understanding the nuts and bolts of how the universe works
I knew that I had to study physics at university, but honestly
I had no expectation of becoming a career. I just needed to know
But I caught the bug and decided to try my luck at the most fun film in physics astrophysics. I
Sent out applications to grad school all outside of Australia because I had a major edge to travel
I got some rejections and got some offers
Ultimately deciding to head to NASA's Space Telescope Science Institute in Baltimore, which is a great town
By the way, even in undergrad I was no longer the smartest person in the room, but in grad school
I sometimes wondered if I was the dumbest
serious ego check serious impostor syndrome
Which I still experience regularly
You'll get used to that but I told myself that if I'm always the smartest person in the room
Then I'm probably in the wrong room grad school had massive ups and downs and I thought of quitting plenty of times
It was amazing
I was using the Hubble Space Telescope to help unravel the connection between quasars and galaxies
As many others also found the two evolved hand-in-hand
Each influencing the other it was so cool to work on an unknown problem like that, finally
I scratched together a thesis and the University gave me a balloon. I had to rent the Hatton robe
I was a newly minted astrophysicist and through connections. I'm an in grad school
I scored a nice job working with the Gemini observatories
This was a postdoctoral position a postdoc which means a short-term job typically two to four years
Most astrophysicists do a couple of postdocs before looking for permanent jobs as that first postdoc was winding down
I had more thoughts of quitting astrophysics. I was just feeling burned out
I needed change. I applied for more Astro postdocs, but also for other jobs I
Ended up having two good offers one was still in Melbourne, but in bioinformatics
the information science of genetics turns out many many other fields science and otherwise
Want the analytical skills of all brands of physicists?
The other offer was an astrophysics postdoc at Columbia University in New York
So do I switch careers or switch cities?
No, is there a very tough question, but I'd always wanted to live in New York
And so I set sail again the real career hurdle was still ahead getting that permanent job
This is where the numbers are against us
There are way more astro postdocs than permanent positions whether at universities
Observatories NASA or private foundations in my case. I got lucky
I scored a professorship at the City University of New York
And that was the first point in my entire career where I thought I might be able to stick with this gig. Oh
And then I started making YouTube videos because God forbid I take it easy for a bit if you're thinking about pursuing physics or astrophysics
In fact many of the hard sciences then your path might look similar to mine
I'm going to focus on the first part of the process getting into a ph.d program
Getting your PhD is pretty much
Non-negotiable there are jobs for those with just undergraduate or masters degrees, but the prospects are relatively scarce
Let me also say right now that it's never too late to start
I know people who started in their 30s 40s 50s even 60s
most are much more sure of their goals than a fresh college graduate and so often have much more focus and
Determination and they can do very well
starting out
Your focus is convincing some folk on a missions committee to actually pay you
To come to a PhD at their University
The first step is to take a ton of mathematics and physics as an undergraduate
most estra PhD programs require a good foundation in the fundamentals of modern physics
It doesn't really matter what you major in but by the time you've taken all of that physics you probably qualify for a physics major
Anyway, and while you're at it
Get good grades
I'm afraid this one isn't negotiable either
Graduate admissions committees are looking for A's and B's a few lower grades won't kill you, but don't make a habit of it
You'll also want to put serious effort into whatever standardized test. Your country has the GRE in the u.s
Now me saying get good grades might sound glib but it's important to emphasize for one thing
Admissions committees folk have to sift through up to hundreds of applications each year
Most of them will filter by your grades before they read your nice personal essay
Also working your butt off as an undergraduate will help you learn whether a life in science is really for you
You may end up finding out that your talents lie elsewhere and that's fine
But at least you'll know that you gave it your best shot
The other thing to do as an undergrad is try to do some research
Commence a prof at your University to give you a small project that looks good on your application
It should get you a letter of recommendation
From that prof but most importantly it'll help you figure out if you actually like research
You should also apply for various REU programs
These are research experience for undergraduate programs, and they may actually pay you to do research between semesters
one
Absolutely critical thing to do as an undergraduate is find a mentor
This could be the prof you're doing research with or just another faculty member or even a postdoc you can talk to
Don't proceed blindly get as much advice as you can. Okay, so it's time to apply to grad school
Research different graduate programs by doing stuff you're interested in at that University
Would you be cool moving to that CDU or even country?
Don't just apply to top-tier schools. There are many truly excellent grad programs that don't have I've been growing on the walls
Visit campuses talk to profs and students there if you can
There are a lot of resources online for how to craft a good application use them send out a bunch of applications
Hopefully you'll get some bias. If not don't despair
You can bolster your application for the next year do some more undergraduate research
Retake the GRE exam or equivalent look into bridge or master programs. These can help prep you for grad school
However, I would not recommend paying lots of money out of pocket to do a master's program just to improve your chance of getting into
a ph.d program at
Any point keep your mind open about other career paths?
There are so many cool things to do out there
Especially if you have a good science undergrad degree once you're in a ph.d program
Then you'll have access to many new mentors who can give you as good advice as I can or better
Find those mentors it's going to be a challenging time
But it will Forge you into a scientist
One piece of advice regarding grad school to find the straightest path to patching together a thesis
Writing this tome may seem daunting, but you have much much cooler work ahead of you. Just get it done
Because once you have that PhD your options open up massively both in the field and out of it
Okay, this gets me to the big question
Should you pursue a PhD?
The reasons to do it you want to spend your life answered the biggest questions there?
Are you want to gaze upon the wonders of the universe and bring this incredible perspective to enrich humanity?
Because you just have to know how it all works
all good reasons
To spend a decade in school for pretty average pay the reasons not to do a PhD are many
Don't do it because you think you're okay at math and can't think of anything else to do besides stay in school
Don't do it if you want to earn the big bucks
Don't do it. If you don't want to have to move city or country every few years until you get that permanent job
Don't do it
if you want to maintain the illusion that you're the smartest person in the room and
Don't do it because you like the idea of yourself as a scientist more than you like doing science
The fact is with the job situation as it is the odds are stacked against getting that permanent position
So you better love the journey and all the awesome science you get to do along the way
The job includes as much or more frustration and boring stuff as it does on locking the mysteries of the universe
You've got to love the latter enough to get through the former
Don't do a PhD because you want to be an astrophysicist
Do it because you want to do astrophysics at least for a while. Okay enough rambling
Myself and other poor suckers on this path will answer specific questions in the comments for now
Let's get on with it and do some actual astrophysics
I have a challenge question based on our recent episodes on cosmic inflation
You'll definitely need to have watched those to get this
In those episodes we saw how an inflating universe can produce bubbles in which inflation stops
each a newly born universe in eternal inflation
This process goes on forever but inflation also has a beginning. So how many bubble universes exist today?
Well, that's not something we can easily calculate
But there is something we can at least estimate
Let's assume that every second there's a set chance of the new universe forming in any given volume of space
So every second many bubble universes are forming across the great sir
Eternally, inflating space-time and every second more universes form than in the previous second because there's more volume
my question is this
compared to the number of universes that formed this second how many more universes form in the following second twice as many a
Thousand times as many less more to answer this you'll need to assume a rate for inflation
Let's assume the minimum rate needed to explain the horizon and flatness problems
That is all distance is increased by a factor of 10 to the power of 26
Every 10 to the power of negative 32 seconds and an extra credit question at that rate
How close to our universe would a new bubble universe need to form in order for the two bubbles to collide?
before inflation
Throws them too far apart write up your answers
Neatly show all of your work and draw some nice diagrams if you can
Submit answers within two weeks of release of this episode to PBS space time at gmail.com with the subject line
Eternal inflation challenge and check your spelling because we filter by subject line
We'll select six correct answers to win your pick of space-time merch
From the merch store as well as the conference of the degree of doctor of space-time, which won't get you any professorships
But your parents will be so proud or if you hate homework, you can just buy that merch link in the description
We'll announce the winners in an upcoming episode
we will also learn some of the crazier consequences of an
eternally inflating
space-time
You you