In this post "academic" mostly refers to "graduate student" but some of the things I say seem to apply to more senior academics (professors, researchers) as well.
How we spend our time. On a typical weekday, I wake up at some point and go into the office. Depending on my meetings and other activities, I go to yoga or for a run before or after this. I usually spent 7-10 hours in my office, depending on how much I slack off and how long it takes for me to finish my major tasks. I try not to work on weekends (at most a few hours) so I can recharge for the upcoming week. My schedule is similar to those of my friends in math/science at Harvard/MIT. Experimental scientists spend more time in lab.
My free time includes meals (which I often spend with friends), 1-2 hours each evening, and weekends. I usually spend my evenings and some part of each weekend pursuing my hobbies, which include reading, blogging, doing things related to women in tech, and a rotating other activity. I spend Friday and Saturday evenings with friends.
My MIT grad student friends have on average 1.5 serious non-research hobbies. Common hobbies include running/biking, doing outdoors activities, doing recreational programming, starting a company, and spending time with a significant other and/or children.
The social life of an academic usually depends on level of introversion. Some academics never leave their offices while others are out 3-7 nights a week. Regardless of whether they do it while socializing or in lab, academics tend to value their wind-down mechanisms.
All of this only holds during times of the year without deadlines.
Advisors. During grad school orientation, I was told that my relationship with my advisor would become more important and demanding than any other relationship in my life. This was no exaggeration. My advisor has the ability to graduate me and he has the ability to cut off my funding. While my advisor gives me a good deal of freedom about what I work on and how I structure my time, we both understand his power.
Paper deadlines. Computer science publishes mainly in conferences. In my area (programming languages), there are two top conferences and a few other highly-regarded, more specialized conferences. In my area of computer science, each conference takes submissions once a year. Acceptance rates can be as low as 15%. Conference submissions are full-length papers; small differences in presentation can make the difference between “accept” and “reject.”
During the 2-3 weeks before a deadline, it is normal for me to work 10-12 hours on weekdays and 8-10 hours on weekend days. One senior graduate student told me what makes or breaks a (computer science) grad student is their ability to “bust their butt” for a deadline. During this time he was working 80 hours a week to finish up a project.
Success. Besides the coarse “promotion” structure (done with Ph.D. vs. not; tenured vs. not), there are many more nuanced factors that determine an academic’s status: 1) which big discoveries they have made and 2) how well they give the impression that they are making big discoveries. Some of this is measurable (for instance, through publication count and citation index) and some of it is more intangible (for instance, reputation in the community).
Fears of academics include being scooped, being wrong, fading into obscurity, and having insufficient intellectual freedom. Many academics are happy just to avoid these situations.
Life goals. We do have goals--though they may not be as concrete as you might like. We may not talk about them because they are often too lofty (for instance, winning the Nobel Prize or Turing Award) or dependent on variable factors (faculty job at a top school; starting a lucrative company) to discuss. The nature of the pressures and prospects we face, as well as the attitudes of our peers, make it highly likely that we will learn to handle a fair amount of uncertainty and risk. For these reasons it is also common for academics to have goals that depend on specific other people (and specific geographic locations) as little as possible.
Spending time with academics. If the academic in your life is willing to make you their hobby, then you can expect to spend a good deal of time with him or her with variability from paper deadlines, grant deadlines, conference and other travel, and teaching schedules. Otherwise how much you see your academic depends on how many common activities you share. Even if you are considered a good friend, this can range from a few times a week to once every few months.
What does an academic look like? My friend Lan made the video below for a science documentary class to capture the life of a grad student. It features three MIT grad students, including me.
rocks, bands, logic (2012) from Lan Angela Li on Vimeo.