This new tune from A Capella Science is the bomb. It’s a hip-hop retelling of the difficult day when mankind harnessed nuclear fission and scientific progress came face to face with war… all set to an Eminem song.
An invisible force at the center of our galaxy
Scientists have theorized that our Milky Way galaxy has a super massive black hole at the center of it, but how did this idea come about? How do astronomers measure something that has actually never been seen in our telescopes?
Above is an animation of star movements in our galaxy over the past 16 years. They all orbit around a point that emits no light in our galaxy. We can measure the mass of these stars and calculate that their orbits require an object with the mass of 4 million Suns. So far this points to a super massive black hole in our galaxy.
The nothing made of something at the center of everything…
This headline got me thinking… is there a force that is not invisible? I mean we’re all comfortable with the idea that gravity, magnetism, and electrical forces are invisible. We can see their effects, but you can’t point to a force.
Even when it comes to tension, friction, or applied force, we always discuss the effects of the force when we discuss them. The force itself is not a thing that we can point to or see. Even pushing a chair across a room, if we could zoom into the atoms of my hand pressing near the atoms of the chair, we would ultimately see nothing there, just space. The electrons in my hand are in an odd sense “aware” of the electrons in the chair, and they repulse each other, due to electromagnetic force (also invisible) and the exclusion principle.
So really, isn’t all force invisible? Someone call Yoda.
Richard Feynman discusses why there is a difference between the past and the future, in this clip from his legendary 1964 lecture series at Cornell: The Character of Physical Law.
It’s well worth taking 45 minutes out of your day to hear Dr. F explain why the workings of nature unfold in one direction. You see, while we innately know that the future is different from the past, and so much of our conscious experience is built around the fundamental just-so-ness of time moving forward, the equations of physics describing phenomena from gravity to friction can be run in either direction without breaking the rules. Yet irreversibility is what we observe.
That’s where entropy and probability come into play. When we take into account complex systems, like the jiggles and wiggles of the uncountable atoms that make up our bodies and this chair and my coffee and our world and even out to the scale of the universe itself, there is simply a greater chance that things will become more disordered than less. It’s not that the universe can’t run in reverse, it’s just that there are so many other ways for it not to.
Or as Feynman says, nature is irreversible because of “the general accidents of life”.
This seven-part series, which Open Culture has assembled in its entirety, captures the physicist in his prime, one year before he won the Nobel Prize and became a household name. Feynman was seemingly born for the scientific stage. He had this uncanny ability to weave profound observations of the universe’s inner workings with off-the-cuff (and often brash) humor. James Gleick wrote of Feynman’s unique style and skill:
He had a mystique that came in part from sheer pragmatic brilliance–in any group of scientists he could create a dramatic impression by slashing his way through a difficult problem–and in part, too, from his personal style–rough-hewn, American, seemingly uncultivated.
This clip was a huge influence on my recent video Why Does Time Exist? Although my take scarcely measures up to Dr. Feynman, you can watch below:
In honor of the first day of summer here in the Northern Hemisphere, a few fun physics facts about summer, courtesy of the Perimeter Institute (check out more here).
Why Does Time Exist?
We know that yesterday is different from today, and that the future is different from the past. But why is that?
Mathematically speaking, the equations that govern how atoms move, how heat is transferred, or how chemical bonds are made and broken can run in reverse with no problem. But they don’t. The arrow of time points forward.
Happy Birthday, Richard Feynman! Celebrate with my video interpretation of his famous ode to the universe and wine. I love this poem more than words can express.
Remember… all life is fermentation.
Previously: Enjoy artist Maggie Chok’s illustrated Feynman poem, where every line is reimagined as typographic art.
The Far Future of the Universe
It’s natural to wonder what the future has in store for us. While we may not be able to predict what will happen to us tomorrow, science has made some pretty strong predictions about what will happen to the universe in the eons to come.
From the rearrangement of the constellations and meteorite impacts to the evaporation of our oceans and the stars themselves going out, there’s a lot of stuff to (not) look forward to.
Sure, the universe might not have a happy ending, but that just makes today more special, doesn’t it? Plus, BLACK HOLES.
Watch the latest It’s Okay To Be Smart (below) and I’ll tell you all about it!
An excellent conversation with the mathematical physicist Freeman Dyson from Quanta Magazine, touching on everything from quantum electrodynamics to why getting kids into science might change the world.
Dyson is often contrarian, but always sharp and intelligent. From founding quantum electrodynamics alongside one of my heroes, Richard Feynman, to such science future fictions as the Dyson sphere, he has a particular way of approaching the known and unknown world that we’d all be well-served to consider.
On the value of math:
I was trained as a mathematician, and I remain a mathematician. That’s really my skill, just doing calculations and applying mathematics to all kinds of problems, and that led me into physics first and also other fields, such as engineering and even a bit of biology, sometimes a little bit of chemistry. Mathematics applies to all kinds of things. That’s one of the joys of being a mathematician.
I love that. No matter your field, you’ll do well to remember that you’re a problem-solver first and an applier-of-specific-skills second.
On the value (or not?) of the Ph.D.:
I’m very proud of not having a Ph.D. I think the Ph.D. system is an abomination. It was invented as a system for educating German professors in the 19th century, and it works well under those conditions. It’s good for a very small number of people who are going to spend their lives being professors. But it has become now a kind of union card that you have to have in order to have a job, whether it’s being a professor or other things, and it’s quite inappropriate for that. It forces people to waste years and years of their lives sort of pretending to do research for which they’re not at all well-suited. In the end, they have this piece of paper which says they’re qualified, but it really doesn’t mean anything. The Ph.D. takes far too long and discourages women from becoming scientists, which I consider a great tragedy.
I think he’s spot-on about many of the Ph.D.’s failings, but I think he simplifies the value of the “title” here, rather than the work one does to get the Ph.D. Therein lies the value, or lack thereof. The Ph.D. process (quite effectively) teaches a manner of thought and problem-solving that is tough (but not impossible) to replicate elsewhere. But a Ph.D. is most certainly not the only way (or even the best way?) to become a scientist, at least with respect to a scientist being not a vocation but being “someone with a generally scientific mindset”.
Finally, on why we need to get every child interested in science:
We should try to introduce our children to science today as a rebellion against poverty and ugliness and militarism and economic injustice.