A New Map of the Universe, Painted With Cosmic Neutrinos
The original version of this story appeared in Quanta Magazine. Of the 100 trillion neutrinos that pass through you every second, most come from the...
Tag : gravity
How Reality May Be a Sum of All Possible Realities
It’s a radical view of quantum behavior that many physicists take seriously. “I consider it completely real,” said Richard MacKenzie, a physicist at the University...
Why This Universe? Maybe It’s Not Special—Just Probable
Cosmologists have spent decades striving to understand why our universe is so stunningly vanilla. Not only is it smooth and flat as far as we...
You Can Use This Silly Game to Do Some Serious Physics
I’m a sucker for interesting online games that don’t have a score or even a goal. In this case, it’s a cartoon space simulator to...
The Physics of Smashing a Spacecraft Into an Asteroid
There are a couple of things to notice. First, after the collision DART is moving backwards, because it bounced. Since velocity is a vector, that...
How Far Would You Have to Tunnel Underground to Lose 20 Pounds?
Now, what if I move outside this sphere? It turns out that the gravitational field due to a spherical distribution produces the same gravitational field...
Why Bigger Things Don’t Always Fall Faster
If there’s one thing that you should learn from physics, it’s that big things are not like small things. I don’t just mean that big...
Can You Make a Hollow Metal Sphere So Big That It Floats?
This works for any shaped object where V is the volume. Notice that this total force from the air only depends on collisions between the...