Anyone announcing the successful sale of tourist trips around the moon would attract ridicule and laughter. Unless your name is Elon Musk. In that case the announcement amounts to nothing more than a logical and rather modest step towards Musk's promise of getting a million people to live on Mars.
You have decided to start a graduate study in physics. Where should you apply? And how to decide which offer to take? A diarrhea of lists attempt to rank "the world’s best universities". Mostly these lists are based on some aggregate of different metrics. Yet, for a postgraduate degree your focus should be on one and only one metric: you want to surround yourself with the best brains. If you're good, the place to hone your skills is there where you get the opportunity to learn from the best. There where you can join those that are making impact in their field of research. What are the high-impact universities in physics?
A shooting star brighter than the sun on the very day an asteroid flyby is predicted. A most remarkable coincidence. And to add to our amazement, the rock whizzing through the skies didn't illuminate a distant ocean or some remote desert, but rather showed its spectacle above one of the very few areas in the world populated by people driving dashcams around 24 hrs a day. No screenwriter would get away with such an unlikely scenario.
But how likely are meteor event like the one in Russia? What are the chances a similar event will occur this century? And what about even bigger events? What was the power of the blast from the Russian meteor? How does it compare to the explosions we humans create?
1:1 In the beginning Newton declared space and time. 1:2 And space was without form, and void; and darkness was upon the face of the deep. 1:3 And Newton said, Let there be force: and there was force. 1:4 And Newton saw the force, that it was good: and Newton divided force from straight motion. 1:5 And Newton called force change of momentum, and straight motion he called momentum conservation. And the evening and the morning were the first day.
Gravity is an amazing force. It can grow enormous structures in the universe. If you ever find yourself under a dark night sky at a spot far away from city light, have a look at the constellation Andromeda. With bare eyes you should just be able to spot a tiny smudge in this constellation. You need good eyes that are well adapted to the dark, and the moon with its overwhelming brightness needs to be out of sight. And it definitely helps if you happen to carry with you a pair of binoculars.
Regulars to this blog know I am partial to game theory. The very idea that mathematical reasoning can teach us a thing or two about the strategies we deploy in social interactions, is most intriguing. Game theory recognizes that humans do possess rational and selfish characteristics, and builds models describing human decisions based on no more than these two characteristics. This minimalistic approach teaches us a lot about the character of economic behavior and the emergence of strategies build on cooperation, retaliation, etc.
Why do people skip the queue, obstruct, cause traffic jams, and create delays for everyone? Who are these anonymous creatures lacking cooperation skills? And more importantly: are you sure others don't classify you as such?
What is the farthest we can theoretically go? Would we ever be able to visit the galaxies shown in Hubble's Extreme Deep Field? Could we even travel beyond these and reach the edge of the observable universe?
So, is it or is it not possible? Can black holes be split? In my last blog I demonstrated that the laws of thermodynamics forbid the splitting of a single black hole. However, I also demonstrated the same laws don't forbid the splitting of a pair of black holes into many. This leaves the door wide open for splitting black holes by smashing them together. Or does it?
Ask a physicist how to split a black hole, and you will receive the reply "That's impossible". Ask for further clarification, and you will get a lecture on black hole thermodynamics.
Black holes are again hitting the headlines. Another record super massive black hole has been unveiled. This time it is galaxy NGC 1277 at the center of which a true monster is discovered to be lurking. Dutch astronomer Remco van den Bosch and co-workers weighed the black hole at the center of this galaxy. They did so by interpreting the stellar kinematics from velocity dispersion measurements obtained with the Marcario Low Resolution Spectrograph on the Hobby-Eberly Telescope at the McDonald Observatory in Austin, Texas. They came to the conclusion that the giant weighs in at 17 billion suns.
In the history of statistics, economy and decision theory, the St. Petersburg paradox plays a key role. This lottery problem goes back a full three centuries to the mathematician Nicolas Bernoulli who first formulated the problem in 1713. Twenty five years later, in 1738, his nephew Daniel Bernoulli presented the problem to the Imperial Academy of Sciences in St. Petersburg. That presentation not only gave the paradox its name, it also created a lot of commotion amongst mathematicians.
Scaling down the observable universe to make it fit within our moon's orbit, the Milky Way gets reduced to a village. We live close to the edge of this village, at a comfortable distance from the central marketplace, where a giant black hole is known to be lurking. Now, this peaceful picture is brutally disturbed by an international group of astronomers who bring us the message that a black hole of at least a hundred solar masses is likely to ambush us in our own backyard. Theta Orionis, a fuzzy star in Orion's sword harbouring a massive black hole?
