Regular

11 pm // After procrastinating all day, now I truly enjoyed the enlightening moment of realizing that a catenary has the form of cosh(x). Loving the beauty of theoretical mechanics.

Regular

Only the real gangstas use math

Ask Ethan: What Could Solve The Cosmic Controv…

Ask Ethan: What Could Solve The Cosmic Controversy Over The Expanding Universe?

“As you pointed out in several of your columns, the cosmic [distance] ladder and the study of CMBR gives incompatible values for the Hubble constant. What are the best explanations cosmologists have come with to reconcile them?”

If you had two independent ways to measure a property of the Universe, you’d really hope they agreed with one another. Well, the situation we have with the expanding Universe is extremely puzzling: we have about 10 ways to do it, and the answers all fall into two independent and mutually incompatible categories. Either you make the measurement of an early, relic signal that’s observable today, and you get a value of 67 km/s/Mpc, with an uncertainty of about 1%, or you measure a distant object whose emitted light comes directly to our eyes through the expanding Universe, and you get a value of 73 km/s/Mpc, with an uncertainty of about 2%. It’s looking increasingly unlikely that any one group is wrong, in which case, we absolutely require some new, exotic physics to explain it.

While many ideas abound, there are five of them that are eminently testable in the next decade or so. Here’s how we could solve the expanding Universe controversy in the best way possible: with more and better science!

Starts With A Bang Podcast #45: Beyond Earth…

Starts With A Bang Podcast #45: Beyond Earth 2.0

With all the planets out there in the galaxy and Universe, it’s only a matter of time and data until we find another one with life on it. (Probably.) But while most of the searches have focused on finding the next Earth, sometimes called Earth 2.0, that’s very likely an overly restrictive way to look for life. Biosignatures, or more conservatively, bio-hints, might not only be plentiful on worlds very different from our own, but around Solar Systems other than our own. Earth-like worlds, in fact, might not even be the most ubiquitous places for life to arise in the Universe.

I’m happy to welcome scientist Adrian Lenardic onto the Starts With A Bang podcast, and explore what just might be out there if we look for life beyond our idea of Earth 2.0!

(Image credit: JPL-Caltech/NASA.)

Is Alien Life Hiding Beyond Earth 2.0?

Is Alien Life Hiding Beyond Earth 2.0?

“It may be the case that life is rare in the Universe, in which case it will require us to look at a lot of candidate planets — possibly with very high precision — in order to reveal a successful detection. But if we search exclusively for planets that have similar properties to Earth, and we restrict ourselves to looking at parent stars and solar systems that are similar to our own, we are doomed to get a biased representation of what’s out there.

You might think, in the search for extraterrestrial life, that more is more, and that the best way to find life beyond Earth is to look at greater numbers of candidate planets that might be the Earth 2.0 we’ve been dreaming of for so long. But non-Earth-like planets could be home to life that we’ve never considered, and we won’t know unless we look. More is more, but “different” is also more. We must be careful, as scientists, not to bias our findings before we’ve even truly started looking.”

If we want to find life elsewhere in the Universe, it only makes sense to look at our own world, where we know it was successful, and to try and find other worlds similar to our own. But that absolutely cannot be the only thing we do, or the only inhabited worlds we’ll even have a chance at finding are the ones similar to our own.

We have many good reasons to favor or disfavor the probability of finding life on a variety of planets and moons out there in our galaxy, but the real truth of the matter is we don’t know how common or rare life is. We don’t know how common or rare a huge variety of processes are, or even whether life is more likely to arise under conditions very different from those we find on our own planet.

It’s possible that Earth-like worlds are the best bet for life in the Universe, but don’t count out the non-Earth-like worlds without looking. Here’s what everyone hopeful for discovering alien life should keep in mind as we search the galaxy.

Wolfgang Paul Was A Great Physicist, Not A Typ…

Wolfgang Paul Was A Great Physicist, Not A Typo Of ‘Wolfgang Pauli’

“Yet recognition almost escaped Paul entirely. Upon his retirement, where he became Professor Emeritus, the University took his office away and moved him to a janitor’s closet in the basement. Despite all of his contributions to the University of Bonn (including singlehandedly getting 100% of the funding for the 500 MeV synchrotron and getting it built there) and to physics over the years, he never complained about it.

Yet when Stockholm called, everything changed. They moved him back out of the basement and into his former office, where he continued his work until the end of his days. Of course, posthumously, CERN chose him as one of the physicists to honor with a street all his own. It still exists today, and I assure you, it isn’t a typo.”

Did you ever see the movie Office Space, where “Michael Bolton” refuses to change his name, go by “Mike,” or do anything that would distinguish himself from the much-more-famous singer with the same name? When confronted about it, his response was, “why should I change? He’s the one who sucks.”

Well, now imagine that you’re a physicist pushing the frontiers of our fundamental knowledge, developing new methods of manipulating particles in our Universe. You’re a hero at your University, a legend in your country, and you’ll go on to win a Nobel Prize. Yet your name is just one letter shy of a much more famous physicist, and you’re forever thought of as a typo of their name.

This is the not-quite-tragic story of Wolfgang Paul, who you should definitely remember as much more than a typo. His quip to Pauli, upon meeting him, is the best nerd joke you’ll read all year.

What do you think of who is behind with their …

What do you think of who is behind with their studies?? Like have you ever had friends or colleagues struggling and taking longer that normal?? I had problem with my studies because of dyslexia and I’m older than anyone else also depression and these kind of fields are so competitive and I feel always judged and hopeless and just old and with no real possibilities…. congratulations on your phd :))

Let me tell ya, I know many people who didn’t complete their studies within the ‘normal’ amount of years. In physics, I would say those who did were a minority. I myself finished my studies two years later than I was supposed to. Still got into a PhD. It’s true, it’s an insanely competitive field and it’s never easy. But I think you have to keep in mind that the science world is a bit different than undergrad/graduate courses, being older doesn’t really matter. What matters is the quality of your work. And comparing yourself to others won’t be very helpful to you. I lost one year due to depression, another to laziness and procrastination (and self doubt, and all of that). I think what got me through is what my high school math teacher once said to me: “the drop will dig into the rock”. Do all you can, but do it. Best of luck!

No, The Universe Cannot Be A Billion Years You…

No, The Universe Cannot Be A Billion Years Younger Than We Think

“There may be some who contend we don’t know what the age of the Universe is, and that this conundrum over the expanding Universe could result in a Universe much younger than what we have today. But that would invalidate a large amount of robust data we already have and accept; a far more likely resolution is that the dark matter and dark energy densities are different than we previously suspected.

Something interesting is surely going on with the Universe to provide us with such a fantastic discrepancy. Why does the Universe seem to care which technique we use to measure the expansion rate? Is dark energy or some other cosmic property changing over time? Is there a new field or force? Does gravity behave differently on cosmic scales than expected? More and better data will help us find out, but a significantly younger Universe is unlikely to be the answer.”

There’s a fascinating conundrum facing modern cosmology today. If you measure the distant light from the Universe, from the cosmic microwave background or from how the large-scale structure within it has evolved, you can get a value for the expansion rate of the Universe: 67 km/s/Mpc. On the other hand, you can also get a measurement for that rate from measuring individual objects through a technique known as the cosmic distance ladder, and you get a value of 73 km/s/Mpc. These two values differ by 9%, and are inconsistent with one another. Recently, one of the groups studying this puzzle claimed that the Universe might be 9% younger than currently expected: 12.5 billion years old instead of 13.8 billion years old.

That is almost certainly wrong, as it would conflict with extremely important pieces of astronomical data. This really is a puzzle, but a younger Universe isn’t the solution. Here’s why.

This Is What Will Happen To Our Sun After It D…

This Is What Will Happen To Our Sun After It Dies

“During the red giant phase, Mercury and Venus will certainly be engulfed by the Sun, while Earth may or may not, depending on certain processes that have yet to be fully worked out. The icy worlds beyond Neptune will likely melt and sublimate, and are unlikely to survive the death of our star.

Once the Sun’s outer layers are returned to the interstellar medium, all that remains will be a few charred corpses of worlds orbiting the white dwarf remnant of our Sun. The core, largely composed of carbon and oxygen, will total about 50% the mass of our present Sun, but will only be approximately the physical size of Earth.”

Looking forward in time, the death of our Sun is easy to envision, as we’ve seen Sun-like stars in their dying phases and immediately afterwards plenty of times. But what happens after that, in the far future? Will our Sun’s corpse remain a white dwarf forever? Will it simply cool down, radiating heat away? Or will something exciting happen?

Maybe we’ll get ejected from the galaxy. Maybe we’ll get devoured by a black hole. Maybe we’ll merge with another object, or experience an interaction that forever changes us from what we were. Maybe we’ll even experience a cataclysm that destroys our stellar corpse entirely!

Although the possibilities are fascinating, there’s an overwhelming statistical likelihood that points to one particular outcome. What is it? Find out today!

How Did This Black Hole Get So Big So Fast?

How Did This Black Hole Get So Big So Fast?

“Recently, a new black hole, J1342+0928, was discovered to originate from 13.1 billion years ago: when the Universe was 690 million years old, just 5% of its current age. It has a mass of 800 million Suns, an exceedingly high figure for such early times. Even if black holes formed from the very first stars, they’d have to accrete matter and grow at the maximum rate possible — the Eddington limit — to reach this size so rapidly. Fortunately, other methods may also grow a supermassive black hole.”

One of the puzzles of how our Universe grew up is how the supermassive black holes we find at the centers of galaxies got so big so fast. We’ve got multiple black holes that come from when the Universe was less than 10% of its current age that are already many hundreds of millions, if not billions, of solar masses in size. How did they get so big so fast? While many hypothesize exotic scenarios like our Universe being born with (primordial) black holes, there is no evidence for such an extraordinary leap. Could conventional astrophysics, and the realistic conditions of our early Universe, actually lead to black holes so massive so early on?

The answer is very likely yes. Come see an extremely favored scenario, with nothing more than conventional astrophysics, that just might get us there.