Starts With A Bang!

The Universe is out there, waiting for you to discover it.

10 Things You Didn’t Know About The Anthropic Principle

"1.) The anthropic principle doesn’t necessarily have anything to do with the multiverse.

The anthropic principle is equally valid regardless of whether there is a multiverse or not and regardless of what is the underlying explanation for the values of parameters in our theories, if there is one. The reason it is often brought up by multiverse proponents is that they claim the anthropic principle is the only explanation, and that there can be no other selection principle for the parameters that we observe. One then needs to show though that the value of parameters we observe is indeed the only allowable one (or at least the most probable one) if one requires that life is possible.”

The Universe exists as it does; we exist in the Universe; therefore, the Universe needed to have such properties that at least allowed for the possibility of us arising. Is that a trivially true statement? Is that simply a useless tautology? Or can something like this actually be informative, and guide us in a useful direction when it comes to our understanding of the Universe? Theoretical physicist Sabine Hossenfelder explores these and other issues, including the multiverse, in this fascinating look into the anthropic principle.

Messier Monday: The Eagle Nebula, M16

"The Eagle Nebula isn’t the brightest nebula in the sky, nor the closest, nor the youngest, nor is it the largest. In fact, it doesn’t even hold any of those distinctions among nebulae in the Messier Catalogue, of which there are only seven!

But the reason this object is so spectacular isn’t because of how extreme it is in any particular way, but because it simultaneously illustrates all of the different stages that occur in a star-forming region.”

The formation of new stars happens in stages: cold molecular gas clouds contract and collapse under their own gravity, forming proto-stars in the densest regions that grow to undergo nuclear fusion. The new stars then emit ionizing radiation, and burn off the rest of the nebula, leaving a young star cluster behind. For the most part, we observe this story in different stages when we look at different objects, but there’s one place in our galaxy where the entire story is being told all at once. It’s the Eagle Nebula: the one place in our galaxy that showcases all the stages of star formation simultaneously!

Had NASA really believed in merit

"Thirteen American women — today known as the Mercury 13 — were selected to participate in the three phases of testing. Jerrie Cobb was the only one who passed them all. Not only did she pass, her scores placed her in the top 2% of all candidates, meaning that if the same criteria that were applied to the Mercury 7 were applied to her as well, she would have been selected. But without official NASA backing, the testing and training programs for women were shut down."

If NASA had really believed in merit, Jerrie Cobb would have been the first female in space, even before Valentina Tereshkova, more than 50 years ago. She still deserves to go.

What is dark energy?

"Right now, all the data points to a cosmological constant, but you never know: it could be a scalar, tensor, or dynamical field of some sort with much more complicated behavior than we presently observe. But it could also just be plain old energy inherent to space itself, and until there’s observation to the contrary, that’s where the smart money is."

Rather than being made up of fixed space and time, general relativity brought along with it spacetime, and the idea that it wasn’t fixed at all but rather dynamical. We discovered that the fabric of this spacetime itself is expanding over time, and by measuring multiple independent lines of evidence, we determined that the expansion itself is accelerating. This general phenomenon is due to dark energy, but what exactly is this dark energy we speak of so frequently? The observations are good enough now that we can (preliminarily) say that it’s a cosmological constant, or the energy inherent to space itself, or the non-zero zero-point-energy of the quantum vacuum. There’s still a little wiggle room, but not much!

The foolish fallacy of cold fusion

"Nuclear fusion, unlike our current terrestrial source of nuclear power — nuclear fission — involves no radioactive waste and no threat of a meltdown. Both the products and reactants of nuclear fusion processes are expected to be clean and pose no threat of a runaway, uncontrolled reaction.

Couple that cleanliness and safety factor with the incredible efficiency of nuclear power — multiple times as energetic per kg as fission and thousands of times more efficient than chemical sources — and it’s no wonder that it’s viewed as the holy grail of energy.”

If you can reach the fabled “breakeven point” of nuclear fusion, you’ll have opened up an entire new source of clean, reliable, safe, renewable and abundant energy. You will change the world. At present, fusion is one of those things we can make happen through a variety of methods, but — unless you’re the Sun — we don’t have a way to ignite and sustain that reaction without needing to input more energy than we can extract in a usable fashion from the fusion that occurs. One alternative approach to the norm is, rather than try and up the energy released in a sustained, hot fusion reaction, to instead lower the energy inputted, and try to make fusion happen under “cold” conditions. If you listen in the right (wrong?) places, you’ll hear periodic reports that cold fusion is happening, even though those reports have always crumbled under scrutiny. Here’s why, most likely, they always will.

The E-cat: cold fusion or scientific fraud?

"Without burying the lede too deeply, the claim of the test is that this device works, produced a total of 1.5 MWh (MegaWatt-hours) of energy over a timespan of 32 days, that the outputted energy was consistently between a factor of 3.2-to-3.6 higher than the inputted energy, and that no known chemical source could possibly be the cause of this reaction. In other words, they’re claiming that this must be a nuclear reaction.

But is this a scrupulous, rigorous test? Or are the researchers fooling themselves, and (possibly) falling victim to an elaborate hoax?”

Last week, outlets reported an independent test of the E-cat, an alleged cold fusion device that could revolutionize energy for our world. Or, alternatively, it could simply be a hoax perpetrated by a charlatan and a team of either accomplices or incompetents. How would you distinguish between the two? When you look at the scientific standards, the results of the “independent test” leave a lot to be desired.

Messier Monday: The Omega Nebula, M17

"The brightest stars here — the blue and red giants — will all be gone in just a few million years, resulting in between one-and-three dozen supernovae that will illuminate not only our skies, but the skies of watchers across our galaxy. In a few tens of millions years more, the entire nebula will be gone as well, having evaporated away completely. At that time, all that will be left is a bright open cluster of thousands of stars, which will slowly dissociate due to gravitational interactions, eventually leading to thousands of isolated star systems not so different from our own: with planets, asteroids, comets, heavy elements, organic molecules, and chances for life."

4.6 billion years ago, a large molecular cloud collapsed in the Milky Way, giving rise to around a thousand or so new stars and star systems, one of which just happened to become our home. But those early days showcased a violent time for our Solar System, and wasn’t so different from what’s currently taking place in the Omega Nebula, just 5,500 light years away in our own galaxy. Take an in-depth look inside, and catch a glimpse of what our Solar System’s environment was like back during its earliest days!

Your city in fantasy

"What he does is he takes modern American cities, their geographical landmarks (rivers, hills, forests/parks, cemeteries, mountains and valleys), their notable man-made structures and townships/counties, and then renders them in the style of J.R.R. Tolkien’s maps from his middle-Earth Universe."

Geographically accurate maps of modern cities, in the fantasy style of J.R.R. Tolkien! Made by a legitimate geography professor, with custom orders available. Check out the incredible work of Stentor Danielson!

How will Black Holes die?

"If you think of particle/antiparticle pairs as being “real” things, and if one escapes from the black hole’s event horizon and the other one falls in, then you’d expect to have just added energy to the Universe: half outside of the black hole and half to the mass of the black hole. But these pairs of particles and antiparticles aren’t real things, they’re only ways of visualizing (and calculating) the energy inherent to space itself."

Nothing in this Universe lasts forever: not life, planets, stars, atoms or even galaxies. But the longest-lived thing of all — black holes — have a limit on their lifetime, too! The phenomenon of Hawking radiation ensures that even they will decay and evaporate after a long enough time. But the popular picture — of particle-antiparticle pairs created outside the event horizon, with one falling in and the other escaping — is wildly oversimplified, and creates the misconception that Hawking radiation is particles-and-antiparticles escaping. It isn’t; it’s a blackbody spectrum of photons, and here’s what you need to know about what actually goes on!

Why do observatories shoot lasers at the Universe?

"As of 2012, for the first time, we’ve used this advanced version of adaptive optics to obtain a cleaner, higher-resolution image than even the space-based Hubble Telescope could obtain!"

If you want to take the best-ever images of objects in deep space, you build the largest possible telescope, you equip it with the best possible camera equipment, and you send it up to space. Right? Only, the “large” part and the “send it to space” part are mutually exclusive! We can build much larger telescopes on the ground than we can send to space, so how, then, could ground-based observatories ever compete with something like Hubble? You need to find a way to adapt to the ever-changing, turbulent atmosphere. Believe it or not, that’s exactly what the lasers these observatories shoot allow us to do!