Physics
esiegel | June 2, 2016"What's really exciting is what comes next. I think we're opening a window on the universe -- a window of gravitational wave astronomy." -Dave Reitze
On September 14, 2015, LIGO directly detected gravitational waves for the first time, from the inspiral-and-merger of two quite massive black holes. Despite the fact that no electromagnetic radiation signal was expected, the Fermi GBM instrument measured a high-energy X-ray event just 0.4 seconds after LIGO’s 200 millisecond detection occurred. According to NASA scientists working on the Fermi mission, there was just a 0.2% chance of a false…
esiegel | June 2, 2016“There is no question that climate change is happening; the only arguable point is what part humans are playing in it.” –David Attenborough
If the Earth didn't have any global warming at all, our planet's mean temperature would be 255 K, or about -1º Fahrenheit: the mean temperature of the Antarctic continent. As it stands instead, our planet is much warmer than that, owing to the warming, insulating effects of the atmosphere, which is largely transparent to (incoming) visible light, but traps a fair amount of the (outgoing) infrared radiation.
Natural color image of Venus from Mariner 10…
esiegel | June 1, 2016"The bedrock nature of space and time and the unification of cosmos and quantum are surely among science's great 'open frontiers.' These are parts of the intellectual map where we're still groping for the truth - where, in the fashion of ancient cartographers, we must still inscribe 'here be dragons.'" -Martin Rees
Inside the nuclear furnace of the Sun, protons and other atomic nuclei are compressed together into a tiny region of space, where the incredible temperatures and energies try to overcome the repulsive forces of their electric charges. At a maximum temperature of 15 million K, and…
esiegel | May 27, 2016"Science is global. Einstein's equation, E=mc^2, has to reach everywhere. Science is a beautiful gift to humanity, we should not distort it." -A.P.J. Abdul Kalam
Over 100 years ago, Einstein shook up the physics world with a number of groundbreaking discoveries: special relativity, brownian motion, the photoelectric effect, and his most famous equation, E = mc^2. This mass-energy equivalence underlies everything from antimatter to atomic bombs to the process that powers the Sun.
The longer a photon's wavelength is, the lower in energy it is. But all photons, regardless of wavelength/energy,…
esiegel | May 26, 2016“[The black hole] teaches us that space can be crumpled like a piece of paper into an infinitesimal dot, that time can be extinguished like a blown-out flame, and that the laws of physics that we regard as ‘sacred,’ as immutable, are anything but.” -John Wheeler
Dark matter is one of the biggest mysteries in the Universe. We can feel its gravitation, we can see its effects on galaxies, clusters and the large-scale structure of the Universe. But when it comes to very small scales, we haven't been able to detect dark matter, either directly or indirectly, leading us to wonder at what it's…
esiegel | May 24, 2016"Reality is what kicks back when you kick it. This is just what physicists do with their particle accelerators. We kick reality and feel it kick back. From the intensity and duration of thousands of those kicks over many years, we have formed a coherent theory of matter and forces, called the standard model, that currently agrees with all observations." -Victor Stenger
The Standard Model plus General Relativity gives tremendous successes, and has so far accurately described every small-scale, quantum interaction (for the Standard Model) and every gravitational phenomenon (for General…
esiegel | May 23, 2016“Love doesn't make the world go 'round. Love is what makes the ride worthwhile.” -Franklin P. Jones
It's been such a busy time here at Starts With A Bang that we're a day late bringing you last week's recap! And we've got to get rocking on it, because there's so much coming up to consider as well! First off, the Patreon campaign is even closer to our next goal, with a total of 128 active patrons. We did a Podcast for Science By Number talking about dark matter/dark energy and inflation and expansion:
and we had a fantastic, busy week on top of that, including:
How many atoms do you share…
esiegel | May 23, 2016"The first amazing fact about gravitation is that the ratio of inertial mass to gravitational mass is constant wherever we have checked it. The second amazing thing about gravitation is how weak it is." -Richard Feynman
One of the strangest, most novel predictions of Einstein's relativity is that mass would not only curve space, but that the curved space would act like a lens. Background light traveling past this mass would become magnified, distorted and stretched. In some cases, arc, multiple images or even perfect, 360º rings would occur.
This image illustrates a gravitational lensing…
drorzel | May 21, 2016A whole bunch of physics posts over at Forbes so far this month:
--Recent Physics Books: Gravitational Waves and Brief Lessons: Short reviews of Janna Levin's Black Hole Blues and Carlo Rovelli's Seven Brief Lessons on Physics.
--The Real Reasons Quantum Entanglement Doesn't Allow Faster-Than-Light Communication: Expanding on and correcting some stuff I didn't like about Ethan "Starts With A Bang" Siegel's take on entanglement as a communications tool.
-- Why Does The Rising sun Change Color?: I watched a bunch of sunrises on the cruise, which led to me scribbling equations, and then a blog…
esiegel | May 20, 2016"To explain all nature is too difficult a task for any one man or even for any one age. 'Tis much better to do a little with certainty & leave the rest for others that come after you." -Isaac Newton
Perhaps the greatest, most successful scientific theory of the past century is Einstein's General Relativity, our theory of gravitation that has answered every challenge to it for the past 101 years with resounding success. Yet before that, Newton's gravity did the same thing for more than twice as long! The culprit that finally brought the universal theory of ground was incredible in its…
drorzel | May 19, 2016Noted grouchy person John Horgan has found a new way to get people mad at him on the Internet, via a speech-turned-blog-post taking organized Skeptic groups to task for mostly going after "soft targets". This has generated lots of angry blog posts in response, and a far greater number of people sighing heavily and saying "There Horgan goes again..."
If you want to read only one counter to Horgan's piece to get caught up, you could do a lot worse than reading Daniel Loxton's calm and measured response. Loxton correctly notes that Horgan's comments are nothing especially unique, just a variant…
esiegel | May 18, 2016"I'm a fan of supersymmetry, largely because it seems to be the only route by which gravity can be brought into the scheme. It's probably not even enough, but it's a way forward to get gravity involved. If you have supersymmetry, then there are more of these particles. That would be my favourite outcome." -Peter Higgs
The “diphoton bump” at 750 GeV is perhaps the best active signal we have for the possibility of fundamental new particles beyond the Standard Model. While the upgraded LHC should collect enough data that we’ll know by the end of the year whether it looks real or goes away, there…
drorzel | May 17, 2016It's one of those days where none of the stuff I probably ought to be writing seems even slightly appealing, so instead I'm going to do something frivolous and morale-boosting, namely think out loud about an imaginary course. Despite being on sabbatical, I do still check my work email, and have caught the edges of a new round of arguments about whether we're providing enough "Gen Ed" science courses pitched at non-majors. The hardest part of this is always meeting the "science with lab" component, because those courses are pretty resource-instensive, and we have a limited set of them that we…
esiegel | May 11, 2016“There’s no god, it’s the elements that control this world and everything on it.” -Scott A. Butler
From hydrogen through uranium and even beyond, the Universe gives us a huge variety of elements that can bond together in practically innumerable ways, creating all the matter we've ever observed in existence. Everything beyond helium in the periodic table way made inside of stars, but not all stars create elements equally.
Artist’s impression of the red hypergiant VY Canis Majoris. Our Sun will become a more modest red giant, but a giant nonetheless. Image credit: Wikimedia Commons user…
esiegel | May 3, 2016"I am become death, the destroyer of worlds." -J. Robert Oppenheimer
The nucleus of the atom holds many secrets, not the least of which is the key to the release of energy hundreds of thousands-to-millions of times more efficient than any chemical means known. In order to build and develop the first atomic bomb, a myriad of challenges needed to be overcome, including the ability to sustain a chain reaction among fissile materials.
The Uranium-235 chain reaction that leads to a nuclear fission bomb. Image credit: E. Siegel, based on the original public domain work by Wikimedia Commons user…
esiegel | April 30, 2016"Trying to understand the way nature works involves a most terrible test of human reasoning ability. It involves subtle trickery, beautiful tightropes of logic on which one has to walk in order not to make a mistake in predicting what will happen." -Richard Feynman
If you were to send a space probe to a distant star system, gather information about it and send it back to Earth, you'd have to wait years for the information to arrive. But if you have an entangled quantum system -- say, two photons, one with spin +1 and one with spin -1 -- you could know the spin of the distant one instantly by…
esiegel | April 29, 2016"Nobody grows old merely by living a number of years. We grow old by deserting our ideals. Years may wrinkle the skin, but to give up enthusiasm wrinkles the soul." -Samuel Ullman
When it comes to the Universe, there are some dead giveaways as to what its age is. Its elemental composition changes, the types of stars that are present evolve, the large-scale structure visible to us morphs, grows and ceases, and the temperature of the cosmic microwave background drops, among many other signs.
Image credit: Suzuki et al. (The Supernova Cosmology Project), accepted for publication, Ap.J., 2011.,…
esiegel | April 28, 2016"The fact that gravitational damping is measured at all is a strong indication that the propagation speed of gravity is not infinite. If the calculational framework of general relativity is accepted, the damping can be used to calculate the speed, and the actual measurement confirms that the speed of gravity is equal to the speed of light to within 1%." -Steve Carlip
According to General Relativity, the speed of gravity must be equal to the speed of light. Since gravitational radiation is massless, it therefore must propagate at c, or the speed of light in a vacuum. But given that the Earth…
esiegel | April 26, 2016"The world is the great gymnasium where we come to make ourselves strong." -Swami Vivekananda
But what does it truly mean to be strong? We have four fundamental forces in the Universe: the strong, electromagnetic, weak and gravitational forces. You might think that, by virtue of its name, the strong force is the strongest one. And you'd be right, from a particular point of view: at the smallest distance scales, 10^-16 meters and below, no other force can overpower it.
Image credit: Sloan Digital Sky Survey, of IC 1101, the largest known individual galaxy in the Universe.
But under the…
esiegel | April 23, 2016"Yes, now there is this technological path. But it's just starting." -Mae Jemison
Earlier this month, Yuri Milner and Stephen Hawking teamed up to announce the Breakthrough Starshot, a $100 million investment in technology that would build a laser array to propel a thin, light "laser sail" spacecraft to approximately 20% the speed of light. If we can achieve these speeds and sufficiently aim these sails at the nearest star systems, we'll arrive at our destinations within a single human lifetime.
Illustration of an exoplanetary system. Image credit: NASA/David Hardy, via astroart.org.
But…