esiegel | September 30, 2016“Everyone has his dream; I would like to live till dawn, but I know I have less than three hours left. It will be night, but no matter. Dying is simple. It does not take daylight. So be it: I will die by starlight.” –Victor Hugo
Whether you’re at rest or in motion, you can be confident that — from your point of view — the laws of physics will behave exactly the same no matter how quickly you’re moving. You can move slowly, quickly or not at all, up to the limits that the Universe imposes on you: the speed of light.
Light, in a vacuum, always appears to move at the same speed -- the speed of…
esiegel | September 29, 2016"Nothing in the standard cosmological model predicts this, and it is almost impossible to imagine how that model could be modified to explain it, without discarding the dark matter hypothesis completely." -David Merritt
Dark matter is a hugely successful theory for explaining a whole slew of observations about the Universe. Just by adding this one ingredient to the mix, we can successfully simulate and reproduce the large-scale structure, CMB fluctuations, galaxy clustering and cluster collision properties observed in our Universe. Without dark matter, there's no other way known to make the…
esiegel | September 28, 2016"Teaching man his relatively small sphere in the creation, it also encourages him by its lessons of the unity of Nature and shows him that his power of comprehension allies him with the great intelligence over-reaching all." -Annie Jump Cannon
A look up at the stars in the night sky shows a clear distinction: some are fainter while others are brighter, some are redder while others are bluer, some are closer while others are much farther away. But what accounts for the differences -- some real and some only apparent -- between these stars? For most of human history, not only didn’t we know,…
esiegel | September 27, 2016"Alexander Hamilton and Thomas Jefferson hated each other so much. But that hate that they had for each other did not come before the love of their country." -David Scott
You can't make America great 'again' without looking at what made us great in the first place. It wasn't industry or manufacturing or our morals or our military might; it was our investment in science, research and development that gave us the capabilities to do the extraordinary.
Mendelian genetics underlie the science of inherited traits, and are essential to choosing the best agricultural crops. Public domain image by…
esiegel | September 26, 2016"We conducted the first fully blind, three-dimensional search for cool gas in the early universe. Through this, we discovered a population of galaxies that is not clearly evident in any other deep surveys of the sky." -Chris Carilli
The Hubble Ultra Deep Field and its successor images represent humanity’s deepest views of the stars in our Universe. But there’s more to the Universe than just stars; even the normal matter in the Universe is more commonly present in the forms of gas and plasma than in stars. Hubble can never image those so far away, since their wavelengths are too long. But the…
esiegel | September 25, 2016“To study things from a scientific standpoint means to take an inventory of them—to find the process in which they are being produced; to connect them with other things; to see things in their causal process. ” -William Harris
As is pretty much always the case, it's been a big week here at Starts With A Bang! So much of what we wrote about has inspired thoughts and conversations I never could have imagined on my own, and if you missed any of what we've covered, take a look back at:
How small is an elementary particle? (for Ask Ethan),
Dark matter proved real by colliding galaxy clusters (for…
esiegel | September 24, 2016"Its continuing mission: to explore strange new worlds, to seek out new life and new civilizations, to boldly go where no one has gone before." -Star Trek, in many incarntions
When Star Trek debuted 50 years ago, we didn’t know that there would be regions of the Universe that were forever inaccessible to humanity, nor that there would be galaxies permanently unreachable to us, even if we managed to develop near-light-speed travel technology. Yet thanks to the existence and dominance of dark energy today, that’s exactly the case. The only workaround, it appears, would be to develop faster-than…
esiegel | September 23, 2016“Between cold fusion and respectable science there is virtually no communication at all. …because the Cold-Fusioners see themselves as a community under siege, there is little internal criticism. Experiments and theories tend to be accepted at face value, for fear of providing even more fuel for external critics, if anyone outside the group was bothering to listen. In these circumstances, crackpots flourish, making matters worse for those who believe that there is serious science going on here.” –David Goodstein
The dream of free, unlimited, clean energy depends only on our ability to find a…
esiegel | September 22, 2016“Alone, I often fall down into nothingness. I must push my foot stealthily lest I should fall off the edge of the world into nothingness. I have to bang my head against some hard door to call myself back to the body.” -Virginia Woolf
If you think about the Universe, what it is today, what it contains and what makes it up, it very much is “something” by any way you’ll attempt to define it. Yet every “something” we know of has an origin, and the only ultimate origin for the first “something” is that it must have come from nothing.
Visualization of a quantum field theory calculation showing…
esiegel | September 21, 2016“All I want is blackness. Blackness and silence.” -Sylvia Plath
Even on the darkest night skies from the most pristine locations on Earth, the night sky is never truly dark. Not even if you look away from the plane of the galaxy, on a moonless night, between the stars and away from any human-made or nature-made sources of illumination. Unlike the views that a telescope like Hubble can get from space, nothing on Earth is ever devoid of photons that have their origin in starlight.
The full UV-visible-IR composite of the XDF; the greatest image ever released of the distant Universe. Every…
esiegel | September 20, 2016
"Science cannot tell theology how to construct a doctrine of creation, but you can't construct a doctrine of creation without taking account of the age of the universe and the evolutionary character of cosmic history." -John Polkinghorne
What is the Universe? What are those points of light in the night sky? Are there other Suns like our own? Do they have worlds around them? What of the larger structures; what are the spirals and ellipticals out there? How far away are they? And how old is the Universe? And finally, how did it all come to be the way it is today, and how do we know?
A…
esiegel | September 19, 2016“It may be that ultimately the search for dark matter will turn out to be the most expensive and largest null result experiment since the Michelson-Morley experiment, which failed to detect the ether.” -John Moffat
Dark matter is a puzzle that’s now more than 80 years old: the presence of all the known, observable, detectable normal matter — the stuff in the standard model — cannot account for the gravitation of the astronomical objects we observe. But despite our inability to create or detect it in a laboratory, we’re certain of its existence in the Universe.
Numerical simulation of the…
esiegel | September 18, 2016“We must free ourselves of the hope that the sea will ever rest. We must learn to sail in high winds.” -Aristotle Onassis
Welcome back to the end of another big week at Starts With A Bang! There's been a lot of fantastic stories that have gone down, including:
Can stars escape from the galaxy, with planets intact? (for Ask Ethan),
Fossilized relic discovered by Hubble is a link to the Milky Way's past (for Mostly Mute Monday),
Is the cosmic distance ladder flawed?,
That's no comet; that's Pluto!,
How certain are we of the Universe's 'Big Freeze' fate, and
Was Earth born with life already on…
esiegel | September 17, 2016“When we think about the present, we veer wildly between the belief in chance and the evidence in favour of determinism. When we think about the past, however, it seems obvious that everything happened in the way that it was intended.” -Michel Houellebecq
If you take anything in the Universe and want to know what its size is, you simply take something whose length is known and compare. On microscopic scales, it isn’t much different: take something of a known wavelength -- like light or another matter particle -- and compare. If your wavelength is too big, you’ll pass right through; if your…
esiegel | September 16, 2016“When you arise in the morning, think of what a precious privilege it is to be alive — to breathe, to think, to enjoy, to love.” –Marcus Aurelius
How old is life on Earth? If all you had to go on was the fossil record, you’d run into severe trouble once you went back more than one or two billion years, as all your rock would have metamorphosed, making examination and identification of fossils impossible. But recently, we’ve discovered another method: to measure the isotopic content of carbon deposits in ancient rock formations.
Hadean diamonds embedded in zircon/quartz, some of which date to…
esiegel | September 15, 2016"Even if I stumble on to the absolute truth of any aspect of the universe, I will not realise my luck and instead will spend my life trying to find flaws in this understanding - such is the role of a scientist." -Brian Schmidt
The discovery of the accelerated expansion of the Universe -- and of dark energy behind it -- in 1998 was one of the biggest physics revolutions of our lifetime. By measuring these distant galaxies and how their distances and redshifts scale in the Universe, we were able to determine that despite everything we knew about matter and radiation, there was an additional…
esiegel | September 14, 2016“Maybe some people don't feel scared when they think about comets and supernovas. Maybe they think it is wonderful.” -Lydia Netzer
What, in our Solar System, has a long tail from boiled-off frozen ices? What simultaneously leaves an X-ray signature when the solar wind collides with those boiled-off atoms, kicking electrons out and causing X-ray emissions? If you guessed a comet, you'd be "traditionally" correct, beginning with Comet Hyakutake in 1996.
Amateur photo of Comet Hyakutake, taken in March of 1996 by John Pane. Image credit: John Pane of http://www.cs.cmu.edu/~pane/hyakutake.html…
esiegel | September 13, 2016“We can only see a short distance ahead, but we can see plenty there that needs to be done.” -Alan Turing
The Cosmic Microwave Background data gave us an unprecedented picture of our Universe in terms of accuracy, with the latest Planck results showing us our Universe is 68% dark energy, 13.8 billion years old and is expanding at a rate of 67 km/s/Mpc. Too bad, then, that the Cosmic Microwave Background isn't the only way to measure the expansion rate, and that direct measurements -- using the cosmic distance ladder -- disagree with that significantly.
A map of star density in the Milky Way…
esiegel | September 12, 2016“It matters not what someone is born, but what they grow to be.” -J.K. Rowling
From 19,000 light years away, Terzan 5 looks a lot like pretty much any globular cluster you'd expect to find: it's massive, concentrated, with a huge number of stars at right around 12 billion years of age. But mixed in there is a second population of stars just 4.5 billion years old, and tremendously represented in number as well.
This wide-field image, based on data from Digitized Sky Survey 2, shows the whole region around the stellar grouping Terzan 5. Image credit: ESO/Digitized Sky Survey 2.
We've never…
esiegel | September 11, 2016“With the first link, the chain is forged. The first speech censured, the first thought forbidden, the first freedom denied, chains us all irrevocably.” -Aaron Satie, Star Trek
It’s been a remarkable week at Starts With A Bang, and I'm especially proud of the stories we've run on Proxima b, Hubble's limits, the dream of Warp Drive and the Cosmic Neutrino background. If you missed any of them (or any of the others), here's what the past week has held:
When will the Sun make Earth uninhabitable? (for Ask Ethan),
What is the biggest black hole as seen from Earth? (for Mostly Mute Monday),
Ten…