“In approximately 2 weeks, another batch of 60 Starlink satellites will be launched, followed by another batch approximately 2-3 weeks later. At this point, the only things that can stop the launches are either a successful legal action or a reaction from the public that’s so negative and so strong that SpaceX and Elon Musk are forced to behave more responsibly. Otherwise, the allure of putting billions of dollars worth of infrastructure in space to support a burgeoning industry that promises to crest 12 figures by 2030 will be the only driving force that matters.
As Professor Karen Yeung has pointed out, “Firms lack sufficient incentives to set, comply with, police and punish violations of their own standards, and markets cannot ensure that firms will behave with integrity.” The night sky belongs to all of us here on Earth, and it’s up to all of humanity — not the questionable ethical compass of one mega-billionaire — to ensure that it isn’t taken from us.”
Beginning in about 2 weeks, SpaceX will begin launching 60 new Starlink satellites every 2-3 weeks until all 1,584 first-round satellites are up, which will occur at some point during 2020. These satellites have not met astronomers’ needs or demands, and represent more than a 100% increase in the number of active satellites in low-and-medium Earth orbit. Unless we collectively act to stop them before that launch happens, we will lose the night skies as we know them.
This Is How Astronomers Know The Age Of The Universe (And You Can, Too)
“The reason that we can claim the Universe is 13.8 billion years old to such enormous precision is driven by the full suite of data that we have. A Universe that expands more quickly needs to have less matter and more dark energy, and its Hubble constant multiplied by the age of the Universe will have a larger value. A slower-expanding Universe requires more matter and less dark energy, and its Hubble constant multiplied by the age of the Universe gets a smaller value.
However, in order to be consistent with what we observe, the Universe can be no younger than 13.6 billion years and no older than 14.0 billion years, to more than 95% confidence. There are many properties of the Universe that are indeed in doubt, but its age isn’t one of them. Just make sure you take the Universe’s composition into account, or you’ll wind up with a naive — and incorrect — answer.”
Earlier this year, there was a report that the Universe could have been a billion years younger than we currently think. Many people still think that you can calculate the age of the Universe directly from the Hubble constant. And even though the concept of the age of the Universe is a simple one to understand, the pitfalls are so numerous that even Nobel Laureates can fall into them.
This Is How Eta Carinae Survived A Near-Supernova Eruption
“In all of astronomy, no stellar event releases more energy than a supernova. Humanity hasn’t witnessed a naked-eye supernova within our galaxy since 1604, but Eta Carinae came close. In 1843, it brightened to become the second brightest star in the sky, gradually fading away by 1857. Almost as much energy was released as in standard supernovae, but Eta Carinae remained intact.”
Over the past 400 years, the brightest object to appear in humanity’s night sky wasn’t a supernova, but rather a supernova impostor. These events are extremely rare compared to supernovae, yet we happened to get lucky enough to discover one just 7,500 light-years away. When we look at it today, we see the remnants of a large ejection, where 10-20 solar masses of material were expelled from a star that still totals more than 100 solar masses. For a long time, it was an absolute mystery how this could have occurred, but 2005-era observations revealed a binary companion with unusual properties, leading to a fascinating suggestion: perhaps a third star was devoured, causing the outburst and the subsequent ejection of matter.
Ask Ethan: Do Ancient Galaxies Get Magnified By The Expanding Universe?
“Do ancient galaxies appear larger to us than they really were, due to the expansion of the Universe? If so, then by how much?”
It seems like the simplest, most straightforward idea in the world: the farther away an object is, the smaller it appears. View the same object when it’s twice as far away, and it will only appear to be half as large in terms of angular size. Place it ten times as far away, and you’ll see it appear just one-tenth the size.
But this is only true in flat, static space. In the expanding Universe, this relationship falls apart, particularly when you factor in dark energy. More distant objects appear smaller the farther away you look, but only to a point. Galaxies that are about 14-to-15 billion light-years away will appear the smallest, and then the same-sized galaxy will actually appear larger the farther away you look! This may be counterintuitive, but there’s real, solid science to back it up.
This Is How Quantum Physics Creates The Largest Cosmic Structures Of All
“If not for quantum physics, the Universe would have been born perfectly smooth, with every region of space having the exact same temperature and density as every other region. As time went on, we would still have matter win out over antimatter, form the light elements through nucleosynthesis, and then create neutral atoms as the Universe expanded and cooled.
But we wouldn’t form stars and galaxies the way our Universe did. It would take many billions of years for even the first ones to form: many hundreds of times longer than we actually see. The existence of enormous galaxy clusters and a large-scale cosmic web would be forbidden, as the seeds of structure wouldn’t be there for them to grow. And dark energy would be the final nail-in-the-coffin, preventing the largest structures from ever forming.
The only reason we have them at all is because of the quantum nature of our Universe. It’s only because of the connection between the smallest and the largest scales — the quantum and the cosmic — that we can make sense of our Universe at all.”
Have you ever looked at maps of the Universe on the largest scales and seen galaxies clumped and clustered together along filamentary lines, with enormous nexuses separated by vast cosmic voids? That’s known as the large-scale structure of the Universe. Have you ever wondered why it looks the way it does?
Advanced LIGO Just Got More Advanced Thanks To An All-New Quantum Enhancement
“The current observing run of LIGO has been going on since April of this year, and there are already more than double the number of candidate signals than the total number of signals from all previous runs combined. This isn’t due to using the same instruments for longer periods of time, but owes this newfound success to some very exciting upgrades, including this clever new technique of squeezed quantum states.
For decades, scientists have had the idea to leverage squeezed quantum states to reduce the quantum uncertainty in the most important quantities for gravitational wave detections. Thanks to hard work and remarkable advances made by the LIGO Scientific Collaboration, this new, third observing run is already seeing more success than any gravitational wave detector in history. By reducing the phase uncertainty in the quantum vacuum that LIGO’s photons experience, we’re in exactly the right position to make the next great breakthrough in astrophysics.”
Did you know that LIGO and Virgo have been engaged in a new observing run since April of this year? Have you heard that the new run is up to 50% more sensitive than prior runs? That’s true, and it’s due to a number of improvements in noise reduction, including one fascinating way to leverage and control how quantum uncertainty plays out. These squeezed quantum states enable you to put the uncertainty where you most want it, and measure the corresponding quantity even more precisely as a result.
This Is Why Scientists Will Never Exactly Solve General Relativity
“One of the most valuable lessons I ever got in my life came during the first day of my first college math class on differential equations. The professor told us, “Most of the differential equations that exist cannot be solved. And most of the differential equations that can be solved cannot be solved by you.” This is exactly what General Relativity is — a series of coupled differential equations — and the difficulty that it presents to all those who study it.
We cannot even write down the Einstein field equations that describe most spacetimes or most Universes we can imagine. Most of the ones we can write down cannot be solved. And most of the ones that can be solved cannot be solved by me, you, or anyone. But still, we can make approximations that allow us to extract some meaningful predictions and descriptions. In the grand scheme of the cosmos, that’s as close as anyone’s ever gotten to figuring it all out, but there’s still much farther to go. May we never give up until we get there.”
In our best theory of gravity, General Relativity, we can compute to arbitrary accuracy the effects on matter of any spacetime that we can write down. Unfortunately, most of the spacetimes that we can dream up in our head aren’t ones that we can write down, and most of the ones that we can write down can only be solved approximately, not exactly.
Sorry Science Fans, Discovering A 70-Solar-Mass Black Hole Is Routine, Not Impossible
“Astronomers aren’t perplexed by this object (or similar ones to it) at all, but rather are fascinated with uncovering the details of how they formed and how common they truly are. The mystery isn’t why these objects exist at all, but rather how the Universe makes them in the abundances we observe. We don’t falsely generate excitement by spreading misinformation that diminishes our knowledge and ideas prior to this discovery.
In science, the ultimate rush comes from discovering something that furthers our understanding of the Universe within the context of everything else we know. May we never be tempted to pretend anything else is the case.”
Did you hear about this “impossible” black hole that “perplexes” astronomers and “defies” theory? If you followed the news cycle last week, that’s probably what you’ve heard. But the truth is far more interesting, and includes facts like:
-this is the fourth black hole we’ve found like it, not the first, -there are two other ways to make black holes that would explain this object in addition to the one way that can’t, -and that we’ve seen each and every one of the steps necessary to make a black hole like this, -but that finding this black hole with this particular method really is revolutionary?
“1.) Galaxy pair AM 2026-424. With two massive galaxies colliding head-on, an intermediate ring of blue stars appears before the inevitable final merger.”
In 1990, the Hubble Space Telescope was launched, providing humanity with unprecedented views of the Universe. Each and every year, with 2019 marking the 30th consecutive year, a series of images get produced that shed light on some aspect of our Universe in unprecedented fashion. Despite Hubble’s big gyroscope failure (and scare) at the end of last year, 2019 has turned out to be no exception, with 10 spectacular new images and 7 almost-as-spectacular honorable mentions.