Scientists Solve The Mystery Of STEVE, And Find It’s So Much More Than An Aurora
“Normally, aurorae are produced by the Sun’s charged particles striking the atoms in Earth’s upper atmosphere. The solar wind particles get bent by Earth’s magnetic field, exciting and ionizing oxygen, nitrogen, and hydrogen. When electrons recombine with ions, they cascade back down to lower energies, creating aurorae from their emission lines. STEVE is distinct from this for multiple reasons.”
It isn’t often that a naked-eye skywatcher gets a chance to observe an entirely new optical phenomenon that’s never been seen or recorded before. Yet earlier this century, that’s exactly what’s happened with a purple/green/mauve ribbon of light that sometimes appears in the sky. Known as STEVE, for strong thermal emission velocity enhancement, this ribbon includes colors never seen in an aurora, appears at lower latitudes than those where aurorae are typically found, and most importantly, isn’t created coincident with the precipitation of charged particles. In other words, it’s an entirely new phenomenon!
Ask Ethan: How Well Has Cosmic Inflation Been Verified?
“To what margin of error or what level of statistical significance would you say you say inflation has been verified?”
So, you’ve got an alternative theory to our best mainstream scientific ideas? Well, guess what: those are the same shoes that every scientific idea we accept today were wearing at one point in the distant past. The thing that separates them from the ideas that fell by the wayside were three remarkable feats:
1. They reproduced all the earlier successes of the previous prevailing model. 2. They resolved or explained puzzles or problems that the previous model had no sufficient answer for. 3. And, perhaps most importantly, they made new predictions that we could go out and test about the Universe, and those predictions were proven correct by the appropriate experimental or observational test.
When Did The Universe Become Transparent To Light?
“The Universe became transparent to the light left over from the Big Bang when it was roughly 380,000 years old, and remained transparent to long-wavelength light thereafter. But it was only when the Universe reached about half a billion years of age that it became fully transparent to starlight, with some locations experiencing transparency earlier and others experiencing it later.
To probe beyond these limits requires a telescope that goes to longer and longer wavelengths. With any luck, the James Webb Space Telescope will finally open our eyes to the Universe as it was during this in-between era, where it’s transparent to the Big Bang’s glow but not to starlight. When it opens its eyes on the Universe, we may finally learn just how the Universe grew up during these poorly-understood dark ages.”
There are two ways that astrophysicists talk about the Universe becoming transparent. The first is when the particles from the Big Bang finally form neutral atoms, becoming “transparent” to the leftover photons from that era. The second is hundreds of millions of years later, when those same neutral atoms are reionized, and starlight can travel freely through intergalactic space. Which one is right? When did the Universe become transparent to light?
We Have Now Reached The Limits Of The Hubble Space Telescope
“Finally, there are the wavelength limits as well. Stars emits a wide variety of light, from the ultraviolet through the optical and into the infrared. It’s no coincidence that this is what Hubble was designed for: to look for light that’s of the same variety and wavelengths that we know stars emit.
But this, too, is fundamentally limiting. You see, as light travels through the Universe, the fabric of space itself is expanding. This causes the light, even if it’s emitted with intrinsically short wavelengths, to have its wavelength stretched by the expansion of space. By the time it arrives at our eyes, it’s redshifted by a particular factor that’s determined by the expansion rate of the Universe and the object’s distance from us.
Hubble’s wavelength range sets a fundamental limit to how far back we can see: to when the Universe is around 400 million years old, but no earlier.”
The Hubble Space Telescope, currently entering its 30th year of service, has literally revolutionized our view of the Universe. It’s shown us our faintest and most distant stars, galaxies, and galaxy clusters of all. But as far back as it’s taken us, and as spectacular as what it’s revealed, there is much, much more Universe out there, and Hubble is at its limit.
What Was It Like When Mammals Evolved And Rose To Prominence?
“65 million years ago, 99.5% of the Universe’s history had already unfolded, and yet the ancestors of modern humans were no better developed than a modern-day lemur. Complex, differentiated animals had already existed for half-a-billion years, but it seems to be mere chance that led to the rise of an intelligent, technologically-advanced species like us. We do not yet know what secrets other planets hold as far as life goes, but here on Earth, the most remarkable story of all was just getting truly interesting.”
It was some 550-600 million years ago that life’s complexity exploded, at least in the fossil record, at the start of the Cambrian period. While that epoch marks
the first complex, differentiated, macroscopic, multicellular, sexually-reproducing animals arising and dominating the oceans, life would go on to develop traits that were absolutely necessary for eventually giving rise to human beings. Animals developed spinal cords, four limbs, moved onto land, became warm-blooded, and more. Most importantly, many such creatures were able to survive enormous extinction events, enabling them to rise to prominence when a previously-occupied niche opened up.
Cosmology’s Only Big Problems Are Manufactured Misunderstandings
“We should always be aware of the limitations of and assumptions inherent to any scientific hypothesis we put forth. Every theory has a range of established validity, and a range where we extend our predictions past the known frontiers. A theory is only as good as the verifiable predictions it can make; pushing to new observational or experimental territory is where we must look if we ever hope to supersede our present understanding.
But we mustn’t forget or throw out the existing successes of General Relativity, the expanding Universe, the Big Bang, dark matter, dark energy, or inflation. Going beyond our current theories includes — as a mandatory requirement — encompassing and reproducing their triumphs. Until a robust alternative can reach that threshold, all pronouncements of “big problems” with the prevailing paradigm should be treated for what they are: ideologically-driven diatribes without the requisite scientific merit to back them up.”
It might seem like no fun to you: to look at all the imaginative alternative explanations to the mainstream scientific thought and declare them all to be insufficient. You might wonder where my imagination is, and what kind of lousy scientist I must be to deride all of these alternative ideas as obviously wrong, and to stick so closely to the prevailing orthodoxy. To an outsider, it might seem like I’m tremendously foolish. But to someone who understands what a scientific theory has to do, you’ll immediately recognize that there are thresholds one needs to surpass to bring about a scientific revolution, If you cannot meet those criteria, you don’t get to play in the same league.
Today Marks The Anniversary Of Neil Armstrong’s Near-Fatal Lunar Landing Vehicle Crash
“Softly landing on the Moon, with no horizontal motion and only slight vertical motions, was a tremendous problem facing NASA. There was no computerized guidance or high-resolution maps of the lunar landing site. The eventual lunar module pilot would have to navigate the touchdown manually. Armstrong was training in Lunar Landing Research Vehicle #1 on May 6, 1968, when something went horribly awry.”
A year prior to the Apollo 11 Moon landing, Neil Armstrong was undergoing his 22nd test flight in the Lunar Landing Research Vehicle, the test vehicle for NASA’s Lunar Module. Designed to simulate lunar gravity here on Earth, with vertical takeoff and landing capabilities, it was the ultimate way to train for one of the most essential parts of the mission: landing on the Moon.
But 51 years ago today, something went horribly wrong. Engineers would later determine that a problem with helium pressure, causing the hydrogen peroxide on board to become depleted and leading to a fuel imbalance and the eventual failure of the reserve attitude thrusters. From a height of approximately 200 feet and with no warning, Armstrong ejected.
Ask Ethan: How Does The Event Horizon Telescope Act Like One Giant Mirror?
“I’m having difficulty understanding why the EHT array is considered as ONE telescope (which has the diameter of the earth). When you consider the EHT as ONE radio telescope, I do understand that the angular resolution is very high due to the wavelength of the incoming signal and earth’s diameter. I also understand that time syncing is critical. But it would help very much to explain why the diameter of the EHT is considered as ONE telescope, considering there are about 10 individual telescopes in the array.”
Humanity has imaged a black hole’s event horizon! It’s been less than a month since the news was announced, and it’s still hard to get over what a phenomenal achievement it was. It’s very difficult to conceive of how, though, we can treat 8 different telescopes and telescope arrays, all stitched together, as acting like a single giant mirror. But that’s exactly what the Event Horizon Telescope did. In fact, that’s what it needed to do, or it would never have been able to achieve the resolutions necessary to construct the first image of a black hole’s event horizon.