The biggest stars in our universe are some of the most fascinatingly complex objects to inhabit the cosmos. Indeed,giant stars have defied full explanation for decades. Especially when they’re near the end of their lives.
Stars power themselves through nuclear fusion, from the smashing together of lighter elements into heavier ones. This process leaves behind a little bit of extra energy. It’s not much, but when those fusion reactions occur at millions or billions of times every single second, it’s enough to keep a star powered for…millions or billions of years.
In fact, you’re doing it right now. Every single second of every single day you are advancing into your own future. You are literally moving through time, the same way you would move through space. It may seem pedantic, but it’s a very important point. Movement through time is still movement, and you are reaching your own future (whether you like it or not).
If you look out on the sky on a nice clear dark night, you’ll see thousands of intense points of light. Those stars are incredibly far away, but bright enough to be seen with the naked eye from that great distance – a considerable feat. But what you don’t see are all the small stars, the red dwarfs, too small and dim to be seen at those same distances.
In response to the Covid-19 global pandemic, schools and universities around the world have shut their doors and told their students to go home. Most of them continued their educational mission, but through remote remote learning platforms rather than in-person lectures.
Some of these universities and schools maintained this status for only a few weeks, while some kept this as the default state for the rest of their spring semester.
The full ramifications of the recent novel coronavirus pandemic are not yet known, and probably won’t be known or even felt for quite some time. Entire industries have been shifted and shuttered over the course of only a few tumultuous weeks due to Covid-19. Some industries and professions have been able to adapt quickly, some have had to close down or to send their workers home, while others are faltering and collapsing.
Time travel into the past is a tricky thing. We know of no single law of physics that absolutely forbids it, and yet we can’t find a way to do it, and if we could do it, the possibility opens up all sorts of uncomfortable paradoxes (like what would happen if you killed your own grandfather).
But there could be a way to do it. We just need to find a wormhole first.
In the image, the Earth hangs serenely in between BepiColumbo’s magnetometer boom (on the right) and its medium-gain antenna (on the left).
But the Earth flyby wasn’t without its tense moments. The spacecraft relies on solar power, and during the loop around Earth it had to spend some time in our planet’s shadow – and out of the sun. To prepare, the mission scientists made sure that BepiColombo was fully charged and nice and warm before the maneuver.
And on April 10, the date of the flyby, it all went swimmingly.
The spacecraft is on a long, winding journey sunwards towards the smallest planet in the solar system, making loop after loop first around Earth, then Venus a couple times, then Mercury itself half a dozen times before parking itself in orbit. The frequent loops are necessary because at launch BepiColombo was traveling at the same speed as the Earth in its orbit (29.78 km/s), and needs to match that of Mercury (47.36 km/s), and it does so by borrowing some energy from the planets themselves.
Once BepiColombo reaches Mercury, it will separate into two individual probes: the Mercury Planetary Orbiter and the Mercury Magnetospheric Orbiter. The twin orbiters will attempt to answer several challenging riddles about the planet nearest to the sun, like the origins of Mercury’s faint-but-still-there magnetic field and atmosphere, and the craters pitting its surface.
But it will take a long time to get there. BepiColombo’s final arrival at Mercury isn’t scheduled until December of 2025, showing how reaching the inner planets of our system can be sometimes more difficult than journeys outward – it turns out that doing planetary dances is more challenging than you might think.
Bacteria come in two basic forms: the kinds that use a lot of hydrogen, and the kinds that don’t. And recently researchers think they’ve found a new bacteria that appear to do both at the same time, allowing it to live in a variety of extreme environments, like the ocean floor.
Its name is Acetobacterium woodii, often shortened to A. woodii, and it seems like it’s a superhero of the small-sized world.
Gravity was the first force of nature to be realized, and in the centuries since we first cracked the code of that all-pervasive pulling power, scientists have continually come up with clever ways to test our understanding. And it’s no surprise why: the discovery of a new wrinkle in the gravitational force could open up vistas of new physics, and maybe even the nature of reality itself.
As the COVID-19 disease continues to wreak its viral havoc on the human population of Earth, governments around the world have closed their schools, shut down non-essential businesses, and told their citizens to stay at home as much as possible. In other words, there’s a lot less human activity on our planet, and it’s led to a detectable drop in seismic activity.