Thursday Throughput: Distant Star Edition

This detailed view highlights the star Earendel’s position along a ripple in space-time (dotted line) that magnifies it and makes it possible for the star to be detected over such a great distance—nearly 13 billion light-years. Also indicated is a cluster of stars that is mirrored on either side of the line of magnification. The distortion and magnification are created by the mass of a huge galaxy cluster located in between Hubble and Earendel. The mass of the galaxy cluster is so great that it warps the fabric of space, and looking through that space is like looking through a magnifying glass—along the edge of the glass or lens, the appearance of things on the other side are warped as well as magnified.
Credits: Science: NASA, ESA, Brian Welch (JHU), Dan Coe (STScI); Image processing: NASA, ESA, Alyssa Pagan (STScI).

[ThTh1] Even the biggest telescopes can only peer so far into the universe. As objects become more distant from the Earth, their brightness falls off as the distance squared. An object a thousand times further away is a million times fainter. As a result, we can only, for example, see stars out to a few million light years. Even supernovae can only be seen out to about 50 million light years.

There is one solution though. When the lens of your telescope isn’t powerful enough to visualize the deep universe, use the universe itself as your lens:

NASA’s Hubble Space Telescope has established an extraordinary new benchmark: detecting the light of a star that existed within the first billion years after the universe’s birth in the big bang – the farthest individual star ever seen to date.

The find is a huge leap further back in time from the previous single-star record holder; detected by Hubble in 2018. That star existed when the universe was about 4 billion years old, or 30 percent of its current age, at a time that astronomers refer to as “redshift 1.5.” Scientists use the word “redshift” because as the universe expands, light from distant objects is stretched or “shifted” to longer, redder wavelengths as it travels toward us.

The newly detected star is so far away that its light has taken 12.9 billion years to reach Earth, appearing to us as it did when the universe was only 7 percent of its current age, at redshift 6.2. The smallest objects previously seen at such a great distance are clusters of stars, embedded inside early galaxies.

…

The research team estimates that Earendel is at least 50 times the mass of our Sun and millions of times as bright, rivaling the most massive stars known. But even such a brilliant, very high-mass star would be impossible to see at such a great distance without the aid of natural magnification by a huge galaxy cluster, WHL0137-08, sitting between us and Earendel. The mass of the galaxy cluster warps the fabric of space, creating a powerful natural magnifying glass that distorts and greatly amplifies the light from distant objects behind it.

One of the realizations of Einstein is that gravity warps the fabric of spacetime — like a bowling ball sitting on a sheet of rubber. It creates divots and warps that change the paths of objects, including light. This was confirmed by Arthur Eddington in 1919 when he observed that stars behind the Sun shifted their position during a solar eclipse, thanks to the Sun’s gravity bending their light. We’ve also seen stars shift and blink when massive objects like black holes pass in front of them.

But the most spectacular lensing occurs in distant galaxies, when the light of background objects aligns just right so that the gravitational field of the galaxy lenses the image. You can get Einstein crosses like so:

Einstein Cross,a gravitationally lensed quasar that sits directly behind the centre of the galaxy ZW 2237+030

Or perfect circles like this:

The image of a blue galaxy is lens by a foreground red galaxy.

Or, if you’ve seen Interstellar, you’ll remember that black hole in that movie had a halo around it. That halo was actually the far side of the disk surrounding the black hole lensed into a halo by the intense gravitational field.

It’s an amazing coincidence to get such a perfect alignment but … it’s a big universe. And hopefully the image will be good enough for JWST to get some more information on one of the earliest stars in the universe, a subject about which we know every little.

[ThTh2] David Wallace-Wells does a deep dive into how we’ve done on COVID-19. He first addresses the “science is changing thing”, about how the healthcare community’s advice changes from time to time.

Our experience of the pandemic has been littered with bad-faith argumentation and instigation, but most of these narrative reversals are not that, or even signs of what Harvard’s William Hanage has called the “motivated reasoning” of the pandemic. One narrative replacing another is one description of the scientific method, and among the many astonishing features of this pandemic is how quickly science was able to process and respond — perhaps without adequate speed, but at least fast enough for vaccines to be designed within two days, manufactured within two months, and rolled out to the vast majority of the world within two years. But the unsteady narratives of COVID-19 are reminders that, as sure as we might have been about how to interpret our experience of it, the stories we told ourselves about what we were dealing with and what we should be doing to protect ourselves were often incomplete, clouded by much more uncertainty and ignorance, wishful thinking and reflexive panic, than we were ever comfortable acknowledging.

But after that, gets into one stat that has been an unwavering guidepost to how we’re doing: excess deaths. 2021 saw more Americans die from COVID-19 than 2020. Moreover, 2021 saw America deviate from her peers. In 2020, our deaths-per-capita were not that much worse than many of our peer nations. But in 2021, we were significantly worse. Over the course of the year, our COVID-19 deaths doubled while European countries saw much smaller increases. The difference? Vaccines. While Americans did OK on the initial round, only 29% of Americans have gotten the booster, a level half of what was seen in Europe. As a direct result, the Omicron wave was far deadlier in the United States than it was in other developed countries (a pattern we are now seeing as Omicron spreads across Asia; poorly vaccinated countries are having ten times the number of deaths as well-vaccinated countries).

There’s a lot of blame to throw around here. Republicans have opposed vaccine mandates and many voices have scare-mongered about vaccines. Employers were reluctant to require boosters and our government did a poor job of encouraging them. The press reported the Omicron was mild without noting that it was only “mild” for those previously exposed or vaccinated.

However you disperse the blame, it’s clear that it didn’t have to be this way. Hundreds of thousands of Americans did not have to die. And we should be focusing very heavily on this right now because COVID-19 is not done with us.

[ThTh3] Wow.

Crash dive of a Kingfisher
Photographer took the perfect picture of diving kingfisher after six years and 720,000 shots to get it right.
Photo: Mario Cea Sanchez pic.twitter.com/VBnsE3IQd1

— dominic dyer (@domdyer70) March 30, 2022

[ThTh4] In other COVID-19 news, Ivermectin still doesn’t work.

[ThTh5] This week, a thread went viral on the mercury thrusters being used by SpaceX and other satellites and whether this represents a danger. Mercury is heavy and so you get a lot of thrust from releasing it. But it’s also heavy so it will return to Earth. There is concern that this could be a dangerous biotoxin.

While I agree that this is a concern, it’s important to keep things in perspective. The most recent analysis indicates that the amount of mercury the satellites would deposit on Earth is about 1% of the mercury we’re spewing out right now with fossil fuel consumption and other sources of industrial mercury (although they do warn that the species of mercury could be more easily bio-accumulated). So while this is a concern, it’s not the end of the world. My bigger concern, actually, would be failed launch that drops 100 kg of this stuff into a small area. And if mercury in the environment concerns you — and it should — phasing out fossil fuels would be a much more fruitful approach.

That said, I agree that we shouldn’t be using a horrifying toxin as rocket fuel.

[ThTh6] Do not try this at home.

A really dramatic example of the Leidenfrost effect

the moisture on his skin boils instantly, forming a layer of steam that insulates for a very short time, a temporary barrier between this person and the molten metal pic.twitter.com/USwGCRlj5Q

— Science girl (@gunsnrosesgirl3) March 29, 2022

[ThTh7] Scary headline of the week.

[ThTh8] A very old film describing what Martian scientists would conclude about this planet. Their model of reproduction is a pretty accurate description of what IVF is like, though.