Author: The Conversation

Elon Musk announced that “the bird is freed” when his US$44 billion acquisition of Twitter officially closed on Oct. 27, 2022. Some users on the microblogging platform saw this as a reason to fly away. Over the course of the next 48 hours, I saw countless announcements on my Twitter feed from people either leaving the platform or making preparations to leave. The hashtags #GoodbyeTwitter, #TwitterMigration and #Mastodon were trending. The decentralized, open source social network Mastodon gained over 100,000 users in just a few days, according to a user counting bot. As an information scientist who studies online communities, this felt like the…

Tech platforms use recommender algorithms to control society’s key resource: attention. With these algorithms they can quietly demote or hide certain content instead of just blocking or deleting it. This opaque practice is called “shadowbanning”. While platforms will often deny they engage in shadowbanning, there’s plenty of evidence it’s well and truly present. And it’s a problematic form of content moderation that desperately needs oversight. What is shadowbanning? Simply put, shadowbanning is when a platform reduces the visibility of content without alerting the user. The content may still be potentially accessed, but with conditions on how it circulates. It may no longer appear as a…

If you surfed the web this morning, you may have seen news of the latest existential threat to humanity: a “planet killer” asteroid named 2022 AP7. Luckily for us 2022 AP7 “has no chance to hit the Earth currently”, according to Scott Sheppard at the Carnegie Institution for Science. He and his international team of colleagues observed 2022 AP7 in a trio of “rather large” asteroids obscured by the Sun’s glare (the other two don’t pose a risk). 2022 AP7 orbits the Sun every five years, and currently crosses Earth’s orbit when Earth is on the other side of the Sun to it. Eventually…

Hidden in the minerals and textures that make up rocks are clues about how and when they formed and were later altered. These changes can occur due to the presence of water-rich fluids and may also be influenced by biological processes. We are planetary petrologists (rock scientists) and participating scientists on the Mars 2020 Perseverance rover mission. Our research involves exploring and interpreting the data sent back by the Perseverance rover from its landing site in Jezero Crater. A mysterious lake Orbital images show that Jezero Crater was once the site of a standing body of water. It held a lake that was…

All stars, including the Sun, have a finite lifetime. Stars shine by the process of nuclear fusion in which lighter atoms, such as hydrogen, fuse together to create heavier ones. This process releases vast quantities of energy which counteracts the ever-present inward pull of the star’s gravity. Ultimately, fusion helps stars to resist gravitational collapse. This balance of forces is called “hydrostatic equilibrium”. However, there will come a time when the supply of fuel in the core of a star starts to run out and it eventually dies. Stars with more than about eight times the mass of the Sun…

If an alien were to look at Earth, many human technologies – from cell towers to fluorescent light bulbs – could be a beacon signifying the presence of life. We are two astronomers who work on the search for extraterrestrial intelligence – or SETI. In our research, we try to characterize and detect signs of technology originating from beyond Earth. These are called technosignatures. While scanning the sky for a TV broadcast of some extraterrestrial Olympics may sound straightforward, searching for signs of distant, advanced civilizations is a much more nuanced and difficult task than it might seem. Saying ‘hello’ with radios and lasers The modern…

A quick look at some TikTok stats shows more than 38,000 posts under the hashtag #Autism, with more than 200 million views. The hashtag #ActuallyAutistic (which is used in the autism community to highlight content created by, and not about, autistic people) has more than 20,000 posts and 40 million views. TikTok is one of the world’s leading social platforms, and has exploded in popularity at a time when other social media megaliths have struggled. It has become an important channel for expression for its young usership – and this has included giving autistic people a voice and community. It’s a good start. In some…

New details have emerged on the severity of the Medibank hack, which has now affected all users. Optus, Medibank, Woolworths, and, last Friday, electricity provider Energy Australia are all now among the household names that have fallen victim to a data breach. If it seems like barely a week goes by without news of another incident like this, you would be right. Cybercrime is on the rise – seven major Australian businesses were affected by data breaches in the past month alone. But why now? And who is responsible for this latest wave of cyber attacks? In large part, the increasing number of data breaches…

In recent years, cafes, supermarkets and online shops have started to trial drone delivery in a handful of locations around the world. More than a dozen drone delivery companies are now running such trials. Just this week, Wing (owned by Google’s parent company Alphabet) announced a partnership with Australian supermarket giant Coles to deliver small items via drone to customers close to a Gold Coast supermarket. Wing is already operating in parts of Canberra and Logan, Queensland. Given the technical success of various trials so far, it is worth exploring whether drone delivery might become mainstream and can actually be scaled up geographically.…

The study of exoplanets, worlds which orbit stars other than our sun, is currently being transformed by the new James Webb Space Telescope (JWST). We will shortly gain our first insight into conditions on rocky, potentially Earth-like worlds beyond our solar system. One of these distant worlds might host life. But could we detect it? We may be able to spot signs of life in the composition of the planet’s atmosphere. We can use a technique called transmission spectroscopy – which divides up light by its wavelength – to search for traces of different gases in starlight as it passes through a planet’s atmosphere.…