Time travel may be fit for machines only (1)
None of the methods of time travel discussed holds any hope for objects like human bodies to be able to do it. And why travel in time anyway(14/21 December 2024, p 54)?
Even assuming it were possible, the dangers would be enough to make it unthinkable: diseases to which one had no immunity, for instance. Not to mention the risk of being involved in complex and probably fatal social situations. Above all, the logical puzzles of doing something like causing the death of one’s own grandfather is enough to stop the enterprise.
A better bet would be information transfer. Isn’t this more likely to be possible? One can imagine miniaturisation reaching a point where we can make cameras that are small enough to go through a wormhole and transmit data.
This would also address an issue often raised by sceptics. If time travel is possible, people at some point in the future will achieve it. So where are they? Well, if tiny cameras have already been sent back to see what we are up to, we may be surrounded all the time by hundreds of them.
Time travel may be fit for machines only (2)
We don’t have to go to the past, we just need to send data to the past. Perhaps 2025 will be the year that I get the message I am hoping to send to myself with the names of the Grand National horse race winners for the next 10 years.
Also time to ditch the pink and blue nonsense
I enjoyed your take on the worthiness of toys and especially agree with the advice to make sure kids have access to all types of toy, not just those traditionally associated with biological sex. My 5-year-old granddaughter is going through a unicorn and Barbie phase, but still enjoys dinosaurs, trucks, diggers, marble runs, farm animals and the rest that she owns. She likes to see motorbikes, cranes and aeroplanes (14/21 December 2024, p 62).
In the same vein, it is unlikely that a preference for pink or blue is genetic in any way. Up until a century or so ago in Western culture, blue was associated with girls and pink and red with boys. How this swapped is an interesting historical tale for another day.
Not-so-invisible gorillas: another explanation
Ian Phillips considers distrust of one’s senses to be the most likely explanation for subjects denying having seen anything unusual in a video despite an unexpected object popping up, even if they could nevertheless convey some details of it. Alternatively, could it be to do with the phenomenon of blindsight? Visual processing involves many layers and brain regions. In blindsight, damage to one area can result in not being aware of any visual image yet still being able to guess the colours and locations of objects correctly (23 November 2024, p 12).
Fate of polar ice should worry us all
Your story “Antarctic ice is at a crisis point” should be a five-alarm wake-up call for the entire planet (7 December 2024, p 8).
The fact that Earth is warming at a worrying rate shouldn’t really be a big surprise, though: 3 million years ago, when carbon dioxide in the atmosphere was at 400 parts per million, the world was 3 to 4掳C warmer than now and sea levels up to 24 metres higher. There is no practical way to pull excess CO2 out of the atmosphere, so this is where we are taking our planet.
However, we are now beyond 400 ppm, and emissions haven’t declined despite big investments in wind and solar, so atmospheric CO2 looks set to be far higher by the end of the century.
I fear there may be more to the upsides of a scare
A study of haunted house visitors showed that of 22 people with elevated inflammation, 18 had reduced levels three days after getting a good scare at the fairground attraction. But there was no control group of people with inflammation who didn’t visit a haunted house. Would they have improved in three days, regardless? It is telling that the original paper notes that seven people without inflammation before the event had acquired it three days later. Maybe just a “three-day bug” going around(7 December 2024, p 12)?
Could alien tectonics be closer than we think?
Instead of looking for evidence of tectonics on distant exoplanets, wouldn’t it be easier to look instead on Mercury? While not tidally locked, it experiences a very large temperature range of more than 600掳C from its day to night side, and its day side remains in sunlight for many Earth months at a time. This compares with the suggestion that tidally locked exoplanet LHS 3844 b has a sunlit-to-dark-side temperature range of 770掳C, and is expected to exhibit tectonic movement (7 December 2024, p 38).
Tectonic movement on Mercury, if it occurs, should be from equator to cooler poles. A very precise scan of Mercury’s surface compared with a future scan will show any movement. A lander that could detect “mercuryquakes” would also be an ideal way to investigate.
To tame urban heat, cut vehicle numbers
The first step in reducing urban heat should be to reduce the burning of fuels. All of the energy used in vehicles eventually ends up as heat. Some of the fuel’s energy is used for propulsion, which becomes heat through mechanical, air and tyre friction. Most is wasted directly as heat. A study of Beijing determined that vehicles raised the city’s temperature by over 1掳C (23 November 2024, p 36).
Kids will get round any ban on online activity
A decade and a half ago, when my son was in year 7, the government in New South Wales, Australia, issued laptops to students them freely roaming the internet. Within a week, he and all of his friends had bypassed these and spent their time watching videos in class (Letters, 14/21 December 2024).
Likewise, the Australian government’s legislation to block children under 16 from using social media is doomed to fail. Children will find ways around the prohibition and share them. Instead of a ban, society must drive responsible use of social media.