LETTER OF THE MONTH<\/span><\/p>\n\n I wonder if I am the only one that thinks the distribution of tiny sensors into the environment is not necessarily a good idea? The news story was in your Lunchtime <\/em>Genius <\/em>newsletter today (17 March). There was no mention in the item of the materials being used to produce these environmental sensors.<\/p>\n\n\n\n There is an obvious silicone chip at the heart of the device along with photo cell and capacitor. There is then a small copper wire aerial coated in plastic.<\/p>\n\n\n\n I assume the structure is also made of plastic. So, is adding all this silicone, copper and plastic into the environment such a good idea?<\/p>\n\n\n\n Simon Biggs, <\/strong>Dudley<\/p>\n<\/div><\/section>\n\n The writer of next issue\u2019s Letter Of The Month <\/em>wins a prize bundle from Atom Studios containing a split wood fibre iPhone case <\/strong>to keep their phone safe from knocks and bumps, a flat universal cable, <\/strong>to allow for versatile charging, and a screen protector.<\/strong><\/p>\n\n In your June 2021 issue, there was a two-page article regarding microplastics.<\/p>\n\n The article influenced the design and content of a sculpture I created for an art show in September 2021. The show\u2019s theme was \u2018our DNA\u2019, for which I built an eight-foot double helix emerging from a FedEx box filled with plastic garbage. Bits of plastic are embedded in the DNA\u2019s structure, causing its amino acid bonds to separate at the top, unfurl and die. It generated lots of interesting dialogue full of concern about the problem of microplastics. Since the show closed, it\u2019s been on display in the Ives Library in downtown New Haven, Connecticut. An enlarged copy of the BBC <\/em>Science <\/em>Focus <\/em>microplastic article is displayed next to it.<\/p>\n\n Mariellen Chapdelaine<\/strong>, on behalf of Joe Fekieta, New Haven, Connecticut<\/em><\/span><\/p>\n\n Prof Phil Hart is correct when he says renewable energy from wind and solar power is dependent on the weather (March issue). But this disregards the scope for energy generation from tidal power. It is not weather dependent and is continuous for 24 hours a day. Why doesn\u2019t he mention this in his review of our energy generation problem?<\/p>\n\n Ivan Dickason,<\/strong> via email<\/span><\/p>\n\n Tidal energy is predictable and consistent where other renewables are not. However, for efficient operations, the water flow speed has to be really quite quick, and that limits the sites around the UK that tidal energy can be deployed. There are a few excellent sites around our coast, and with the right technology they could make a useful contribution to our power needs, but at a much reduced scale to the likes of wind and solar.<\/p>\n\n Personally, I\u2019m a fan of tidal and tidal barrage technologies as contributors to our energy mix, but they are not the \u2018big dogs\u2019 in the game currently, and unless government policy changes to support their development and deployment, and eventually commercial scale production, they will likely remain somewhat niche for the near to medium term.<\/p>\n\n Prof Phil Hart, <\/strong>Cranfield University<\/p>\n\n I was both interested and concerned by your article about space junk (March issue). I believe it raises a bigger question: when we have gone a long way to unbalancing our own planet, how far should we continue this problem into space, with further exploration, before addressing the current buildup of space junk? Using Antarctica as an example, we spent centuries exploring and exploiting the ecosystem before controls were put in place to reduce and to some extent reverse the damage that had already been done. While I appreciate that satellites in Earth orbit have revolutionised many aspects of our lives, is it necessary to litter outer space and other planets with waste before we have cleaned up our own? The financial side of this is a separate aspect, where the money could be beneficially spent closer to home.<\/p>\n\n Nick Tupper, <\/strong>Surrey<\/em><\/span><\/p>\n\n In the March issue, we said that shape memory polymers for healing wounds were being developed by Virginia Tech. This should have been credited to Syracuse University.<\/p>\n\n Email<\/strong> \u2022 reply@sciencefocus.com<\/a><\/p>\n\n Post<\/strong> \u2022 BBC Science Focus<\/em><\/em>, Eagle House, Colston Avenue, Bristol, BS1 4ST<\/p>\n\n Twitter<\/strong> \u2022 @sciencefocus<\/a><\/p>\n\n Facebook<\/strong> \u2022 www.facebook.com\/sciencefocus<\/a><\/p>\n\n![\"\"\/](\"https:\/\/dj9jqhxgw9833.cloudfront.net\/uploads\/sites\/42\/2022\/05\/fda312d8-af7d-4a40-a69c-c4a1c8839874.jpg\")
<\/figure>\n\n\n\nJust plastic pollution?<\/strong><\/strong><\/h4>\n\n\n\n
WRITE IN AND WIN!<\/strong><\/h5>\n\n
![\"\"](\"https:\/\/dj9jqhxgw9833.cloudfront.net\/uploads\/sites\/42\/2022\/05\/Write-in-and-win-1024x689.png\")
\n\n![\"\"](\"https:\/\/dj9jqhxgw9833.cloudfront.net\/uploads\/sites\/42\/2022\/05\/IMG_2333.jpg\")
Nature\u2019s art<\/strong><\/h4>\n\n
\n\n![\"\"](\"https:\/\/dj9jqhxgw9833.cloudfront.net\/uploads\/sites\/42\/2022\/05\/GettyImages-598229340-1024x675.jpg\")
What about tides?<\/strong><\/h4>\n\n
\n\n![\"\"](\"https:\/\/dj9jqhxgw9833.cloudfront.net\/uploads\/sites\/42\/2022\/05\/0ad6f23f-e482-4b07-b5c9-74d63e76d12b.jpg\")
Space junk<\/strong><\/h4>\n\n
\n\nOops!<\/strong><\/h4>\n\n
\n\n