LETTER OF THE MONTH<\/span><\/p>\n\n Your interesting article on future cities (July issue) praises the idea of 15-minute cities, where the idea is that all shopping and entertainment should be within a 15-minute walk or cycle trip. But wouldn\u2019t this disadvantage a significant part of the population? Estimates for the UK show that by 2030, six million people over 65 will have a long-term illness or disability. These people cannot walk or cycle significant distances, and are unlikely to have the balance for an electric scooter. Without door-to-door transport, these people will be totally isolated. <\/p>\n\n\n\n And then there are builders, plumbers and electricians who bring their supplies and tools with them and can hardly walk or use a bicycle. And anyone relying upon a delivery of large items like sofas and electric goods needs delivery to the door. Cities have to accept that there is a fundamental need for door-to-door transport (which can be made electric) alongside cycling or walking, or the city will fail many of its residents. <\/p>\n\n\n\n Dr Peter Stokes,<\/strong><\/strong> Kent<\/p>\n<\/div><\/section>\n\n The writer of next issue\u2019s Letter Of The Month <\/em>wins a set of Edifier TWS330 NB earbuds. <\/strong>These water-resistant earbuds will see you through a sweaty workout or a rainy commute, and are kitted out with noise-cancelling tech to create an immersive listening experience. Plus, they have quick-charging capability, with 10 minutes of charge offering 60 minutes of listening time. edifier.com<\/a><\/strong><\/p>\n\n I was reading Dr Katie Mack\u2019s article about the James Webb Space Telescope (June issue), and my question is, where does the past begin when it comes to travelling through space? For example, is Voyager\u2019s location, 14 billion miles from Earth, still considered to be in the \u2018now\u2019 or our present time? If so, at what stage in its outward journey through space will it begin to enter into \u2018the past\u2019? <\/p>\n\n Tony Jackson, <\/strong>Cornwall <\/span><\/p>\n\n Everything we see is in our past! Currently, when we receive a signal from Voyager 1, we\u2019re hearing from it as it was more than 21 hours in the past. And when we look at the Sun we\u2019re seeing it as it was about eight minutes ago, and even if you look at something across the room you\u2019re seeing it as it was several nanoseconds ago. In a cosmological sense, because of relativity, there\u2019s no way to define \u2018now\u2019 that\u2019s universal \u2013 it\u2019s necessarily dependent on where you are and what you\u2019re doing. <\/strong><\/p>\n\n Dr Katie Mack, <\/strong>astrophysicist <\/strong><\/p>\n\n I just read Pete Lawrence\u2019s article about noctilucent clouds (June issue). I thought you might be interested to see a couple of photos I took on a flight back from Mexico on Friday morning. Earlier in the flight we also saw the aurora borealis. Enjoy! <\/p>\n\n Patrick Salmond, <\/strong>via email <\/span><\/p>\n\n I was reading the article by Dr Katie Mack (June issue) about the new telescope that will enable us to peer back in time with more clarity, and it made me think. We are able to peer back in time to galaxies forming 10 billion years ago because inflation meant that parts of the Universe grew faster than light speed, meaning the light from earlier objects is still catching up with us. If that is correct, then surely there are possible life forms that are even further out from us looking back on us potentially billions of years in the past. This would mean that if they had the technology to send us information, they could tell us our future. Is that an accurate assumption or have I overlooked a fundamental restriction to that being possible? <\/p>\n\n Stuart Young, <\/strong>via email <\/span><\/p>\n\n It\u2019s just a property of relativity in the Universe, not inflation or anything moving faster than light, that means that when we see distant objects, we\u2019re seeing things as they were in the past. Relativity means that everything we see is in the past. Wherever you are, you\u2019re getting an outdated view of what you\u2019re seeing, because the light that was emitted from the thing you\u2019re looking at takes time to reach you. <\/strong><\/p>\n\n So by the time a signal reaches you, time has passed for whatever sent it, and your information is already out of date. That doesn\u2019t give us any option for seeing the future. <\/strong><\/p>\n\n Dr Katie Mack,<\/strong> astrophysicist <\/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 Instagram<\/strong> \u2022 @bbcsciencefocus<\/a><\/p>\n\n Editor<\/strong> \u2022<\/strong> Daniel Bennett<\/p>\n\n\n\n Managing editor<\/strong> \u2022<\/strong> Alice Lipscombe-Southwell<\/p>\n\n\n\n Commissioning editor<\/strong> \u2022<\/strong> Jason Goodyer<\/p>\n\n\n\n Online staff writer<\/strong> \u2022 <\/strong>Sara Rigby, <\/p>\n\n\n\n Staff writers<\/strong> \u2022 <\/strong>Alex Hughes, Holly Spanner<\/p>\n\n\n\n Editorial assistant<\/strong> \u2022<\/strong> Amy Barrett<\/p>\n\n\n\n Art editor<\/strong> \u2022<\/strong> Joe Eden<\/p>\n\n\n\n Picture editor<\/strong> \u2022<\/strong> James Cutmore<\/p>\n\n\n\n Claire Asher, Rob Banino, Hayley Bennett, Peter Bentley, Steve Boswell, Daniel Bright, Steve Brusatte, Dean Burnett, Marcus Chown, Stuart Clark, Kate Darling, Emma Davies, Cathal Duane, Alastair Gunn, Adam Hart, Tom Ireland, Christian Jarrett, Stephen Kelly, Pete Lawrence, Nish Manek, James Minchell, Dann Mitchell, Radha Modgil, Stephanie Organ, Ceri Perkins, Helen Pilcher, Andy Potts, Helen Scales, Julia Shaw, Jacob Stead, Colin Stuart, Ian Taylor, Valentin Tkach, Luis Villazon, Mario Wagner, Myriam Wares. <\/p>\n\n\n\n Business development manager \u2022<\/strong> David D\u2019Souza<\/p>\n\n\n\n Newstrade manager \u2022<\/strong> Rob Brock<\/p>\n\n\n\n Subscriptions director \u2022<\/strong> Jacky Perales-Morris<\/p>\n\n\n\n Direct marketing manager \u2022<\/strong> Kellie Lane <\/p>\n\n\n\n Head of apps and digital edition marketing \u2022<\/strong> Mark Summerton <\/p>\n\n\n\n Laurence Robertson 00353 876 902208 <\/p>\n\n\n\n Director of licensing and syndication \u2022<\/strong> Tim Hudson<\/p>\n\n\n\n International partners manager \u2022<\/strong> Anna Brown <\/p>\n\n\n\n Production director \u2022<\/strong> Sarah Powell<\/p>\n\n\n\n Production coordinator \u2022<\/strong> Lauren Morris<\/p>\n\n\n\n Ad services manager \u2022 <\/strong>Paul Thornton<\/p>\n\n\n\n Ad designer \u2022 <\/strong>Julia Young <\/p>\n\n\n\n Publisher \u2022 <\/strong>Andrew Davies<\/p>\n\n\n\n Group managing director \u2022<\/strong> Andy Marshall<\/p>\n\n\n\n CEO \u2022 <\/strong>Tom Bureau <\/p>\n\n\n\n Chair, editorial review boards \u2022<\/strong> Nicholas Brett<\/p>\n\n\n\n Managing director, consumer products and licensing \u2022 <\/strong>Stephen Davies <\/p>\n\n\n\n Director, magazines and consumer products \u2022 <\/strong>Mandy Thwaites <\/p>\n\n\n\n Compliance manager \u2022 <\/strong>Cameron McEwan <\/p>\n\n\n\n UK publishing coordinator \u2022<\/strong> Eva Abramik <\/p>\n\n\n\n Contact UK.Publishing@bbc.com<\/a> <\/p>\n\n\n\n![\"\"](\"https:\/\/dj9jqhxgw9833.cloudfront.net\/uploads\/sites\/42\/2022\/08\/GettyImages-1292075242-1024x702.jpg\")
<\/figure><\/div>\n\n\n\nAccessible cities, please<\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/h4>\n\n\n\n
WRITE IN AND WIN!<\/strong><\/h5>\n\n
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\n\nPast times <\/strong><\/h4>\n\n
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Noctilucent clouds <\/strong><\/h4>\n\n
\n\nCan aliens see our future? <\/strong><\/h4>\n\n
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\n\nTHE TEAM <\/h4>\n\n\n\n
EDITORIAL<\/strong><\/h5>\n\n\n\n
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PUBLISHING<\/strong><\/h5>\n\n\n\n
BBC STUDIOS, UK PUBLISHING<\/strong><\/h5>\n\n\n\n
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