This time on Ask!, Dr Chris explains how tree rings helped scientists confirm last summer was the hottest for 2000 years. Also, how were the pyramids built? And where are we with understanding and treating Alzheimer's disease? Like this podcast? Please help us by supporting the Naked Scientists

Chris Smith covers another cast of interesting queries submitted by listeners. They include: Why do we have accents? Is there such a thing as the "devil's hour?" What is acid reflux? Is there such a thing as race? If you had unfettered access to the James Webb Space Telescope, what would you point it at? Like this podcast? Please help us by supporting the Naked Scientists

Dr Chris takes on listener questions: how long can someone survive without food and water? Why are some of us more prone to hangovers? Do gorillas drink water? Does spicy food cause vivid dreams? What causes insomnia? Like this podcast? Please help us by supporting the Naked Scientists

In this week's selection of science questions, Dr Chris explains the impact of sweetners on the body, what happens when we suffer a stroke, and where the other half of the moon disappears to... Like this podcast? Please help us by supporting the Naked Scientists

Why are viruses so contagious? Are there any treatments for macular degeneration? How are we treating depression with psychedelics? Why do people lose their sense of smell? Is cloud seeding a real thing? Dr Chris Smith and Relebogile Mabotja have all the answers... Like this podcast? Please help us by supporting the Naked Scientists

Is our perfect total eclipse just a total coincidence? Where do our dreams come from? Can you launch a missile without it being picked up by satellites? Which animals have the best memory? Do humans have any instincts? Can gravity be 1g on a planet with a greater mass than Earth? Where could we go when Earth becomes uninhabitable? What was there before the beginning of the Universe? Dr Chris Smith and Clarence Ford have all the answers... Like this podcast? Please help us by supporting the Naked Scientists

Why did the eclipse move west to east across the Earth? Why are we so interested in nuclear fusion? Could we ever breathe underwater? What is the opposite force to gravity? Would alcohol sterilise a drowning fly? What the difference between cancer and cancerous growths? Are lactose introlerant mothers allergic to their own milk? Like this podcast? Please help us by supporting the Naked Scientists

Do animals ever get lost? Do ants count their steps? Could we recreate the greenhouse effect on Mars? Why can you hear some aircraft, but not others? Could we mine the Moon? Is it ever too late to stop somking? Do people with autism have a different brain structure? Dr Chris Smith and Clarence Ford have all the answers... Like this podcast? Please help us by supporting the Naked Scientists

Dr Chris answers more listener submitted questions including, Why is South Africa on the bottom of the world map? Why are countries interested in landing on the moon again? How do undersea cables work? What is the Square Kilometre Array? Why are my car keys better at unlocking my car than my TV remote is at controlling my TV? Like this podcast? Please help us by supporting the Naked Scientists

Chris Smith answers science questions from the public. Does the rate of nail growth differ between men and women? What are the advantages of a nose swab over a mouth swab? What could improve the connectivity of my remote? Accounting for the rotation of Earth, does a plane flying from London to Cape Town fly in a straight line? How does a colour printer work? Like this podcast? Please help us by supporting the Naked Scientists