# Tags / gravity

## Tagged with “gravity” (10)

1. ### 6.67 x 10^-11 – The Number That Defines the Universe.

Episode four of A Further Five Numbers, the BBC radio series presented by Simon Singh.

Newton’s equation of gravity included a number G, which indicates the strength of gravitation. It took 100 years before the shy Englishman Henry Cavendish (he left notes for his maids because he was too shy to talk to women) measured G to be 6.67 x 10^-11 Nm²/Kg². It allowed him to weigh the Earth itself. There has been an ever-greater desire to measure this number with accuracy, which even implied an antigravity at times. How did we measure this tiny number and what does it mean for the universe? The Astronomer Royal Martin Rees explains that a large value for G would mean that stars would burn too quickly and a low value would mean that the stars would not form in the first place, so is G perfectly tuned for life? Is God a mathematician?

### Thought experiment of the day

Imagine holding a slinky at the top and letting the bottom go until, after some boucing, it come to rest. Now, let go of the top of the slinky. Now ask yourself… “what happens to the bottom of the slinky?”

If that just blows your mind a little then this podcast gives lots of great explanation, in an way and fun way to understand.

#### My favourite part:

Neil deGrasse Tyson on the futility of trying to understanding anything before its too late!

>When you know about it you know about it… Life is too short for me to worry about something I have no control over that I don’t even know will happen. Someone said ‘if Earth is going to be swallowed by a black hole or if there is some disturbance in the spacetime continuum should we worry about it?’. My answer is ‘no’ because you won’t know about it until it crosses your… your place in spacetime.

>Your beats come to you when nature decides it’s the right time… be it the speed of sound, the speed of light, the speed of electrical impulses we will forever be victims of the time delay between information around us and our capacity to receive it.

3. ### Marcus Chown on 10 Bonkers Things About the Universe

Marcus Chown of New Scientist Magazine on his Top 10 Bonkers Things About the Universe

4. ### Mary Roach: Packing for Mars

She took us into the world of cadavers and examined the anatomy, physiology and psychology behind sex. Now, Mary Roach discovers the surreality and weirdness of space.

For example, what happens when you’ve been in space for a year? And is it possible for a human body to survive a bailout at 17,000 miles per hour? From the space shuttle training toilet to NASA’s crash simulation tests, Roach explores the strange universe.

http://fora.tv/2010/08/19/Mary_Roach_Packing_for_Mars

5. ### Science & The City: What Time Is It?

Famed screenwriter Charlie Kaufman and theoretical physicist Brian Greene dissect time as we know it. What is the smallest unit of time, and what does it look like? For starters, you should stop looking at the clock, and start looking at the universe.

http://www.nyas.org/Publications/Media/PodcastDetail.aspx?cid=f3f02313-c697-49da-b298-9b00f2e3d541

6. ### Dark Secrets: What Science Tells Us About the Hidden Universe

No mystery is bigger than dark energy - the elusive force that makes up three-quarters of the Universe and is causing it to expand at an accelerating rate. Join a panel of Lawrence Berkeley National Laboratory scientists who use phenomena such as exploding stars and gravitational lenses to explore the dark cosmos.

http://www.uctv.tv/search-details.aspx?showID=17426&subject=pet

7. ### Lawrence Krauss: Life, The Universe, and Nothing

Lawrence Krauss is a professor in the Department of Physics at Arizona State University. His lecture entitled Life, the Universe and Nothing was recorded at the Isabel Bader Theatre in Toronto on March 27th, 2009.

http://www.tvo.org/TVOsites/WebObjects/TvoMicrosite.woa?bi?1255208400000

8. ### 6.67 x 10^-11 – The Number That Defines the Universe.

Episode four of A Further Five Numbers, the BBC radio series presented by Simon Singh.

Newton’s equation of gravity included a number G, which indicates the strength of gravitation. It took 100 years before the shy Englishman Henry Cavendish (he left notes for his maids because he was too shy to talk to women) measured G to be 6.67 x 10^-11 Nm²/Kg². It allowed him to weigh the Earth itself. There has been an ever-greater desire to measure this number with accuracy, which even implied an antigravity at times. How did we measure this tiny number and what does it mean for the universe? The Astronomer Royal Martin Rees explains that a large value for G would mean that stars would burn too quickly and a low value would mean that the stars would not form in the first place, so is G perfectly tuned for life? Is God a mathematician?

9. ### Radiolab - DIY Universe

Can you make your own universe? We usually think of the universe as “everything that exists,” so how could you make another one? Well, physicists have been speculating about the existence of multiple universes for some time now. And for Robert, the obvious next question was: “Can we make one?” So he invited physicist Brian Greene to his kitchen to speculate about just that. And it turns out, it’s not such a far-fetched idea. There are scientists right now trying to figure out whether it’s possible and what it would take. According to Brian, it would require a tiny black hole, a dash of reverse-gravity, and a lot of luck. But the laws of physics don’t rule it out.