Lilly from New York City sent me this question a few weeks back. (I am sorry, I have been quite busy, and have not been able to get to your questions everyone, I will, promise!) She wanted to know what was there before the big bang which started our universe. Well the answer is probably going to not make you very happy Lilly, but it is the consensus among scientists that there was no "before the big bang". You see, the big bang was not just the start of space, it was the start of the universe. One of the properties of the universe is that time goes forward. So, the big bang was the start of time. If it is the start of time, there could not be anything before time started.
Friday, December 19, 2008
Sunday, September 28, 2008
In this episode I decided to answer three questions at once. Austin from Massachusetts wanted to know how rockets can get away from our gravity. Well it is not done all at once, and it is not done from Earth. Typically space ships get up into orbit about oh 10 000 km up in space. That sounds pretty far, but GPS and communication satellites are about 40 000 km away from our home planet. So, once they get there they start to accelerate (speed up) and until they reach about 7 km/s (that is 25 500 km/h or 15 750 mph, which is pretty fast no matter how you measure it). That is fast enough to win what is really like a tug of war with the Earth's gravity.
Olivia from Washington state wanted to know if space ships had ever been to the Sun. Well of course not manned ships, but there have been a few unmanned ships that have gone. The closest flyby of the Sun was by a ship called Helios 2. She also wanted to know where the Sun came from, how was it created? Well, I touched on this in Episode 18. Basically there was this REALLY big cloud of molecules. Now, even single molecules have gravitational pull, so they started being attracted to on another. After a time (a really long time, about 50 000 000 years) the stuff at the center of this cloud really could be called a star. Oh when did this happen? The Sun is probably about 4.5 billion years old.
I hope you enjoy episode 22.
Friday, August 1, 2008
Jenna (I hope I spelled your name correctly...) wants to know how your brain controls your fingers. This is a really neat question, and because I am a psychologist, I did not have to ask anyone but myself. One of the very neat things about this is that the left half of your brain controls the right side of your body. Oh, and even though it feels like you move as soon as you want to, it takes at least 300 msec before anything actually happens in your fingers. The key to the whol thing is a neurotransmitter called acetylcholine.
I hope you enjoy episode 21, keep the questions coming!
Wednesday, June 18, 2008
Originally I was going to do a few updates on previous shows for episode 20, then this gem of a question came in about neuroscience and psychology, how could I refuse?
Wednesday, April 30, 2008
Monday, March 3, 2008
There must be questions that you think, "Well Dave, that was interesting and all of that, but could you tell me more about......" For example, I know that in episode 17 I mentioned how fish actually have memories, but, well our questioner wants a bit more info. (Her Dad ran into me at a podcast meetup and even asked me to tell him more. I refused, because, well, I thought I would save it for the show :-). So, is there more you want to know about some topic? Let me know!
Sunday, March 2, 2008
Welcome to our new home on the internet. Here you can submit questions to me via email, as well as comment on the episodes. Here is the questions for episode 18, Addie from California asks: Where was the first form of structure (dust, stone, etc) formed and what was it?