Recent content by colinr

just wondering, and please shout at me if I'm way out line, but... If gravity propagates at c, the aren't all the arguments about the total mass of the universe and it collapsing irrelevant, because the universe is expanding so fast that gravity couldn't keep up and make it collapse.

I have just learned that gravitaional energy propagates as particles called gravitons and also as waves. I was wondering if gravitons are to gravity as photons are to light, and therefore, what is the speed of gravity? Does anyone know if this actually exists?

The coolest thing i ever saw in a microwave was this. Fill a glass with milk, put an ordinary tungsten filament light bulb so that the metal part is completely immersed in the milk. Put the glass in the microwave and the bulb will light up! It looks amazing, but still to this day I can't...

The reason I ask is I was wondering if space was not expanding would the Earth actually spiral towards the Sun

If all space is expanding, does this include the space between the Earth and the Sun and perhaps. the space between a nucleus and an electron.

Think the first one is trigonometry: The elevation blocks form the side "opposite" to the angle of elevation of length or height 0.0186m The 1.00m track is the hypotenuse in this case joining the top of the block to the angle you are looking for. So it should be: sin(angle of elevation) =...

you're a star, thank you

how can that be possible, how can you measure the speed or distance of something you can't observe. I'm assuming you can't observe something traveling faster than the speed of light.

I am struggling to come to terms with the theory of inflation. The figures I've been presented with mean that the Universe for a very short time expanded at a speed much greater than the speed of light. Is that possible?

We're a British school, budget = 0 and liquid nitrogen is out of the question (unless anyone knows how I can make it out of fresh air)

well we know that, that's why its so funny

well ok, you don't, but it is better to work in the same units for stuff like this when you're new to the subject

well don't you need to know how many metres are in a light year before you can think about how many 25 cm are in 2 million light years

Has anyone seen this movie yet. "Professer" Vin Diesel describes a planet as having a surface temperature at night of -300 degrees celcius. Is it just me, or is that catergorically the worst piece of science fiction writing ever. If you know one better, I'd love to hear it.

I'll give you a clue to start you off, there are about 10^16 metres per light year.