SionR25

Hi everyone I was wondering how effective CSC cameras, e.g. Samsung NX1000 and similar, are for astrophotography? I am planning on buying one regardless but was wondering with its full sized sensor, light body and other DSLR features would it be good for astro imaging? Many thanks

Had the interview today and got an offer . They didn't ask me about guitars though. I had a question on calculating distance of horizon, why you aren't pulled to the floor of the ISS and what happens to a sealed room if a fridge is left open inside it.

For a particle moving with speed V don't you need to add on the kinetic energy (1/2 mv^2) as well. I know this probably won't make a massive difference at low speeds but I thought I read it somewhere.

Just a little thing, don't get heat and temperature mixed up. Temperature flows to a cooler area via the process of heat. Heat is the transfer of energy via temperature. If your thinking of doing physics at a higher level in school, don't let this catch you out .

Thanks for the answer . Seems nice and simple.

Hi all, I have an interview with Lancaster University and have been tipped off that because I have put in my personal statement that I play guitar I will very likely be asked to explain what the physics are behind an acoustic guitar, but to be honest I'm not completely sure what it is. I have an idea it is to do with resonance and the natural frequency of the sound waves but could anyone help explain what goes on inside the box? Many thanks, Sion

I think it is because photons are mass-less, the energy they contain is not needed to move it as a photon/wave is a way of transferring energy. The definition of a wave is a transfer of energy. A photon is one little part of a wave. Imagine it as water, a water wave when pushed will keep going until the energy you gave it in the push is dissipated by the water hitting a physical barrier. With light that energy is dissipated in the same way, transferring the energy to an electron. Don't know how clear that explanation is but hope it helps. Sion

Here is the link for things created from particle accelerators. http://public.web.ce...cience3-en.html Scroll to about half way to the sub heading 'Spin offs and stimulation of industry'. Sion

Might have been a bit over the top . Sion

Ok, thanks . Sion

Do we know that features on other large bodies and planets won't move with time though? Sion

I think you also have to consider things that have cropped up from CERN as well. Without CERN there would be no internet. Here is a list of things that have come about because of particle accelerators. Accelerators [*] semiconductor industry sterilisation - food, medical, sewage radiation processing non-destructive testing cancer therapy incineration of nuclear waste power generation (energy amplifier)? source of synchrotron radiation (biology, condensed matter physics...) source of neutrons (biology, condensed matter physics...) Particle detectors Crystal Detectors medical imaging security

Couldn't you really say the same about earth as it is now. Hardly any land in the southern hemisphere, most of i concentrated in the north, or even either side of the pacific. Sion

A good example of how this is used now is the detection of Muons. If we could see them they would disappear shortly after coming through our atmosphere. But they travel at extremely quick speeds so they do actually make it to the earths surface and we can detect them. Sion

Found this picture on wikipedia showing the distribution of maria across the whole lunar surface. Not much at all on the far side.

Thanks for the explanation I should probably finishing reading this before posting anymore questions . Sion

Yep, thats the idea. Its the biggest source of energy we know so the best thing to try and recreate to meet our own energy needs. Sion

Sorry to be awkward here , but isn't the definition of momentum; mass x speed. So if you are taking photons to not have any mass then surely p=0? We just started this at school before summer, looking at (can't remember the name ) the thing with one black side and one silver that will spin in a vacuum when light shines on it. As it was the last week no one really felt like doing any theory on it . Sion

Each element is defined by he number of protons it has within its nucleus. Hydrogen is the most basic element and only has one proton. In extreme pressures and heat of a star, two hydrogens (two protons) are forced together to make helium, which has a proton number of two. This process is the same for all other elements, just greater number of protons being forced together. It isn't a chemical process hence not every element is shown to contain hydrogen. Sion

Thats a very good image, can't wait for the skies to clear up here so I can try some widefield shots. Hope you dont mind but I tried some editing on your pic to help remove the colour cast. I reduced the reds in levels in photoshop then reselected Sagittarius and Scorpius with lasso tool and boosted their reds back to roughly how they were. If you want any help with photoshop just send me a message . Sion EDIT: Colour in Sagittarius and Scorpius hasn't come up to well in uploading for some reason

For questions 1+2 the answer is just to release the pressure or heat it up.... a lot. For question 3 it depends on the metal, some go transparent and some have other changes. A bit more complicated some experience changes in their electron orbitals, E.G. p + s subshells change for transition metals which causes a rearrangement of the electron structure. I don't think it would be viable to use metal hydrogen as a material, unless it was found to have superconducting properties, in which case it might be worthwhile. Sion

At Surrey uni open day today one of the physics lecturers said we should hear if they have found it or not within the week. Sion

Thanks for the information. Out of interest which Uni did you go to and how did you find it? I usually don't have problems with maths, one of my strong subjects and I take part in Maths challenge every year and have won a silver award the last four times. Thank again, Sion

This is still a possibility but recently it has been discovered the expansion of the universe is accelerating, due to dark energy, and not being slowed down by gravity as we thought it might. Because of this we think it is more unlikely the universe will collapse back in. Sion

Reading further into E=mc2is this because everything moves through spacetime at the same speed? If you are stationary, to achieve the same speed as someone moving your clock needs to run faster. Vice Versa, if someone is moving their clock has to run slower because they are moving through space and the time needs to be slower. Simplified a bit (I know the real equation is a bit different but don't have book on me atm) movement in spacetime= movement through time + movement through space. So as one gets smaller the other gets larger and vice versa. Sion