The science of flatulence and the fear of a zombie apocalypse are two subjects that continue to taunt modern man. This is according to the creators of AsapSCIENCE, a YouTube channel that has added these two subjects to its list of the top five science questions of all time.Mitchell Moffit and Gregory Brown, whose AsapSCIENCE has 4million viewers, are no strangers to answering weird science questions.They have answered questions about what your urine says about you and what happens when you die.They were asked by The Guardian newspaper for their five favourite science questions of all time and they are:Are silent farts more deadly?After much investigation, their verdict is "yes". The reason for this is the "sink agent" in farts - the higher proportion of sulphur. Louder farts are diluted, they explained, because they contain more air.Why do we procrastinate?It turns out that putting off what you are meant to be doing is linked to how close or far away you think the results of that activity are, they explained.If the reward for the activity is distant, then you are more likely to put it off.To overcome this universal problem, the pair suggest being positive, setting deadlines and trying to eliminate distractions.Does being cold make you sick?Although the increasingly prevalent view is that being cold does not make it more likely that you will catch a cold, more people do get infected in winter.More people stay indoors, where viruses are likely to hang out. D rier weather means there is less pathogen-blocking mucus in the nostrils and less vitamin D is manufactured by the body because of decreased sunlight, weakening the immune system.Could a zombie apocalypse happen?No, but you could get a virus that induces zombie-like behaviour. Moffit and Brown suggest that the rabies virus could theoretically create a super hungry, aggressive brain-dead being that is not in control of its actions.Should you use the "snooze" button?Although the snooze button might seem like a good idea in that it allows you to wake up gradually, it actually does the reverse. By allowing you to go back to sleep and start a new sleep cycle, then waking you again, it leaves you feeling tired throughout the day. ..