Is this the reason why this year is unusualy warm? (at least one of the reasons?) Las year we had a 15 cm (in some places even 30cm) thick layer of snow but this year there is none.

Is what? Huh? What are your referring to there? Surely you aren’t suggesting the BA announcing BAfacts somehow heats the planet?

The new BAfacts deal may warm your heart and mind but I doubt it could physically alter planetary temperatures!

As for the cause of planetary warming the theory of Human Induced Rapid Global Overheating (HIRGO) – often more mildly and less straightforwardly called the Anthropogenic Global Warming theory – is probably the best explanation. Our Sun is certainly not resposnible despite the recent rise towards the solar maximum sunspot cyle~wise and .. well, I could go on but we’d be getting a fair way off-topic if I did.

Any noticeable warming certainly isn’t due to perihelion which occurs around the same place and at the same distance every year. If Earth’s orbit is changing at all it would be drifting very, *very* slowly outards as teh Sun gradulaly loses mass intheform of the solar wind. Our worlds orbital eccentricity (range of circular-to-ovalness) also shifts predictabley to a very small extent over tens of thousands of years and will not have perceptible effects over mere decadal timespans.

@17. dawilts : January 5th, 2012 at 7:55 am

“Why do times of Earth at perihelion and aphelion vary in date more than other phenomena such as the start of the seasons?[Emphasis added.]

When the seasons start and indeed whether you get them at all also depends to some extent on where on this planet you live. Just thought I’d mention that.

@16. Neil Haggath : Sadly, your probably right – but is the solution to avoid the word ‘apocryphal’ and substitute “factoid” in its place or to educate people better instead? I’d much prefer the latter choice.

What’s the back story on your twitter wallpaper (twallpaper?)? Cigarettes and Bacteria(tm) would make a great band name, but I don’t think that’s what you’re going for.

And a couple of weeks on either side.

“Why do times of Earth at perihelion and aphelion vary in date more than other phenomena such as the start of the seasons?

It is actually due to the presence of the Moon. The Earth and Moon both orbit every month around a point called the Earth-Moon barycenter, which is on average about 4700 km (2900 miles) from the Earth’s center. Because perihelion and aphelion are defined by the distance between the center of the Sun and the center of the Earth, the Earth’s position in its monthly motion around the Earth-Moon barycenter greatly affects the time of perihelion and aphelion. Due to the fact that the position of the Moon doesn’t repeat from year to year on the same date, neither does the position of the Earth with respect to the Earth-Moon barycenter. This produces what appears to be a quasi-random variation in the dates of perihelion and aphelion.”

Agreed, but I suspect that with today’s dumbed-down education standards, most people are too thick to know what “apocryphal” means – or know how to spell it!

If I may make a suggestion: Is there a possibility to include it here on the blog somewhere? Maybe a little box on the right saying “BAFact of the day” or so?

Seconded by me.

Not everyone uses Twitter, and not everyone uses Google+, either. And why should only those benefit who do? (Maybe one could start a conspiracy around that. )

Er.. NOT seconding the start of any conspiracy theories though. More than enough of those arise “naturally” for want of a better word and hardly improve our world much at all.

Personally, I don’t use twitter at all and agree the BA should post them on his blog here or maybe on facebook which I do use a bit mainly for sharing links and articles such as, well, many that appear here.

@7. Blargh & # 8. Graviton : Regarding “factoid” that’s news to me.

I always just thought it meant a small interesting fact – something you’d get in a sidebar or list. I never got the impression that it connotated unreliability at all.

The word ‘apocryphal’ would seem to better fit your definition provided in comment #7.

Umm, Phil, the fact that the time and date of perihelion shifts (calendrically) each year has a lot more to do with the fact that there aren’t an integer number of days in a year (i.e. the fact that we add a leap day ever four(ish) years). In order for what you’re saying to be correct, Earth’s orbit would have to be precessing by around a degree per year!

“a piece of unreliable information believed to be true because of the way it is presented or repeated in print”

Yeah, but will it trend?

Awesome, though, Phil! I’ve really missed the “Bite Sized Astonomy” you used to do on the old BA site, and I think with your Twitter Prowess you’re back in that sort of game again!

CJSF

Have fun with the Phacts, Fil! Looking forward to seeing them