By Nick Hughes – By recent estimates, the Milky Way is just one of 2 trillion galaxies in the observable Universe, and the region of space that they occupy spans at least 90 billion light-years.
If you imagine Earth shrunk down to the size of a single grain of sand, and you imagine the size of that grain of sand relative to the entirety of the Sahara Desert, you are still nowhere near to comprehending how infinitesimally small a position we occupy in space.
And that’s just the spatial dimension. The observable Universe has existed for around 13.8 billion years. If we shrink that span of time down to a single year, with the Big Bang occurring at midnight on 1 January, the first Homo sapiens made an appearance at 22:24 on 31 December. It’s now 23:59:59, as it has been for the past 438 years, and at the rate we’re going it’s entirely possible that we’ll be gone before midnight strikes again.
In the grand scheme of things we are very, very small. more> https://goo.gl/Dp2NaC
Posted in Book review, EARTH WATCH, History, Leadership, Media, Science, Technology
Tagged Humanity, Milky Way, Philosophy, Space, Time, Universe
The Direction of Time, Author: Hans Reichenbach.
Time’s Arrow, Author: Martin Amis.
By Mathias Frisch – Common-cause inferences are so pervasive that it is difficult to imagine what we could know about the world beyond our immediate surroundings without them.
Astronomical observations provide a particularly stark example. How do we know that the points of light in the night sky are stars?
The approach using laws and initial (or, in this case, final) conditions to calculate backward in time to the existence of the star would require data on the surface of an enormous sphere of possibly many light years in diameter.
Stuck here on Earth as we are, that just isn’t going to happen. So what do we do?
Well, we can make use of the fact that we observe points of light at the same celestial latitude and longitude at different moments in time, or at different spatial locations, and that these light points are highly correlated with one another. (These correlations can, for example, be exploited in stellar interferometry.)
From these correlations we can infer the existence of the star as common cause of our observations. Causal inference may be superfluous in some idealised, superhuman version of physics, but if you actually want to find out how the Universe works, it is vital. more> https://goo.gl/mGuqhX
Posted in Book review, Education, Energy & emissions, History, Nature, Science, Technology
Tagged Common-cause, Organization, Physics, Technology, Test & measurement, Time, Universe
By Ted Shaffrey – There is no snooze button. If you unplug it, a battery takes over. As wake-up time approaches, you cannot reset the alarm time. Once it goes off, to stop it you must get out of bed, go into the kitchen or bathroom, and punch the day’s date into a telephone-style keypad. That’s the only way to stop the loud ‘ding-ding’.
It was invented by Paul Sammut, a 25-year-old engineer who lives in Hoboken. He started working on the gadget because he was finding it hard to get up and make it to work on time after college. more> http://tinyurl.com/bovr7z4