GPS Archive

2016 – Forget Trump, it was Einstein’s year

Posted January 24, 2017 By admin

Somewhat predictably Time magazine named Donald Trump as their person of the year. I understand the reasoning, but cannot agree. The year undoubtedly belonged to Albert Einstein, but to understand why, we need to understand the deep importance of his theories and the effect they have on our everyday lives.
Two stories stand like book ends to the year; seemingly unconnected, but that is wrong. They are connected by the work of Albert Einstein.
The first was the announcement in February of the discovery of Gravitational Waves. Confirmation from the Laser Interferometer Gravitational Wave Observatory (LIGO) of the capture of the signal on Sept. 14, 2015, caused quite a stir worldwide. Some described it as one of the greatest scientific discoveries of the last 100 years. Why? In essence, it gives us the ability of seeing the universe in a whole new way. Suddenly we are not only able to see the Universe, but now hear it. Whereas before we were deaf to space, now we can hear its music. And what will this mean? Ultimately it will take us all the way back to the start – back to the big bang. The very act of creation may be opened to us.
The second story was the December story that Uber was to use driverless cars in San Francisco. To be fair, it was short-lived. California officials ordered a shutdown after concerns of the cars running red lights. However, surely this is the thin end of the wedge. Driverless cars are here to stay and are set to revolutionise the transportation industry, the insurance industry and all service industries that employ drivers. We are on the verge of a huge shift in how we use the car.
What links these two stories? The General Theory of Relativity (GTR). Einstein’s 1916 masterpiece. Gravitational waves were predicted by Einstein as a consequence of the theory. No theory – no gravitational waves. And for driverless cars? One of the essential elements of the whole system is GPS. Without it, there could be no driverless cars and without the GTR there could be no GPS system. The network of satellites that provide GPS have to constantly take account of the effects of the GTR. If the adjustments were not made then every day the GPS system would be thrown out by miles, rendering it useless.
These stories are a reminder of Einstein’s legacy and our dependence on it. Long after The Don has gone, Einstein will still be influencing and remaking our world and our understanding of the universe. So whilst today’s news cycle may be dominated by Trump, when we look back to 2016 in a hundred years time it will be Einstein people will talk about.

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Einstein, GPS and our World

Posted October 6, 2013 By admin

The sat nav in our car would be fundamentally floored without our knowledge of relativity, indeed it would be so inaccurate as to be useless and increasingly our world is dependent on GPS (or to be more precise GNSS). Such systems are startling proof of the modern world’s reliance on the work of Albert Einstein.

Global Navigation Satellite Systems (GNSS) of which the Global Positioning System (GPS) is the most common are technologies reliant on an understanding of both Special and General Relativity. The systems are based on very precise timing pulses emitted by satellites and picked up on the ground. A comparison of signals from several satellites triangulates the position of the receiver. Such accuracy requires knowledge of timing down to billionths of a second. However, two effects alter the flow of time: the satellites motion and the gravitational field of the earth.

Special relativity explains the motion and General Relativity the earth’s gravitational effects. Both theories accurately predict the time lost by the satellite (7 micro seconds) and gained by the earth’s gravity (45 micro seconds). The net effect is that the clocks on the satellite gain 38 micro seconds per day. It doesn’t sound much, but if this difference wasn’t understood and accounted for, the systems inaccuracy would grow at 10 kilometers per day! That wouldn’t just send you to the wrong road, but the wrong town. The system is simply impossible without understanding the effects of relativity.

Yet how important are such systems really? If it didn’t work, we would simply go back to maps. Well, not quite. Like most modern technologies they have quickly become ubiquitous and essential in ways unforeseen when introduced. In 2011 the Royal Academy of Engineers in the United Kingdom published a survey on society’s reliance and vulnerabilities on GNSS. It reported that the European Commission estimates that 6.7% of Western Countries GDP (800 Billion Euros per annum) is dependent on such satellite systems.

Here is a sample of ways and uses for GNSS:

  • Road transport – commercial and freight management, emergency services and in car use.
  • Aviation – most commercial aircraft use such systems as well as the development of global traffic control.
  • Shipping and Rail transport.
  • Science – scientific applications are widespread.
  • Security- including the tracking of vehicles and suspects.
  • Heavy vehicle guidance – for example in highway construction and open cut mines.
  • Surveying, Mapping and geophysics.
  • Telecommunications – GPS timing is important of telecommunications applications.
  • Financial services – Global financial systems increasingly need precise timing for international money transfers.
  • Social activities.

However, as the survey highlighted, there are a number of issues arising from certain vulnerabilities of GNSS ranging from system related failures, atmospheric and interference both accidental and intentional, which places all the uses above at substantial risk in the future.

GNSS and in particular GPS have become essential in both a technological and economic sense to our modern world and such reliance is only likely to increase. Our reliance and the systems vulnerabilities reveal how much of our modern world is reliant and at risk from the technologies flowing from the work and theories of Albert Einstein and prove how he continues to make and shape our modern world.

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