{"id":30106,"date":"2017-04-29T17:54:49","date_gmt":"2017-04-29T12:24:49","guid":{"rendered":"https:\/\/yaabot.com\/?p=30106"},"modified":"2024-01-24T18:21:14","modified_gmt":"2024-01-24T12:51:14","slug":"is-time-travel-possible","status":"publish","type":"post","link":"https:\/\/entropymag.co\/is-time-travel-possible\/","title":{"rendered":"A Brief History of Time Travel"},"content":{"rendered":"\n

Time travel subtly intertwines with our measurement of time through clocks and calendars – artificial constructs we’ve put up. But how do we know time exists? How can we say for sure that time is passing by? Say, it did actually exist. When did the Universe\u2019s clocks start ticking? It is generally accepted that the concept of time came into existence after the Big Bang. But who put the batteries in that clock? <\/p>\n\n\n\n

Time has continued to confound physicists and philosophers for centures. Oxford defines time as an indefinite, continued, progress of existence and events in the past, present and future, regarded as the whole. And we\u2019ll take their word for it. What about time travel, though? What if you could go back in time and change your past? Or what if you could travel hundreds of years into the future and meet your great-great-great-something grandchildren? How exciting would that be?<\/p>\n\n\n\n

The history of Time Travel<\/strong><\/h2>\n\n\n\n

Early stories of time travel feature a character goes away or sleeps for some time, only to be reawakened in a future society. The idea of time travel first appeared in the Hindu Text, the Mahabharata<\/em>, in the 9th<\/sup> century BC. The Mahabharata mentions the story of a King called Raivata Kakudmi<\/em>, who travels to heaven in order to meet the Ultimate Creator Brahma. When he returns to Earth, he is shocked to have learnt that many years have passed. The Japanese tale of Urashima Taro<\/em> is one of a fisherman who visits an undersea palace, and on returning home, realises that 300 years have passed.<\/p>\n\n\n

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\"The
The Time Mission Novel by HG Wells<\/figcaption><\/figure><\/div>\n\n\n

The term ‘Time Machine’ was coined by the author H.G. Wells, who penned a\u00a0novel with\u00a0the same name. It introduced the concept of forward as well as backwards time travel. The novel went on to gain cult status, and has been adapted into comic books, television series, as well as two feature films. Since then, time travel (or manipulation) has been the topic of many popular movies such as the X-men <\/em>series, Source Code, Back to Future (I, II &III),\u00a0 The Edge Of Tomorrow, and The Terminator<\/em>, \u00a0among many others. <\/p>\n\n\n\n

In the 1985 hit Back To The Future<\/em>, a boy named Marty travels back in time using the time machine invented by an eccentric scientist. He meets his parents there and accidentally attracts his mother’s attention, putting his existence at stake. He must make his parents fall in love. In the Edge of Tomorrow<\/em>, Major William Cage (Played by Tom Cruise), has to save Planet Earth from an alien species, after being caught in a time loop. All in all, the genre of science fiction itself has espoused the idea of time travel with great enthusiasm.<\/p>\n\n\n

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\"Edge
The Edge of Tomorrow<\/figcaption><\/figure><\/div>\n\n\n

What about actually doing it in real life?<\/strong><\/h2>\n\n\n\n

Before jumping into the answer, we need to understand a few things, including the Theory of Relativity<\/a>. According to Einstein’s theory, time passes differently – that is, at different rates – for people who are moving relative to one another. What does this tell us?<\/p>\n\n\n\n

First of all, there is no ‘absolute’ frame of reference. Whenever you measure an object’s velocity, momentum, etc, it is always with respect to something else. Secondly, the speed of light stays constant no matter who measures it or how fast the person measuring it is going. Thirdly, nothing can go faster than the speed of light.<\/p>\n\n\n\n

Related: A Brief History Of Life<\/a><\/strong><\/p>\n\n\n\n

The Twins’ Paradox<\/strong><\/p>\n\n\n

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\"Illustration
Illustration of the Twin Paradox<\/figcaption><\/figure><\/div>\n\n\n

Let\u2019s take a look at the Twins\u2019 Paradox. Take two twin brothers. Say one twin travelled to space, while the other stayed back here on Earth. Consider that the twin in space travels for 10 years at the speed of light. When that twin comes back to Earth, he seems to have hardly aged at all, while his twin brother has aged 10 years. <\/p>\n\n\n\n

In fact, he has technically jumped 10 years into the future! A concept called time dilation. Although it is noticeable at velocities comparable to the velocity of light, this concept exists all around us. This shows that all of us are moving into the future, at different rates! According to Caltech Physicist Kip Thorne, replacing the twins in the earlier scenario with corresponding mouths of a wormhole, you could, in fact, created a time machine!<\/p>\n\n\n\n

The Grandfather Paradox<\/h2>\n\n\n\n

A popular\u00a0concept called The Grandfather Paradox<\/em> poses a challenge\u00a0to the concept of time travel. According to it, in a theoretical scenario, \u00a0if you\u00a0were to go back in time and kill your\u00a0grandfather before your\u00a0father is born, your\u00a0would prevent your own\u00a0birth, thus making it impossible to go back in time and kill your grandfather in the first place. <\/p>\n\n\n\n

But in fact, there is a loophole in that one too. A proposed ‘many universes’ interpretation of quantum mechanics by British physicist David Deutsch puts forward another theoretical scenario. It proposes that\u00a0alternate, or parallel universes exist. You\u00a0would therefore go to another universe, kill your\u00a0grandfather there – thereby losing your\u00a0existence in that universe only. This gives an interesting twist to the Paradox.<\/p>\n\n\n\n

Has anyone done it before?<\/h2>\n\n\n\n
\"Russian
Russian Cosmonaut Sergei Avdeyev<\/figcaption><\/figure>\n\n\n\n

Technically, yes. Russian Cosmonaut Sergei Avdeyev is considered Earth’s first-time traveller. Across 3 visits to the Mir station in space, he spent around 747 days in low Earth orbit. Sergei circled Earth a whooping 12 thousand times, travelling a total of 515 million kilometres. Sergei Avdeyev is one-fiftieth of a second “younger” than if he had stayed on Earth. This means that he has travelled one-fiftieth of a second into the future, experiencing 0.02 seconds less than the rest of us here on Earth. This is of course, nearly nothing. But it’s obvious that if we can somehow attain exponentially higher speeds, the time dilation factor could end up being significant.<\/p>\n\n\n\n

Will nature support us?<\/strong><\/h2>\n\n\n\n

All these concepts are on the brink of reality, tipping into the realm of science fiction. It does make you wonder – does time travel go against the laws of nature? But then, isn\u2019t everything that humans have done on this Earth doing just that? According to Hawking.org<\/a>, Professor Stephen Hawking proposed the Chronology Protection Conjecture. According to the conjecture, on a macroscopic scale – the laws of physics have actually conspired to prevent us from travelling through time! We humans though, keep chanting \u201cNothing is impossible!\u201d on a regular basis. There is nothing wrong in that, but in cases such as time travel, it is<\/em>\u00a0a little far-fetched. <\/p>\n\n\n\n

To travel into the future, we will need to travel at a speed greater than the speed of light. Think of travelling back into the past, and we are faced with a lot of paradoxes. Let’s face it – the odds don’t seem to be in our favour. But then again, a hundred years ago, the concept of man flying seemed impossible. We can continue to do what we humans do best-hope!<\/p>\n","protected":false},"excerpt":{"rendered":"

Explore the possibilities and paradoxes of time travel. Can we journey to the past or future? Learn about theories and scientific ideas <\/p>\n","protected":false},"author":2,"featured_media":30122,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[567,566,568],"_links":{"self":[{"href":"https:\/\/entropymag.co\/wp-json\/wp\/v2\/posts\/30106"}],"collection":[{"href":"https:\/\/entropymag.co\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/entropymag.co\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/entropymag.co\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/entropymag.co\/wp-json\/wp\/v2\/comments?post=30106"}],"version-history":[{"count":1,"href":"https:\/\/entropymag.co\/wp-json\/wp\/v2\/posts\/30106\/revisions"}],"predecessor-version":[{"id":36707,"href":"https:\/\/entropymag.co\/wp-json\/wp\/v2\/posts\/30106\/revisions\/36707"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/entropymag.co\/wp-json\/wp\/v2\/media\/30122"}],"wp:attachment":[{"href":"https:\/\/entropymag.co\/wp-json\/wp\/v2\/media?parent=30106"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/entropymag.co\/wp-json\/wp\/v2\/categories?post=30106"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/entropymag.co\/wp-json\/wp\/v2\/tags?post=30106"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}