Showing all posts about physics

Back to the future, I met my parents before they met each other

29 October 2010

Twenty-five years on and people are still asking questions about 1985’s Back To The Future. One that consistently crops up regards the apparent inability of George and Lorraine, Marty McFly’s parents, to remember him, and the part he had in bringing them together, many years earlier.

And to a degree the question makes sense. It would certainly be easy to forget a person you knew only briefly — like for a week — from thirty years earlier. But surely you’d remember anyone who played a big, and very active, part in bringing you together with your future spouse.

The conundrum is this: you tend to remember the people who brought you together in life. You’d certainly remember the person who played Johnny B Goode in such dramatic fashion at the Enchantment Under The Sea dance. And, given that Lorraine had such a crush on Marty in 1955, she’s unlikely to have forgotten him altogether.

What can change over time though are individual perceptions and memories of a person. While I doubt George and Lorraine had forgotten Marty (aka Calvin Klein) all together, they would have forgotten exactly what he looked like after a while. Twenty to thirty years is a long time to remember something like that, more so when you don’t have a photo either.

Even so though, who in their right mind is going think their child, born years after the event, could possibly have had anything to do with their meeting? Can we get back now to simply enjoying repeat screenings of this classic, without the excess analysis?

Originally published Friday 29 October 2010, with subsequent revisions, updates to lapsed URLs, etc.

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For the universe is a hologram and I have touched the sky

25 October 2010

All sorts of ideas have been devised in an effort to make sense of the universe, some more… notable than others. For instance, a couple of years ago New Zealand scientist Brian Whitworth speculated that the cosmos was just a giant virtual reality simulation (Internet Archive link).

Meanwhile US astrophysicist Craig Hogan, who in 2008 ventured that the universe is a hologram, is now preparing to test the idea, after spending the last couple of years building the world’s most precise clock.

Black hole physics, in which space and time become compressed, provides a basis for math showing that the third dimension may not exist at all. In this two-dimensional cartoon of a universe, what we perceive as a third dimension would actually be a projection of time intertwined with depth. If this is true, the illusion can only be maintained until equipment becomes sensitive enough to find its limits. “You can’t perceive it because nothing ever travels faster than light,” says Hogan. “This holographic view is how the universe would look if you sat on a photon.”

Originally published Monday 25 October 2010, with subsequent revisions, updates to lapsed URLs, etc.

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We made it back to the future, but in a parallel universe

9 July 2010

If you’re a dyed-in-the-wool Back to the Future fan I hope you weren’t taken in by the claim that last Monday, 5 July, was “Future Day”. That being the day Marty McFly and Doc Brown arrived in the future when they travelled forward in time during 1989’s Back to the Future Part II.

The arrival of the time travellers from 1985 last Monday may not have been all bad though, had it have happened. In the twenty-five years since the release of Back to the Future, and only five years out from 2015 — the setting for much of Back to the Future Part II — we still have ground to make up in terms of matching some of the advances in technology seen in the movie trilogy.

So far we’re still lagging in the development of:

  • Flying cars (actually they exist, but are far from in everyday use)
  • Hoverboards
  • Time travel

We have however made advances in other areas, with the advent of:

  • The World Wide Web
  • Smart phones
  • High Definition TV (if that’s much of innovation really, considering we’ve had low-def TVs for years)

There’s still another five years to go though, perhaps by then we’ll at least have hoverboards that are able to match what we can do with skateboards today.

Originally published Friday 9 July 2010, with subsequent revisions, updates to lapsed URLs, etc.

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You can travel no further back in time than 1955

18 August 2009

The Time Traveler’s Wife is the latest in a long line of time travel themed movies, and according to physicist Dave Goldberg, makes for a more realistic representation of time travel than most of the (fiction) served to date.

But this is interesting, time travel is (theoretically) only possible to points in time where a time machine already exists, according to Goldberg.

In other words, for Marty McFly to travel from 1985 to back to 1955, as he did in Back to the Future, a DeLorean like time machine would already need to have been in existence in 1955…

According to Einstein’s picture of the universe, space and time are curved and very closely related to each other. This means that traveling through time would be much like traveling through a tunnel in space — in which case you’d need both an entrance and an exit. As a time traveler, you can’t visit an era unless there’s already a time machine when you get there — an off-ramp. This helps explain why we’re not visited by time-traveling tourists from our own future. Futuristic humans don’t drop in for dinner because we haven’t yet invented time travel.

Of course the concept of time travel — in the form of the Flux Capacitor — did exist in 1955, it simply hadn’t taken physical form… does that count?

Originally published Tuesday 18 August 2009, with subsequent revisions, updates to lapsed URLs, etc.

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The Big Bang might have been big, but it sounded like a hum

31 October 2003

Judging by the amount of press it generates, it seems we just love talking about the Big Bang, the theory that explains the existence of the universe. And why not? We wouldn’t be here now talking about it, if it er, hadn’t have happened. Theoretically speaking that is.

The latest revelations published in New Scientist suggest the Big Bang was more of a deep hum rather than an explosive, booming, bang. Whether it was a bang or a hum though, there’s no doubting its volume, which was certainly loud.

Another news service carrying the same story compared the noise levels as being similar to a jet aeroplane with its engines operating at full power just ten or so metres above your house.

A little like the noise that Concorde used to create perhaps? Theoretically speaking that is .

Originally published Friday 31 October 2003, with subsequent revisions, updates to lapsed URLs, etc.

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